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OGRESS!VE

FURNACE
HEATING

PROGRESSIVE
FURNACE HEATING

By ALFRED G. KING

A PRACTICAL MANUAL OF DESIGNING, ESTIMATING

AND INSTALLING MODERN SYSTEMS FOR

HEATING AND VENTILATING

BUILDINGS WITH

WARM AIR

Supplemented by

A COMPLETE TREATISE ON THE CONSTRUCTION AND
PATTERNS OF FURNACE FITTINGS

By WILLIAM NEUBECKER

NEW YORK
SHEET METAL PUBLICATION COMPANY

1914

, t

BY
The Sheet Metal Publication Company

TABLE OF CONTENTS 3

CHAPTER I.

The Chimney Flue Character and Size of Flue Area and
Height Required How Correct Tests are Made Loca-
tion of the Chimney Common Sources of Trouble
Chimney Flue Troubles.

CHAPTER II.

The Furnace History of the Furnace Character and Size
of the Furnace Furnace Casing and Top Location of
Furnace Methods of Setting The Cold Air Supply Size
of Furnace Required.

CHAPTER III.

Pipe, Fittings and Registers Size and Location of Reg-
isters Table of Sizes Required.

CHAPTER IV.

Installation of the Furnace Tabulated Estimate How to
Determine Size of Furnace Required Sizes of Pipes and
Risers.

CHAPTER V.

Trunk Line and Fan-Blast Hot Air Heating Methods of
Trunk Line Piping Sizes of Piping for Trunk Lines
Fan-Blast Heating Methods of Installation A Typical
Installation of Fan-Blast Heating.

CHAPTER VI.

Estimating Furnace Work How to Estimate An Illustrated
Example Form of Estimate Sheet Determining Cost.

CHAPTER VII.

Intelligent Application of Heating Rules Heat Losses are
the Basis of Sizes Required An Automatic Air Damper.

CHAPTER VIII.

Practical Methods of Construction A Detailed Illustration-
Superior Work Brings Best Results School House
Warming and Ventilation An Example of Fan-Blast
Heating for Schools A Trunk Line Installation.

CHAPTER IX.

What Constitutes Good Furnace Work Dust Discharge
The Casing The Furnace Top The Piping Concern-
ing Bends Heating Surface Added Cost of Hard Firing
An Example of High Class Work.

387478

4 TABLE OF CONTENTS

CHAPTER X.

Ventilation The Need of Pure Air Amount of Fresh Air
Required Methods of Ventilating A Ventilating
Chimney.

CHAPTER XL

Ventilation by the Use of Propeller Fan Methods Em-
ployed Volume of Air Moved by Fans of Various
Sizes Efficiency of Exhaust Fans Tables of Speed and
Capacity.

CHAPTER XII.

Humidity and the Value of Air Moistening Reduction of
Fuel Results of Investigation Coke Air Moistener
The Herr Humidizer The Water Pan The Hygro-
meter.

CHAPTER XIII.

Recirculation of Air in Furnace Heating Quality of Air
Air Outlet Necessary Heating Windward Side Op-
position to the Method Obtaining Best Results Con-
necting Duct.

CHAPTER XIV.

Auxiliary Heating from Furnaces Computing Size of Radi-
ator Heating Surface Required Installing the Ap-
paratus.

CHAPTER XV.

Temperature Regulation and Fuel Saving Devices Fuel
Saving Appliances Electric Regulators Non-Electric
Regulators How to Sell Thermostats The Cost of Heat
Regulation How to Attach Thermostats Automatic
Draft Regulators Operation and Installation Chain
Control of Drafts.

CHAPTER XVI.

Fuel Its Chemical Components and Combustion Classifi-
cation of Coal Methods of Burning Coal Coal: The
Universal Fuel.

CHAPTER XVII.

Cement Construction for Furnace Men Concrete Mixtures
Mixing Concrete Tools Required Determining Qanti-
ties Methods Employed.

TABLE OF CONTENTS 5

CONSTRUCTION AND PATTERNS
OF FURNACE FITTINGS

CHAPTER XVIII.

Remarks Conical Bonnets or Hoods Furnace Casings
Various Styles of Collars Patterns for Collar on Pitched
Bonnet Patterns for Collar on Straight Bonnet Fasten-
ing the Collars to the Bonnet Elbows Applying the
Rule Elbows Less Than Right Angles Seaming the
Circular Joints Oval Elbows Developing the Patterns
for a Reducing Elbow T Joint Between Pipes of Un-
equal Diameters at an Angle Construction of Riveted
Joints in Tees Construction of Cold Air Shoes Pattern
for Shoe Connecting to Center of Furnace Patterns for
Shoe Connecting to One Side of Furnace Frictionless
Cold Air Duct Elbows Seaming Cold Air Duct Elbows
Developing and Constructing Floor Register Boxes
Rule for Determining the Size of the Register Box
Table of Areas of Round Pipes and Registers Pattern
for Floor Register Box in One Piece Pattern for Floor
Register in Four Pieces Quick Method of Joining Collar
to Register Box Two Other Methods of Connecting
Register Boxes Construction of Combination Header
and Register Box Boots or Wall Pipe Starters Devel-
oping the Pattern for a Round to "Oval" Frictionless
Starter Various Styles of Frictionless Starters Offset
Boot Developing the Patterns Wall Pipes or Risers
Covering Single Wall Pipes With Paper Double Wall
Pipes Metal Flues in Brick Walls The Various Fittings
Used in Furnace Piping Compound Wall Pipe Offsets
Patterns for a Double Offset Fittings for Truck Line
Heating Systems Short Rule for Reducing Joint De-
'termining the Unknown Diameter of the Main Pipe
Pattern for a Fork of Equal Prongs in Trunk Line
System Determining the Unknown Diameter in an Un-
equal Two Pronged Fork Placing the Half Profiles
Previous to Developing the Patterns Three Equal
Pronged Fork Method of Drawing Three Pronged Fork
so That the Patterns for One Will Answer for All Times
Unequal Three Pronged Fork Finding the True Sec-
tions and Placing the Two Profiles in an Unequal Three
Pronged Fork Finding True Angles in Cold Air Duct
Elbows Method Employed When Developing the El-
bow Patterns True Angles in Warm Air Elbows Find-
ing True Angles With Line and Bevel.

6 TABLE OF CONTENTS

CHAPTER XIX.

Rules, Tables and Useful Information Weights of Steel-
Gauges and Weights of Black Sheets Galvanized
Sheets Weights of Galvanized Pipe and Elbows Sheet
Copper Sheet Zinc Net Weight Box Tin Plates Stock
Sizes Tin Pipe Roofing Tin Tables Cost of Stand-
ing Seam Tin Roofing Weight, Strength and Size of
Wire Wire Gauge Dimensions of Registers Size of
Registers Weights and Measures Common Fractions
and Decimals Millimeters and Decimals Gallons in
Rectangular Tanks Gallons in Round Tanks Barrel
Capacity of Tanks and Cisterns Areas and Circumfer-
ences of Circles Rules Relative to the Circle Melting
Points of Metals Boiling Points of Fluids Horse Power
of Belting Cubical Contents of Rooms,

CHAPTER XX.

Receipts and Miscellaneous Information To Clean Brass
To Clean Zinc To Clean Water Front of Rust To Re-
move Lime Deposit From Water Front Government
Receipt for Cleaning Brass To prevent Rusting of Iron
and Steel To Prevent Polished Iron From Rusting
To Clean Zinc How to Clean Steel Tapes To Paint
Galvanized Iron To Keep Plaster of Paris From Setting
Too Quickly To Solder Galvanized Iron A Flux for
Tin Roofing Fluxes for Various Metals To Keep
Soldering Coppers Hot A Good Soldering Acid A Non-
Corrosive Soldering Paste. Waterproof Glue How to
Make Putty Fireproof Cement for Furnaces Rust
Joints Friction of Water in Passing Through Pipes
Heating Capacity of Stove and Furnace Coils.

Index I Furnace Heating Page 269

Index II Furnace Fittings Page 276

INTRODUCTORY.

A large part of the following text is compiled from a
series of articles written for SHEET METAL.

To this text new material has been added, and the
original work has been edited, revised and extended to make
the book a useful, practical and instructive treatise on the
subject of furnace heating.

Few of those at present engaged in the installation of
the warm air furnace realize the possibilities of warm air
heating.

The trouble has been with the many furnace dealers who
have failed to be honest with themselves. Instead of adopt-
ing and following the motto "onward and upward" and work-
ing to uplift and develop the science of warm air heating
(for it is a science) their rule seemingly has been "downward
and cheapward," if the use of such 'an expression is permis-
sible. They have thus done much to discredit this method
of heating with the house owner and even with physicians
and heating and ventilating engineers, who, of course, regard
it strictly from the standpoint of efficiency and economy. It
has not been the furnace (as it should be constructed) or the
method of furnace heating (as the work should be installed),
but rather the cheap, claptrap methods of furnace building
and installation which have in a measure served to bring
discredit on the dealer and manufacturer alike.

It is one of the peculiar laws of progression that while it
often takes years of constant labor, energy and attention to
work out the salvation of a business or a principle, the repu-
tation and standing thus attained may be throttled as it were,
over night, or, putting this thought into a concrete form
bearing on our present discussion, one good job of heating
will sell two or three other jobs and one poor job will result
in the loss of ten others.

The indications point to a much more general popularity for
the warm air furnace and an encouraging view obtains for a
general expansion of the industry, hence every precaution should
be taken to safeguard its growth.

8 INTRODUCTORY

Cheap competition work, the feverish endeavor to beat
out a competitor by lowering prices to ridiculous figures, the
use of inferior furnaces and materials, the catering to so-
called "operation work" where from ten to one hundred or
more houses are fitted with heating apparatus and where
the saving of from five to ten dollars per house is looked upon
as being a good stroke of business these are some of the
causes of condemnation brought about by the contractor.

Cheap furnace construction, the use of inferior materials,
the gross overrating of capacities and the sale of furnaces to
dealers who are ignorant of the principles of heating have
been the manufacturer's contribution to the unsatisfactory
conditions which long existed in this field. In actual results
attained, this practice of cheap work is demoralizing.

The inability to properly warm a room may be due to
faulty construction, an improper location of stack or register,
lack of capacity at the heart of the system the furnace or
any one of a dozen other causes. The dissemination of gas
and dust into the rooms, the excessive consumption of fuel,
the dry, oppressive atmosphere present in the heated dwell-
ing these and other marks of failure or unhealthful condi-
tions may be remedied by the application of common sense
methods.

ALFRED G. KING.

January, 1914.

Progressive Furnace Heating

CHAPTER I
THE CHIMNEY FLUE

The preparation for the installation of a furnace heating
system should begin with the foundation of the building to
be heated if the best results are to be expected from the
operation of the apparatus. The erection of a chimney flue
of proper size placed in the proper location is one of the
principal points of building construction, making, as it does,
for efficiency and economy in so far as the heating apparatus
is concerned. Chimneys defective in construction and those
located in isolated or inaccessible parts cause a large share
of the failures of furnaces to work properly. It therefore
behooves the installer to look well to the character and
position of the chimney.

The human body has been likened to a furnace, and it
is indeed a heating apparatus of the most delicate and intri-
cate kind.

The mouth and nose may be called the draft door and
chimney of the human furnace, and should the nose become
clogged and the throat filled with matter, the fire of the
body is suffocated for want of oxygen, the furnace ceases to
work and the body dies.

As the ability of the human furnace to breathe properly
is necessary, just so is the ability of the hot air furnace to
breathe properly a necessity, if the full measure of work and
activity of either are to be maintained.

The question of the chimney for use with a furnace is
so important that it is the first thing to be examined when
planning to install a heating apparatus.

Character and Size of Flue.

It is a well established fact that the draft in a chimney
flue is spiral that, as the air in the flue is heated and
expanded by the hot gases and products of combustion, it
rises in the flue, ascending with a spiral motion and increas-
ing in velocity according to the amount of air passed through
the grate of the furnace. In other words, the greater the
opening resulting from the setting of the draft door, the
more active will be the combustion of the fuel, and, if the

FLUES AND CHIMNEYS

chimney be of the proper height and area, the greater the
velocity of the draft.

It is by reason of the fact that the draft is spiral that
a round smooth flue is preferable to all other styles of chim-
ney construction. Next in value is the square flue, or one
as nearly square as conditions of construction will permit.
Fig. i illustrates a round tile flue encased in brick, represent-
ing the best possible type of construction. Should we suppose
the tile to be 12 inches inside diameter, the chimney would
have an area of 113 square inches.

Fig. i Brick Chimney with Round Tile Flue.

Fig. 2 illustrates a square tile-lined flue, encased in brick.
Assuming the width to be 12 inches, same as the diameter
in Fig. i, this flue would have an area of 144 square inches,
or 31 square inches of area more than the round flue, and yet
the latter will do the same work equally well, if not better.

Builders, and frequently owners, complain that a tile-
lined specially built flue is costly. It is costly not to build
it. It is a continual fuel saver, and by saving from one to
three tons of fuel yearly will soon pay for the increased cost.
Very few investments will afford the same return in dividends
as will the money expended for a good chimney flue.

The depth of a rectangular flue should never be less than
the diameter of the smoke pipe which enters it.

Do not be deceived into thinking that a flue full large
for the work means a corresponding increase in the consump-
tion of fuel, as tests have demonstrated that a poor flue will
frequently consume more fuel than one of proper size, and at
the same time produce less results in heat units delivered to
the rooms to be warmed. When fuel is burning under the
former condition there seems to be no life to the combustion.

FLUES AND CHIMNEYS

The fire is a dull red, the smoke pipe is cool, and the tem-
perature of the gases in the flue is so low that proper condi-
tions of draft are out of the question.

It is all important that the furnace dealer should post
himself thoroughly on chimney construction. It is the first
and most necessary study in qualifying as a heating expert.
A furnace man has no business to install furnaces when he
is not capable of advising as to proper chimney construction.

Beware of long narrow flues, because but a small portion
of the area of such can be counted upon to prove effective.

Fig. 2 Brick Chimney with Square Tile Flue.

For example, a flue 4 by 16 inches may be rightly considered
as being no more effective than a 6 inch round pipe. The
dead air area in the ends of this rectangular flue is of no value
whatever. On the contrary, it is frequently a hindrance,
owing to friction and down-draft likely to prevail. Fig. 3
illustrates this fact, the shaded portion of the flue representing
its effective area. If a flue be built of brick without a tile
lining, it should be pointed smooth on the inside, not plastered,
as the plaster lining will loosen and drop down in patches,
frequently taking a quantity from between the bricks, thereby
loosening them and damaging the chimney.

By adding to the height of a chimney the velocity of the
flue may be increased at small expense. The area, however,
cannot be well increased without considerable cost, and it
should therefore be great enough from the start to fulfill all
possible requirements.

All chimneys should be built straight from bottom
to top without offsets of any character. Where an abrupt

FLUES AND CHIMNEYS

offset is made in a chimney a place is provided upon which
soot will lodge and after a time clog the flue opening, as
shown by Fig. 4. This is a common cause of the failure of
many flues in city houses where a block is built up solid
with openings or area-ways left for passage between houses,
the second floor being set out over the area-way. Chimneys
are often offsetted three or four feet in this style of building
construction, and as a result prove a great detriment to the
successful working of the furnace,

Fig. 3 Rectangular Flue Showing Effective Area.

A chimney to be effective at all times and under all con-
ditions of wind and weather, should extend at least two feet
above the highest part of the roof. The wind will travel over
the roof of a house or that of an adjacent building and
practically cut off the draft of a low chimney beneath. Fig.
5 illustrates this condition, the arrows indicating the direc-
tion of the wind and the dotted portion of the chimney show-
ing the height to which it should have been erected.

Area and Height Required.

A chimney has two principal factors area and height.

There must be sufficient area to pass the volume of air
required to properly burn the fuel. Three hundred cubic
feet of air is necessary to supply the oxygen required to con-
sume each pound of coal.

For example, suppose we are operating a furnace having
a 27 inch grate, the rate of combustion being 4 pounds of
coal per square foot of grate per hour. A 27 inch grate has
practically 4 sq. ft. of area, hence 4X4=16, the number
of pounds of coal required per hour; and 16X300=4,800 cu.
ft. of air per hour, the volume iiecessary to properly burn
this amount of fuel.

One authority says: "Each atom of carbon requires for
its perfect combustion two atoms of oxygen. When this

FLUES AND CHIMNEYS 13

union is effected it burns to carbon dioxide and yields per
pound 14,500 B.T.U. (heat units).

Fig. 4 'Offset Flue Showing Accumulation of Soot.

"If, however, through insufficient air supply there is but
one atom of oxygen to one of carbon, the result is carbon
monoxide yielding 4,500 B.T.U., or less than one-third the
heat given off where combustion is perfect."

Fig. 5 Effect of Wind on a Low Chimney.

We know the statement of this chemist to be true, be-
cause it has been demonstrated that when the flue is too small
and too little air passes upward through the coal, the fire has
nc life or activity, and the fuel is consumed without pro-
ducing effective results.

14 FLUES AND CHIMNEYS

The height of the flue should be sufficient to clear the
roof of the building or any surrounding roofs or obstacles,
so that the wind striking the roof will not cut off the draft by
being deflected over the top of the chimney, as illustrated by
Fig. 6, which gives another example of the action of the
wind upon a low chimney.

Fig. 6 Illustrating Action of the Wind Upon a Low Chimney.

The height (preferred) of the chimney for the average
house is from 30 to 40 feet, and this height is sufficient for
the velocity or sharpness of draft demanded.

Many owners of buildings have mistaken intensity of
draft for volume, and many heating contractors test chimneys
by setting fire to a newspaper and crowding the same into
the chimney flue through the opening for the smoke pipe.
If the charred paper goes up the flue with a roar they think
the chimney is perfectly satisfactory. The fact is that a six
inch pipe would show exactly the same results.

FLUES AND CHIMNEYS 15

How Correct Tests Are Made.

Draft gauges of various kinds are used for testing pur-
poses. Among heating engineers the strength of draft in a
chimney is measured by the inches of water required to
equalize it.

Fig. 7 illustrates a portable draft gauge with a funnel.
A piece of glass testing tube is heated and bent to the form
shown. The funnel is made of tin and is of sufficient size to
cover the ordinary smoke pipe hole of the chimney. Some
felt cloth or soft felt paper tacked or pasted around the smoke
pipe opening will allow the funnel to seal the opening tightly
and thus will show more accurate results. A gauge scaled
in inches and tenths of an inch is adjusted into the upright
end of the tube as shown. The tube is fastened to the small
end of the funnel with plaster of Paris and is filled with water
to a point one-half way up the scale.

Fig. 7 Portable Draft Gauge with Funnel.

A column of water 28 inches high (or to be exact, 27.77)
is the equivalent of one pound presure.

In reading the testing gauge the difference in height be-
tween the two columns should be noted. If a chimney draft
was balanced by a column of water one inch high the strength
of the draft would be 1/28 of a pound per square inch of area.
The chimney draft of a good flue will equal at least .2 of an
inch of water, as shown by the scale.

FLUES AND CHIMNEYS

If a bent glass tube can-
not be procured, or if the
heating contractor cannot
bend a tube, a draft gauge
as illustrated by Fig. 8
may be made of straight
pieces of glass tube and
some short pieces of rub-
ber tubing. A small piece
of iron pipe is inserted into
the smoke flue and the
draft gauge attached as
shown.

The following table com-
piled by a standard author-
ity may be used in connec-
tion with the testing gauge :

Fig. 8 A Simple Draft Gauge Easily Constructed.

Height,

water,

in inches.

.1
.2

3
4
5
.6-

7
.8

9
i.o
i.i

1.2
1-3
M
1-5

1.6

1.8
1.9

2.0

Pressure

in Ibs.
per sq. ft.

521
1.042

I-563
2.084
2.605
3.126

4.168
4.689
5.210

5-731
6.252

6773
7.294

7.815
8.336
8.857
9.378
9.899
10.420

Velocity,
ft. per sec.

15.05

21.3

26.06

30.1

33-6

36.8

39-8

42.5

45-1

47-5

49-9

52.1

54.2

56.3
58.2
60.2
62.0
63.8
65.6
67.3

Velocity,
ft. per min.

903
1278

1564
1806
2Ol6
2208
2 3 88

2550
2706
2850
2994
3126
3252
3378
3492
3612
3720
3828
3936
4038

FLUES AND CHIMNEYS

The area of a flue must be determined by measurement,
as no form of testing will give the requirements, which are
determined by the work in hand. The size of furnace to be
connected with the flue determines the area required.

Suppose a furnace with an 8-inch smoke outlet is re-
quired. An 8 inch pipe has an area of 50.265 square inches,
and under the most favorable circumstances of draft a round
flue less than 8 inches in diameter or a square flue 8X8 inches
in size should not be used. If a rectangular flue is provided,
the narrow sides of the same should not be less than 8 inches.

The following table of flue areas will serve as a guide to
flue construction, it being assumed that the chimney is from
forty to sixty feet in height, or such as would be used for a
two or three story building:

TABLE OF FLUE SIZES.

Equivalent

cubic feet of

space to be heated.

10,000 to 15,000

15,000 to 25,000

25,000 to 40,000

40,000 to 75,ooo

75,000 to 125,000

125,000 to 200,000

Round tile,

Rectangular

standard

tile,

sizes.

standard sizes.

8 in.

8^ x &/ 2 in.

10 in.

S l / 2 x 13 in.

12 in.

13 x 13 in.

16 in.

13 x 18 in.

20 in.

18 x 18 in.

24 in.

18 x20 T / 2 in.

Brick,
inside di-
mensions.
8x 8 in.
8x 12 in.
12 x 12 in.
12 x 16 in.
i6x 16 in.
16x20 in.

When soft coal is used as fuel, 25 per cent, should be
added to the rated size of flue.

Location of the Chimney.

We have previously mentioned city built houses and the
character of their construction ; in connection therewith there
is another point which should be considered in providing the
chimneys. They are usually built in the party wall separating
the parlors or front rooms and the custom in this respect fre-
quently locates the flue but ten feet or less from the front
wall of the building. No matter in which direction the house
faces the chimney will be found in the same location. Sup-
pose the structure be five rooms deep ; it may extend from
eighty to one hundred feet from front to rear wall. Again,
suppose the house faces the south, the chimney being within
ten feet of the front wall; it is then necessary to run the
warm air pipes from fifty to seventy feet toward the north,
a condition beyond all reason to insure satisfactory and
economical service.

The chimney should be centrally located, to the north
and west rather than to the south and east in order that the
longer warm air supply pipes may extend to and serve rooms

FLUES AND CHIMNEYS

on the south and east sides of the building, and the shorter
and more direct pipes to those rooms on the north and west
sides of the building.

If possible to do so, it is well to erect the chimney up
through the center of the building where the greater part of
it will be surrounded by warm air, or rooms which are heated.
In such a flue the smoke will not condense so rapidly, nor the
gases cool as quickly as in a chimney built in an outside wall.
When a chimney flue is erected in an outside wall it should
be two bricks thick on the outside and, if possible, should
be provided also with an air space between the bricks, as
illustrated by Fig. 9. This air space should be closed and
sealed at the roof line.

DEAD AIR SPACE

Fig. 9 Air Space on Exposed Side of Chimney.

The flue for use of the heating apparatus should have no
other openings than that at the top and that for the smoke
pipe. It should extend from twelve inches to two feet below
the smoke pipe opening in order to provide a pocket for the
soot.

We have called attention to the fact that the smoke and
other products of combustion ascend the chimney flue spirally,
and therefore a round chimney is the best form of chimney
construction. Next in efficiency is the square flue, and last
the rectangular flue.

Common Sources of Trouble.

In connection with the construction of the chimney, there
are some points which should have careful attention of the
architect and owner as well as the heating contractor.

Make the foundation for the chimney sufficiently solid
and strong to support the weight of it. We have known
chimneys having two flues to settle and break an opening
between the flues, thereby destroying the draft, as illustrated
by Fig. 10.

Beware of chimney tops. As a rule not more than one
in ten of the chimney tops offered for sale is adequate in size
or will improve the work of the flue. A chimney is only as

FLUES AND CHIMNEYS

large as its smallest area, and an 8XS-inch flue (64 sq. in.)
having a top 7 inches round (internal diameter) has but 38.48
sq. in. of area.

! 1

i i

1 !

I 1

1 1

! 1

1 i

1 1

Fig. 10 Partition Walls between Flues Frequently Crack
and Spoil the Draft.

Abrupt offsets should not be made, as flues of this nature
clog with soot. The contractor should be careful to make the
smoke connection of the size called for by the furnace, and
should not reduce the pipe to save breaking out and en-
larging the smoke pip.e hole.

Chimney Flue Troubles.

Chimney flue troubles are many, and when there seems
to be sufficient height and area look for trouble from one of
the following sources :

(a) The smoke pipe may protrude so far into the flue as
to cut off the draft.

2O FLUES AND CHIMNEYS

(b) The chimney may be contracted or enlarged at some
point. A chimney is only as large as its area at its smallest
point. An enlargement at some point frequently acts as a
damper to reduce the velocity of the draft.

(c) Loose clean-cut doors, open space around smoke pipe
collar, or cracks in the flue admit cold air and spoil the draft.

(d) There may be openings in the flue for other smoke
pipes besides that provided for the furnace. A flue for use
of a heating apparatus should not serve for any other purpose.

(e) The flue may be plugged with soot or filled with
rubbish. Birds build nests in chimneys, and falling plaster
and soot may jam in the flue, particularly if there is an offset
in the chimney. Two or three pieces of brick tied in a burlap
bag drawn up and down the flue by means of a rope is a
good method of cleaning it of soot or other obstruction.

These are some of the ordinary sources of trouble with
chimneys, and while there are others they are not sufficiently
common to cause frequent trouble.

A good flue is a delight to the experienced heating en-
gineer and contractor, while a poor flue is a bane to him and
a source of trouble and expense to the owner of the building.

CHAPTER II
THE FURNACE

Having determined that the chimney flue is adequate
for the requirements demanded of it and that its location,
if possible, is at such a part of the building as to prove most
efficient, let us now consider the heart of the system; the
furnace proper.

History of the Furnace

The hot air furnace was the original form Which de-
veloped the later date methods of heating, and its advent, or
we may possibly say its invention, was the direct result of
necessity. Probably many of our readers know the story of
the introduction of the furnace; nevertheless the telling of
its history is interesting enough to bear repetition. The open
fireplace had been found to be extravagantly wasteful of fuel
and inadequate to properly heat the exposed parts of a room.
The fireplace heater and later the stove were evolved to pre-
vent this waste and to make possible a means to locate the
source of the heat where it would prove most effective.

With the growth of the country, the forests were cut
away. As towns and cities grew in size, the cost and in-
convenience of obtaining fuel, and the further fact that this
centralizing of business and the people, demanded larger and
larger buildings to accommodate the conditions, made it im-
perative that some method should be produced whereby the
labor of attending so many fires could be overcome.

This led to the invention, if it may be called so, of the
hot air furnace, which in its early stage was nothing more
than an extremely large stove encased in brick combining,
in a measure, the principles of Dr. Franklin, who in 1744 in-
vented the wood stove, with the hollow back or casing, hav-
ing an air duct or cold air tube through which air from out-
side the building was heated and introduced into the room in
which the stove was located.

The discovery and use of anthracite coal as a fuel proved
a great factor in developing the possibilities of furnace heat-
ing. The early development of the furnace was largely the
result of experimenting by Mr. Henry Ruttan. We are aware
that many of the older manufacturers of warm air heating

FURNACE REQUIREMENTS

apparatus have a sort of "me too" argument in this direction.
It is certain, however, that when Mr. Ruttan in 1862 wrote
the following words, he expounded the true principles of
furnace heating and ventilation, principles we cannot neglect,
if we are to meet with success in our work.

Mr. Ruttan said : "If you open your aperture at the top,
and the air you bring in is warm, or if you open the aperture
at the bottom, and the air you bring in is cold in either case

Fig. ii To Ventilate and Cool a Room.

the body of air will not budge ; your warm air will go through
the body, straight to and out of the top aperture ; and the cold
air will do the same through the bottom aperture. The con-
sequence is easily seen you will neither warm, cool, nor
ventilate the room."

"If you want to ventilate your room to warm it, and
open the bottom aperture, you will succeed in both ; because
the fresh air will be the warmest, and will not stop until it
comes in contact with the ceiling, where spreading out in a
level strata over the whole ceiling, it will keep its relative
position to the whole body until it reaches the bottom and
passes out through the aperture. If we want to ventilate our
room to cool it, we must let the air out at or near the top.

FURNACE REQUIREMENTS 23

"If on the other hand, we wish to ventilate our house to
warm it, we must take the air out at or near the bottom, thus
keeping up a continual exhaustion of the heated air; and if
we wish to set the whole body of air in the room in motion,
upward or downward, we must, of course, bring in the neces-
sary amount of outside air to do it."

Fig. 12 To Ventilate and Warm a Room.

Figs, ii and 12 illustrate these principles, and to those
who are making a study of this subject we recommend that
they fix them indelibly upon their minds, as they combine the
true principles governing hot air heating and ventilation.

Character and Size of the Furnace.

It is not our purpose to comment on or advocate any
particular type of furnace, except in a general way to note
such distinctive features as will assist the furnace man to make
the proper selection for any work in hand.

The bricked-in furnace has been succeeded by the more
up-to-date portable setting, or casing, and except in very old
buildings the former style of furnace is seldom seen.

The grate is a very important part of a furnace. Enough
open space should be provided to permit the passing of suf-
ficient air to meet the requirements when re-charging with

24 FURNACE REQUIREMENTS

fuel, and the bars should be strong enough to carry the heavi-
est load without sagging or binding.

Beware of cheap furnaces. They are expensive at any
price. A few dollars saved in the price of the furnace itself
must result in the furnishing of lighter castings, a smaller
capacity, less radiating power, and cheaper construction
throughout.

In a good furnace there will be from twenty-five to thirty
square feet of heating surface to one of grate surface. There
should be a deep fire pot, and a grate of sufficient area for the
work in order that the rate of combustion will not exceed
four pounds of coal per square foot per hour in coldest
weather. Definite rules will be given later for ascertaining
the proper size of furnace and grate area.

The gases in the combustion chamber must not be cooled
by allowing the cold air to come in contact with the outside of
this chamber. A furnace does its best work under conditions
of perfect combustion, and one so constructed that the in-
coming cold air will be partially tempered by the flue gases
in their exit from the furnace before coming in contact with
the hot plates of the combustion chamber, will show a higher
rate of efficiency per square foot of grate surface than will a
furnace in which the cold air passes immediately over the hot
plates or heating surfaces.

If the chimney flue is of sufficient size and is properly
constructed, a temperature within it of 300 degrees will be
more than adequate for perfect draft. The excess of fuel re-
quired in many furnaces is due not only to poor combustion,
but to the escape, at a high temperature, of the gases into the
chimney flue. By bringing the cold air into contact with the
heat of these gases much of this lost heat may be utilized
and saved. In the construction of the furnace the joints
should be gas proof and dust proof under all circumstances.

Furnace Casing and Top.

All furnace casing should be made double with an air
space between the inner and outer casing sufficient to act
as a non-conductor and keep the outer casing cool. Asbestos
paper or mill board is frequently placed between these two
casings, or as a covering for the outer one. This is not a
necessity, however, providing there is sufficient air space
between the inner and outer casing. Our preference is for
a black iron inner casing and a galvanized iron outer casing.
No single cased furnace will do good and economical work.

There are many opinions as to the proper style of top
or bonnet. The style used may be in a measure dependent

FURNACE REQUIREMENTS 25

upon the height of the cellar, or the manner in which the
leader pipes are attached. Any one type of top is not adaptable
to all cases. Fig. 13 illustrates a straight side flat top, hav-
ing a hoop or iron band around the top to hold about one
inch of sand. A deflector is placed on the inner side as in-
dicated by the dotted lines. The leader pipes are taken off,
back of or on the inner side, of the deflector.

Fig. 14 shows a common form of pitch top to which the
leaders are connected by bevel elbows. Unless a deflector is

'SAND BAND

/ DEFLECTOR

DEFLECTOR.^

Fig. 13 Straight Side Flat Top Bonnet

Fig. 14 Common Form of Pitch Top.

1 SAND BAND %

--..^ DEFLECTOR Y^"'
I)/ OR 2 BAND x

ASBESTOS
CEMENT

Fig. 15 Desirable Type of Bonnet.

used the hot air will short-circuit into the shorter and more
direct leader pipes.

Fig. 15 illustrates what we believe to be the very best
type of top. The deflector has a deep pitch toward the center.
Above this the top is flat, having a one-inch sand hoop around
the edge. The bottom is provided with a similar hoop one
and one-half or two inches wide which fits tightly over the
furnace casing and protrudes slightly above the upper edge.
After the openings for the leader pipes are cut in and the
pipes attached, the remaining portion of the pitched side of

26 FURNACE REQUIREMENTS

the top is covered to the depth of one inch with plastic asbes-
tos cement. This is supported in position by the extension
of the -iron band fastening the top to the casing. The casing
being double, the top of the hood being protected by sand,
and the sides of the top protected with asbestos cement, there
can be no loss of heat from the furnace.

All leader pipes should leave the top at the same level
and should be properly aligned. The careful alignment of
them makes not only a better looking job, but a better work-
ing one as well. Do not take the leader pipes from the top
and from the side on the same job. Air will move toward the
point of least resistance, and heated or expanded air will move
vertically through the nearest aperture; therefore the leader
pipes taken from the top will rob those taken from the side.

We know a furnace man who thinks it best to take the
longer runs from the top and the shorter runs from the side,
and strange to say he has considerable success. Human
ingenuity, however, is many times a failure, and we prefer
to stick to methods, which have proven successful.

Location of the Furnace.

In locating the furnace many of the details entering into
the construction of the building, such as the position of the
piers or posts supporting girders, the position of division
walls, of the chimney flue, etc., must be taken into considera-
tion. When the north and west sides are well protected from
the prevailing winds of the winter season, the furnace should
set as near to the center of the building as conditions will
allow. When the building is exposed on all sides the furnace
should be placed more to the north and west of the center,
and, provided the chimney has been built in accordance with
our suggestions given in the second article of this series, this
location is made available without the use of a long smoke
pipe. Under ordinary conditions the furnace should set not
more than 6 feet distant from the chimney flue. The warm
air pipes supplying the rooms to the north and west, or to
the principal rooms on the first floor, should be as short as
possible. It is far better to double the length of the smoke
pipe, if necessary, to locate the furnace to the north and west,
than it is to double the length of the warm air pipes, if con-
tingencies arise which make it imperative to select between
the two courses.

Methods of Setting.

We are aware that many of those engaged in the busi-
ness of installing furnaces have their individual opinions as to
the correct method of setting a furnace. However, while we'

FURNACE REQUIREMENTS 27

respect such motives it would seem to the writer that some
furnace men are inclined to stick to certain methods and
principles simply because they have had more or less suc-
cess in one particular direction by following the usual method.
The up-to-date furnace man should permit existing conditions
to shape the method of setting the furnace, and he should be
competent to judge what particular method of the number
in vogue is best suited to the job in hand. Some furnace men
are careless in their methods of preparation for the installa-
tion of a furnace, frequently setting the furnace directly on
the dirt cellar bottom when it seems sufficiently hard to sup-
port its weight. This method results in a source of dirt and
dust. The heat in the ash pit will dry out the earth so that
the jarring, incident to attending and shaking down the fire,
will cause particles of dirt to be carried upwards and into the
rooms by the air currents passing through the furnace.

The best practice is to build a cold air pit under the fur-
nace, such as is illustrated by Fig. 16. The brick pier shown
in the center will support the weight of the furnace and assist
in dividing the cold air supply. Note that a corner of the pier
is toward the cold air duct, thus allowing an equal distribu-
tion of the cold air to each side of the furnace.

';'._--. -. !." : -.-....<

. : =Ll== ; .: :! i=::is-!>i-

Fig. 16 The Cold Air Pit.

The pit should not be less than 12 inches nor more than
16 inches in depth. In building it a place should be excavated
of sufficient depth to allow a filling of broken stone or brick
about 4 inches deep. This should be covered by a layer of
coarse sand and cement, leveled and well tamped down. The
floor of the pit, which is also the foundation for the wall and
pier, should be constructed of brick laid in cement and
plastered smooth. This may add a trifle to the cost of installa-
tion, but will prove in the end to afford the most satisfactory
job.

Frequently, because of the low location the building oc-
cupies, there is trouble from water if excavation is made be-
low the surface of the cellar floor, and in such cases the air
duct must be connected to the furnace above the floor level.

28 FURNACE REQUIREMENTS

For this purpose a special type of casing must be used, as
illustrated by Fig. 17. The frame of the opening shown is
called a shoe. Do not connect the cold air into a shoe on one
side of the casing only, as this style of connection will not
afford sufficient air to the opposite side of the furnace, as the

Fig. 17 Casting for Use when Cold Air Duct is Above Floor.

air space through the furnace bottom around the ash pit and
fire pot is shaped very much like a horseshoe, as seen in
Fig. 18. The shoe should be placed at tjie rear, or, what is
better, a sparate opening or shoe should be provided for con-
necting the air into either side.

Fig. 18 Proper Location of Shoe for Cold Air Duct

Care should be exercised in setting a furnace to care-
fully cement or pack all joints where they are necessary, and
the casing should be fit absolutely air tight. Loose joints in
the furnace castings will allow dust and gas to enter the warm
air distributing pipes, and a leaky casing interferes with the
proper working of a furnace precisely in the same manner
as a leaky chimney interferes with the draft.

FURNACE REQUIREMENTS

Fig. 19 Three Methods of Supplying Cold Air.

30 FURNACE REQUIREMENTS

The furnace must set sufficiently low to insure giving the
proper pitch to the longest warm air pipes, and, if necessary
to secure this desired feature, the furnace may be placed in
a pit. When conditions make this course essential, build the
pit of ample size and allow plenty of room for setting the
furnace. Sufficient space should also be provided in the pit
at the front of the furnace to facilitate the removal of ashes
and the work of attending to the apparatus.

The Cold Air Supply.

The furnishing of an adequate amount of cold air, to-
gether with a proper manner of supplying the furnace with
it, is no doubt the key to successful hot air heating, and we
can therefore consider this the most important part of furnace
installation. An inspection of present day furnace work in
some localities would in ninety-nine jobs out of every hundred
either show no provision whatever for an outside cold air
supply or, if provided, it would be an ill-shaped or leaky duct
made of rough boards. It is just as important to eliminate
all possible friction from the movement of the cold air as it
is to provide easy movement of the heated air. Where a gal-
vanized iron duct is attached, curved elbows should be used
rather than miter elbows, and the cold air pipe should drop
to the floor at an angle instead of pitching down vertically.

Fig. 19 shows three methods of supplying cold air, the
sketch on the left illustrating a common type of wood boxing
frequently found on cheap work. The center illustration
shows a duct made of galvanized iron, a marked improvement
over the former, which can be still further bettered, however,
by the use of curved elbows, as shown on the right. This
latter type of duct may be easily connected to an underground
tile, and, when provided with a cold air chamber or air cleans-
ing box on the inside of the opening through the cellar wall,
it makes an admirable method of handling the fresh air.

In towns or cities where trouble is experienced from dust
or soot laden air, it is advisable to filter or cleanse the supply
by means of cheesecloth baffles. There are numerous plans
of using these cleansing baffle cloths, but only one general
method. The outside air upon entering the basement flows
into a cold air chamber, striking at a sharp angle a series of
filter screens partially covered with cheesecloth, which are
set in the cold air chamber at such an angle that the incom-
ing supply is compelled to make a number of right angle
turns in passing the baffles. The chamber should be as-
sembled in such a manner that one side (in the form of a
door) opens to permit the ready removal of the screened

FURNACE REQUIREMENTS 31

frames for cleaning. Do not use starched muslin or cloth of
smooth texture for this purpose. The rougher the surface of
the cloth the better will be the results obtained. Some recom-

Fig. 20 Air Filter Having Cloth Baffles.

mend that the cloth screens be coated with oil to assist in
collecting the dust, but we have found cheesecloth well suited
to the purpose without such a coating.

Fig. 21 Air Filter Having Wooden Baffles.

Another style is made of permanent wood baffles so ar-
ranged that the first one next to the fresh air inlet acts as a
deflector, precipitating a large portion of the dust to the bot-
tom of the box or chamber.

32 FURNACE REQUIREMENTS

The two styles are illustrated in Figs. 20 and 21, using
for illustration that recommended by prominent furnace manu-
facturers, which method cannot be too highly commended.
These screens not only filter the supply, but also act as a
damper to control the velocity of the incoming air before it
enters the cold air duct. As the inlet for cold fresh air should
be on the north or west side of the building it is necessary
to make some provision for controlling the velocity of the
prevailing winds of winter, and this, as well as the cleansing
of the air, is accomplished by the method illustrated.

The cold air from outside the building should enter the
furnace through the pit. The recirculated air should be con-
nected to furnace by attaching the piping to shoes on either
side of the casing, or, if necessary to connect the inside cold
air ducts into the main cold air supply, they should enter this
duct in such a manner that there will be no possibility of
the cold air entering the circulating ducts. Fig. 22 illustrates
one method of accomplishing this result.

CIRCULATING DUCT

OUTSIDE AIR

C/RCULAT/NG DUCT-

Fig. 22 Combining Recirculated Air with Cold Air.

Some furnace men claim that all ducts, both outside and
inside, should be arranged with dampers so that one or the
other system only may be used. Our experience has been
that occupants of a building will not give the required atten-
tion to dampers, or, if they attend to them at all, will not do
so properly. We therefore recommend the connection shown
by Fig. 22 which should be installed without dampers of any
kind other than a single one by which the outside cold air
can be entirely shut off when a recirculation of the inside air
only is desired. It is understood that the outside cold air
is taken from a cold air chamber, which will control the flow
of air in windy weather and which is not directly connected
to the outside.

In area, the ^old air duct should be three-quarters that
of all of the warm air pipes leading from the furnace top.
We think this rule is very generally known among furnace
men, and, while not absolutely accurate, is sufficiently so

FURNACE REQUIREMENTS 33

for all purposes. These conditions do not hold in figuring the
capacity of the ducts for recirculation of the inside air. These
ducts should be equal in area to the warm air pipes, or nearly
so.

To arrive at the proper size of the cold air duct we figure
on the expansion of the outside air when heated to a normal
degree. For the recirculating ducts we figure on the quantity
of air delivered by the warm air pipes, which, after supplying
heat to the various rooms, is not cooled sufficiently to make
any considerable depreciation in its bulk or volume.

Size of Furnace Required.

The furnace man is held responsible by the furnace man-
ufacturer for most of the trouble and for the largest share of
the present condemnation of the furnace and of warm air
heating. Are the trade justly open to criticism or are the
manufacturers at fault? This question is of interest to every
person who desires to see this class of heating work elevated
to a higher standard.

The furnace man is at fault in adopting methods neces-
sitating cheap competitive work. The manufacturers are,
however, the chief offenders. Before proceeding further per-
mit us to insert a word of praise for those manufacturers who
are giving definite information to the furnace man as to the
ratings of their furnaces, best methods of installation, etc.,
and who are placing conservative ratings on their goods.
We think it is not stating the case too strongly when we
declare that one-half the hot air furnaces produced are grossly
overrated.

If furnace heating is to be placed on the higher plane it
deserves there are many manufacturers who must rate their
furnaces on a more conservative basis. The practice of de-
termining ratings on the basis of casing sizes must be dis-
continued. All methods of figuring capacities that do not
take into consideration the cooling surfaces of a building
i. e., the heat losses through glass (windows), outside doors
and walls when computing the necessary size of furnace,
must be abolished if we are to meet with success.

Last, but not least, the evil practice of selling furnaces
to any one who has the money to buy and pay for them, with-
out regard to the purchaser's fitness and ability, or to his
knowledge as a furnace man, must cease if clap-trap methods
and cheap competition are to be overcome. If the past prac-
tices are allowed to prevail we shall reach that stage where
the owner will refuse to pay for his furnace until he has had
at least one winter's trial of the apparatus and assured him-
self of its satisfying qualities.

34 FURNACE REQUIREMENTS

We shall not presume to dictate to manufacturers how
they shall rate their furnaces. In view of the exigency of the
case they should, however, adopt a basis by which all cooling
surfaces of a building are reduced to an equivalent from
which the schedule of the probable performance of the fur-
nace can be made, and from which the furnace man can
select the size suited to any purpose.

The heating surface of the furnace must be sufficient to
warm the amount of air the cubical contents of the building
will demand, and the air outside of the building is always
cooler than the air within. It is a law of nature that the
temperatures of adjacent bodies will equalize. A certain
portion of the heat is diffused or lost by transmission through
walls and windows; therefore the furnace must not only be
large enough to heat the air within the building with from
two to four changes of air per hour, but it must also have
sufficient capacity to compensate for the losses by diffusion.
The heat losses in two buildings are never the same and yet
when reduced to equivalent glass surfaces or equivalent wall
surface they are easily determined.

Manufacturers of steam and water warming apparatus
have based their ratings on these factors and the steam fitter,
by any one of a dozen rules, can determine accurately just
what size of boiler is necessary for any particular require-
ment.

Let us see how readily this style of figuring may be adapted
to the furnace. We will take for example a house 30 by 40 feet,
having ten rooms to be heated. The house has twenty windows
averaging 3 by 6 feet, and three outside doors 3 by 8 feet (in-
cluding transoms). First floor ceilings are 10 feet, and second
floor ceilings 9 feet high. The approximate cubical contents to
be warmed would be:

30 X 40 X 10 plus 30 X 40 X 9, or 22,800 cubic feet.
The glass surface (doors counted as glass) would be:
3' x 6' = 18 X 20 = 360
3 'X8' = 2 4 X 3= 72

Total glass surface 432 square feet.

The wall surface would be:
30 + 40 = 70 X 2 = 140 X 19 (height of ceilings )= 2, 660 sq. ft.

Assuming, as we properly may, that 4 square feet of exposed
wall equals I square foot of glass in cooling surface or heat loss,
we have :

2,660-^-4 = 665,
the glass equivalent of the wall surface, which, plus 432, the

FURNACE REQUIREMENTS 35

square feet of actual glass, gives the total equivalent of glass
as 1,097 square feet.

Let us figure on two changes of air per hour, and the total
amount of air to be warmed hourly will be 22,800X2, or 45,600
cubic feet. The loss of heat by transmission through ordinary
glass windows is determined as being approximately 0.8 B. T. U.
(British Thermal Units) per square foot per hour, per degree
difference in temperature, or, in other words, in this case the
outside temperature being at o (zero) and the temperature of
the rooms 70, the difference, 70 o, would be 70; therefore,

1,097 X 0.8 X 70 = 61,432 B. T. U.

We also know that one heat unit will raise 55 cubic feet of
air one degree in temperature. Assuming that the hot air at
the registers enters the rooms at 120, we proceed as follows:

45,600 -f- 55 X 120 = 99,480 B. T. U.

A good quality of anthracite coal contains approximately
14,500 heat units, of which about 10,000 are actually available
for heating in a properly constructed furnace with a combustion
of 3 pounds of coal per square foot of grate per hour ; therefore,
10,000 X 3 = 30,000 B. T. U. per hour per square foot of grate.

To arrive at the correct size of grate to properly heat this
house we add the required heat units, 61,432 -(- 99,480 = 160,912,
and divide by 30,000 = 5.36 square feet. Therefore we require
a grate having 5.36 square feet of area.

This is based on zero weather for the winter, and, judging
from the present rating of some furnace manufacturers, they
are taking long chances and are expecting mild weather the
better part of the heating season.

CHAPTER III
PIPE, FITTINGS AND REGISTERS

Furnace fittings such as elbows, boots, offsets, tees, etc., are
made in a great variety of shapes, the construction and patterns
for which are treated by William Neubecker in the concluding
portion of this book.

We desire particularly to call attention to some common errors
and offer suggestions for their correction. In considering the
question of piping a job of furnace heating, we should naturally
suppose that the later day advanced methods were far superior
to those used years ago. Investigation would reveal that in
many respects this is true also that in almost as many other
respects it is not the case. The old plan, followed in the early
days of warm air heating, of running round or square flues or
risers, has not been improved upon up to this time in so far as
good service is concerned. True, there have been marked im-
provements in the designs of boots, tees and register boxes, but
are these improvements such that they have a bearing on the
reduction of friction or on increasing the flow of air through
the piping? We think that they concern principally the money
end or cost of the work. The infinite variety of stock patterns
of all kinds of furnace pipe fittings, such as adjustable elbows
and the like, make it easier and quicker to install a job, but for
all-around efficiency, give us the furnace work of the good old
days, when round or square risers were used, when all joints
were soldered and the fittings were shaped on the job, being made
to conform to the conditions of the work.

The flow of air through piping is one of the first parts of the
business that should be studied by the furnace man. The illus-
tration, Fig. 23, represents a 12 inch diameter round pipe supply-
ing a 3^ by 12 inch riser. Friction? Yes! and plenty of it.
The flow of air in a pipe the area of which is 113 square inches
is attempting to enter a pipe the area of which is but 42 square
inches, or nearly two-thirds less in capacity. This shows a con-
dition frequently found on present day furnace installations.
Follow the effect of work of this character down to the furnace
and it will develop that the principal results attained will be an

HEATING EQUIPMENT

excessive coal consumption and a shortening of the life of the
furnace due to an overheating of its castings.

/<?' 'ROUND -113"
Fig. 23 Two Much Taper, Causing Friction.

How may this evil condition be avoided? This question nat-
urally follows. And the answer is by enlightening the architect
as to its dangers, and at the same time having partitions provided
in the buildings in which flues of suitable shape and area may
be installed. Note by illustration, Fig. 24, such a partition furred
out to accommodate two 8-inch round flues, one supply an 8
by lo-inch first floor register, the other feeding a second floor
room. An 8 inch round pipe having an area of 50 square inches
will give as good service as an 8 by 8-inch square pipe, although
the area of the latter is 64 square inches. It will afford 30 per
cent, better service than can be obtained from a riser 4 by 16
inches. In the average house the studding are set 16

Fig. 24 Using Old Style Round Pipes.

inches on centers, and if 2 by 4 inch single studding are used,
a riser 3^ by 14 inches will be the largest possible pipe that
can be installed.

38 HEATING EQUIPMENT

The new type of side wall register has offered an improvement
in the method of supplying a first floor register and a riser from
the same hot air pipe. Of this register we shall speak later.
Of the boot, one type of which is illustrated in Fig. 25 we wish
to say, that, after allowing the full width of the studding, the

Fig. 25 Bo'ot for New Type of Side Wall Register.

space usually occupied by lath, plaster and baseboard, together
with about 2 inches of the floor, we can still use a riser 7 inches
deep, which, when properly baffled, has the capacity to supply
both register and riser.

Fig. 26 Arrangement Causing Back Pressure and Friction.

On much of the cheap furnace work we find the riser extend-
ing below the cellar joists and the warm air or leader pipe con-
nected to it at right angles as illustrated in Fig. 26 a practice

HEATING EQUIPMENT

causing back pressure and friction. A homely illustration of
this may be witnessed by turning the nozzle of a garden hose

Fig. 27 Side Wall Register with Proper Boot and Double Pipe.

directly against a flat board first, and then setting the board at
an angle of, say, 45 degrees. Note the difference in the flow
of the water from the hose as it strikes the board. There is
but one application proven by the experiment transition boots
are valuable, too valuable, in fact, to be dispensed with.

All risers of single pipe construction should be thoroughly
covered with asbestos paper. Better than this, however, is the
double pipe illustrated by Fig. 27 which also shows the installa-

4O HEATING EQUIPMENT

tion of a side wall register and a proper type of boot for leader
connection.

As to the size of the warm air or leader pipes, it does not
seem necessary to write much, as the sizes of such pipes, and
also the fact that they should be as direct and as short as possible,
are well established and generally known to most furnace men.
No leader should be less than 8 inches in diameter. First floor
rooms, 12 by 12 feet to 16 by 16 feet, or similar in area, should
have 9-inch leader pipes. For second floor rooms of equal size
8-inch leaders are sufficient. First floor rooms having an area
equal to from 17 by 17 feet to 21 by 21 feet should have 10-
inch leaders. Same size second floor rooms, 9-inch leaders
First floor rooms 22 by 22 feet to 28 by 28 feet should be sup-
plied with 12-inch leaders, and for second floor rooms of similar
size lo-inch leaders should be provided. Rooms in excess of
this size had best be supplied by two registers and separate leader
pipes. The above schedule is based on lo-foot ceilings for first
and 9-foot ceilings for second floor. For extreme exposures
or an abnormal amount of glass surface 15 to 25 per cent, should
be added to the above areas according to circumstances.

In general the risers to second or third floor rooms may be
25 per cent, smaller than those for the first floor, as the velocity
of air in a verticle pipe is approximately 25 per cent, greater
than in a horizontal one.

The character of the construction of the building should be
carefully considered in determining the size of any part of a
hot air heating system. The infiltration of cold air around loose
windows and doors, and the loss of heat through poorly con-
structed walls, should have an influence when determining sizes,
and the delivery of a surplus amount of air at a correspondingly
lower temperature to the various rooms means economy in the
consumption of fuel and longer life for the apparatus.

Size and Location of Registers

The proper locating of the registers on a job of warm air
heating has much to do with the perfect distribution and the
free circulation or passage of the air conditions which contribute
so largely to the successful operation of the system. Improper
location and incorrect size of registers insure partial if not total
failure.

Registers will allow of a discharge of air equal to the full
amount of the net air capacity only when situated along or in
the inner wall of the room in which they are placed. Fig 28
shows a small floor plan, the dotted lines indicating the exposed
portion of the room, which is that outside these dotted lines.
The warm air registers may properly be located at any point on

HEATING EQUIPMENT 41

the inside of the lines for good service. However, there are
some conditions which a wise judgment on the part of the furnace
man will caution him to note and provide for. One such condi-
tion is the placing of a register as far as possible toward the
north and west on the inside of a room, as warm air can be
delivered toward the north more easily through a basement

Fig. 28 Plan Showing Location of Registers.

leader pipe than it can be circulated toward the north in the
room itself. The location of the registers on Fig. 28 illustrates
this principle.

The register in a staircase hall which opens into the second
or third floor halls should be placed about six feet from the floor
in the side wall, the circulating register being located in the
floor at a point immediately below the warm air register.

Where a long room is exposed on either end, such as a parlor

4 2

HEATING EQUIPMENT

in a city-built house, or a house erected in a solid block, the
registers may be located at each end of the mantel, as shown
by Fig. 29.

Fig. 29 Location of Risers in City Building.

The risers may be built, in the brickwork or, if necessary,
they may be encased in studding at either end of the chimney
breast. This will permit of the use of round risers, which should
serve the registers located about six feet from the floor; and the
very best results will be obtained by setting them in this manner.
It is well to use two circulating registers located as shown on
sketch.

In figuring the capacity of registers it is well to allow 50 per
cent, of the fret-work size. We are aware of the fact that
many manufacturers claim to make registers of which two-thirds
the fret-work size is net air capacity, but many of such are
over-rated. More errors of judgment are committed through
underestimating than through overestimating the size of registers.

HEATING EQUIPMENT

The following table is submitted as a guide and is based upon
ordinary conditions of exposure :

Size of room. Size of leader pipe.
8x 8 ft. to 9x12 ft. 8 in. ist floor
Sin. 2nd floor
9 in. ist floor

8 in. 2nd floor
10 in. ist floor

9 in. 2nd floor

10x12 ft. to 12x14 ft.
14x16 ft. to i6x2oft.
20x20 ft. to 20x24 ft.

12 in. ist floor
10 in. 2nd floor

Area of riser.
40 sq. in.

48 sq. in.
56 sq. in.
75 sq. in.

Size of register.

8xio in. to 8x12 in.

8x Sin. to Sxio in.
10x12 in. to 10x14 in.

Sxio in. to 8x12 in.
10x14 i n - to 12x14 i n -

8x12 in. to 10x12 in.
14x16 in. to 16x20 in.
12x14 in. to 14x16 in.

CHAPTER IV
INSTALLATION OF THE FURNACE

There is something fascinating in the construction of a first
class piece of work, whether it be an intricate piece of mechanism,
a handsome and well-appointed home, or a heating apparatus
installed to properly warm the same ; therefore we may well
say that we have now reached a highly interesting and attractive
portion of our discussion of progressive furnace heating, namely,
that of considering the practical, as well as the theoretical, side
of actual furnace installation.

We shall aim to approach the subject from the very beginning,
starting with the actual planning of the heating apparatus, and
for illustration will consider a good-sized suburban home, ex-
posed on all points of the compass. Fig. 30 shows the first floor
of the building, the rooms to be warmed being the Parlor, Living
Room, Library, Dining Room, Reception Hall and Rear Entry.
Fig. 31 shows the second floor, consisting of a Den and Alcove,
four Chambers, Bath Room and Hall, making a total of fourteen
rooms to be supplied with heat.

The first heating system we will consider will be one in which
no provision is made for any ventilation further than that or-
dinarily obtained from a properly constructed hot-air furnace
installation.

Assuming that a chimney flue of good construction and
adequate area has been provided in the proper location (as is
the case for the residence illustrated), the first step is to suitably
tabulate the information necessary to enable the construction
data to be figured. We refer by this to the size and location of
the various rooms, the number and size of windows (glass
area), counting outside doors as glass surface, and the amount
or area of all outside exposed wall for each room. As we have
stated before in these articles, the only correct method for de-
termining furnace capacity involves a consideration of the vari-
ous cooling surfaces of a room or building.

FURNACE INSTALLATION

i'ig. 30 First Floor Plan, Giving Square Feet of Wall and Glass Exposure

FURNACE INSTALLATION

ALCOVC

s'-o'sd'-O"
Wail Exp. 90? II
Glass 36? j |

i i

Fig. 31 Second Floor Plan, Giving Square Feet of Wall and
Glass Exposure.

FURNACE INSTALLATION 47

This tabulated information follows, and for convenience all
rooms are numbered.

Sq. ft. of

Cubic Sq. ft. of ex- exposed

Room. Size. feet. posed glass. wall.

No. i Parlor 14/9x14' xii' 2,244 60' N. & W. 316

' 2 Living room... 15' XIS'QXII' 2,607 57' N. & E. 338

' 3 Library I5'3xi3'9xii' 2,310 48' S. & E. 319

' 4 Dining room... 15' XIQ' xii' 3,135 60' W. 374

' 5 Reception hall.. 9' x25'6xii' 2,519 24' N. (^) None

' 6 Rear, entrance. . 4' xio'6xii' 462 18' E. 132

: 7 Den 14' xis' xio' 2,100 60' N. & W. 290

' 8 Alcove 9' x 9' xio' 810 36' N. 90

' 9 Chamber 14' xis'6xio' 2,170 60' N. & E, 295

" 10 Guest room 12' xis' xio' 1,800 48' S. & E. 270

" ii Chamber 12' xis'6xio' 1,860 42' W. 156

" 12 Bath room 7'9x 8'6xio' 650 18' W. 75

" 13 Chamber 11' xi3'9xio' 1,520 54' S. E. & W. 355

" 14 Hall 9' X25' xio' 2,200 24' S. 120

NOTE. Glass exposure of hall, first floor, estimated at one-half
actual figures. Measurement into bay-window taken for dining room.

When estimating pipe sizes, area of flues and registers re-
quired, and the size of furnace necessary to properly handle
the work, we have many rules to select from to guide us in
the calculations. One authority states that the size of air pipes
for the first floor rooms may be obtained by dividing the out-
side wall surface of each room by 3, the result giving the proper
cross-sectional area in square inches of the desired air pipe. For
the second floor take 5 as the divisor, and for the third floor 6,
using always the pipe having an area next larger than that given
by the computation. To illustrate, the size obtained by rule
might be 74 square inches ; therefore the next larger size of pipe
would be 78 square inches, or one 10" in diameter.

For rooms having an excessive amount of glass surface the
area of the air pipe should be increased twenty-five per cent.,
and those having a northern and western exposure should have
increased sizes of supply pipes.

This rule is based upon the fact that in the average type of
building, the windows and outside doors (total glass surface)
amount to practically one-sixth of the total exposed wall sur-
face, and, further, it is estimated that four square feet of ex-
posed wall surface is equivalent to one square foot of exposed
glass surface.

While an application of the above rule leaves much to the
good judgment of the furnace man, it is the beginning of a
practical method for recognizing the difference in the cooling
surfaces of a room, and it furnishes great improvement over
the "hit-or-miss" methods so commonly used.

48 FURNACE INSTALLATION

Those who consider the heat unit in estimating capacities;
figure that one square foot of an ordinary brick wall will trans-
mit or lose 1 6 heat units per hour, and that each square foot
of glass surface will lose heat at the rate of 85 heat units per
hour, these ratios being based on zero weather outside and an
inside temperature of 70 degrees. Multiplying the total exposed
wall surface by 16, the total glass surface by 85, and adding the
products, will give the total hourly heat loss. For the first floor,
multiply this result by 0.0094 to obtain the cross-sectional area
in square inches of the warm air pipe. For the second floor the
multiplier is 0.0047.

These multipliers are obtained as follows: The heat trans-
mission which must be offset by the air supply is based on de-
livering the air into the rooms at 140 degrees in zero weather
and allowing this air to cool to 70 degrees before it escapes. If,
the air supply were only cooled one degree to give up the amount
of heat necessary there would be fifty-five times as many cubic
feet of air required in an hour as there are heat units lost in
transmission, since fifty-five cubic feet of air cooling one degree
will only give up one heat unit. As, however, each cubic foot
of air is to be cooled 70 degrees, the amount of air needed in
an hour is obtained by taking 55/7oths of the number of heat
units. As this is the number of cubic feet of air per hour,
dividing by 60 will give the cubic feet per minute. In the first
floor rooms the velocity which air will get in a furnace heating
system, due to the height of the first floor registers above the hot
zone of the furnace, is about 200 feet per minute. Dividing
the total amount of air needed in a minute for heating the room
by the velocity \vith which this air will flow, will give the num-
ber of square feet of area in the pipe needed to conduct the
required amount of air. Multiplying this result by 144 gives
the area of the pipe in square inches. Expressed numerically
the operation is : Heat units X 55 X 144 -r- 70 -r- 60 -f- 200 =
heat units X 0.0094. If for second story rooms 400 feet velocity
is allowed, as such velocity can be attained, the multiplier for
the number of heat units becomes 0.0047.

The above are a few of the rules for determining capacities
and pipe sizes, and we would say in this connection that any
rule that properly takes into consideration the cooling surfaces
of a building may be used with safety.

We like very much Mr. Prizer's rule for estimating the capacity
of furnace required, and his method of determining the sizes of
warm air pipes. Taking into consideration the cubic feet of air
space, of exposed wall surface, and of exposed glass surface,
Mr. Prizer reduces the cooling surface of each room, to an
amount which he calls "Equivalent Cubic Feet."

FURNACE INSTALLATION 49

The rule is as follows: Taking the actual cubic feet of space
in a room as a basis, add 75 cubic feet for each square feet of
exposed glass surface, and 8 cubic feet for each square foot of
exposed wall surface. The provision for exposure is covered
by adding ten per cent, to the glass and wall surface for a
northern or western exposure, and deducting ten per cent, from
the exposed glass and wall surface for a southern and eastern
exposure. All outside doors, of course, are figured as glass
surface, the same as with other rules. Should storm doors be
provided, or double doors, those outside are then counted as
exposed wall surface.

Adding together the totals thus obtained will give the Equiva-
lent Cubic Feet of space to be warmed. The entire space in
halls, provided the first floor hall opens into the second or possibly
the third floor as well, is considered in figuring the size of pipe,
etc., for the first floor hall. This rule, of course, is useful only
when regarded in connection with tables giving the area of
pipes and ducts for use with Equivalent Cubic Feet and with
furnaces rated to take care of a certain amount of Equivalent
Cubic Feet. However, it furnishes an exact basis on which to
work and we consider it a very good and pronounced advance
in the methods of estimating furnace work.

The illustrations included show tne sizes of windows and doors
and size of rooms, and we shall consider the same floor plans,
giving data as to sizes of pipes, sizes and locations of regis-
ters, etc.

To determine the proper size of furnace for this work, we
may use in our calculations any one of a number of rules. For
instance, it is generally recognized that one square foot of grate
area in a furnace will properly care for 5,000 cubic feet of space
in the average dwelling. Using this rule in determining the
size of furnace required, we figure the total cubic space to be
warmed in the residence illustrated, as being a little more than
26,000 cubic feet, and dividing this amount by 5,000, show
that a furnace having 5 1/5 square feet of grate is required,
or one with an area of approximately 750 square inches. A
circular grate, 31 inches in diameter, conforms to this require-
ment. This rule, we may say, is based upon the most extreme
climatic conditions prevailing and for locations where the
thermometer reaches from 10 to 20 degrees below zero.

A preferred rule and one which may be applied with safety
is to determine the total amount of glass surface in the rooms
to be heated and the total net exposed wall surface. It is cor-
rectly estimated that I square foot of grate in a furnace is
capable of taking care of 300 square feet of glass surface or its

50 FURNACE INSTALLATION

equivalent, 4 square feet of exposed wall surface being considered
the equivalent of i square foot of glass.

Considering now the residence illustrated, we find a total glass
surface of a little more than 600 square feet. The total exposed
wall surface is 3,130 square feet, and after deducting the glass
area from this total amount, we have a net exposed wall surface
of about 2,500 square feet. Reducing this net amount to its
equivalent in glass surface by dividing by 4, on the basis men-
tioned, gives a product of 630 square feet of equivalent glass,
which, added to the actual glass surface, 690 square feet, makes
the total 1,239 square feet of glass.

Now, applying the rule just given, we divide this sum by 300,
and learn from the result that a furnace having a little more
than 4 square feet of grate surface would probably do the work.
Other formulas used in like manner show that a furnace with
from 4 to 5^2 square feet of grate surface would be the size
necessary for this requirement.

No person without experience is capable of applying any
one of the rules with precision. The judgment of an experienced
man increases the value of all rules, hence by using them in ac-
cordance with what his better knowledge of the conditions sur-
rounding the work teaches him, the result will be more in keep-
ing with that obtained by practical experience. In our opinion
for this work a furnace should be placed which has a grate
area of about 700 square inches, which would mean a 3O-inch
grate.

When working out the estimate for the sizes of the warm air
pipes in the cellar, the same discrepancy is found when applying
miscellaneous rules as is noted when determining the size of the
furnace. Good judgment based upon practical experience de-
mands that no warm air leader pipe in the basement should be
smaller than 7 inches in diameter, no matter what the size of
the connection may be.

Given herewith is a schedule showing the sizes of warm air
cellar pipes, of vertical flues, and of registers required for this
residence, and in this connection attention should be called to
the fact that every register and vertical flue is supplied by a
separate warm air pipe, with the exception of the library and
the guest chamber above.

A baseboard register is planned for the library, while a com-
bination vertical flue, supplied by a 1 3-inch warm air leader,
serves the library and guest room over it. The character of this
flue and the position of the register are indicated in Fig. 27.

FURNACE INSTALLATION

Fig. 32 First Floor Plan, Showing Sizes of Flues and Registers.

52 FURNACE INSTALLATION

Fig. 32 shows a plan of the first and Fig. 33 a plan of the
second floor. The sizes of all registers and hot air flues are
given, together with their locations.

The fireplaces in the parlor and living room prove to be natural
ventilators for these rooms.

Size of warm air Size of Size of

Room. cellar pipe. vertical flue. register.

Parlor n 6^x14 12x14

Living Room 10^2 6 xi5 10x13

Library 13 7 xi5 10x12

Dining Room n 6^x14 12x14

Reception Hall II 6^x14 12x16

Rear Entrance 7 3J^x 8 6x 8

Den 7J 3j^xi I 8xio

Alcove 7 3^x 8 6x 8

Chamber 4 xi2*^ 10x10

Guest Room (See Library) 3/^xn 8xio

Chamber 8 4 xi2^ 10x10

Bath Room 7 3^x 8 6x 8

Chamber 7^4 4 xi2^2 loxio

Hall (Included with first floor)

Arrangement is made to recirculate the inside air from the
lower floor. A 30" X 30" circulating register is set in the panel-
ing of the main stairway, this register opening into a chamber
24" X 36", located under the stairs. Connecting with this
chamber is a i6"X 30" duct, which is carried along the ceil-
ing of the basement to that certain point, where a vertical drop
to the floor of the basement can be made without interfering
with the passage-way or piping. At such particular point the
drop is made and the duct then connected into the cold air pit
of the furnace at the side opposite to that from which the cold
outside air enters the pot. This duct is provided with a damper.

Fig. 34 shows a plan of the basement and illustrates the man-
ner of locating the furnace and of installing the piping. The
sizes of all leaders are marked, and also the location and size
of the circulating duct, the cold air chamber, the cold air duct,
and the smoke connection.

The cold air or filtering chamber is 3' X 4' 6" in size, and is
provided with baffles on which cheese cloth is stretched sufficient
to cover about two- thirds of each bafflle, all of which are remov-
able for cleaning. The sash of the window is hinged at the top
and a chain connecting to it is run to a convenient point outside
of the cold air chamber, by means of which the supply of cold

FURNACE INSTALLATION

Fig. 33 Second Floor Plan, Showing Sizes of Flues and Registers.

FURNACE INSTALLATION

Fig. 34 Basement Plan, Showing Method of Locating Furnace and Piping

FURNACE INSTALLATION

air is controlled. Fig. 35 shows a sectional view of this cham-
ber with the cold air duct leading from it. This duct is 14" X
36" in size, and built of cement with an arched cement top.

The installation of an apparatus as here described will cost
double the amount usually paid for the cheap work ordinarily
placed. The owner, however, will have the desired satisfaction
of being able to thoroughly warm the house, regardless of the
condition of the weather or the direction of the wind.

Fig. 35 Sectional View of Filtering Chamber.

A few general directions for the installation in question should
be given, as follows:

Place dampers in all leaders, except that feeding the reception
hall.

Connect all dampers with chains running to a switchboard or
chain plate, located in rear entrance of first floor, or at some
other point equally convenient.

Thoroughly cover all basement piping with heavy asbestos
paper.

56 FURNACE INSTALLATION

Make use of anti-friction connections in joining leaders to
vertical air flues. This style costs more, but is worth more than
it costs.

Give a good pitch to all leaders, as air will not travel through
a horizontal pipe without friction.

Many other minor directions might be included. However,
the furnace man accustomed to superior work will recognize in
the data supplied all that is required to cover a good job.

CHAPTER V
TRUNK LINE AND FAN-BLAST HOT AIR HEATING

Every one identified with furnace heating understands, we
believe, that more friction prevails in conveying air or water
through several small pipes than when combining the same vol-
ume and carrying it through one or more larger pipes. With
plenty of headroom in the basement the pipes may be made
round; under other conditions they should be rectangular in
shape.

In starting to lay out a trunk line job the designer of the
system should keep in mind the following rules and plan
accordingly :

(a) A single pipe feeding two or more smaller ones must have
an area equal to the combined area of all pipes supplied by it.
See Fig. 36.

Fig. 36 Plan of Trunk Line.

(b) In order to eliminate the friction due to choking and the
presence of pockets, the top line of all piping should be straight ;
therefore any "drawing in" or reduction of the piping must be
made at the sides and bottom. Fig. 37 illustrates this condition.

(c) A certain pitch of the piping having been established it
should be continued from the furnace to the last register or riser
supplied.

(d) Do not make reductions too quickly. Often a single reg-
ister supplied will not change the size of the main service pipe,
and such connections, when near the furnace, should be taken

58 TRUNK LINE HEATING

from the side of the trunk line at the bottom line of the pipe, as
illustrated by Fig. 38.

(e) Branches, if of considerable length, may be run from the
top of the trunk line, and where the construction of the building
permits, the branch may be carried between joists as indicated
by Fi g- 39-

These include the most essential points considered in laying
out the piping of a trunk line system, and although practically

Fig. 37 Elevation of Trunk Line.

every job presents new difficulties necessary to meet and over-
come, the rules herein submitted form a safe starting point in
developing the system of piping.

\ ^Damper

BRANCH

Fig. 39 Connection Carried Between Joists.

Select a furnace of generous size for the work, one having
an area for the passage of air of from 40 to 50 per cent, greater
than the area of the trunk lines. Work of this character is not
cheap and if the furnace man is considering a low or even mod-
erate priced installation he must not figure on a trunk line system.
But if the best is to be selected with a view to procuring durabili-
ty, or length of service without repairs, as well as comfort and
satisfaction from the use of the apparatus, such a system prop-
erly installed will suitably answer every requirement. In this
age of specializing, trunk line heating may be properly regarded
as a specialty requiring the attention of specialists, and of your
best workmen none are too skillful for such work.

When necessary to change direction with a trunk line, do not
make an abrupt turn at right angles; rather turn with a long
sweep in order that the air can move in the new direction with-
out any considerable friction.

It is usually the case that two or three registers or risers are
supplied by the trunk line at or near to the end of it and that

TRUNK LINE HEATING

two or three branches lead from it between the furnace and the
extreme end. With round piping these branches should be taken
from the tapering sleeve, reducing the size of the trunk line.
When rectangular piping is used (and this style is preferable),
take the branches from the side of the pipe at the bottom, as
the air in passing through hugs the top, seeking the first outlet.

Fig. 38 Connection Taken from Side of Trunk Line.

Fig. 40 will show clearly the reason for this and illustrates how
and why the connection of a branch does not interfere with the
hottest air traveling along the upper side of the trunk line to
its extreme end.

Openings for Branches
Fig. 40 Rectangular Trunk Line, Showing Out for Branches
and Method of Reducing Area.

Secure the trunk lines firmly in place by straps of light band
iron screwed or nailed to joists. A quarter turn in each vertical
upright will afford a good appearance to the hanger and per-
mit it to fit snugly against the joist. Fig. 41 gives an outline of
the method for its use.

Fig. 41 Method of Supporting Trunk Line.

The furnace man who wishes to construct a job that will surely
please and delight his customer, as well as prove a source of
great satisfaction to himself, will do well to try out this system

60 TRUNK LINE HEATING

on the next installation of good size, when we predict he will
become a convert to the principle of moving air in large volumes
and ever after remain a stanch advocate of the idea. Air cools
quickly in small pipes, and consequently must be heated to a
higher temperature than when otherwise carried.

Suppose a furnace job erected by the regular method requires
two 10", two n", three 8" and one 12" pipes. Their combined
area would be 600 sq. in. and the total circumference approx-
imately 254.5 inches. If a single trunk line could be substituted
a 28" pipe with an area of 615.7 S Q- m - would be needed. The
circumference of a 28" pipe is 88 inches, and therefore the
cooling surface in the small piping is nearly three times that in
the one 28" trunk line.

The brainy successful furnace man, ever on the lookout for
ideas and methods that will enable him to do better work, finds
much food for thought and study when considering the trunk
line system of furnace piping. Those who never attempt to rise
above the old tried out, and often worn out, methods of doing
a certain line of work never advance farther than to obtain pos-
sibly the name and reputation of good all around workmen.

While not believing in the right of the furnace man to experi-
ment at the expense of a customer, there are certain theories,
methods and suggestions which must necessarily be tried out
in actual practice if we are to progress in our business, and
there is no house owner but wants the best character of heating
apparatus if obtainable at a price within his means. This can
signify but one thing to the furnace man: He must (as he
should) accept the full responsibility for his work, guaranteeing
to make any changes necessary to the complete fulfillment of
his agreement with the owner.

The same care in the proper installation of the furnace, size
of same, and method of introducing fresh air and exhausting
the foul, is as essential for the trunk line system as for the
regular system of piping, to insure a successful working job.

A method of running furnace pipes, which has been styled
the "trunk line system," finds much favor among furnace men
in certain localities. However, in other parts of the country it
is little known or adopted, probably because a considerable
amount of study and care need be exercised in its installation
if good results are to be obtained from its use. The system
covers a simple positive method of conveying air to the various
stacks and registers of a furnace heating system.

When planning for the installation of the trunk line system
the sizes of furnace, stacks, registers and cold air supply remain
the same as for the regular method, the only difference between
the two systems lying in the manner of running the basement
pipes.

FAN BLAST

Fan Blast Hot Air Heating

In discussing the subject of warm air heating and the pos-
sibility of apparatus for such purpose, we have thus far con-
sidered only those systems which circulate the air by reason of
the difference in the specific gravity or weight of the warmed
cr expanded air, and that of the denser cold air admitted through
the cold air duct.

In localities where electric current is available for power, an
electrically operated and controlled fan may be employed to
good advantage in connection with the furnace. It is possible
with the use of a fan as an auxiliary to the heating apparatus
to change the air frequently and positively, no matter what may
be the direction or velocity of the wind or the location (as to
exposure) of the rooms to be warmed.

Fig. 42 Diagram of Arrangement for Exhaust System.

A system of this kind would be called a "mechanical system,"
"fan-blast system" or a "warm air fan system," and is particularly
adaptable when employed to ventilate buildings in which many
people congregate, such as a church, school or public hall, and
also for large residences of the modern type.

Some of the larger residences of this class could not be
warmed with an ordinary hot air system except by the installa-
tion of two or more furnaces, each located in different sections
of the building, while with a fan-blast hot air apparatus the fur-
naces (if more than one be necessary) may be located at some
central and convenient point in the basement, and the trunk line

FAN BLAST

method of piping, as described in a recent article, used to con-
vey the heated air to the several risers or stacks. Warm air
ducts when few in number not only present a neat appearance,
but are greatly to be desired when the efficiency of the installa-
tion is to be considered.

Should a fan be employed in connection with a heating and
ventilating system, either one of two methods may be adopted.
They are known as the exhaust and the plenum methods, and
are separate and distinct from each other in the manner of in-
stallation and operation. The exhaust method, which is il-
lustrated by Fig. 42, is installed as follows:

Air Motor and

Screens Moistening Fan *

Fig. 43 Arrangement for Plenum System Shown in Plan.

The furnace is located in the usual manner and place. The
cold air is admitted to the furnace in the usual manner through
a cold air duct connecting with a pit under the furnace, and is
drawn upward over the heated surfaces of the furnace, warmed,
and conveyed to the several rooms through air ducts and registers.
The foul or impure air is exhausted from each room through a
foul air register connecting with a foul air duct. These ducts
extend to the attic of the building, where an exhaust fan of
sufficient size is located which propels or drives this air from
the building through an opening in the wall or through roof
ventilators. In other words, the fan creates a vacuum which
pulls the pure warm air through the building and exhausts it to

FAN BLAST 63

the atmosphere, after the heat conveyed by it has cooled and
the air has become foul owing to the respiration of the occupants
of the building, or by other sources of contamination. The suc-
tion produced by the fan causes an infiltration of air through
crevices around doors and windows, the amount varying in
volume according to the size and speed of the fan.

The plenum method, as illustrated by Fig. 43 is the system more
generally used in connection with furnace heating. In arrang-
ing the apparatus the outside air is admitted through a wire or
grill screened opening in the outside wall into a chamber within
the basement of the building. Here it may be filtered to re-
move dust and dirt and may also be moistened if such a condi-
tion is desired.

The air then passes through a duct to the fan, which propels
it forward through the furnace and warm air ducts into the
various rooms to be warmed and ventilated.

The foul air is exhausted through registers into ducts or flues
which extend upward through the building to a point well above
the roof.

With this system in operation the air leakage around out-
side doors and windows is outward, as the fan drives the air
through the system and into the rooms under a slight, though
constant, pressure and a certain definite air change may be
figured and secured whatever may be the condition of the weather.

The ventilation of a building is now considered by both archi-
tect and owner to be as essential as the heating system, and a
modern residence is not considered complete unless it is well ven-
tilated. All persons versed on the subject of ventilation, and
who are competent to advise, say that there can be no ventilation
when a building is warmed by direct steam or hot water or by
a furnace without a generous admission of fresh air to the
building, and the mission of the furnace has not been fulfilled
until this fresh air feature has been provided.

We have met with the argument that it is expensive to burn
the fuel necessary to warm so large a volume of fresh air, a
perfectly true statement. To this we may answer and likewise
the services of a physician are costly, and which is the cheaper
in the end: a coal bill based upon the warming of sufficient
fresh air to insure healthfulness, cheerfulness and comfort, or
a coal bill based upon no ventilation or recirculated air, with the
attendant consequences of ill health, doctors' fees and loss of
time from business, to say nothing of the discomfort attending
such experiences.

When a residence is but sparsely occupied (as the majority

64 FAN BLAST

of all residences are) an air change three times per hour will
provide all of the ventilation necessary, and this rate of air
change may be obtained with very little increased expenditure
for fuel provided the apparatus is properly arranged and it
may be increased to five or six changes per hour at times when
the rooms are to accommodate an exceptional number of people,
as at the time of a social gathering.

With a fan furnace system installed, an air change of five
times per hour may be easily obtained without an excessive ex-
pense for fuel.

When the building is unoccupied, or but sparsely so, it is not
necessary to use the fan, and the expense of its operation may
be saved. This is particularly true when a system of this
character is installed to warm and ventilate a school building.
Certainly it is not necessary to operate the fan when the rooms
are unoccupied, and a school building is occupied only six or
seven hours a day, never more than eight hours.

All ventilating ducts should be provided with close fitting
dampers located above the outlet register. Within a short time
after school is dismissed the fan should stop running and these
dampers should be closed, and remain closed until possibly eight
o'clock the following morning when the attendant should open
them and put the fan in operation.

At periods when the atmosphere is heavy or depressing or
on occasions when the building is to be generally well occupied,
the turning of a switch sets the fan in motion and the effect is
at once apparent in the condition of the atmosphere.

Experience obtained in testing the movement of air by a fan
has demonstrated that it is better and more economical to use
a large fan run at low speed than it is to move the same volume
of air with a smaller fan run at high speed. The areas of all
ducts and stacks for both fresh and foul air should be carefully
figured, and the installation be made in such a manner as to
avoid all of the friction possible in moving the air. For this
purpose there is an abundance of definite and dependable data
to be had.

The warm fresh air should enter the room above the breath-
ing line ; therefore, the inlet registers should be located about
seven and one-half or eight feet from the floor.

The outlet or ventilating registers should be placed near the
floor line, preferably just above the floor or the base board, and
the location of both fresh air and foul air flues and registers
should be in the inside walls of all rooms.

FAN BLAST 65

Fan Blast Heating with Trunk Line Piping

The possibilities of good furnace work are shown by the in-
stallation of the hot air furnace in the residence illustrated here-
with, which also affords a good example of the fan blast system
used in connection with trunk line piping.

This residence is a brick structure containing nine rooms with
bath and the usual halls, closets, etc., and as the photograph,
Fig. 44 shows, the building stands alone and is exposed on all
four sides to the elements. The building is not ventilated that
is, there is no provision made for exhausting the foul air through

Fig. 44^Residence in Which the Heating System was Installed.

ventilating ducts or otherwise except by means of the fireplace in
the library. The heating apparatus is installed in quite the same
manner as has been described on pages 57 to 60.

The fan forces the cold air under a slight and constant pressure
through the furnace, and thence into the various rooms to be
warmed, thus giving positive service to each room. The em-
ployment of extra large ducts admits of a larger volume of air
supply than would be possible with the regular style and size of
basement piping. The schedule of sizes and exposures of the
various rooms is as follows:

66 FAN BLAST

FIRST FLOOR.

Wall Glass

Wide, Long, High, Surface, Surface,

Room. ft. ft. ft. Cu. ft. Sq. ft. Sq. ft.

Living Room 14 16 10 2,240 300 51

Dining Room 14 16 10 2,240 300 90

Library 12 14.6 10 1,740 270 51

Kitchen 14 14.6 10 2,030 220 60

SECOND FLOOR.

Hall inc. 2nd floor 8 22 10 3,344 80 54

Bed Room No. i 13.6 15.6 9 1,881 261 42

Sewing Room 8.6 10 9 765 72 24

Bed Room No. 2 13 14.6 9 1,692 247 42

Bed Room No. 3 13 14.6 9 1,692 216 42

Bath Room 5.6 II 9 540 50 15

Bed Room No. 4 10 14 9 1,260 216 54

Totals 19,424 2,232 525

The size of furnace required may be determined by the rule
that one square foot of grate should be provided for each 5,000
cu. ft. of space to be warmed.

The cubical contents of the various rooms as shown by schedule
is nearly 20,000 cu. ft. ; therefore, 20,000 -=- 5,000 = 4 ; this
number indicates that a furnace having 4 sq. ft. of grate should
be selected.

Another rule, and one we consider more accurate, is that I sq.
ft. of grate in a furnace of good construction is capable of tak-
ing care of 300 sq, ft. of glass or its equivalent in exposed wall
surface, 4 sq. ft. of exposed wall being considered equal to I
sq. ft. of glass.

Having a total exposed wall surface (gross) of 2,232 sq. ft.,
and a total glass surface (outside doors considered as glass),
of 525 sq. ft., we proceed as follows : 2,232 -=- 4 = 558 equivalent
glass surface; 558 + 525=1,083-^300 = 3.6 sq, ft. requiring
a furnace having a grate 3.6 sq. ft. in area or about 26 inches
in diameter. However, as we desire to handle a larger volume
of air than would be required with the regular or old style
system, we deem it advisable to increase the grate area practically
20 per cent., and therefore estimate to use a furnace having a
grate area of 4.3 sq. ft. or a grate 28 inches in diameter.

Figs. 45 and 46 show the first and second floor plans of the
residence on which the sizes of all registers and risers are noted,
and their location shown. The compactness of the system may
be determined at a glance.

The sizes of both risers and registers are larger than would
regularly be employed.

FAN BLAST

The basement plan of the building is illustrated by Fig. 47, and
it will be seen that the piping takes up but little space, and being
rectangular in form interferes but little with head room in the
basement.

The duct work is constructed entirely of galvanized iron. The
risers and register boxes are made of tin. Each branch duct
has its independent damper for regulating the air supply to each
room, and the casement opening through which the cold air is

Fig. 45 Plan of First Floor.

admitted to the cold air chamber is covered with a window, the
sash of which is hinged at the top and which, used as a damper,
may be opened or closed to regulate the amount of air delivered
to the fan. These dampers are not shown on the plan.

The value of the positiveness of such a system as that illustrated
can scarcely be realized. It must be admitted by practical fur-
nace men that a building can seldom be found where the air is
properly and, we might say, satisfactorily supplied and distributed

FAN, BLAST

Such installations are the exception rather than

by a furnace,
the rule.

We know that we challenge argument by this statement, yet
we believe every fair minded practical furnace man will agree
with us.

It seems a pity that there is but one fireplace in the residence
illustrated. Fireplaces are natural ventilating flues, and a fire-
place in the living room and a ventilating flue in the wall of

eWfeni

Fig. 46 Plan of Second Floor.

the dining room and possibly the hall would make the system an
ideal one for both heating and ventilating in the winter, or for
cooling and ventilating in the summer.

The fan is a 24" direct connected electrically driven fan, which,
when used, is run at low speed, is noiseless, and requires very
little power to operate it. The wiring is connected to a switch
located in the dining room, from which point the fan is put in
operation or stopped.

A chain from the window in the cold air box also runs to the

FAN BLAST

dining room, and the window used as a damper may be opened
wholly or in part without entering the basement.

By enlarging the cold air box sufficiently, filters for removing
dust or impurities from the air might be installed, and if desired
an air moistening apparatus might also be employed.

A marked improvement in the system illustrated would be the
addition of two large registers one in the side panel of the
staircase and one in the inner wall of the living room, connecting

y i

Fig. 47 Plan of Basement.

by means of a duct directly with the air pit of the furnace on
the side opposite to that where the fresh air is admitted.

These would be called rotating air registers, and would be
used for rotating or recirculating the air within the building at
periods when it was not sufficiently occupied to require the fresh
air service.

Of course this duct would be properly dampered with a close
fitting damper to be closed when the fan is in operation or when
the fresh air service is in use.

CHAPTER VI
ESTIMATING FURNACE WORK

In estimating a job of furnace heating, having determined the
sizes of furnace, registers and piping, we advise the grouping
of items figured for the work. For instance, under the head
of "Furnace" we would include the following:

Cost of furnace, plus 10 per cent., and freight and cartage.
Foundation, casing, cold air duct, cement and asbestos.

Under the item of "Piping" include the number of feet of
each size of leader or basement pipe, the number of feet of each
size of riser; then, in turn, collars, dampers, elbows, boots, reg-
ister boxes and any extra fittings.

Under "Ventilation" include the number of feet and size of
circulating pipes, floor register boxes and any special dampers.

Under "Registers" include the number and size of all warm
air registers, faces and borders, the number and size of all ven-
tilating registers, faces and borders.

Under the item of "Labor" should be estimated the actual
labor of installing the apparatus, masonary and carpenter work
(if needed) and labor expenses, such as car fares, board, etc.
In estimating the labor on an ordinary house or residence job
of furnace heating, it is well to regard the digging of the cold
air pit and the building of the brick foundation as constituting
half a day's labor; and later, that the setting of the furnace,
cementing, casing, smoke connection, cutting for the clean-out
doors and leaders constitute another half a day, making a total
of one day, not usually figured. Estimate from one-half day
to one day for cutting holes in floors and walls, one-half day
for running risers and one day for ventilating work, setting
registers and finishing. This totals three days' work for two
men, which should be sufficient to install the job complete.

Under "Miscellaneous" estimate smoke connection and damper
and all incidental expenses not otherwise charged, and finally add
the item of "Profit," remembering that it costs 10 per cent, to do

ESTIMATING 71

business, and if you add but 10 per cent, to your figures you will
lose money on the job, besides assuming the responsibility of
the work. You are entitled to a profit upon your labor and also
upon the expenses paid in shouldering the responsibility of the
contract.

Do we hear somebody ask why 10 per cent, is added to cost
of furnace under this item? If so, we would answer that it is
to cover time spent in estimating and closing the job, and this
rate of percentage is but a small margin to pay for this work.

Fig. 48 View of House Used as Basis of Estimate.

We advise the use of a small loose-leaf estimating book, say,
5x7 inches in size, indexed, in which may be marked or pasted
such tables and data as will facilitate quick figuring, lists of
material with net costs figured out, etc. Mistakes in estimating
are due usually to haste when compelled to compile an estimate
hurriedly, and a book with prices, etc., figured out at leisure,
the figures checked to insure accuracy, will prove invaluable to
the furnace man.

There are many rules for rapid estimating, some of which
are excellent when used with good judgment. Those which

72 ESTIMATING

one man may study out and apply with ease may prove hard
to adapt by another man, and we had rather employ our own
data, collected and classified in an estimating book, than to at-
tempt to use or apply many of the rules given by various
authorities.

The photograph shown herewith is that of what would be
termed an eleven-room house. It is of frame construction and
well built, the outside wall being protected by the use of heavy
building paper, applied over well covered siding, after which the

LIBRARY
L/ i2"xi8'Side Wall Keg
^ 4"}/2 'Riser
To N.t. Chamber

Fig. 49 Plan of First Floor.

walls are covered with clapboards and shingles. The building has
slightly more than the ordinary amount of glass exposure and,
as it stands alone, without the protection of adjacent structures,
it may be considered a difficult house to warm.

The building faces nearly due east, the chimney noticed on the
photograph being on the north side.

When considering a furnace job for a dwelling we have fre-
quently heard the remark passed that the building could not be
heated satisfactorily with hot air, owing to the fact that it was

ESTIMATING

unprotected from the influence of wintry winds a statement,
however, which cannot be borne out by results, provided the
heater and piping can be properly installed. In the case where
such a statement proves true, it may usually be traced to the fact
that the building is poorly constructed and the apparatus inade-
quate, owing to incorrect estimating or to the apparatus being
improperly installed.

Fig. 49 is a plan of the first floor, containing five principal
rooms, parlor, library, dining room, kitchen and reception hall,

Fig. 50 Plan of Second Floor.

together with a vestibule, pantry and a cookery in which the
range is located.

Fig. 50 shows the second floor, with four bedrooms, a sewing
room and bath room.

The necessary information as to sizes and exposures of rooms
should be tabulated in an estimate book kept for the purpose,
and for this building the data would appear as follows :

74 ESTIMATING

TABLE OF EXPOSURE.

Cubic Exposed

First Floor. Size. Contents. Glass. Wall.

Parlor 15x15x10 2,250 72 228

Library 15x15x10 2,250 72 198

Dining Room 16x16x10 2,560 64 256

Kitchen 12 x 15 x 10 1,800 64 loo

Reception Hall 9 x 22 x 10

Second Floor Hall 9 x 21 x 10 3,870 8l

Second Floor.

S. E. Chamber 14 x 15 x 9 1,890 72 189

N. E. Chamber 14 x 12 x 9 1,512 72 162

Sewing Room 7 x g'g" x 9 621 18 45

N. W. Chamber ioxi5x 9 1,350 36 189

S. W. Chamber I3xi5x 9 1,755 64 188

Bath Room 7x 9x 9 567

Toilet 3'6"x 5x 9 155 46

With this data in hand, properly scheduled, the person es-
timating may use any one of the various rules given from time to
time in these articles for determining the size of furnace, pipes,
registers and fixtures. These we do not deem it necessary to
repeat, and instead will follow with a tabulated statement of
sizes of pipes and registers as they should appear on the record
for estimating.

TABLE OF SIZES.

Diameter of Size of ver- Size of

Room. cellar pipe, tical flue. register. Notes.

Parlor 13 in. 7 x 22 12x18 Side wall reg.

Library 13 in. 7 x 22 12 x 18

Dining Room 12 in. Floor register 14 x 16 Floor

Kitchen 12 in. 7x16 12 x 14 Side wall reg.

Reception Hall 12 in. Floor register 14 x 16 Floor

S. E. Chamber (See Parlor) 4" x 12" 8" x 12" Wall reg.

N. E. Chamber (See Library) 4" x 12" 8" x 12"

Sewing Room 8 in. 4" x 10" 7" x 10"

N. W. Chamber 9 in. 3^" x 1 1" 7" x 12"

S. W. Chamber (See Kitchen) 4" x 12" 8" x 12"

Bath and Toilet 8 in. 4" x 10" 7" x 10"

Total area of basement pipes, 768 sq. in.

When requested to furnish an estimate of the cost of a furnace
installation, the heating contractor should first measure the build-
ing, that is, obtain the sizes of the rooms to be warmed, the
square feet of glass surface, and the square feet of exposed wall
surface, making note at the same time of any extraordinary
outside exposure.

The next step is to inspect the chimney flue to which the fur-
nace will be attached, making a careful examination of its area,
height and location.

Then observe and mark the points of the compass, the direc-

ESTIMATING 75

tion the building faces, and, as far as possible, study the character
of its construction. The location of the chimney and the points
of the compass will determine where the furnace must be set
in the basement.

Next examine the basement of the building to ascertain if the
furnace can be set in the proper location to do the best work
and note also, at the time, if there is any obstruction, due to
building construction, which would interfere with the proper
alignment of the piping. It is preferable that the furnace occupies
a position well to the north and west sides of the house. Note
further if proper provision can be made for the cold air supply,
which should preferably be taken from the north or west side.

It is advisable now to make a small sketch of each floor (not
necessarily drawn to a scale) and to locate on it the permanent
fixtures in each room, such as the tub, closet and washstand in
the bath room, the sink, cupboards and other fixtures in the
kitchen, etc.

The registers for hot air heat should be located in or along
the inner walls of each room, and in this connection note on
Figs. 49 and 50 the dotted lines drawn diagonally across the
rooms. The registers should be placed at some point on the
inner side of the room, as determined by the dotted lines.

The furnace man should similarly divide the rooms on his
sketch, and then examine each to see at what point the register
can be placed without interfering with the location of furniture
and fixtures.

Having obtained the necessary data and information, as noted
above, the contractor may now return to his place of business
to figure out his bid for the work. The details of the job should
now be tabulated as given above, the proper sizes of all pipes,
registers and fixtures and of the furnace being arrived at by
the use of some good rule, taking into account the exposure,
glass and outside wall surfaces of the various rooms to be
warmed.

To facilitate the figuring of costs, the heating contractor should
have convenient lists, giving net prices of registers, register boxes,
various sizes of leaders, dampers, elbows, boots, single and
double heads, etc., and as a further help, an estimate blank, pre-
pared for the purpose, should be used to show the various items
necessary for the job.

Fig. 51 shows a basement plan of the residence used for illus-
tration. The location and size of furnace, the size and method
of running leaders, and the size and location of cold air chamber
and cold air duct are given on the plan. The details and forms
to be observed and followed in preparing a clear and concise

7 6

ESTIMATING

tabulated description of the material aand labor necessary to do
the work we shall describe and discuss herein.

It is not essential, however, that the furnace man adopt the
particular forms outlined in these articles. An estimate blank
which will give, in order, all the information necessary to enable
the estimator to figure accurately on the material required, to-
gether with the size and cost thereof, will prove as valuable and
suitable as the form we submit for this purpose.

A table showing the sizes and exposures of the rooms to be
warmed is first necessary, followed by one giving sizes of flues,
registers and cellar pipes. With this information in hand, next

Fig. 51 Plan of Basement.

comes the selection of the proper size of furnace, and by "proper"
size we mean that size that will furnish the necessary heat at
a reasonable expense for fuel.

Many manufacturers rate their furnaces on the basis of a
certain number of cubic feet of air the different sizes are able
to warm, such as 10,000, 12,000, 15,000, etc. The only safe
method for the furnace man to follow, if he accepts the ratings
given, is to calculate the entire cubical contents of the building
to be warmed.

ESTIMATING 77

Numerous rules for quick estimating are practised, a depend-
able one working on the basis that a square foot of grate should
take care of 5,000 cubic feet of space. Figuring on this basis,
we have in the residence described in our previous article, 20,580
cubic feet of space to heat, and 20,580 -r- 5,000 = 401 square feet
of grate necessary for the work, or a grate 27 inches in diameter.

One square foot of grate surface is estimated to be capable
of caring for 300 square feet of glass surface or its equivalent,
and we know that 4 square feet of wall surface has about the
same cooling value as I square foot of glass. Turning to Our
estimate of sizes and exposures, we find we have 663 square feet
of glass and 1,555 square feet of exposed wall ; hence : 1,555 H- 4
= 338 + 663 = 1,051 square feet of equivalent glass; 1,051 -=-
300 = 3.5 square feet of grate, or a grate about 25^ inches in
diameter.

Still another rule totals up the area of all basement leader
pipes, on the principle that the combined area should be from
one and one-fourth to one and one-half times the grate area of
the furnace, according to the character of the work. Note that
for the residence illustrated the area of the basement pipes is
768 square inches, and we estimate a furnace having a 26 inch
grate with an area of 530 square inches.

Select a furnace of only such height that proper pitch or
elevation may be afforded the basement leaders, which should
pitch upward from the furnace at least one inch in each foot
of length.

In estimating the cost of this piping it is customary among
some furnace men to figure on an average length of 10 feet for
each basement leader a rule-of-thumb method, the use of which
should be discouraged and the value of making a sketch or
plan of the work is here apparent. The basement leaders should
be erected and run with no abrupt turns. Long, circular bends
or turns, as shown on Fig. 51, should be arranged for wherever
possible, and, with a plan to guide one, it is possible to measure
quite accurately the length of each leader.

For each first floor room we figure:

Basement leader (Size) (Length)

Extra for bends (If necessary)

Casing collar

Damper in pipe

For the second or other upper floors we figure:

Basement leader (Size) (Length)

Extra for bends (If necessary)

Casing collar

78 ESTIMATING

Damper in pipe

Riser (3' longer than height of ceiling)

Boot

Elbow

The length and size of smoke pipe should now be included,
and do not forget to provide a damper for the same. The esti-
mate sheet should show:

Smoke pipe diameter, length, gauge iron, damper, elbows.

The cold air supply should next be estimated, and the follow-
ing items made note of :

Cold air pit (Under furnace)

Cold air chamber

Baffles in chamber (If desired)

Cold air duct

Damper

It is not essential that a printed estimate sheet be used, but
if in such shape, the form will prevent the omission of items
in making up the estimated cost of the work, although one figur-
ing such work constantly becomes accustomed to setting down
the items in proper rotation.

The cost should be made up as follows:

Furnace . . . . (Size) (Kind)

Furnace casing

Furnace pit (If necessary)

Registers and borders

(List of sizes, kinds and costs.)

Pipe and fittings

(Here should follow a list, room by room, of all leaders, bends,

collars, boots, elbows, etc.)

Smoke pipe and damper

Cold air chamber

Cold air duct

Cold air pit

Covering of piping

Carpenter and mason work

Labor tinner and helper

Labor expenses

Freight and cartage

Incidental expenses

The above should form the basis of the cost of the job, to
which should be added the percentage of profit desired, and in
connection with this item of profit we would call particular atten-
tion to a very common error, viz. :

The average dealer, having ascertained the cost of the work
as accurately as he can figure, will, if he desires a profit of 20
per cent., add this amount to his figured cost, and having secured

ESTIMATING 79

the contract, the cost being, say, $300, for $360, assumes that
he clears $60 if he receives $360 for the work, and possibly rely-
ing on the report so frequently heard that it cost 10 per cent,
to do business, will think his profit is $30. Not at all ! Suppose
that the cost of doing business is 10 per cent, (an estimate en-
tirely too low). Remember this is not figuring on the cost
price, but rather on the selling or contract price. Consider the
volume of business done yearly as $25,000, and the expense of
doing it $2,500. This is the 10 per cent. The contract price is
$360, and 10 per cent, is $36, which must be added to the cost,
making it actually $300 + $36, or $336.

Now, with 10 per cent, profit added, the contract price should
be $336 + 10 per cent., or $369.60, and, as before stated, this
is entirely too low, for the actual expense of conducting a busi-
ness is seldom less than 20 per cent.

This charge is based on all the unproductive expenses of the
business, such as rents, team and driver, office help and all other
labor not included directly in a job, insurance, postage, interest
on money invested, value of real estate, etc., etc. It is called
the "overhead" expense of the business, and, as such, is charge-
able to every article sold or every contract taken, as a cost.

Will our doubting readers figure up the volume of their busi-
ness the past year, total their unproductive expenses for the
same period, and then ascertain their overhead expenses? Do
not be surprised if the rate equals 40 per cent, of the volume
of business transacted, from which it must be appreciated that
this is doubtless the most important item in making up an
estimate,

CHAPTER VII
INTELLIGENT APPLICATION OF HEATING RULES

The movement of air under varying conditions should be the
constant study of the furnace man, for only by a familiarity
with this subject is he assured a satisfactory way out of the
trouble which sooner or later will be met in the installation of
his hot air work. In the foregoing articles we have touched
upon the subjects of air movement and air velocities, and in a
general manner have considered the flow of the heated air and
also of the cold air.

It is possible to lay down certain rules governing the sizes of
piping, registers, cold air supply, etc., but there never was and,
moreover, never will be a rule to fit all cases ; therefore, to make
its use valuable the rule must be applied with good judgment,
and this good judgment cannot well be exercised unless the inter-
ested person is familiar with and can adapt it to the conditions
surrounding the work.

When estimating on a job of furnace heating it must be re-
membered that conditions prevailing in a section where the ther-
mometer scarcely ever reaches zero are not the same as those
prevalent in a more rigorous climate, say where a temperature
of 25 degrees below zero is not unusual. Further, a hot air heat-
ing apparatus, planned and intended for a well built and conse-
quently warm structure would not suffice for the same work if
installed in a loose, poorly constructed building ; therefore a rule-
of-thumb method used in estimating for the former would not
give adequate results for a building of the latter type.

We have dwelt upon this same subject from time to time in
our preceding articles, quoting various rules, acting on the prin-
ciple that information of such character cannot be consulted too
frequently or discussed in too many different forms, inasmuch
as it is the foundation of all good furnace heating practice.

The heat losses of a building determine the size of every part
of the heating apparatus. The use of the heat unit in making

APPLYING RULES 81

calculations is highly advisable and can be followed with advan-
tage. The air delivered by the furnace should have a tempera-
ture not above 150 degrees, and 140 degrees is better. With this
temperature at the furnace the rooms heated should be main-
tained at 70 degrees. The difference, then, between the tem-
perature of the furnace and that of the rooms is 70 degrees, or,
in other words, in maintaining this temperature in the rooms
the air drops from 140 to 70 degrees, and in doing this amount
of work each cubic foot of air delivers i.i heat unit.

Each square foot of single thick glass (and the full window
opening as well as outside doors should be counted as glass)
will cool 85 heat units per hour.

Each square foot of net outside wall surface in a building
of frame construction (that is, deducting windows and doors)
will cool approximately 20 heat units per hour.

The value of the cooling surface of brick walls varies accord-
ing to their thickness. A 9 inch wall will transmit or cool 30
heat units per hour, a 13 inch wall 24 heat units.

The size of leader or the area of the hot pipes is, of course,
determined by the amount of warm air required, and this is
fixed by the amount lost from the room as well as by the tem-
perature of the hot air at the register.

Working on the basis of the above data, the loss for glass
surface will be 85 -f- i.i = 77 cubic feet. At a velocity of 300
feet per minute, each square inch of pipe area will deliver ap-
proximately 20 cubic feet of air per hour ; therefore each square
foot of glass will require 77-7- 120 = 41/64, or about 2/3 square
inch, and in like manner we find that each square foot of outside
wall surface requires 1/7 square inch.

The hourly leakage of warm air from the room will about
equal its cubical contents, requiring approximately i/ioo square
inch of pipe area. The total pipe area necessary is therefore
2/3 of the glass surface, plus 1/7 of the wall surface, plus
i/ioo of the cubical contents of the room, this rule applying to
first floor rooms. The flow of air in the leader to a second or
third floor room is probably 500 feet per minute, and proper
allowance should be made for the increased velocity, which will
afford a reduction of approximately one-fourth in the area of
the leader.

For example, consider a first floor corner room 12 by 15 feet
with a 10 foot ceiling, having three windows 3 by 6 feet in size.
Glass surface, 3 X 6 X 3 = 54 square feet.
Net wall surface, 12 -f- 15 = 27 X 10 = 270 54 = 216
square feet.

APPLYING RULES

Cubical contents, 12 X 15 X 10= 1,800 cubic feet.

54 X 2/3 = 36

216 X 1/7 = 3!

i,8ooX 1/100= 18

36 + 31 + 18 85 square inches of pipe area, or a pipe
about io^4 -inches in diameter; therefore an inch
pipe should be used.

For a second floor room of similar size and exposure: 85 21
(one-fourth of 85) = 64 square inches, or a leader pipe 9 inches
in diameter.

The total area of all leaders should equal from one and one-
fourth to one and one-half times the area of the grate.

The net register area should be 25 per cent, greater than the
area of the pipe serving it.

SECONDARY OR MOTOR BLADP. i

Fig. 52 Automatic Air Damper.

Another very good rule for determining heat losses is based
upon the assumption that one square foot of glass will cool one
heat unit per hour for each degree difference in inside and out-
side temperature, and that the loss through exposed walls is
one-quarter that for glass surface.

The rule is : Add one-quarter of the wall surface to the glass
surface and multiply by 75 for rooms having a south or south
and east exposure ; by 85 if a north or north and west exposure
for zero weather temperature, and by 100 if location is in a more
rigorous climate. This will give the hourly loss in heat units.

There is a considerable variance in regard to the size of the
fresh air duct. Averaging the area as given by several authori-
ties demands that the area of the duct for cold air should equal
80 per cent, of the combined area of all warm air pipes leading
from the furnace. We believe that the cold air supply should
equal the area of all warm air leaders in order to distribute an
abundance of pure air to the rooms heated, and while fuel

APPLYING RULES 83

consumption will be slightly increased under these conditions,
in our opinion economy at or from this point should not be
considered.

In connection with the air supply, we desire to call attention
to an automatic atmospheric air damper or regulator for con-
trolling or restricting the movement of air where the movement
is due to gravity or natural conditions.

Fig. 53 Application of Damper to Cold Air Supply.

Fig. 52 illustrates a small regulator, 4 inches high by 12 inches
wide, adapted for a capacity of 80 cubic feet per minute at a
velocity of 300 feet. The primary or main blade moves from
an open position to a nearly closed position and is actuated by
a secondary or motor blade. The motor blade is located in a

Fig. 54 Fully Open Position.

representative position to be acted upon by the velocity pressure
of the passing air and works against the action of the adjust-
able weight shown at the right hand side. Both primary and
secondary blades are of aluminum.

The opening in which the primary blade moves has circular

84 APPLYING RULES

top and bottom, and the blade moves back and forth one-eighth
of a turn, except on sudden impulses, when it may go as far as
one-quarter of a turn.

This regulator was devised by an engineer at St. Paul, Minn.,
and its application to the cold air supply of a furnace is shown
by Fig. 53.

Fig- 55 Partly Closed Position.

At each of the two sides of the regulator are magnetic retarders
to prevent the oscillation of the blade and so that the blade moves
from one position to another steadily. The magnetic retarding
device acts as a retarder with substantially no resistance and
consists of an aluminum disc placed between the jaws of perma-
nent magnets.

Fig. 56 Nearly Closed Position.

Figs. 54, 55 and 56 show the device with the main blade in a
fully open, a partly closed and a nearly closed position. When
the movement of air, either hot or cold, is placed under control
to the extent made possible by this regulator, indirect ventilation
can be secured with a greater degree of positiveness and satisfac-
tion than is possible at the present time.

u... I :':::.! I

Fig. 57 First Floor Plan.

CHAPTER VIII
PRACTICAL METHODS OF CONSTRUCTION

All methods of direct heating depend in operation upon the
infiltration of outside air to supply or replace the oxygen con-
sv.med by the occupants of the building and by the artificial light-
ing equipment. It is probably needless to add that the amount
so secured is inadequate to maintain the air reasonably pure
without, in addition, opening windows or doors, and the relief
afforded by this latter method, while partially effective, is only
obtained at a direct loss in fuel consumption.

With the ordinary form of furnace heating an abundant quan-
tity of pure air is supplied when an outside air duct is used
in connection with the apparatus. It is obtained without a re-
circulation of the air within the building, which is a desirable
condition, for while recirculation assists the movement of the
air, it does not assist the ventilation. If the furnace is of such
capacity that the incoming outside supply can be warmed, when
admitted to the rooms at a low temperature, and at the same
time be under proper conditions of humidity, there can neither
be any question as to the ability of such an apparatus to properly
heat an average sized residence or building, nor any question
as to the purity of the air it supplies.

We have known many furnace men to advocate the principle
of taking the air supply to the furnace from all, or a part, of
the basement, claiming that the recirculation of the air to the
basement in this manner not only purified it by reason of the
natural leakage or infiltration of outside air into the basement,
but also produced this result without 'the loss of the heat units
necessary in warming cold outside air. However, we strongly
condemn this practice. It is impossible to obtain air too pure
for breathing, or, we might add, too much of a supply, and.
according to our belief, no better results can possibly be secured
than those obtained from the use of a ventilating stack into which
foul air ducts from each room are connected.

CONSTRUCTION METHODS 87

As has been already stated in these articles, the air in a resi-
dence sparsely occupied and lighted with electricity is but slightly
contaminated, and we know of no reason why such air should
not be recirculated. The circumstances surrounding each indi-
vidual job of furnace heating should determine the manner in
which the apparatus should be installed, and, as an example, we
refer to the residence used to illustrate this article. The floor
plans (Figs. 57 and 58) show the first and second floors of an
average sized dwelling containing eight rooms, with the usual
halls, bath room, and pantry, which is located in a neighborhood
free from dust and dirt, and the evil influences of smoke and
gases emanating from factories or mercantile establishments.

The level of the first floor is some 10 feet higher than the
street, from which it is separated by a lawn, perhaps 100 feet
deep, affording conditions which favor a pure air supply. The
fireplace in the library furnishes an outlet for the impure or
contaminated air.

The basement plan (Fig. 59) shows the installation of the
furnace, cold-air chamber and duct, and the warm-air leader
pipes, the sizes of all being plainly marked.

The cold air is admitted to the cold-air chamber through a
comparatively small opening, the cold-air duct being nearly twice
the area ordinarily used in order that in zero weather the harsh
effect prevailing when admitting a volume of frosty air to the
furnace may be overcome. In mild weather an abundance of
slightly warmed air is carried to the rooms.

The sizes of risers and registers are shown on the floor plans,
and attention is called to the method of bringing the warm air
supply to the parlor through a register located in the mantel, as
well as to the location of the register, under window seat in the
dining room.

This is an example of furnace heating such as is in every-day
use during cold weather, and the conditions so ably handled by
the furnace contractor reflect great credit on his judgment and
ability. We consider the job worthy of study and comparison
by furnace men.

It seems as if at the advent of every fall season there is needed
a series of articles setting forth and explaining the few impor-
tant factors of furnace installation. Whether this need is due
to the fact that the tinner has been so busy with roofing and
spouting during the summer months that he has forgotten the
many things learned during the past winter, or whether the
presentation of old familiar information in new dress is required
to awaken him to a study of the latest ideas in such installa-
tions, we do not know, but we do learn from observation that
as soon as some new idea or method is evolved and offered to

Fig. 58 Second Floor Plan.

CONSTRUCTION METHODS 89

the trade, many of the old-time tinners at once claim Missouri
as their home and ask to be shown.

Experience has demonstrated that a furnace job in order to
be successful in operation must be of sufficient size (both in the
furnace and accessories used) to perform the necessary work
well under the most adverse circumstances; also, that it is im-
portant for it to be so constructed that the air may travel freely
and without unnecessary friction from outside the building
through the cold-air chamber, cold-air duct, furnace, leaders and
risers to the registers, if the building is to be heated easily and
economically.

In order to arrange for this result we must follow the air
from its introduction into the building to insure that all sharp
angles or abrupt turns in the piping are eliminated and that
the connections of the leaders with the risers or stacks are
made with boots of such shape that the air is not retarded at
the base of the riser. The old practice of connecting a round
pipe leader directly into a shallow rectangular heat flue cannot
be too severely condemned.

The air moves under a very slight pressure, a slight obstruc-
tion materially retarding its movement, and while the use of
fittings of special form will add considerably to the cost of the
job, the successful furnace man appreciates that correct practice
calls for their use and acts accordingly, often refusing to install
the work if the cheaper competitive methods are desired.

It is the desire for cheapness on the part of building con-
tractors and the readiness of some furnace men to cater to this
class that have brought furnace heating into disrepute. How
is it possible to convince interested people of the superior advan-
tages of furnace heating when the public mind is poisoned by
the results of work of this character? The proper method to
pursue in order to raise the standard is to absolutely refuse to
install a job except given at a price which will warrant the use
of material, good in quality and up to date in design.

A certain large commercial house adopted as a slogan the
phrase, "The quality is remembered long after the price is for-
gotten." This motto might well be hung with advantage over
the desk of the furnace man to be kept in mind when estimat-
ing on and installing furnace work.

As an example, consider the job illustrating this article. Figure
over the work from the data given as the job should be installed,
and then make an estimate based upon cheap competitive work.
The difference will be under $100, representing at prevailing
interest rates $5 or $6 a year. The former job will prove en-
tirely satisfactory in service, with a minimum amount of atten-
tion and fuel consumption, giving a maximum of comfort and

L&unc/ry

(SegeJ-<3f>/e Ce/fe/~

'x ,_,
x * v
\. X
X \

vx.

!i
i

W'x36

\ S \ ^ ^, N ' \Q" ' *

;:^/

/s^''.

Co/cf ^ /s- Due/- Q

Coo/

Fig. 59 Basement Plan.

CONSTRUCTION METHODS 91

convenience. The latter will prove expensive in operation, will
require close attention, and will consume at least 25 per cent,
more fuel, to say nothing of the unsatisfactory heat produced.
The owner will readily pay the difference for the better job,
if these facts are properly set before him. It is therefore to
the financial interest of the dealer to become sufficiently familiar
with his subject to intelligently present these advantages.

School House Warming and Ventilating

It is said and truthfully so that a man never stands still
in his profession. He either advances, becoming more and more
proficient, or loses ground and finally becomes a "back number."

There are many furnace men good mechanics who, while
entirely competent to install almost any kind of a warm air sys-
tem once it is designed or laid out, will balk and appear ignorant
when questioned as to air change, the requirements for ventila-
tion, the State laws governing school house warming and ven-
tilation, etc.

We illustrate an example of school house warming and ventila-
tion designed to comply with the requirements of a State law
which demands that each pupil in each school room shall be
supplied with not less than 30 cubic feet of fresh air per minute.
This amount of air is considered as a minimum, some cities
demanding as much as 50 cubic feet per pupil per minute.

The proper ventilation of school rooms is now considered as
important as the heating of them, and six States Massachu-
setts, New Jersey, New York, Pennsylvania, South Dakota, Utah
and Virginia require the enforcement of a law demanding 30
cubic feet per minute per pupil.

Main, Montana, North Carolina and Vermont require the
approval of school houes plans, and South Carolina, Minnesota
and Wisconsin will make no State appropriation to school dis-
tricts who do not submit plans which must be approved by the
Board of Education, all of which goes to show that the various
States are falling into line and adopting the standard set by
Massachusetts, requiring 30 cubic feet of air per pupil per minute.

Can this be accomplished when a furnace is used for heating?
Yes, but not with the furnace alone, as a purely gravity system
will not act with sufficient rapidity to produce the necessary
change of air.

By employing the fan-furnace system for such service a defi-
nite air change may be provided, and this system we illustrate
herewith.

Each school room is heated and ventilated. The halls and
cloak rooms are heated, but not ventilated.

CONSTRUCTION METHODS

CONSTRUCTION METHODS 93

Fig. 60 shows a plan of the first floor, and Fig. 61 a plan of
the second floor. Each floor contains two class or school rooms,
24 X 32 feet in size, with a ceiling 13 feet 6 inches in the clear,
and each room is designed to accommodate 45 pupils.

To determine the amount of fresh air to be supplied we pro-
ceed as follows:

45 X 30 (cubic feet per minute) = 1,350 cubic feet per

room per minute.

1,350 X 4 = 54OO cubic feet per minute for all four
school rooms.

To provide for and distribute this air in the volume required
a 30 inch motor-driven disc fan is installed, as illustrated on the
basement plan (Fig. 62). This fan, running at the medium
speed of 450 revolutions per minute, delivers 6,700 cubic feet
of air per minute, and requires about y 2 h. p. to operate it. At
maximum speed, or 575 revolutions per minute, the fan delivers
10,000 cubic feet of air and requires I h. p.

This shows the size of fan to be sufficient for all conditions
of service, and for easy and economical operation a i l / 2 h. p.
motor is installed.

The speed of the fan is regulated from a rheostat located in
the room of the principal of the school.

The warm air registers, 24 X 30 inches in size, are located
about 8 feet from the floor. The fresh air entering each school
room under a slight pressure is diffused, and, seeking the cold
walls, is slowly chilled as it settles to the floor, where it is drawn
off through 24 X 24 inch registers into the ventilating flues. These
registers are located at the floor line, and the change of air is
accomplished without any drafts or discomfort to the occupants
of the room.

The boys' and girls' toilets in the basement are ventilated by
means of special window ventilators.

The cold fresh air enters the cold air room in the basement
through two windows having hinged sash, and the fan is placed
in a 32 inch duct leading to the pit tinder furnaces. A by-pass,
30 X 36 inches, in the form of a duct, connects the cojd air
directly from the cold air chamber to the furnace pit. This is
for use when the fan is not in operation, and it is provided with
a damper which is closed when the fan is in use. This duct
is not shown on the basement plan. It is located beneath the
floor, immediately under the galvanized duct used in connection
with the fan.

In planning the building the architect had provided four flues,
18 X 36 inches in area, and one flue 16 X J 6 inches in area, to
serve the rooms on each side of the hall. These flues are made

CONSTRUCTION METHODS

96 CONSTRUCTION METHODS

use of for warm air and ventilation, as shown by plans, and
while they are somewhat larger than is necessary, their large-
ness is a good fault.

The basement rooms which receive heat from the system are
the play room, girls' and boys' toilets.

The construction of the air pit under the furnaces is a partic-
ular feature of the installation. The furnaces proper are sup-
ported on brick piers, which are built in the pit under the
center of each furnace, and a deflector in the pit divides the
cold air supply uniformly to both furnaces, each of which has
a 35 inch pot, is encased in brick and has a cast iron front.

The top of furnaces is covered by a galvanized iron hood or
top casing, from which the hot air trunk lines are taken, as
indicated on the plan of the basement.

The installation of two furnaces is desirable, as during periods
when but little warmth is necessary and it is required only to
temper slighty the incoming fresh air, one furnace will produce
all of the heat desired, this arrangement making a decided re-
duction in the amount of fuel consumed.

When estimating work of this character and figuring for a
certain definite change of air, there are some facts in connec-
tion with the selection of a fan which should be considered.

The speed of the fan conditions the volume of the air deliv-
ered; that is, the volume varies directly as the speed. Doubling
the number of revolutions of the fan doubles the volume of air
delivered.

The pressure varies as the square of the speed; that is, if
the speed is doubled, the pressure is increased four times and
the power required to drive a fan varies as the cube of the
speed. For example, if the speed is doubled, the power re-
quired is increased eight times.

It is therefore more economical to use a large fan at slow
speed than a smaller fan at greater speed, and the mistake of
selecting too small a fan should not be made. The motor for
operating the fan may be directly connected to the fan or belted
to the fan, as illustrated on the basement plan.

CHAPTER IX
WHAT CONSTITUTES GOOD FURNACE WORK

Having so frequently been asked the question, "What do you
mean by good work?" or "What constitutes good furnace work?"
we will proceed to consider a number of features which char-
acterize really good furnace work, and then ask ourselves if
we are conforming to such a standard.

A good firm foundation of masonry, whether of bricks or of
concrete, is the first provision for a good job. On new work
the foundation for the furnace, and also the cold air pit, should
be built before the cellar is cemented, and if the cold air is to
cross a section of the basement below the floor level, this trench
should also be constructed before the concrete for the floor is
put down.

Both pit and trench should be constructed of hard brick laid
in cement, or of carefully mixed concrete. It is better to build
the walls of the pit of brick laid in cement. The top of the
trench may be built of concrete laid over wood forms or re-
inforced with perforated sheet steel now obtainable for the
purpose.

Dust Discharge

A frequent complaint about furnace heating is that dust is
discharged into the rooms. Ninety-nine per cent, of this trouble
is caused by the absence of a suitable foundation, the furnace
resting on the cellar bottom, or upon a poorly constructed
foundation.

The heat from the ash pit will soon dry the earth bottom so
that the dust from it will be carried upward into the rooms, or
if a poorly constructed or uneven foundation is used, the joints
of the furnace will open up, due to the racking of the castings
when shaking the grate. Not only is this a source of annoy-
ance, but it also shortens the life of the furnace, and renders
the castings liable to cracking, due to unequal expansion of the

9 8

GOOD FURNACE WORK

metal. When a furnace is set upon an even, smooth foundation
the parts will fit in their proper places without straining.

The Casing
Having properly set the furnace, the next item of importance

RISER

63 Connection with Riser Improperly Made.

to consider is the casing. Some furnace men prefer a double
casing the inner one of black iron and the outer one of gal-

Fig. 64 A Connection Better Than That Shown in Fig. 63.

vanized iron with an air space between while others prefer a
single casing, covered on the outside with asbestos and lined on

GOOD FURNACE WORK

the inside with bright tin, plain or corrugated. Either method
seems to us a mark of good work. The practice of encasing
the castings in a single casing is a mark of cheap work and
should be condemned. We know of some furnace men who
use the single casing and cover it with a black iron casing, leav-
ing an air space I to \y 2 inches between. This shield serves
to confine the heat and increase the efficiency of the furnace.

The Furnace Top

The furnace top has been discussed in a former chapter, but
we would say, however, that a top with a reflector or cone in

Fig. 65 The Best Method of Making Connection.

the center which throws the rising hot air toward the outer
circumference of the casing is to be preferred to any other type.
The warm air pipes may be taken from the top or on a slant,
as the height of cellar and character of the job will allow. The
cone fastened to the under side of the top provides an air space
in the center, making the insulation of the top by covering a
comparatively unimportant matter.

The Piping

The hot air pipes or basement leaders are essentially an im-
portant part of furnace work, and in laying out this part of
the work the furnace man should keep in mind the fact that
the installation of the piping, if not properly done, will cause
the apparatus to prove a failure.

100

GOOD FURNACE WORK

In planning the piping every effort should be made to elimi-
nate friction. This may be accomplished by shortening the
runs and dispensing with all abrupt angles. Every bend in-
creases friction and reduces the velocity of the air current.

Concerning Bends
Of course, bends are unavoidable, but it is a mark of good

Fig. 66 Suitable Location for Rotating Register.

work to find all bends made with a long sweep or easy turn.
It requires but little obstruction to turn a current of air which,
owing to its elasticity, will rebound when striking a surface
at a right angle. Fig. 63 of the annexed diagrams illustrates
a connection to a riser improperly made. The direction of the

GOOD FURNACE WORK " 101

air is indicated by arrows. Fig. 64 shows a modified form of
connection, showing an improvement in the direction of air
currents. Fig. 65 shows the best method available, and the easy
passage of the air into the riser will be quickly noted. Such
methods of making connections indicate good work and a knowl-
edge of the handling of air on the part of the furnace man.

Heating Surface

Thus far we have said nothing regarding the value of large
heating surface i. e., a good generous size of furnace, particu-
larly in regard to the fire pot and grate. A job may be ever
so carefully installed, but if it be lacking in capacity it will
prove inadequate and wasteful of fuel. Good work demand^
an economical furnace one whose grate area is sufficient to
hold enough coal to give off the necessary heat units with slov;
combustion, and a pot and drum, or heating surface, sufficient
to warm the volume of air demanded without heating to ex-
cessive temperatures, and in this connection it is well to remem-
ber that the higher the temperature of the furnace the greater
will be the waste of heat in the chimney.

We favor the recirculation of the air in the principal room:;
of the first floor. We know that many wise ones condemn
this practice, yet there seems to us no reason why the air from
the living rooms and hall should not, under ordinary conditions,
be returned to the furnace for reheating, as it is not contami-
nated to any perceptible extent.

When rooms in one part of the house are "thrown together,"
as the parlor, reception room, library and hall, one large rotat-
ing register placed at some central point, preferably in the hall,
will be found sufficient. The staircase is a particularly good
place for the installation of the rotating register, as the space
under the steps allows of making a large galvanized duct con-
nection to the register. Fig. 66 illustrates the idea.

The extra expense of installing the apparatus in the right
manner is money well invested in fact, like putting the money
in a bank which pays large dividends.

Added Cost of Hard Firing

If a heating system of scant capacity or of poor construction
is installed, which necessitates hard firing, with the attending
waste of fuel, it is not uncommon to find such an apparatus
using from 20 to 30 per cent, more fuel than would otherwise
be found necessary.

The additional expense of installing an adequate and properly
constructed apparatus would at this rate be paid for in four

IO2 GOOD FURNACE WORK

or five years, and the annoyance of using a poor apparatus for
that period would have been eliminated. There is absolutely
no excuse for doing poor work or installing inadequate mate-
rial when the argument of dollars and cents can be so strongly
used with possible customers, and good furnace men are alive
to this fact.

Importance of Installing High Class Work

Notwithstanding the fact that the makers of hot-air heating
apparatus, the heating engineers, physicians and others in au-
thority, who have devoted their time and attention to studying
the conditions and results surrounding cheap furnace work,
advocate and prove the need of ventilation and the circulation
of air in connection with furnace heating, the sheet metal worker
or furnace man unfortunately continues to figure and install
cheap, unsanitary and unhealthful work, and when asked the
reason, will invariably give as an excuse that the owner will
not pay the additional price required for any other system.
He may add, further, that his business rival will surely figure
on doing a cheap job, and thus, by reason of the bugaboo of
cheap competition, the furnace dealer will exert no effort to raise
the standard of furnace work, fearing the possible loss of a
contract.

We wish that it were within our power to impress upon the
trade the fallacy of such reasoning, and that we could clearly
show to the contractor the damage he is doing to his business
standing in the community and to his reputation as a heating
contractor by installing cheap and inferior work.

A job or two may be lost by taking a stand against and refus-
ing to install low-priced work, but very soon a comfortable
business of the right sort will have been established.

As an example of good furnace work, we show the basement
and floor plans of a compactly built two-and-a-half-story sub-
urban residence. The first and second floors are of cement con-
struction, and the third or half-story is of frame work.

Fig. 67 illustrates the first floor plan, showing four rooms and
a pantry. The reception room, living room and dining room
are to be warmed and ventilated, while the kitchen is to be
ventilated, but not warmed.

On the second floor (Fig. 68), four bedrooms and two bath-
rooms are to be heated and ventilated, and on the third floor,
the plan of which is not shown, a bedroom is also to be simi-
larly supplied.

The living room and dining room on the first floor, and the
bedroom, over dining room, on the second floor, are ventilated
by means of open fireplaces.

GOOD FURNACE WORK

103

Fig. 67 First Floor Plan.

104

GOOD FURNACE WORK

: ' ; T 1 - " ; ": '' I 1 v. ' : .' : . ' <*-&>) w'tii&\- v.V.T 1

Fig. 68 Second Floor Plan.

GOOD FURNACE WORK

105

The servant's bedroom and bathroom are ventilated by con-
necting the ventilating ducts with a 9 X 10 inch ventilating flue,
built against the kitchen smoke flue, from which it is heated.

The ventilating ducts from all other rooms connect into a
13 X 19 inch vent flue, through which a 9 inch terra cotta smoke
flue is carried. This is the smoke flue which serves the furnace.
The ventilating flue is carried up through the first story 13 X 13
inches in size, being enlarged before the ventilating ducts of the
second floor are connected into it. The support afforded the
tiling in carrying the weight of it by this method of construction
is a particularly good feature.

The kitchen is not included in the above arrangement. At a
point near the ceiling this room has a 10 X 14 inch ventilating
register connected into the 9 X 10 inch vent flue, mentioned
above, for the purpose of carrying ofl the steam and odors of
cooking and also the excessive heat from the range, and it is
utilized in both summer and winter.

The basement plan, on which is shown the furnace, duct work
and the arrangement for supplying fresh, cold air is illustrated
by Fig. 69.

The following is a schedule of the sizes and description of all
pipes, ducts and risers; the location and sizes of all registers are
given on the plans, and require no further explanation :

SCHEDULE.

Warm air,

cellar Warm air,
pipe, in. flue, in.

Warm air,
Ventilating register, Descrip-

duct, in.

6%x 14
6^x14

First Floor.

Living Room 1 1

Dining Room 1 1

Reception Room and

Halls 210

Kitchen Ventilated at a point near ceiling only.

Second Floor.

Bedroom No. i 7 l />

Bedroom No. 2 7

Bedroom No. 3 pA

Bedroom No. 4 8

Bath 6

Serv. Bath A

Third Floor.

Bedroom No. 5 8

size, m.
12 x 16
12 x 14

2--I2X 14

4 xii

3 1/2 x

10 X IO

3^2 x ii

3^2 x

g]/2

Sx 10

4 x 16

3^x

8x 10

4 x i2 l / 2

4 x

10 x 10

3/2 x 8

3/x

7x 10

->iX x

10 X 10

tion.

Floor

Special

baseboard

Floor

Sidewall

4 x 12^2 4 x 12^2 10x10

The method of ventilation and the size and kind of ventilating
registers follow :

io6

GOOD FURNACE WORK

. 69 Basement Plan.

GOOD FURNACE WORK 107

Ventilating
register,

First Floor. size, in. Description.

Living Room Open fireplace

Dining Room

Reception Room and Halls

Kitchen 10 x 12 Sidewall

Second Floor.

Bedroom No. 1 8 x 10

Bedroom No. 2 7 x 10

Bedroom No. 3 8xio

Bedroom No. 4 10 x 10 Open fireplace

Bath 6x 8 Sidewall

Servants' Bath 6x 8

Third Floor.
Bedroom No. 5 10x10

In building a ventilating chimney of the character shown, it
should be lined with terra cotta, in order that it will be perfectly
smooth and also be able to retain the heat from the smoke flue
which passes through it. The plan of the flue shown on the
present job is clearly shown on the second floor plan, Fig. 68.

The cold air is admitted to the cold air chamber through a
24 X 30 inch screened opening in basement window, and baffle
screens for filtering this supply should be provided in the cold
air chamber.

To obtain the practical value of this article, we ask the fur-
nace man to make his own estimate on this work, as herein rec-
ommended, and then to estimate for an ordinary form of cheap
furnace heating for the same house. It is understood that the
owner builds the ventilating chimney and the ventilating flue
adjacent to the kitchen smoke flue, and that all other materials
and labor are to be furnished by the heating contractor.

If estimated correctly the figures will show a difference of
approximately $185, or a total difference, when including the
cost of the flue, of about $250.

The difference in the results obtained from increased warmth
and the comfort and healthfulness of a perfectly heated and
ventilated home cannot be measured when compared with those
secured from cheap work. Cleanliness and freedom from dust
are. assured the housewife with the former, and finally, as of
vital interest to our readers, the installation of such an apparatus
is a standing advertisement to the furnace man.

CHAPTER X
VENTILATION

The sciences of heating and ventilation are inseparably linked,
and in the construction of a home, both should be considered
jointly and proper provision made for the installation of an appa-
ratus which will not only heat but ventilate as well. Profes-
sional men and laymen throughout the country are awakening to
the importance of ventilation, and a word about it and its value
will help to spread a proper understanding of its importance.

By ventilation is meant the process of changing or renewing
the air within a room or building in order that the supply may
remain sufficiently pure for breathing purposes. This statement
indicates to us several facts : First, that ventilation is a method ;
second, that air confined within a room or building becomes
foul and unfit for breathing; and, third, that pure air is neces-
sary to sustain life.

Ventilation is a subject which until recent years has com-
manded too little attention from those who should be vitally
interested, and the acquisition of an adequate system of ventila-
tion in connection with the heating system is not now the luxury
it once was considered it is a necessity of today. The ventila-
tion of a home is even of more importance than the heating of
it, and we are coming to realize this, making provision for it as
we recognize its worth, and the time is approaching and that
not far distant when no dwelling of any size, or of the least
importance, will be constructed without provision being made
whereby the occupant may periodically remove the foul air and
admit a pure supply.

That we may the more readily comprehend the many phases
of this important subject, let us determine, if possible, what air
is and note the properties of its composition. Air is an invisible
liquid we call atmosphere, which surrounds the earth in a belt

VENTILATION 109

several miles in thickness. It is invisible (we cannot see it) ;
it is transparent (it does not obstruct our vision) ; it is insipid
(we cannot taste it) ; it is inodorous (pure air we cannot smell).
It is composed principally of oxygen (one part), nitrogen
(about four parts), and a very small proportion of carbonic acid
gas and watery vapor. The volume of carbonic acid gas is from
two to four parts in 10,000. The amount of vapor in the air
is conditioned by the proximity to a body of water or the tem-
perature of it.

Oxygen is the life-sustaining quality of the air. The nitrogen
is necessary to dilute it, and the carbonic acid gas to rarify and
purify it. Carbonic acid gas or carbon-dioxide is poisonous, and
will, when present in the air in any considerable quantity, cause
dullness, headaches, and produce fainting spells. This condition
is noticeable in a room in which the air contains 10 parts in
10,000. Frequently the air in a crowded hall or public room
is vitiated to the extent of 25 or more parts in 10,000, rendering
it so unfit for breathing that persons having delicate constitutions
will faint. This is also true of many factories or workrooms
in which a large number of laborers are employed. Air breathed
or inhaled into the lungs of people under conditions such as
these, inhaled into the room, and breathed over and over again,
is more or less laden with, the germs of disease, which is all
the more deadly should any of the persons present be suffering
from a malignant affliction.

Carbonic acid gas is the result of all combustion. Oxygen is
the life-giving quality in the atmosphere. The oxygen in the
air of a room is consumed by the burning of candles, coal oil
in lamps or stoves, and by gas. Occupants of a room by breath-
ing consume the oxygen, and their exhalations are full of car-
bonic acid and other poisonous gases. If a man be shut up
within a small, tight enclosure, his breathing will consume the
oxygen, and the poison and gas from his exhalations will soon
act to poison and suffocate him.

The amount of carbonic acid gas in the air we breathe should
never exceed six parts in 10,000, and when present in a greater
proportion it will cause headache and a feeling of stuffiness.
Relief from this condition in the form of ventilation may be
had more cheaply by the combination of a ventilating apparatus
and a warm air furnace than by any other method, and we shall
endeavor to make this plain to our readers as we progress with
this discussion.

no VENTILATION

It is well that we fully appreciate how vastly improtant is
the necessity for providing pure air to those who are compelled
to labor or remain indoors. The vitiation of the air is not caused
entirely by the respiration from our bodies, although it is a matter
of record that from i l / 2 to 2 l / 2 pounds of water are daily evapo-
rated from the surface of the skin of a person not actively
engaged in work of recreation that is, a person in still life.
Another form of vitiation is the burning up of the oxygen in the
air by gas lights, coal, coal oil lamps, or candles. A flame to
which no oxygen can reach will sputter and die out.

The mechanics of the sheet metal trade will understand the
need of pure air from some statistics recently compiled. These
figures were given by medical authorities, after diligent research,
and are to be relied upon. Of the deaths of those between 15
and 45 years of age in the United States last year, 28.4 per cent,
died from tuberculosis or consumption. The death rate among
certain classes of labor due to consumption is:

Marble and Stone Cutters 541 of every 100,000

Cigar Makers 479 of every 100,000

Printers 453 of every 100,000

Servants 430 of every 100,000

Formerly the percentage of death from consumption among
cigar makers headed the list, but the International Cigar Makers'
Union, a progressive labor body, by agitation and an aggressive
campaign for light and air and more sanitary workshops, has
reduced the percentage of deaths from this disease more than
50 per cent, in the last ten or fifteen years.

This, then, is the need of proper ventilation, and we shall
endeavor to show how adequate ventilation may be provided
by the proper installation and use of a hot-air furnace. The
amount of fresh air necessary to supply varies somewhat with
the conditions and use of a building, depending, of course, upon
the use to which the building is to be put. Dr. Billings, an
authority on ventilation, estimates as follows:

VENTILATION in

Kind of Building. Cubic Feet Per Hour.

Hospitals 3,6oo ft. per bed

Assembly Halls 3,600 ft. per seat

Workshops 2,000 ft. per person

Theaters 2,000 ft. per seat

Office Rooms 1,800 ft. per person

The schedule given applies to buildings with no contamination
of the air except from the respiration of the occupants and the
burning of the oxygen due to gas lighting.

Another authority states that the amount of carbonic impurity
given off or excreted by an adult female is 0.4 to 0.5 cubic feet
per hour, and by an adult male, 0.6 to 0.7 cubic feet per hour,
the average for a mixed assemblage being about 0.6.

Dr. De Chaumont, a French chemist, made some tests along
this line, and states that when the organic matter in the air
begins to be appreciated (smelt) by the senses, and the air is
said to be "rather close," there is present slightly more than
four parts of carbonic impurity per 10,000 cubic feet of air.
When the smell begins to be disagreeable, and the air within
the room seems "close," the carbonic impurity is 6.5 parts in
10,000 cubic feet. When the smell is decidedly offensive and
the air "very close," the carbonic impurity is about 12 parts in
10,000 cubic feet. We may add that the air at this time has
reached the danger point in its impurity.

Methods of Ventilating

No building of any considerable size can be ventilated except
by mechanical means, although a residence or small building
may be provided with a ventilating chimney, which will answer
every purpose. A galvanized iron or copper ventilator of the
type commonly known as the "Globe," or those of similar con-
struction, when placed on a one-story building, such as a chapel,
school or the like, will allow abnoxious gases, smoke or steam
from manufacturing to pass into the atmosphere, the currents
of surrounding air, or the wind, producing a suction which
exhausts the air from within the building. Many good ven-
tilators of a similar character are manufactured and have proven
practical.

A ventilating chimney when used in connection with a hot-air
furnace will give the very best results. The requirements are
that, in place of the ordinary brick flue, a large shaft or brick

112

VENTILATION

shaft should be erected through the center of the house or build-
ing. Through the middle of this stack the smoke pipe is run,
which, if the building be a low one, may be made of terra cotta
pipe, tightly cemented at the joints. However, a wrought iron
stack is preferred, which may be carried to any height desired.
Fig. 70 shows a plan of such a stack, in which A is the wrought
iron stack, and B the smoke and ventilating space. Fig. 71 is a
sectional view of such a stack as might be used in a two-story

Fig. 70 Plan of Ventilating Stack.

building, and shows the stack resting on a cast iron bed plate
supported by a brick pier. It should be properly stayed with
iron braces, one for each eight or ten feet of height. A good
style of such a brace is illustrated in the plan, Fig. 70. It is
made of heavy wrought iron and consists of a ring surrounding
the stack, to which are bolted four braces, the ends of which
are split and turned in opposite directions for tying into the
brickwork as the stack is being constructed. On the top of the
shaft should be placed a heavy galvanized iron hood, supported
by upright standards of iron 18 to 24 inches in length, as shown.

The wrought iron flue is placed in sections and riveted and
braced as the stack is being built. This is also true of the frames
for the foul-air registers or openings.

The heat from the smoke pipe or flue will expand the air in
the ventilating shaft and cause an upward movement of the air,
which will exhaust the foul air from each room connected to it.

A cold flue is of no use as a ventilating shaft, inasmuch as
no means being provided for expanding the air and overcoming

VENTILATION 113

the pressure of the atmosphere (14.7 pounds at sea level), the
air in the flue remains "dead" or inactive, and it is absolutely

Fig. 71 Sectional View of Ventilating Stack.

necessary to overcome this pressure on the flue before an upward
movement of the air in the shaft can take place.

CHAPTER XI
VENTILATION BY THE USE OF PROPELLER FAN

In the preceding chapter we discussed a method of ventila-
tion that might be termed "natural ventilation." However, not
all buildings are so constructed that a ventilating flue of the
character mentioned therein can be erected except at such a con-
siderable expense that the owner is loath to consider such a sys-
tem. Since electricity has become so common for lighting pur-
poses, and by reason of the fact that nearly every town has a
separate electric plant, or contracts for electric current from
some adjoining city, the matter of obtaining proper ventilation
of our homes, or in other buildings, can easily be arranged for.
By this statement we refer to the proper use of an electric pro-
peller fan.

This covers a method which should be carefully studied by
the furnace man. It is one so simple of adaptation, and yet so
effective in operation, that it provides a long-felt want.

The electric current ordinarily used by an incandescent burner
is sufficient to operate a fan which will thoroughly ventilate any
residence of medium proportions and construction, and the ex-
pense of running the fan is so slight as to be scarcely worthy of
mention, particularly when the results attained are regarded in
their true light.

We have reference to the propeller type of fan as illustrated
in Fig. 72. A fan of this character is designed to move air
against a very slight resistance, the blades being curved, pro-
pelling the air forward by impact, and when installed in the
attic of a building it exhausts to the atmosphere direct or through
a short duct.

A system of ventilation of this kind consists of register faces
or open panels placed in the baseboard of each room to be ven-
tilated and connected to an upright tin or galvanized iron duct
from each room, terminating in the attic of the building, which
is used as a plenum chamber. An opening in one of the gable
ends of the attic is made and framed to the size and diameter
of the fan, the flange of which is bolted to this frame. An

FAN VENTILATION 115

attic window may be arranged for the purpose, the framework
being built in such a manner that the window may be closed
when fan is not in use. See Fig. 73.

The fan is now ready for the wiring to the motor. A rheostat
or speed controller is attached in a convenient place on the first
floor, by which the fan may be started, stopped or the speed of
it controlled. These fans are made for two speeds, namely,
medium and maximum. Medium speed fans vary according to
size in the number of revolutions per minute, from 800 for the
18 inch to 200 for a fan 6 feet in diameter, and this type is rec-
ommended for ordinary ventilating work on account of being
practically noiseless in operation.

Maximum speed fans vary from 1,000 revolutions for the
1 8 inch to 270 for a 6 foot fan.

The following table gives the size, revolutions per minute,
horse power and cubic feet of air moved for medium speed
fans from 18 to 72 inches in diameter:

Propeller Fan.

Diameter of
fan, inches.

18
24

3 2
36

42
48
60

Horse
power.

1/8

1/2

5/8

3/4

13/4

2 1/2

Revolutions
per minute.

800
600
450
425
350
300
250

200

Cubic feet of
air delivered.

2,000

4,000

6,700

9,500
12,600
16,700
25,700
37,000

In handling or moving air by a fan the amount delivered

FAN VENTILATION

depends upon two factors, viz., size and speed. Further, if
the air is forced through a duct or ducts, the element of friction,
due to resistance encountered, must be considered.

There are some few rules which it will be well to remember :
i. The amount of air delivered by the fan varies directly as
the speed of it. Doubling the number of revolutions doubles
the volume of air delivered.

Fig. 73 Propeller Fan in Attic Window.

2. The air pressure varies as the square of the speed; for
example, if the speed is doubled the pressure is increased four
times. As we desire by the method described to deliver the air
directly to the atmosphere, this rule need not be regarded as
important for our purpose.

3. The power required is increased eight times when the speed
is doubled. Thus it is more economical to use a large fan at a
low speed than a small fan at a high speed to move the same
volume of air.

4. The temperature of the air to be moved affects the pres-
sure required and the power necessary. Increasing the tem-
perature of the air reduces its weight and diminishes the power
necessary to handle a given volume.

Let us consider, in ventilating an eight-room house, that there

FAN VENTILATION 117

are five rooms in which the air is to be completely changed four
times hourly. These rooms average 15 X 20 feet and have 10-
foot ceilings. 15 X 20 X 10 X 5 = 15,000 cubic feet of air to
be moved, which, when multiplied by four, the number of air
changes, equals 60,000 cubic feet to be moved hourly, or 1,000
cubic feet per minute. By reference to the table given above
it will be seen that only a very small fan is necessary for this
work.

The proper amount of pure fresh air must be admitted through
the cold air duct and warmed by the furnace to such a degree
that the various heat losses of the rooms are taken care of and
a uniform desirable temperature is maintained.

Many heating contractors contend that, providing the impure,
contaminated air is removed by an exhaust fan, the inward
leakage around windows and doors is sufficient to supply all
of the pure air necessary for the ordinary residence. This is
not true, for, considering that this applied to the building noted
above, it would be necessary for 200 cubic feet per minute to
leak into each of the five rooms figured, and cold air admitted
in such quantities would produce unpleasant drafts dangerous
to the health of the occupants. One of the first considerations
in the movement of air for ventilation is that there shall be no
drafts experienced by the occupants of the room or building.

There is a great advantage in installing a fan of this charac-
ter, viz., that proper ventilation may be provided during the
warm weather period, when the heating apparatus is not in use.
The effectiveness of any method is measured by the conditions
of the weather. A heavy atmosphere or excessive velocities of
the wind will have a much greater effect upon any system of
natural ventilation than it will upon a positive mechanical system
as above described.

Let all furnace men become acquainted with every phase of
this all important subject. There is no doubt but that heating
and ventilation are to be inseparably bound together, and we
must look to our system of warming to assist us in our methods
of ventilation. On the other hand, every furnace man of experi-
ence knows also that it is easier to warm a well-ventilated build-
ing than it is to heat one in which the air is foul or dead.

Efficiency of the Exhaust Fan

Exhaust fans are efficient for clearing factory rooms of smoke,
poisonous gases or the fumes from chemicals used in manufac-
turing, and by the admission of a sufficient quantity of fresh air
properly warmed it is possible to keep the rooms at a comfort-
able temperature and the air fresh and pure. Furnaces may be
used in connection with exhaust fans for this purpose, and for

n8 FAN VENTILATION

warming and ventilating small factories or other buildings a
system of this kind is efficient and may be installed at low cost.
The fan may be driven by a motor, belt driven or direct con-
nected, and as nearly all of the larger towns, as well as cities
of any size, have an electric light and power plant, the power
to operate the fan may be secured at a nominal cost, as an
exhaust fan run at low speed requires but a small amount of
power to drive it, owing to the fact that the air is usually moved
against a very slight resistance.

In this connection we quote from an article by Wm. H. Hayes
which was recently published in SHEET METAL. Mr. Hayes says:

"I am indebted to one of the largest and best known blower
concerns for the capacity table printed in this article. This is
presented for the reason that the power required to drive ex-
hausters is an important factor when a deal is being negotiated
in the piping business. Yet it is a factor very often regarded
as one of small importance.

"By referring to this table the reader will see how increasing
the speed of a fan by a few revolutions will more than double
the amount of power required to drive it. Take, for example,
the 40 inch exhauster fourth in the lower table; 4 horse power
will drive it 1,090 revolutions per minute, yet to drive it 1,785
revolutions, an increase of speed of but 695 revolutions, requires
17.35 horse power. The reader will note also the last stat:ment
made underneath the table, viz. : 'If the suction area is less
than the inlet of the fan, the power and volume will be reduced
and the pressure increased.' Thus, if it is a question of power
with the prospective purchaser, sell him a larger fan.

Speed, Capacity and Horse Power Required for Steel Plate

Exhaust Fans

"I am indebted to the same concern for another table, given
below, and which shows how speed can be cut down and power
saved by adopting t'.ic suggestion.

"To quote the American Blower Company: 'Supposing we
have 284 square inches of area in all the branch pipes and the
main suction pipe after the last branch is taken in 19 inches
in diameter. The various sizes of fans which can be applied,
with their respective results, are shown in the table below, this
being based on 100 feet of suction pipe, 100 feet of discharge
pipe, four elbows in the pipe and a properly proportioned
separator :

FAN VENTILATION 119

Brake voc ^^RJ^ rt ' ONC>0x ^vr5fBrake 00 ^^ ^ooo^oot/jrt
horsepow'r o ^ -< oi oi co -<f ^t 10 IN. I horsepow'r^o o\ K HJ t< oj^ o\ UJ>^H ^ ^

c per minute ~ of co co uSvcT t^co o co' [ per minUvte <^ Tf vo" K o 1 of 10 tx ^"oo" ^ <u

P TVT
jr. ivi. . .

oo 10 IN

horseoow'r "^ ^ ^ *> ^ M . ^ ^ ' horsepow'r rj-vd od w rj- 1< ^ 10 ON d\'C J3

r OO** 1 ^* 1 *^^ CO CO Tj" fl\ ^ HH KH o^ 04 O4 COTJ "^ Q-^

f ^ ^

C^ u< /^* t * .f 2. O l *^ O *O OOQOOQ t ^'^rH

1-1 Cubic ft ^O^OOOiOioOOn. V^UDIC I t . 0\ t^vo 00'^ < ^'QO*OO^*

^ per minute ^ ?"? "t 7 ^ ^ ^ ^ . per minute^-^ SS^oJ d S Sc5 ^f a ^ *S

O M NO W Q\ W tX O\ O\-N I TJ p TIT 04 CO O TfOO ^fcoO4 Ol O'>" ^i

ID r> TVT o *-" tx t^oo oi\oo>oo 1-tV' * "* -<i-orxiocooi M o ooo > '^
JX. lr^. JVl. 01 o oo t^vc voioiori-Tf (a^^^^t^^^ bf . .

cr tn

Brake O ^ Os ^ x o to co ^ vo f ? r a k ^ ^.^
i d . C >corj-iot>q\o4 ^-^qtv.1 horsepow r oi co
, horsepow roooooMM^oioiiu

R P M

Diam. inlet f B r a k e ,v

,vo jovo o vo tooo o
(inside)in.2 a ^^ o^ ol ot ^ oT orsepow'r 2 3 ^ ^ S K S d 5

p e riphery.>->^:
N inches " 2 rj J? 2" ^"2 N - per minute - w ^ ^^T K a ^ oi t<^

O O e

. P. M...

^
No. of fanffg^SRSSRig No. of fan^ft^^^^^ R<2 .2

I2O FAN VENTILATION

Size of fan. Speed. Horse power.

45 inches 1,300 R. P. M. n 2/3

50 inches 1,010 R. P. M. 8 3/4

55 inches 810 R. P. M. 7 "

60 inches 650. R. P. M. 5 2/3

"Thus it will be seen that to use a 60 inch fan instead of a

45 inch fan is to reduce the power more than one-half."

CHAPTER XII
HUMIDITY AND THE VALUE OF AIR MOISTENING

Up to the present time practically every furnace man seems
to have had but one object in view when installing a hot-air
furnace; namely, to install a furnace of such size and in such
a manner that each dwelling or building may be satisfactorily
warmed, notwithstanding the most adverse conditions of wind
and weather prevailing. True, there are those in the trade who
keep in touch with all the later improvements, who read and
study the results of various experiments calculated to better the
general conditions of warm-air heating in other words, k^eps
up to date but they are few in number.

Humidity and the value of air moistening cover a subject
that should be carefully investigated and learned by all heating
contractors. It is a subject easy to understand and, when prop-
erly understood, easy of application. Many articles of great
value on this topic appear from time to time in the trade press,
and the furnace man who gives them but scant or passing atten-
tion is missing instructive literature which will later prove of
vast importance and necessity to him.

We know that the earth is surrounded by a belt of atmos-
phere several miles in thickness and that this air contains more
or less vapor, the amount varying according to the temperature
or its proximity to a body of water. Those of our readers who
have lived in the vicinity of, or have visited the shore of any
one of the Great Lakes, or even many of those inland bodies
of water less extensive in area, may have noticed that, as a
rule, they lie in a basin and are approached down a hill, which
is sometimes very short and abrupt, and again at other times
long or gradual in its descent. No matter which geographical
condition exists, it is very apparent that the atmosphere after
the crest of the hill is passed becomes very balmy, humid and
of a satisfying nature, all of which is due to the proximity of
the body of water. We may reach or obtain this same delight-
ful condition and enjoy this same balmy atmosphere within our
homes.

The writer believes that this subject is too little understood
and is given too little attention by furnace men.

122 AIR MOISTENING

The great Architect of the Universe never intended that we
should pass one-third or more of our lives shut up in almost air
tight boxes ; neither did he intend that we should be compelled to
breathe tainted and poisoned air, yet this is what we are doing
day after day with the result that as a nation we are heir to all
sorts of diseases of the throat and lungs, tuberculosis, bronchitis,
etc.

This condition and the effects of it will perhaps be better
realized when we say that statistics show that over 30 per cent,
of all deaths in this country are due to diseases of the throat and
lungs, and today the treatment most generally prescribed by the
physicians for such ailments is more fresh air, and by this advice
is not meant the outside air, such as comes to us within our homes,
baked by the average heating apparatus, but clean, pure, and
humid air, such as an out-of-door climate provides.

There is no form of artificial warming apparatus by which this
ideal condition may be produced and sustained so well as by a
hot air warming system properly installed.

The average steam or hot water warming apparatus provides
only for heat. The introduction of a supply of fresh air is
generally overlooked entirely, or when introduced at all is only
provided for in the homes of well-to-do people, who have ample
means to pay the increased expense of installation and main-
tenance of such an apparatus.

As we have said before, it is by reason of the moisture in the
air that it carries and retains heat, and the dryer the air, the
more difficult it is to heat.

The air is capable of carrying a large amount of moisture.
This may be noticed during a fog and again by the dew deposited
during the night at certain seasons of the year. In tropical coun-
tries the dew deposited is frequently so heavy that the eaves drip
water, and if this condition did not exist the tropics would not
be habitable.

A year or two ago, when discussing the importance of air-
moistening, the writer remarked somewhat as follows: "The
process of refining or manufacturing raw material into a finished
product has been carried on for many centuries. Had some-
body stated to the architects of ancient Rome, or to the archi-
tects and constructors of our own national capitol, or of our
more modern buildings, that in the twentieth century we would
be manufacturing climate, they would all alike have disbelieved
the statement, and considered that the speaker was bereft of
reason." However, that is exactly what we are accomplishing 1

AIR MOISTENING 123

in hundreds of buildings today and it has come to be a very
important factor of an up-to-date heating and ventilating ap-
paratus, more particularly in our schools and public buildings.
We can now provide an air supply for any building that will be
free from soot and dust, that will be pure and also accompanied
by a constant relative humidity, regardless of the condition of
the outside air, or the location of the structure.

The principal installations of air-moistening apparatus have
been placed in connection with the fan or blower system of heat-
ing. Very few have as yet been used with a warm-air furnace
as the source of heat.

Let us consider briefly the term humidity with the fact that it
is necessary that there be some moisture in the air we breathe.
When the air is so laden with moisture that it is deposited in the
form of de\v, it has reached the point of complete saturation,
or what is k.iown as the "dew point." This deposit or dew is
formed by the radiation or giving off of heat from trees, plants,
etc., this action reducing the temperature of the surrounding
air to the point of complete saturation, when the moisture will
be deposited. We will consider that this point is one hundred
per cent. In the most arid deserts there is some degree of
moisture present in the air, probably thirty or thirty-five per
cent, of complete saturation. In ordinary or temperate climates
the prevailing percentage may be from fifty to seventy-five, the
rate depending largely upon the temperature.

The dryer the air, the more difficult it is to heat. At high
altitudes the atmosphere is dryer than that found at low points,
hence it is cooler and more difficult to heat, as the cold air ab-
sorbs less moisture than the warm. On a hot summer's day,
with the thermometer around 90 degrees Fahr., the air is capable
of absorbing about fifteen grains of moisture for each cubic
foot. At 32 degrees Fahr. (freezing), the air will absorb but
little more than two grains per cubic foot. It is apparent then
that by reason of the moisture present, the air carries and re-
tains heat. The heating apparatus which employs an air-mois-
tener to properly saturate or humidify the air is not only provid-
ing a healthful climate within the building, but is accomplishing
it at less cost for maintenance than would otherwise be possible.

Reduction of Fuel

Exhaustive tests have demonstrated the fact that the saving
in fuel effected by adopting proper methods of air moistening
will pay the cost of such effort to say nothing of the increased
comfort and health fulness secured and probable saving in the
expense of physicians' services.

124 AIR MOISTENING

Results of Investigation

One physician says: "Investigations have proven that the
higher the degree of temperature, which increases the capacity
for water, the greater will be the weight of a cubic foot of
saturated aqueous vapor; therefore, by the addition of heat to
the colder outside atmosphere entering the building, there must
be an additional amount of vapor added to overcome the de-
ficiency existing between the weight of a cubic foot of saturated
aqueous vapor as received from the furnace from the outside,
and the weight of a cubic foot of saturated aqueous vapor raised,
by the addition of heat units, to the higher indoor temperature
to produce a normal condition of the latter/'

So much regarding the need of proper humidity. Now, let
us for a moment consider the effect of it in connection with the
proper warming of a house or other building.

We have said, and our readers have no doubt frequently read
the statement, that a room heated to 60 degrees F., with a
humidity of 55 per cent., is much more comfortable than a room
heated to 75 degrees with a lower percentage of humidity. The
climate, and when warmed to 60 degrees F. a building is com-
fortably heated. In this country we all know that a tempera-
ture of 70 degrees F. is the standard for living rooms, offices,
or other rooms where the occupants are inactive.

The average warmed building, having no ventilation, is as dry
as the desert of Sahara, and many eminent physicians have called
attention to the bad results arising from it. The irritation of
the mucous membrane of the throat and lungs, causing bron-
chitis and catarrh, is one of the worst evils consequent upon this
condition of the air.

If in cold weather we are using outside air to supply the fur-
nace, and this outside air is at 65 per cent, (as we measure
humidity), we reduce the moisture to probably 30 or 35 per cent,
in warming our rooms to 70 degrees Fahr. In continuing to
pour warm air into the rooms under these conditions the radiated
heat seems to penetrate through the air within, but without
warming it. If we devise and employ some method of moisten-
ing it, the moist, humid air will hold and absorb the radiated
heat and give it off to all cooler bodies within the room.

Humidity has been aptly called "Nature's great bed-blanket
for all her children," and without it they would perish. Dry air
extracts the moisture from the body, and it is accordingly neces-
sary to warm the rooms to a greater degree in order to feel com-
fortable.

If our readers will note the difference between the English
climate and that of America, a very good illustration of these

AIR MOISTENING

125

facts is apparent. The Englishman complains of the American
winter climate because our homes, which to us are only comfort-
ably warmed, are to him overheated. The American finds the
reverse to be the case when visiting England, and complains of
the cold. The human body can be likened to a furnace and the
heat developed within it must be given off as rapidly as it is
produced if we are to remain healthy. This dissemination is ac-
complished largely by perspiration. The Englishman is accus-

TO DRAIN

Fig. 74 'Galvanized Iron and Wire Air Moistener.

tomed to a low rate of perspiration, the American to a higher
rate, the difference being due to the fact that each has grown
up in or become susceptible to a different climate.

Now, regarding the probable saving in fuel by changing these
conditions, it is competently estimated that 25 per cent, of the.
cost of heating is expended in raising the temperature within
our homes from 60 to 70 degrees. This being established it fol-
lows that one-fourth of the cost of fuel can be saved by main-
taining the temperature of the rooms at 60 degrees and pro-
viding for the loss in moisture (humidity) due to heating the
air; in other words, by keeping the percentage of humidity at
65 or 75. The result will be a sensible temperature within the
rooms which, if no thermometer is at hand to consult, will seem,
and in fact is, entirely comfortable.

How may we provide for properly moistening the air? This
question naturally follows in our discussion of the subject.

There are several methods by which the air supply of a warm-
air or furnace-heating system may be moistened and made humid.
The common practice of placing a small cast iron receptacle in

126

AIR MOISTENING

the side of a furnace casing, called a "water-pan," "vapor-pan,"
etc., is but a feeble effort in this direction, and it does not amount
to anything for the purpose intended. True, the water in this
pan evaporates into the air supply of the furnace, but it is very
much the same as would be the effort of the arid dry air of a
desert to take its moisture from a small brook.

The cold air may be admitted through a chamber in which
are a number of compartments filled with crushed coke, over
which small streams of water from a perforated water pipe
trickle down, keeping the coke wet. A drip-pan at the bottom may
connect with an overflow pipe leading to a drain.

iX) J=>ijo 3 cffe
Fig- 75 The Herr Humidizer.

Fig. 74 illustrates this method, the coke being broken into small
pieces and held in a galvanized iron and wire rack inside the
boxing at the cold-air inlet.

Another method is the spraying of the air by means of one or
more small atomizers or sprays playing on the incoming air.

There is but little difference as to whether the air is moistened
before or after it is heated, except that moist, humid air absorbs
the radiated heat better than the dry air. Spray nozzles of
brass may be obtained and they are of simple construction. The
centrifugal action prevents the openings from clogging. For a
job of any considerable size or importance a bricked-in humidify-
ing chamber with cemented floor properly drained may be pro-
vided in the basement and water pipes with sprays be placed
in this chamber.

An apparatus for spraying the air, after it has been heated.

AIR MOISTENING

127

known as the Herr Humidifier, has been found to be very effec-
tive and is strongly recommended by those who have tried it.
This device seems to us to be worthy of careful investigation
on the part of the furnace man. It has been greatly improved
and some few defects in the original apparatus have been cor-
rected.

Fig. 76 Humidizer Attached to Furnace Casing.

ig- 75 shows a view of the humidizer proper the spray
nozzle and adjustments. The small stream of water passing
through the apparatus strikes the spoon C and is deflected in
the form of a fine spray, which saturates the air in the top cas-
ing of the furnace. The size of this stream of water, and con-
sequently the amount of moisture mixed with the air, is regulated
by the adjusting bar B.

Fig. 76 shows the method of attaching the humidizer to the
casing top of the furnace, and Fig. 77 shows a complete installa-
tion of the same, with an apron provided to utilize the drip from
the spray nozzle.

We believe that no further description of the device is neces-

128

AIR MOISTENING

sary, and that the utility of it will be apparent to every practical
furnace man.

The hot air as it rises to the top of the casing is moistened
by the fine spray of water, which is absorbed, and then passes
through the leader pipes to the rooms above, producing balmy,

Fig. 77 Complete Installation of Humidizer.

natural atmosphere. Tests have shown a relative humidity of
from 60 to 65 per cent, of complete saturation.

Placing the Water Pan

The feeble effort to obtain these results by using a water pan

AIR MOISTENING

129

in connection with the furnace, we all no doubt are familiar
with. The pan is located at the wrong point to be effective, even
to a small degree. The water should be above the source of
heat.

A much more effective water pan may be made by
riveting and soldering a strip of galvanized iron around

Fig. 78 Sectional Elevation and Plans Showing Proper Location
of Water Pan.

the inside of the top casing, immediately under the openings for
the connection of hot air leader pipes. This ring should be from
two to two and one half inches wide with the inside edge turned
up a little over one-half of an inch. In Fig. 78 the sectional
elevation illustrates the idea and the plan above shows a little
cup riveted on the side of the casing as a device for filling small
holes in the casing connecting with the pan on the inside of the
casing.

The Hygrometer

To properly understand the relation of humidity to heating
we must know that the sensible temperature (that is, the temper-

130

AIR MOISTENING

ature felt by the body) corresponds to the temperature of the
wet bulb thermometer; therefore, the dryer the air, the greater
is the difference between the actual and the sensible temperatures.
We measure or determine the temperature and humidity of
the air with an instrument known as a hygrometer or hygro-

Fig. 79 The Hygrometer.

phant. On this instrument two standard thermometers are pro-
vided, one (a dry bulb) showing the temperature of the air, and
the other (a wet bulb) showing the temperature due to evapora-
tion (Fig. 79). In the center is a fixed scale, and to the right
of this is mounted a cylinder upon which is inscribed columns

AIR MOISTENING 131

of figures with headings numbered from "i" to "22." This
cylinder may be freely turned by the knob shown at the top of
the instrument, and the figures appearing at the top of the col-
umn represent the difference in the reading of the dry and the
wet bulb thermometers. Revolve the cylinder until this number
appears at the top and note the number opposite the figure on
the fixed scale representing the reading of the dry bulb thermo-
meter. This number gives the percentage of humidity.

For example (note illustration), the dry bulb thermometer
shows 70 degrees and the wet bulb 60 degrees. 70 60 = 10
number at the top of the cylinder which has been revolved until
this number appears.) Now note the cylinder number opposite
the figure 70 on the fixed scale. It is 56, which is the relative
humidity or percentage of moisture in the air, according to the
thermometer readings. This is a most interesting as well as in-
structive instrument.

CHAPTER XIII
RECIRCULATION OF AIR IN FURNACE HEATING

It is generally recognized that many of the objections to fur-
nace heating are brought about by reason of the installation of
cheap, unsatisfactory, and unsanitary work, or through the ig-
norance displayed by the unskilled man in laying out and in-
stalling the job.

We will consider some of these objections, their cause and
how they can be remedied and the work made satisfactory.
Probably the first and most frequent objection heard is that made
to the condition of the air within a building when it is warmed
by a hot air apparatus, viz., that it is overheated and "stuffy."
The frequency of this fault we must admit; and it is brought
about through the installation of too small a furnace and the
provision of too small an area for the cold or fresh air duct. A
further source of complaint is found in the quality of the air
supplied.

Quality of Air

Let us consider for a moment this complaint and the cause of
it. If a certain size of a building requires the consumption of
12 pounds of coal per hour to transmit the necessary number of
heat units to take care of the exposure or cooling surfaces, a
certain size of grate will be required to properly burn this amount
of fuel, and, in its turn, the heating surfaces of the furnace
which transmit these heat units to the air passing through it,
must be of a certain area if these surfaces are not to be over-
heated in the effort of transmission. This means, for example,
that should 12 pounds of coal per hour be burned on a grate
having three (3) sq. ft. of area, the rate combustion would be 4
pounds of fuel per sq. ft. of grate per hour. Assuming that
.from each pound of fuel, 8,000 heat units are available for warm-
ing purposes, then 8,000 X 12 = 96,000 units per hour will re-
sult from 12 pounds of fuel burned on 432 sq. in. of grate.

Supposing that a furnace having but 288 sq. in. or 2 sq. ft. of
grate area was installed to warm this building, the attempt to

RECIRCULATION OF AIR

133

burn the fuel required on the reduced grate area requires so high
a rate of combustion that the air passing through the furnace
is overheated, thereby destroying its invigorating qualities, and
making it unfit to breathe and "stuffy" in effect.

Air Outlet Necessary

Another reason for this condition (stuffy atmosphere) is due
to the fact that many furnace men are trying to introduce warm

Pur not in ~z^; ~
circulation.

Fig. 80 Poor Air Circulation when Room has No Outlet.

air into a room which has no air outlet, except the leakage around
windows and doors, doubtless overlooking the fact that only as
much air can be admitted to a room as the amount which passes
out, and the effort to heat the room in this manner makes neces-
sary such an increase in the temperature and velocity of the in-
coming air as will drive it into the rooms.

Heating Windward Side

Right along this line is the complaint that during the prevalence
of high winds it is impossible to heat the rooms on the windward
side of the house. This complaint, as well as the preceding one,
can be overcome wholly or in large part by the proper recircula-
tion of the air within the building. Fig. 80 represents a closed

134

RECIRCULATION OF AIR

room without air outlets, except the leakage through walls and
around windows. Note the manner of the circulation of the
air, or rather the fact that there is practically no circulation of
it. Place a rotating register and flue as indicated by Fig. 81 anil
note the difference in the movement of the air.

Supposing the room is on the side of the house most exposed
to the strong winds of winter; the placing of a rotating register
and flue along the outside wall of the room will do much t.->
improve the circulation of the air in it, and consequently the
proper warming of the room. Fig. 82 illustrates this condition.

Fig. 81 Perfect Circulation of Air when Rotating Register and Return
Air Flue are Employed.

In illustrating our discussion of furnace heating, we have for
convenience frequently shown floor registers. We do not like
floor registers. From a healthful standpoint they are bad, as
they collect dirt and organic matter, and often much of the bad
air in a room may be traced to the filth and dirt which has col-
lected in the boxing under a floor register. If circumstances
make necessary the use of floor registers, the face should be lifted
out and the boxes wiped out at least monthly with some germ
destroying wash.

Opposition to the Method

As stated in a recent chapter, there are some people identified

RECIRCULATION OF AIR

135

with furnace manufacture and installation who advise against
the recirculation or rotation of the air within a building. These
advocate a positive method of ventilation notwithstanding the
consequent expense to be incurred in bringing about this desired
condition.

The objection to the recirculation of the inside air seems to
be based entirely upon the feeling that the quality of the air is
lowered and that the health of the occupants thereby is endan-
gered.

We believe that the filtration of air through outside walls and
windows, considered with the fact that ordinarily less than half
a dozen people inhabit a single dwelling, renders the contamina-
tion of the air to the point of stuffiness next to impossible.

Fig. 82 Showing Effect of High Wind Against a Building Heated
with Hot Air.

On occasions when a social function is given and a considerable
number of people are present, the return air registers can be
closed and the outside air used exclusively. This is also true in
the event of any of the occupants being sick or affected with a
contagious disease.

While we recommend ventilation and plenty of it the fact
remains that a very great number of furnace heating plants are
installed without any form of ventilation, and the amount of
fresh air admitted is limited because of conditions stated in this
article. The installation of return air ducts with rotating registers
in the principal rooms, will aid in the distribution of the fresh

136

RECIRCULATION OF AIR

air admitted through the cold air duct, and this feature will not
only make the furnace heat more positively, but will distribute
the air at the least possible expense for fuel.

Obtaining Best Results

The furnace by itself cannot warm the building. It can do
nothing more than warm the air, and it is up to the furnace man
to take this warm air and provide methods for its carriage and
distribution.

Division in
Co/cf Air Duct.

5 w/ngifiQ D Q/njoc. r&'
Fig. 83 Proper Construction of Return or Recirculated Air.

The failure to obtain proper results when the recirculation
feature has been introduced in furnace heating, is usually found
to result from the fact that poor judgment has been exercised
by the furnace man who has not fully understood the method
to be followed.

Connecting Duct

Ordinarily the circulating duct should not be connected to the
casing, or to the cold air pit of the furnace, but rather to the

RECIRCULATION OF AIR 137

cold air duct ; and dampers should be arranged in such a manner
that return air or fresh air may be used at will. The cord or
chains operating these dampers may extend to a convenient place
on the 'first floor. Fig. 83 shows the method of connecting the
duct.

We recommend to the furnace man that he study the methods
of return air circulation, and the advantages to be gained from
the installation of such a system when properly erected.

CHAPTER XIV
AUXILIARY HEATING FROM FURNACES

When warming a building with a hot air furnace it frequently
happens that there are some rooms or portions of the building
which, owing to structural conditions or remote location, cannot
well be warmed in the regular manner with hot air.

These conditions, which would interfere with the running of
hot air pipes, will not interfere with the installation of hot water
piping, and therefore several methods have been devised of com-
bining a hot air and hot water heating apparatus, making use of
but one fire for supplying the necessary heat for both systems.

This is accomplished by installing a somewhat larger furnace
than would be required for hot air alone, and by placing a coil
of pipe in the fire pot of the furnace or suspending above the
fire a hollow casting, called an auxiliary heater, through which
the water may circulate and receive the heat. The hot water
circulating through the coil or casting is distributed through
piping to one or more radiators located within the rooms to be
warmed.

It is not necessary for the furnace man to be adept that is,
thoroughly versed in the practice of steam fitting in order to
successfully install combination jobs of this character.

Computing Size of Radiator

Probably the first knowledge that should be acquired pertain-
ing to this method is to learn how to compute the size of radiator
necessary to warm a room. This is determined by considering
the cooling surfaces of the room, glass and exposed wall, much
the same as for hot air heating. The following simple rule will
give fairly accurate results :

First Ascertain the square feet of glass surface (windows
and outside doors).

Second Ascertain the square feet of exposed wall surafce
(outside walls, windows not deducted).

AUXILIARY HEATING

139

Third Ascertain the cubical contents of the room to be
warmed.

Divide the glass surface by 2.

Divide the exposed wall surface by 20.

Divide the cubical contents by 200.

Fire Pat of
Furnace

rtetu

Fig. 84 Plan and Elevation of Pipe Coil,

The product of these results plus 60 per cent., will give the
amount of hot water radiation necessary to warm the room to
70 degrees in zero weather with the water at a temperature of
1 80 degrees Fahr.

If the furnace contractor is in the habit of estimating accord-
ing to loss per hour of heat units, he may determine the total

140

AUXILIARY HEATING

loss for the room in heat units and divide this sum by 150; this
calculation will give the square feet of radiation required.

Heating Furnace Required

The next item to consider is the amount of heating surface
to be provided in the furnace to supply the radiation required.
This heating surface may take the form of a pipe coil as illustrated
by Fig. 84, which shows a plan and elevation of a pipe coil, or

Fig. 85 Cast Iron Auxiliary Heater.

of a hollow casting as illustrated by Figs. 85 and 86. These cast
iron auxiliary heaters are made in a variety of shapes and sizes.
Each square foot of surface in the pipe coil shown by Fig. 84 if
placed low in the fire pot, so that the hot fire comes in contact
with it, will supply 50 sq. ft. of radiation with hot water at 180
degrees or 60 sq. ft. of radiation with the water at 160 degrees

Fig. 86 Another Form of Cast Iron Auxiliary Heater.

at the radiator. If the coil is suspended above the fire it will
supply from 25 to 30 sq. ft. of radiation.

Should a hollow casting similar to that illustrated by Figs. 85
or 86 be employed as heating surface in the furnace, it is sus-
pended above the fire and varies in efficiency from 20 sq. ft. of
radiation supplied for each square foot of heating surface in

AUXILIARY HEATING

141

O^erf/ow

Furngce.

Fig. 87 Typical Arrangement of an Auxiliary Hot Water
Heating Apparatus.

142

AUXILIARY HEATING

Ovzrf/ow.

Fig. 88 Domestic Hot Water Supply from Furnace.

AUXILIARY HEATING

Fig. 89 Overhead Piping of Auxiliary Hot Water System.

i/l/l AUXILIARY HEATING

the casting, to possibly 25 or 30 sq. ft., depending upon how
much of the casting is direct heating surface and how far above
the fire it may be located.

Installing the Apparatus

The method of installing the piping and of connecting to the
radiators has more to do with the success or failure of a job
of this character than the construction of any other part of the
system. Fig. 87 is a typical illustration of an auxiliary hot
water heating apparatus and shows two radiators supplied by
a coil in the furnace.

Note the small tank at the top of the system. This is called an
expansion tank. Water when heated from 32 to 212 degrees (the
boiling point) expands 1/25 of its volumne, and unless some
provision were made for taking care of this expansion the
system would overflow when heated, and when the water in the
system was again cooled and contracted, the upper part of the
system would fill with air which would interfere with the cir-
culation. The tank should be located in such a position that
the bottom of it is well above the top of the highest radiator
and the pipe connecting the tank with the system (called the ex-
pansion line) should be connected as indicated on the illustration.
Ordinarily an expansion tank of from eight to twelve gallons'
capacity is sufficient for a combination job. An eight gallon tank
will take care of 200 to 250 square feet of radiation and a twelve
gallon tank, 300 to 400 square feet.

The size of pipe to be used in connecting to the radiators is
determined by the size of each radiator.

A I inch pipe will supply 35 or 40 square feet of radiation
on the first floor above the furnace or 60 to 70 square feet on
the second or third floor. In like manner a ij4 inch pipe will
supply 60 to 70 square feet on the first floor, or 90 to no square
feet on the second or third floor. A \y 2 inch pipe will supply
100 to no square feet on the first floor or 150 to 160 square feet
on the second or third floor, and the main flow pipe from the
furnace must have an area equal to the combined area of all
radiator connections.

An installation of this kind is known as a circulating job, and
no radiators or pipes are valved. The radiators are employed
in exactly the same manner as would be a storage tank for do-
mestic hot water use. If the radiators were valved and the valves
should be closed, the excess of heating surface would boil the
water in the system. The cooling surface of the radiators pre-
vents this happening when they are in service.

Another method of installing an auxiliary hot water apparatus
is illustrated by Fig 88, which shows a cast iron auxiliary heater

AUXILIARY HEATING 145

employed within the furnace. The piping system shown in the
illustration indicates another of the several methods that may be
used. The expansion tank is connected from the high point of
the system, and therefore air valves on the radiators are not re-
quired, as all air in the system passes to the atmosphere through
the expansion tank.

It is well that the furnace man should become acquainted with
the methods of estimating and installing auxiliary heating systems,
as they are frequently desired by the house owner.

Auxiliary heaters are frequently employed for furnishing hot
water for domestic use and are installed in connection with the
kitchen boiler or storage tank.

The piping is usually cross-connected with that from the kit-
chen range and valved so that the auxiliary heater may be cut
out during the summer season when the furnace is not in use.
Fig. 89 illustrates an installation of this kind.

An expansion tank is not required on a system of this kind,
as the water is used under pressure, and a job of this character
would be designated as a pressure system.

The heating surface required in the furnace auxiliary heater
is i square foot for each 20 gallons of water in the storage tank
or kitchen boiler.

CHAPTER XV

TEMPERATURE REGULATION AND FUEL SAVING

DEVICES

The value of a good temperature regulator seems to be neither
understood nor appreciated by the heating contractor.

What the governor is to an engine the thermostat is to a fur-
nace. The governor, attached to an engine, prevents the engine
from "running away'' or speeding when the load or work it is
doing is suddenly lightened, in other words, it regulates the
speed of the engine automatically, preventing useless waste and
possible danger.

The thermostat or temperature regulator, attached to a furnace,
prevents the overheating of the building and consequent waste
of fuel. It also prevents possible damage due to overheating the
furnace.

There are some features of temperature regulation which, if
brought to the attention of the house owner in a convincing
manner, should effect a ready sale of an appliance of this nature,
as little necessity exists for argument on the part of the furnace
man when such features are made known.

We have mentioned the saving in fuel, which may be effected
by a system of thermostatic control. The health of the occupants
of the home, and the comfort experienced, may also be considered
as desirable features of temperature regulations.

A brief argument in favor of the thermostat may be made by
considering these three features :

(a) Saving in fuel and consequent low cost of maintenance.

(b) Healthfulness due to uniformity of temperature.

(c) Personal comfort as a result of having a watchman (ther-
mostat) in charge of the furnace, to open or close the draught
doors at the required moment.

Briefly stated, the work to be performed by the furnace may
be considered as follows:

Consulting a table of temperatures compiled by the United
States Government, giving maximum and minimum temperatures
of some thirty cities, and covering all sections of this country
and Canada where heat is required in winter, we find that the
average number of degrees the temperature is to be raised arti-
ficially is 80. In Charleston, S. C., it is 47, while in Duluth,
Minn., it is 108.

TEMPERATURE REGULATION 147

The average winter temperature for the period we call "the
heating year'' is a little under 40 F. As we have already re-
marked, in this country we demand a temperature of 70 within
our homes, and therefore we must raise the temperature approx-
imately, an average of 30. It requires just so much heat, or
the expenditure of just so many heat units to produce this result,
and for every degree above 70, shown by the thermometer,
there is a loss of fuel in a direct ratio to the increase in tempera-
ture, and this loss at a low estimate is 25 per cent.

Of the healthfulness due to a uniform temperature, it seems
necessary only to state that all physicians and scientists, who
have made a careful study of the subject, report and agree, that
next to the proper ventilation of our homes, a uniform degree
of heat is essential to the good health of the occupants. We
are safe in saying that few colds, and few of the more serious
diseases so prevalent in winter, will be experienced, if a uniform
temperature is maintained in the home.

Finally comes the question of personal comfort. It has been
stated that this is the age of personal comfort, "the automatic
age" and "the electrical age." It is now that the furnace man
may deliver the solar plexus blow the final argument.

The period when artificial heat is necessary comes as regularly
as the time when food is necessary to sustain us, and the per-
sonal comfort, due to the work of the thermostatic watchman
in attending the furnace, cannot well be calculated.

We may repeat what we had occasion some time ago to re-
mark regarding the thermostat. "It is a boon to the busy man
and a delight to the lazy man, and is more than self-sustaining,
paying for itself in a season or two, after which it earns money
for the owner at a rate never excelled by the best savings insti-
tution."

Arguments and facts such as these, when brought to the at-
tention of the users of hot air furnaces, should make possible
the sale of a good many thermostats, and materially add to the
business of the furnace dealer.

Fuel Saving Appliances

Each pound of anthracite coal when used for fuel in a furnace
gives off approximately 14,500 heat units. About 10,000 of these
are available for heating purposes, the remainder being utilized
principally in warming the air in the chimney flue to produce
sufficient draft to carry off the smoke and products of combus-
tion.

148 TEMPERATURE REGULATION

In considering the question of economy in fuel we may say
first of all that it is a poor policy to select a furnace with a grate
so small that it is necessary to keep the fire in a continual state
of activity to properly heat the building. The frequent "stirring
up" of the fire by a shaking of the grate and the addition of
more fuel are as wasteful as they are unnecessary. With a fur-
nace having a grate of adequate size, or perhaps a little larger
than is absolutely essential, the very best result is obtained in
the way of economy, provided the heater is fired in an intelligen!
manner. There is great waste in intermittent firing. By this we
mean the opening of the draft door of the furnace, forcing the
fire to greater activity and allowing the building to become over-
heated, requiring the opening of the windows. The coal should
be permitted to burn just enough to give ofif the required heat
units to keep the building warmed to the desired temperature.

This can be accomplished only by the use of some good system
of temperature regulation which will automatically control the
fire by opening and closing the draft and check dampers of the
heater. The appliances to perform this work are called "regu-
lators" or "thermostats," and there are many good and reliable
kinds to be had.

It will be impossible here to illustrate and describe all of the
various makes, and therefore we shall select several of those
most commonly used, showing the manner by which they ac-
complish the service demanded of them and for which they are
intended. It will be of interest to our readers to know some-
what of the history of temperature regulation, or of the inven-
tion and application of methods for automatically controlling
the drafts of a heating apparatus. A device for this purpose
was invented by a Frenchman, named Du Moucelle, of Paris,
in 1853. The first practical temperature regulator in this country
was invented in 1883 by W. S. Johnson, of Milwaukee, Wis.,
who placed it on the market in 1884. Some four years later W.
P. Powers (then in the plumbing and steam fitting business),
of La Crosse, Wis., devised a vapor thermostat for operating the
draft doors of a furnace.

At about this time (1885) an electric thermostat was devised
in Minneapolis, Minn., and later put on the market by the Elec-
tric Heat Regulator Company. This regulator in an improved
form we shall later illustrate and describe.

These regulators and thermostats have been followed by num-
erous other varieties, all of which may be divided into two gen-
eral classes, viz., electric and non-electric. In the list of the

AND FUEL SAVING 149

electric thermostats and regulators are included the Minneapolis,
Jewell, Beckam, Beers, Honeywell, and among the non-electric
we find the Johnson, Powers, Regitherm, Howard, National, and

others.

Many of the automatic regulators en the market are used
principally for the control of steam and hot water heating ap-
paratus, for the control of gas and liquids, and for the control
of water and other liquids in tanks. This latter is styled "tank
control."

We shall consider and describe only those which are especially
used for the control of a furnace those whose operation is di-
rectly governed by the temperature of the air within a room of a
residence or similar building.

Electric Regulators

The Minneapolis, Honeywell, Jewell, Beckam and Beers regu-
lators make use of devices for the electric control of the ap-
paratus, which are quite similar in the operation performed. This
appliance is placed on the wall of one of the principal living
rooms of the residence. Fig. 90 shows the device as used with
the Minneapolis regulator. Fig 91 shows the device with its
shield or cover, on which is mounted a mercury thermometer.
It consists of a frame holding a piece of metal in the form of
a loop or ring with a tongue or strip of metal suspended from
the bottom of the loop. One end of the loop is attached to the
frame, the other end and the suspended tongue hanging free.
The slightest change of temperature will expand or contract the
ring causing a side movement of the suspended tongue or arm.
An electric battery (consisting of two or three cells of dry bat-
tery) is used to generate the electric current through two wires,
which are attached to posts or pins located one on either side of
the suspended arm. Small thumb-screws or pins are set in these
posts, so adjusted as to allow the points to almost touch the sus-
pended blade. As the temperature of the room rises the loop
expands throwing the blade against one set screw closing the .
electric circuit and operating the motor or driving power of the
thermostat, which, in turn, operates the draft of the furnace by
closing the draft door and opening the check door. When the
temperature of the room has lowered the blade gradually works
over against the pin on the opposite side of the frame. The
action of the motor is then reversed and the draft door is opened
and the check damper closed.

The driving power or motor of the Minneapolis, shown by
Fig. 92 consists of a strong spring within the motor which is

150

TEMPERATURE REGULATION

wound up like the spring of a clock. Two arms or cranks point-
ing in opposite directions work the chains connected with th<>
draft doors.

Fig. 90 Thermostat
with Screen Removed.

Fig. 91 Thermostat
with Screen Attached.

The motor of the Beckam, Fig. 93, and also that of the Honey-
well regulator, is operated by a ball weight attached to a chain
which is run over a sprocket pulley wheel and is wound or drawn
up in much the same manner as the weights of an old-fashioned
Swiss clock.

The Beers regulator uses two weights, each hung by a pulley
wheel, as shown by Fig. 94, which figure also illustrates in a
general way the method of adjusting the chains to the draft of the
furnace.

Non-Electric Regulators

We will now consider some of the non-electrics, among which
are found the Powers and Regitherm. There are other non-
electric thermostats in the market, many of them being used
only with a steam or a hot water heating apparatus. Those
mentioned here will be sufficient, however, to show some of the
methods employed.

AND FUEL SAVING

The Powers thermostat operates on the vapor principal. On
the wall of one of the living rooms of a residence is located a
metal disc composed of two plates fastened together at the edge.
This is about 12 inches in diameter, and about I inch thick.

Fig. 9

The metal of the plate is spun in corruga-
tions to give flexibility. A liquid is placed
within the disc which will vaporize at a
very low temperature, and which gen-
erates a pressure within the disc. Fas-
tened to the back of the disc, and open-
ing into it, is a small hollow tube.
Through this tube the pressure of the
vapor is conveyed to a diaphragm motor
located above the furnace. The pressure
en the disc of the diaphragm lowers the
arm, to the end of which the draught doors are connected by
chains. This movement closes the draught door and opens the
check damper of the furnace, checking the fire. As soon as the
room cools, the pressure on the diaphragm is removed. The
arm of the motor then returns to its former position, closing
the check and opening -the draught door of the furnace.

Fig. 95 shows the diaphragm motor of the Powers regulator
and the method of attaching same to the furnace. It is held in
position above the furnace by a pipe rod, attached to ceiling. The
small hollow pipe, conveying the power from the thermostat to the
motor, can be seen as it passes through the space between floor
and ceiliing, and thence along the ceiling to point above the
motor, where it drops, and is connected into the upper side of
the diaphragm.

The Regitherm is a temperature regulating device, entirely
different in principle from any of the others. The thermostat and
motor are combined into a single instrument which may be called

I5 2 TEMPERATURE REGULATION

a thermal motor. Fig. 96 will give a general idea of its appear-
ance. The vital part or motor consists of a closed metal bellows,
so constructed that it readily expands and contracts along the
line of its axis. A cross section of the folds is roughly shown
by Fig. 97. The theory of this construction is that strain is
brought on the point marked A, and no bending occurs at B,
which is the point of greatest weakness.

Fig. 94 Beers Regulator Attached.

This bellows contains a quantity of volatile liquid, extremely
sensitive to minute variations of temperature. The bellows is
rigidly attached at one end to the frame work, and at the other
to a lever, which is moved up and down by the expansion and
contraction of the bellows.

A unique feature of the device is the fact that the power to
adjust the dampers is derived entirely from the changes in tem-
perature of the air of the room in which the Regitherm is lo-
cated, and the movement of the bellows is communicated to the

AND FUEL SAVING

153

dampers of the furnace by means of a small steel wire or cable
passing over pulleys and connected to a lever above the furnace.

Unlike most of the temperature regulators, the Regitherm does
not accomplish the desired result by the alternate opening and
closing of the dampers. Some intermediate position is assumed,
and a slight shifting of the dampers takes place whenever the
temperature conditions in the rooms above are changed. It may
be set to control the temperature at any point between 60 and
80 degrees.

Fig. 95 Diaphragm Motor Attached to Furnace.

We have given somewhat of the history of temperature regula-
tion, and quite fully described some of the various apparatus, in
order that the furnace man may post himself regarding the sub-
ject and also gain a general knowledge of the apparatus used,
and the methods adopted to automatically control the work of
the furnace.

It is a part of the furnace business which has been neglected,
and for no apparent reason. The average type of regulator is
easily installed, reasonable in price, and its sale can be made a
profitable and desirable adjunct to the furnace business.

154

TEMPERATURE REGULATION

The value of a good temperature regulator seems to be neither
understood nor appreciated by the heating contractor.

What the governor is to an engine the thermostat is to a fur-
nace. The governor, attached to an engine, prevents the engine

Fig. 96 Thermal Motor.

from "running away" or speeding when the load or work it is
doing is suddenly lightened, in other words, it regulates the
speed of the engine automatically, preventing useless waste and
possible danger.

Fig. 97 Principle of Constructing Thermal Motor.

The thermostat or temperature regulator, attached to a fur-
nace, prevents the overheating of the building and consequent
waste of fuel. It also prevents possible damage due to over-
heating the furnace.

AND FUEL SAVING 155

By selling and attaching temperature or automatic damper
regulators the furnace man not only provides the means of safety
and economy to the owner, but in so doing adds another branch
to his business which will materially increase the profits of the
same each season.

How to Sell Thermostats

We have mentioned three arguments in favor of temperature
regulation, economy, healthfulness and comfort. These fea-
tures of economy and satisfaction are prominent factors to be
considered.

Thermostats are easily sold when their merits are brought
to the attention of house owners in the right manner. Practically
no argument is necessary on the part of the heating contractor
to effect the ready sale of a thermostat when the convenient and
economical features above referred to are made known to him.

Considering the first feature, that of economy, we may say
that one shovelful of coal saved daily for the heating season will
approximate one ton saved for the season. Intermittent firing
or coaling of the heating apparatus is one of the wasteful items
to contend with. Remembering how frequently it has been neces-
sary to coal the furnace, due to forgetfulness in leaving the draf \
doors open, the owner will readily understand the situation when
the statement is made that the use of any good system of tem-
perature regulation will save from one-quarter to one-third of
the fuel ordinarily consumed when operating the furnace with-
out such a device.

How can we show the owner that this saving is possible ? There
should be no trouble in proving to the owner that intermittent
firing is costly. We have already referred to the temperature
bulletin issued by the U. S. Government, which shows a wide
variance of the demands for heat; it being necessary in certain
portions of the extreme north to raise the temperature frequently
through 80 to 100 degrees, while in southern cities, for instance
in Charleston, S. C, it is necessary to raise the temperature an
average of 47 degrees. When we consider that a change of 10,
20 or 30 degrees, up or down in the temperature, frequently
takes place within a few hours time and that the regulator will
condition the fire in the furnace to accommodate this sudden
change, we can understand that automatic regulation will effect
a great saving.

In this country a week of solid cold weather is the exception
rather than the rule. In Canada the week of mild weather in
winter is the exception rather than the rule. Consequently, we
have very much more need of temperature regulation in the
United States than they have in Canada.

156 TEMPERATURE REGULATION

Of the second feature, healthfulness, we need add but lit-
tle in addition to what has already been said, as all who have
investigated the subject know the desirability of keeping the
temperature uniform within the home. Uniformity of tem-
perature is considered as necessary as is ventilation or heat-
ing.

The next feature to consider is personal comfort, and here
is the chance for the delivery of a telling and conclusive argu-
ment. In business, as well as in pleasure, this age is spe-
cialized with automatic devices. Think of the number of
automatic devices which increase the efficiency of business,
and the intensity of pleasure. Then why not automatic per-
sonal comfort? Doesn't that sound good? The heating sea-
son comes just as regularly each year as does dinner time each
day. The comfort and convenience of having an automatic
watchman in charge of the furnace to open and close the
drafts as required, is an argument which ought to appeal as
well to the busy man as to the seeker after personal comfort.

The Cost of Heat Regulation

Automatic temperature regulating devices cost the owner
from twenty-five to fifty dollars, according to the character
and make of the device. At the price named there is a fair
profit to the furnace contractor for installing the same.

As a matter of fact, the thermostat really costs the house
owner nothing, for it saves many times the interest on the
investment each season until the saving made pays the cost
of the installation, after which it earns money for the owner
at a greater rate than any ordinary business investment he
may have. It would seem then that the cost whether twenty-
five or fifty dollars is not prohibitive. In fact, it should not
be considered when the economical, healthful and comfort-
able features brought about by its use are known and appre-
ciated.

How to Attach Thermostats

It is possible that the failure to sell and install more thermo-
stats is due to fear, on the part of the heating contractor, that
he may not be able to install the apparatus correctly.

If it is a fact that the furnaceman is letting slip this oppor-
tunity to better his work and add to his profits through ignor-
ance of the construction and method of installation of auto-
matic heat regulators, a very little investigation of the subject
will show that the average thermostat is quickly and easily
attached and adjusted.

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157

All thermostats have a positive and a negative action of the
motor or other mechanism which controls the drafts. This
positive or negative action of the motor or other mechanism
opens or closes the draft and check doors automatically in con-
junction with each other, the check damper opening as the draft
door closes, and vice-versa ; therefore no matter what type of a
thermostat is to be installed it must be attached in such a manner
that the draft and check doors will operate together, and to
accomplish this result the chain connections to the doors are run
over pulleys hung from the joists above the furnace and con-
nected in the most simple manner.

1 MOTOR

ioo\

CHECK

Fig. 98 Method of Attaching a Minneapolis Regulator.

Fig. 98 illustrates a method of connecting the Minneapolis
Regulator. The driving power of this thermostat is a motor
operated by a strong spring and its approximate location is shown
on the sketch. Note that in order to prevent the sagging of
chains between pulleys a wire is employed, to which the ends of
chains running over or through the pulleys are attached.

Fig. 99 illustrates the manner of attaching a Honeywell Regu-
lator to a hot air furnace. The driving power of this regulator

158

TEMPERATURE REGULATION

is a motor operated by a weight. This weight is suspended by
a chain, the links of which fit over the teeth of a sprocket, and
the winding up of the motor consists of pulling up the weight
much as one would wind an old fashioned grandfather's clock.

Practically all of the so-called electric thermostats make use
of two cells of dry battery for supplying the current for con-
trolling the motor, and through this the drafts of the furnace.

CABLE JO

THERMOSTAT

MOTOR

Fig. 99 Method of Attaching a Honeywell Regulator.

Three copper wires of a size simiar to that used for connecting
door bell batteries are insulated in red, white and blue covering
and encased in the form of a single cable. These wires are
attached to various parts of the thermostat where directed, and
the cable then extends down to the basement, and to the motor
of the regulator, where the wires are separately connected to
certain parts of the motor.

The cells of dry battery should be connected together as
shown by Fig. 100 which represents the top of the cells. The
white covered wire in the cable should be attached to the bat-
teries as indicated on the sketch. The wiring of all thermostats
and regulators is practically the same, and the regulator is now
ready for adjustment and attachment to the furnace.

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159

In this connection we desire to speak of the check damper
of the furnace. The check damper door of many furnaces is in-
accessible for use with a regulator and also is frequently not of
proper construction. When this is found to be the case it is best

WIRES TO MOTOR-

Fig. 100 Method of Connecting Dry Battery.

to employ a specially designed balanced check damper, as illus-
trated by Fig. 101. This check damper should not take the place
of the regular smoke pipe damper, which should continue to be
used and which should be located at a point in the smoke pipe
between the furnace and the check damper.

It would be quite impossible in a brief article to describe the
manner of installing all thermostats now on the market. We can

101 Balanced Check Damper.

say, however, that all are substantially alike in principle and are
easily attached when this principle is clearly understood.

Automatic Draft Regulators

Before leaving the subject of temperature regulators we desire
to call attention to another type of device for handling the drafts
of the furnace. We refer to a device for putting the drafts on
the heater at some pre-determined hour of the morning.

i6o

TEMPERATURE REGULATION

Fig. 102 illustrates one type of such apparatus and Fig. 103
another type. These devices are known as draft regulators,
although, strictly speaking, they do not "regulate" the draft.

Fig. 1 02 "Mono" Type of Regulator.

The office of this type of regulator is to automatically close the
check damper and open the draft door of a heater in the morn-

TO DAMPCRS

Fig. 103 "Peerless" Type of Regulator.

ing, thus allowing the fire to burn and the rooms to become warm
that the family may rise and dress comfortably.

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161

Operation and Installation

An ordinary type of alarm clock is the medium by' which this
type of regulator is controlled.

Assuming that it requires about an hour to heat the house
comfortably and that the hour of arising is seven o'clock, the
heater is coaled in the evening before retiring and the dampers

Fig. 104 Controlling Drafts from Living Room.

are then closed. The alarm clock is then wound and set at six
o'clock. There is no alarm on the clock, but in its stead the
mechanism of the clock trips a little lever which allows a weight
to fall a distance of twelve to fifteen inches. Chains are attached
to this weight, which connect with the drafts of the heater, and
when the weight falls these chains open the draft door and
close the check damper.

This has been called an invention for a lazy man. We think,
however, that the method of running the apparatus with drafts
closed at night and opened automatically in the morning will
appeal to any person who realizes the health fulness of sleeping
in a cool room and how comfortable it is to rise and dress in a
warm room. Aside from these features, the use of such a device
will cause a considerable saving in fuel,,

1 62 TEMPERATURE REGULATION

Chain Control of Drafts

A simple method of controlling the drafts of the furnace from
one of the living rooms on the first floor should also be provided
as an accessory to the furnace.

A rod of light weight iron may be hung from an arm located
above the furnace and the draft doors of the heater connected
to this rod by means of chains. From one end of the rod, a
chain, passing over pulleys, is connected to a plate located against
the base-board, in a room above the furnace, by a hook on the
end of the chain, and an eyebolt on the plate. Hooking the
chain to the upper eye opens the draft doors of the furnace and
lowering it to the bottom eye closes the drafts. Fig, 104 shows
the method of making this attachment. The ornamental plate
may be of cast iron, bearing the name of the heating contractor
and is a standing advertisement for him.

Some furnace manufacturers furnish similar plates and chains,
but we find that these are seldom made use of by the furnace
men.

It is the consideration given by the live furnace contractor to
devices of the above description that makes for success, and
marks his work as above the average in the consideration of the
house owner and possible customer.

CHAPTER XVI

FUEL: ITS CHEMICAL COMPONENTS AND COM-
BUSTION

To the great mass of people coal is known simply as coal
anthracite or bituminous hard or soft. Most users of coal as
a fuel for heating or cooking accept of conditions as they are
found locally, and burn the fuel found or more properly sold
in the local market, without regard to its value as a heat produc-
ing commodity. To such people a ton of coal is simply a ton of
coal nothing more.

We wish to discuss this question, and try to determine and
make clear what preparation is necessary to properly burn cer-
tain kinds of fuel in the hot air furnace.

The principal factor of value in coal for use as a fuel for
heating is the amount of fixed carbon it contains carbon being
the principal heat producing matter in all fuels.

It is said by those wizards of the present age, the chemists,
that all coals contain two exactly opposite matters, namely : com-
bustible or heat producing matter, and non-combustible or non-
heat producing matter. They sub-divide these matters ai
follows :

Combustible Matter

Volatile Matter (Gas)
Fixed Carbon (Coke)

Non-combustible Matter :
Moisture (Water)
Ash (Refuse)

In addition to the above, there is present a rank impurity
called sulphur. This is sub-divided as follows:

(a) Volatile sulphur, which disappears in the smoke and
products of perfect combustion ; and

(b) Iron pyrites or sulphuret of iron, which causes the coal
to clinker and run on the grate bars.

To deviate a little from the subject, we desire to say that many
of our readers live in localities where a fuel is burned which is
mined locally, and where these last conditions are particularly

164 COMBUSTION OF FUEL

noticeable. For instance, in certain sections of Illinois a coal
is mined and used which is fed to the furnace or stove in large
chunks. A short time after the coal has been supplied to the
furnace or stove, and while the large chunks are still intact, a
slight rap with a poker or slice-bar will cause it to separate or
break into small pieces, and after burning for a period it be-
comes semi-liquid and can be stirred on the grate like a mass of
molten lava.

A like condition is found in certain varieties of coal mined in
West Virginia, Ohio, and some other localities.

Another condition, due to the presence of iron pyrites in some
varieties of coal, is the fusing or attaching of particles of ash
and partially burned coal into a mass of clinker. This is par-
ticularly noticeable in furnaces or heaters not properly con-
structed to admit of perfect combustion of the fuel.

Returning to the consideration of the chemical analysis of coal,
as given above, we may say that all coal contains gas, coke, water,
sulphur, and refuse, and for all purposes the coal which con-
tains the most fixed carbon (coke), together with the greatest
percentage of volatile matter (gas), is the most valuable for use
as a fuel.

We say "for all purposes," as the great mass of users of coal
as a fuel fail to consider that certain varieties of coal are best
adapted for certain kinds of work.

The proportions of volatile matter and fixed carbon, as found
in some varieties of coal, seem to have been blended for certain
uses.

Some anthracite coal is very rich in carbon, containing pos-
sibly 85 to 90 per cent., and low in the percentage of volatile
matter (gas) ; does not clinker, and when once thoroughly ig-
nited will burn for a long period. These features make it par-
ticularly adaptable for use in stoves, furnaces, and other heat-
ing apparatus.

Some cannel coal is so full of gas and so low in carbon, con-
taining as high as 60 per cent, of volatile matter, that it can be
lighted with a match. While speaking of cannel coal, we may
mention the fact that the word "cannel" is a corruption of the
word "candle." In Lancashire, England, the name "candle" was
first given to this variety of coal owing to the fact of its being
easily lighted, and that when kindled it burns with a highly
luminous yellow flame, much like a lamp, without melting. The
Lancashire pronunciation of the word candle is "cannel," and
in England and Soctland the farmers used this coal for candles
hence its name.

COMBUSTION OF FUEL 165

Experience has taught us that it is unprofitable to burn an-
thracite coal under boilers used for power, and that where the
generation of steam is the main object sought, we should use a
coal with a good percentage of fixed carbon and a fairly large
Dercentage of volatile matter, or gas, as such coal contains a
larger amount of heat units than any other combination or blend-
ing of these elements. On the contrary, it has been proven
conclusively that anthracite is far superior to any bituminous
coal for use in a stove or heating apparatus, owing to the larger
percentage of fixed carbon and the smaller percentage of vola-
tile matter contained in k.

This may seem strange to those who have not studied the sub-
ject, and yet it is easily accounted for. When under a
factory or other power boiler, the best and most economical
results are obtained from burning the largest possible number
of pounds of coal per hour on each square foot of grate, and a
blower is frequently used to supply large quantities of air, and
thus stimulate combustion in order to accomplish this result,
when the latter conditions prevail, we demand a slow rate of
combustion and try to burn as little coal per square foot of grate
per hour as possible to maintain the desired temperature.

Tests have shown that certain manufacturing needs demand
a certain grade of coal that for each different kind of coal there
is a specific manufacturing or commercial need.

We have compared anthracite and cannel coal as being the
extremes in the percentage of fixed carbon and volatile matter
contained. There are several kinds of coal which may be classi-
fied between these two varieties. These may be classified as
follows, the percentages given being a fair average:

Kinds. Volatile Matter. Fixed Carbon.

Anthracite 7 per cent. 85 to 90 per cent.

Semi-Bituminous 18 per cent. 75 to 80 per cent.

Bituminous 24 per cent. 70 to 72 per cent.

Semi-Gas 30 per cent. 60 to 65 per cent.

Cooking 33 per cent. 58 to 60 per cent.

Gas 37 per cent. 55 to 58 per cent.

Our discussion of fuels would not be completed without say-
ing a few words about coke.

Coke is a brittle, porous solid. It is a dark gray in color, and
is artificially manufactured by a process called "coking," which
consists in expelling all of the volatile matter (gas) fromi
bituminous coal, this process being usually carried on in ovens
made of firebrick. Charcoal is introduced into the top of the
oven and, being lighted, a little air is admitted through openings

1 66 COMBUSTION OF FUEL

in the front. When the coal in the oven ceases to emit smoking 1
vapors the supply of air is cut off, and the oven allowed to cool
for a day or two. A door in the front of the oven is opened,
and the hot coke is then raked out. Water is thrown upon it
to stop further combustion. A net ton of coal (2,000 pounds)
will make from 1,000 to 1,600 pounds of coke, depending upon
the character of the coal. Coke does not smoke when burning,
and gives off a large amount of heat.

As we are considering the relative value of different varieties
of coal as a fuel for heating apparatus, rather than the value
of the coal as a commodity, this latter subject has no place in
our discussion, and yet there is one thought to which we wish
to call attention.

As stated, from 1,000 to 1,600 pounds of coke are available
for each 2,000 pounds of bituminous coal thus converted.

By inquiry at any gas-making establishment gas-works we
call it where coal-gas is produced, our readers will find that
about 10,000 cubic feet of gas are obtained from 2,000 pounds
of bituminous or coal-gas. When we consider the value in heat
units, or as a heat producer, of 1,000 to 1,600 pounds of coke
plus 10,000 cubic feet of coal-gas, we may learn something of
the real value of one tone of bituminous coal.

To burn coal, coke, gas, or any other fuel it is necessary to
mix* oxygen with it. Therefore it is necessary to admit a suffi-
cient amount of atmosphere to supply this oxygen. The car-
buretted hydrogen (gas) and the carbon of the fuel must each
be supplied with the necessary amount of oxygen, and be kept
at the required temperature to produce the chemical action neces-
sary for perfect combustion.

Some idea of the volume of air necessary may be obtained
by considering the statement that for the complete combustion
of the volatile constituents of a ton of coal 100,000 cubic feet
of air is required. This is figured from certain definite data,
which show that we are obliged to make use of five cubic feet
of air to supply one cubic foot of oxygen, and to obtain 20,000
cubic feet of oxygen, the amount necessary for the complete
combustion of a ton of coal, requires five times twenty or 100,-
ooo cubic feet of atmosphere air.

The admission of too little air will allow much of the gas to
pass off unburned, and the admission of too much air will cool
the fire or combustion chamber of the furnace and reduce the
temperature, thus preventing perfect combustion.

From the above statement, it is evident that in order to obtain
the best resuts form the fuel used, we must build our furnace
in such form that the gases or volatile matter in the fuel can be

COMBUSTION OF FUEL 167

properly ignited and burned, and from this, also, we may es-
tablish the fact that a furnace which will give good results with
Pennsylvania anthracite as a fuel will prove a flat failure with
Illinois bituminous coal.

It is entirely a matter of proper furnace construction, taking
into consideration the character of the fuel to be used and the
locality where the furnace is to be installed, and in our considera-
tion of the construction of furnaces as best adapted for burning
certain grades of fuel, we shall neither discuss the production
of the apparatus from the standpoint of the manufacturer, nor
cover the merits of any particular type of furnace.

The several simple sketches, Figs. 105, 106 and 107 illustrate
the three general methods employed in furnace construction to
provide a means for the passing off of the smoke and products
of combustion, and there are many forms and variations of each
idea.

Fig. 105 represents the direct method and involves a direct
passage into the smoke flue of the products of combustion. By
it all air moving through the furnace is warmed by the direct
radiation of the heat from the fuel consumed. All furnaces of
this type are wasteful of fuel, and yet there are certain grades
of coal, full of iron pyrites, sulphur and other impurities, which
can be successfully burned only in -a furnace of this kind. In
any other type the tarry smoke will encrust the heating surfaces
of the furnace, rendering them practically useless, or what is
still worse, will completely clog the flue passages through it.

Fig. 106 illustrates the semi-indirect plan of furnace construc-
tion, and it is safe to say that ninety per cent, of the manufac-
turers adopt this method or some form of it in their type of
warm air apparatus. It is well known that in order to success-
fully burn a large percentage of the coal gas or carburetted
hydrogen, it must be retained within the fire chamber until suf-
ficient oxygen can mix with it to produce combustion. This
means that for every cubic foot of coal gas extracted from the
fuel, two cubic feet of oxygen must be applied or enter into
union with it to cause perfect combustion, and, as stated in the
precious chapter, it will be remembered that in five cubic feet
of reasonably pure air there is present but one cubic foot of
oxygen.

Hence, to properly consume a cubic foot of coal gas requires
the admission of ten cubic feet of air into the fire chamber of
the furnace.

Now, in order to do the work advantageously this supply
must be admitted at a certain time, a certain place, and in a
certain manner, and it is by reason of these essential require-
ments that the goods of so many manufacturers of furnaces

1 68

COMBUSTION OF FUEL

have "fallen down" on efficiency tests. As stated before, too
little air will not prevent the gas from passing off unburned,
while an overabundant supply will cool the fire chamber too
much and retard combustion.

In the effort to retain the gas within the furnace until it shall
be consumed, the manufacturers use some form of the indirect
method illustrated by Fig. 106, although this effort is exerted
in vain unless other matters are also provided for at the same

Fig. 105 Construction
for Indirect Draft.

COMBUS

Tl'ON CHAMBER

GHATE

ASH PIT

Fig. 106 Construction
for Direct Draft.

time. An active fire will produce a cubic foot of coal gas very
quickly. Suppose the rate of combustion is four pounds per
square foot of grate per hour, and the size of grate three square
feet. The hourly consumption of coal in such a furnace would
be twelve pounds. If we consider bituminous gas coal as a
fuel (10,000 cu. ft. gas to a ton of 2,000 Ibs.), the coal burned
will produce about sixty cubic feet of gas per hour, each pound
of fuel burned giving off five cubic feet of gas, and requiring
f.'fty cubic feet of air to consume it.

Now, we have said that the air must be admitted at a cer-
tain place, time and manner. The place should be at a point just
above the normal level of the fire in order that the air may
mingle with the gases arising from the fuel. The gas ring ap-
pliance usually included, and shown on Figs. 105 and 107, is
made of cast iron. A fire-pot may be provided with firebrick
lining so set, or held in place, as to provide an air space between

COMBUSTION OF FUEL

169

the brick and the outer iron cylinder, the air passing upward from
the base and into the fire chamber through small holes in the
lining, as illustrated by Fig. 108.

The proper time for the admission of this air is when the gas
is burning off from a fresh charge of cool, because probably
eighty-five per cent, of all gas in the coal burned is given off
during the hour following the time that the additional fuel is
added, provided the draught is on the furnace.

The manner in which this air should be admitted is in small
sprays above the fire, and its temperature should be practically
the same as that of the gas. When the supply is taken in through
a gas ring, or through the top of the firebrick, as shown by Fig.
108, its velocity is about four times as great as that of the air
passing in the lower draught door and upward, and should this
volume of air move upward through the coal, the rate of com-
bustion would be so rapid that a large share of the gas would
pass out of the smoke pipe unconsumed.

Fig. 107 Construction for Semi-Indirect Draft.

The principle shown by Fig. 107 is used in the construction
of furnaces for both hard and soft coal.

The indirect method illustrated by Fig. 106 is adapted more
particularly to building furnaces for hard or anthracite coal,
and a wonderful variety of forms and ideas is followed by
manufacturers in carrying out the principle shown. The per-
centage of volatile matter in anthracite coal is so small that little
or no attention is given to burning the gases. Combustion is
not so rapid as with soft coal, and any air admitted above the
fire has a tendency to chill it. The temperature in the fire

170

COMBUSTION OF FUEL

chamber should be high, in order to provide for complete com-
bustion, and the firepot for burning anthracite should be almost
straight up and down or possibly a little larger in diameter at
the grate line than at the top; also, its surface should be cor-
rugated.

6/tATS

Fig. 1 08 Fire Pan with Air Holes in Lining.

By considering the foregoing facts regarding the furnace con-
struction we shall accept the following definite conclusions :

(a) That furnaces should be selected according to the character
of the fuel to be used.

(b) That the gas or volatile matter in all coal other than
anthracite is of greater value than the carbon (coke) for heat-
ing purposes.

(c) That, in order to utilize the greatest number of heat units
in bituminous and semi-bituminous coal, it is necessary to make
proper provision for burning the gas first and. the coke last, or,
stated in another form, to appropriate the full value of the gas
for heating, retaining the coke for rekindling requirements.

(d) That the loading of a fire with fresh fuel obstructs the
volume and velocity of the air admitted through the grate, mak-
ing it necessary to inject a sufficient quantity of air above the
fire to properly burn the gases.

(e) That unless this deficiency is provided for all com-
bustible gases, such as hydrogen, carburetted hydrogen, and
carbonic oxide, will escape up the chimney flue, the smoke plainly
indicating the loss sustained.

(f) That in introducing heated, and consequently rarefied
air, into the combustion chamber of the furnace in small jets,
through a gas ring, or perforated firebrick, a sufficient supply
of oxygen can be admitted without cooling the gases and perfect
combustion obtained from the thorough mixture of the oxygen
with the gases.

As an all-important part of a furnace, the grate should be
of such shape and character that the ashes may be removed
from the firepot without stirring up the body of unconsumed coal

COMBUSTION OF FUEL 171

lying above them. The nature or size of the opening between
the bars has little to do with a greater or lesser consumption
of coal. The grate is simply a cradle which holds the fuel and
the amount burned is governed by the quantity of air passed
through the grate.

It is possible to consume the fuel without benefit, under which
circumstances, of course, the combustion will not be perfect,
and while the fire appears dead or passive, yet more fuel is
burned than would be the case if the combustion were positive
and the fire active. The remedy for such a condition is found
in the admission of air oxygen in the right place and manner
and in sufficient quantity.

Coal : The Universal Fuel

A brief narration of the facts regarding the discovery and
development of the coal deposits of the world, and particularly
those of the United States, will prove interesting to all persons
connected with the manufacture and installation of heating ap-
paratus.

Coal is the universal fuel, and without its use it is doubtful
if the nations of the world could have made such progress in
manufacture and civilization as history has recorded.

We are accustomed to think of coal as being principally a
product of the United States; and while it is true that we now
lead all other nations in the tonnage of coal mined, this stand-
ing has been reached only in recent years.

We know that more than 2,000 years ago coal was an article
of commerce in certain parts of the Chinese empire and had
been known for years prior to that period. It is also recorded
that coal was shipped into London in the year 1240.

Virginia bituminous coal was mined as early as the year 1750
and in 1768 anthracite coal was mined in the Wyoming Valley,
Pennsylvania, near what is now the city of Wilkes-Barre, and
in the years 1770-76-91 coal was mined in other sections of
Pennsylvania.

It is related that in the year 1812 Colonel Geo. Shoemaker
of Pottsville, loaded nine wagons of coal from the Schuylkill
region and hauled it to Philadelphia where, with difficulty, he
sold two loads and gave the other seven loads away. He was
regarded as an imposter and with some trouble avoided arrest
by getting out of the city.

White & Hazard, owners of a wire-works at the Falls of
Schuylkill, bought one of the loads and a whole night was spent
by their workmen in efforts to make the coal burn. They gave

172 COMBUSTION OF FUEL

up and quit their work, leaving the door of the furnace closed
and one of the workmen returning for some forgotten clothing
found everything red-hot.

This effort to burn coal is exceedingly interesting when we
consider that 100 years later (1912) the United States produced
about one-third of all the world's supply, leading England by
millions of tons and Germany, her next nearest rival, by a
tonnage three times greater.

As a matter of fact this great development has taken place
\vithin the last forty years as the coal production in the United
States in 1866 was less than 15,000,000 tons.

CHAPTER XVII

CEMENT CONSTRUCTION FOR FURNACE MEN

When engaged in the business of installing warm air heating
appartus the sheet metal worker should be independent of other
contractors. In making this statement we mean to say that in
order to reap the full benefits accruing from a contract the fur-
nace man should install his work without the services of a car-
penter or mason. He should be sufficiently familiar with the use
of carpenters' tools to do his own cutting and framing, and he
should also be able to construct foundations, cold air pits, and
ducts, and to instruct his men how to build them without the
assistance of a mason or cement contractor.

The present period is sometimes called the age of cement, by
reason of the fact that cement is now so generally used in build-
ing construction of all kinds, and we desire to call attention
to the proper method of mixing and using cement.

A volume would be required to treat this subject in a thorough
manner. We shall, however, in this brief article be able to show
how to use cement successfully, and also to point out the rea-
son why so many furnace men fail to obtain proper results when
attempting to build pits and ducts of concrete.

Concrete Mixtures

All cement mixtures are not alike in strength or consistency.
A certain mixture that might be best for one class of work would
not do for work of another class. Mixtures of concrete of
greatly different strength and costs can be made of the same
materials, simply by combining them in different quantities.

In our discussion of concrete mixtures we shall make use of
two terms which should be explained. These terms are aggre-
gates and voids. Aggregates are the solid and coarse ingredients
which are bound together by the cement in making a mass of
concrete. Materials such as sand, gravel, trap rock or crushed
stone, cinders, etc., are known to cement workers as aggregates.

Voids are the air spaces between the particles of aggregates
which must be filled or removed from all cement work in order

174 CEMENT CONSTRUCTION

to make the work substantial. For example, the voids in sand
are rilled with cement and this mixture is used to fill the voids
in gravel or broken rock.

The ability to judge by sight or determine by test the propor-
tions of materials for a cement mixture is gained only through
long experience, and it is essential that the mixture be right for
the work in hand. A certain mixture for a foundation pit or
duct in a cellar which is always dry would not do for building
a foundation pit or duct, which of necessity must be watertight
on account of a cellar being wet at certain periods of the year,
nor would a mixture suitable for building a sidewalk be right
for use in constructing a cistern.

Concrete mixtures are classified in two different ways. First
as to richness, meaning the quantity of cement used, and sec-
ondly as to consistency or wetness.

When so classified a cement mixture is known as rich, medium,
ordinary and lean. A i :2 14 mixture would be called a rich
mixture. The formula I 12 14 indicates one barrel of cement
(four bags to the barrel) to two barrels of sand, and four barrels
of gravel or broken stone or other coarse aggregates.

A I 12.5 15 mixture is one barrel of cement, two and one-half
barrels of sand and five barrels of broken stone or loose gravel,
and this combination of materials would be classified as a ''medi-
um" mixture.

A I 13 :6 mixture measured in like manner is known as an
"ordinary" mixture, and a I 14 :8 combination of cement, sand
and gravel as a "lean" mixture.

In consistency the mixture may be "very wet," "medium
wet" or "dry," the amount of moisture necessary depending
upon the work for which it is intended.

For use in building foundations and ducts for furnace work
a "medium" or "ordinary" mixture "medium wet" is desirable,
provided the pit or duct is not to be waterproof. If the pit
or duct must be waterproof on account of a wet basement, or
trouble at certain periods from surface water, the mixture should
be a i :2 14 (rich) or a I 12.5 15 (medium), and in consistency,
medium to very wet.

Mixing Concrete

There are several methods of mixing the concrete. The sand
and cement may be mixed dry, and this mixture spread layer
upon layer upon the broken stone, gravel or aggregate before
the water is added, or the sand and cement may first be^mixed
with water into a mortar, and this mortar then mixed with the

CEMENT CONSTRUCTION 175

broken stone or gravel, after which, in either case, it should
be turned with a shovel until a thorough mixture of the ingredi-
ents is obtained, or until all particles of the aggregates are
thoroughly coated with the cement paste.

There are several kinds of cement to be had, the best for
general uc2 being that called Portland.

Fig. 109 Trowel for Round Corner Work.

Portland cement consists principally of limestone and slag
crushed separately and dried to remove all moisture, after which
each ingredient is ground extremely fine. After being combined
in a certain proportion this mixture is calcined or burned to a
clinker. This clinker is then cooled, pulverized fine, and mixed
with a certain quantity of gypsum, when it is ready for the
storehouse, where it is kept free from moisture until shipped
or supplied for use.

The Tools

For use in constructing cement ducts, pits and other work
of like character, but very few tools are required and these are
inexpensive.

Fig. no Trowel for Square Corner Work.

Other than a shovel, hoe and ordinary trowel there are a few
tools which are useful and convenient. Fig. 109 illustrates a
smoothing trowel for round corner work. Fig. no a smoothing
trowel for square corners. Fig. in another form of a round
corner smoothing trowel. Fig. 112 shows two forms of a tamper
(a tool for tamping or pounding the cement mixture to remove
the voids), which may be made from any heavy iron casting
planed smooth on the lower side and to which a handle mav

176 CEMENT CONSTRUCTION

be fitted. These tools and a leveling board and straight edge
are all that the furnace man will require for the class of cement
work he will be called upon to construct.

Determining Quantities

In connection with cement work the following data will prove
useful in determining quantities :

Fig. in Trowel for Another Form of Round Corner.

A bag of natural cement weighs 94 pounds.

A bag of Portland cement weighs 94 pounds.

A barrel of natural cement equals three bags, and weighs
about 282 pounds.

A barrel of Portland cement equals four bags, and weighs
380 pounds.

A cubic foot of crushed or broken stone weighs about 90
pounds.

Fig. 112 Tools for Tamping.

One bushel of cement and two bushels of sand mixed to-
gether to form a cement mortar will cover 3^2 square yards
one inch thick, or 6^4. yards one-half inch thick. (This rule
applies for a smoothing mixture for use over rough concrete,
brick or stone.)

CEMENT CONSTRUCTION 177

Methods

To make cement mortar (as above) adhere to old or finished
cement work, the surface of the old work should be thoroughly
soaked with water, then dust on a little neat cement, after which
apply the mortar coat before the dusted cement has set.

Another method equally as good is to mix a thick paint of
cement and water and brush it carefully over the surface of
the old work after it has been thoroughly wet with water; then
apply the mortar coat quickly before the paint coat has set.

It is not a difficult matter to construct good cement work if
care is exercised in the selection and mixture of materials. Do
not guess at quantities. All materials used should be carefully
measured or weighed.

CHAPTER XVIII.

CONSTRUCTION AND PATTERNS OF FURNACE
FITTINGS

Including Bonnets, Collars, Elbows, Cold Air Connections,
Register Boxes, Transition Boots, Shoes, Tees, Offsets, Etc.

By WILLIAM NEUBECKER

This chapter treats the various methods for develop-
ing and constructing the many styles of furnace fittings, as
well as the rule to be followed for finding the true angles
of elbows from given dimensions. In designing the shape of
any fitting care must be taken not to reduce the given area, but
to have the same area throughout the entire fitting and to draw
easy, graceful, frictionless curves to facilitate the flow of air.
While there are many styles of fittings which can be purchased,
having single as well as double walls, it is to the advantage of
the furnace man to understand the method of developing the
various pattern shapes, a knowledge of which will enable him
to lay out any required shape or size.

FURNACE FITTINGS

Conical Bonnets or Hoods

179

The first subject to be taken up will be development of the
bonnet or hood. A good type of a bonnet is shown in Fig.
113 with a deep deflector. The method of developing the net
patterns for the bonnet and deflector is shown in Fig. 114 and
is accomplished as follows : Draw any vertical line as A B, upon
which set off the vertical hight of the bonnet as X E, bearing
in mind to make this 3 inches higher than the largest size leader
pipe to be taken from it (to give room for dovetailing the collar.

Fig. 113 Typical Conical Bonnet with Deflector which Determines
the Angle of Collar.

Set off the half diameter of the casing as X C, also the half
diameter of the top of the bonnet E G. Now extend C G until
it intersects the center line at F. Using E as cented with radius
equal to E G, draw the quarter circle G6, which divide into
equal parts as shown. This quarter circle represents the plan
on the line E G and would be the quarter pattern for a flat top
casing minus the edges. Now using F as center with radii

Quarter
2* Pattern of
// Deflector

SECTION B HALF ELEVATION
Fig. 114 Developing Patterns for Bonnet and Deflector.

equal to F G and F C, draw the arcs G 6' and C C 1 . On the arc
G 6' lay off the girth of the quarter circle as shown by similar
numbers G to 6'. From the center F draw a line through 6'

i8o

FURNACE FITTINGS

intersecting the outer arc at C 1 . Then will C C 1 6' G be the
quarter pattern for the bonnet, to which edges must be allowed
for riveting and seaming. With radius equal to D. G, from D l
as center, draw the arc i" 6". Set off on the arc i" 6" the girth
of the quarter circle as shown, and draw the radial lines i" D 1
and 6" D 1 . This gives the quarter pattern minus the laps fcr
the deflector.

Fig. 1 16 Collars Joining a Straight Bonnet.

^-=s=^- jf

Fig. 115 Spacing

the Casing Rings. Fig. 117 Collars Joining a Flat Top Casing

The left half of the diagram is constructive, showing the
seaming of the deflector to the bonnet at H, and the seaming
of the bonnet to the casing collar at J. When laying out the
various patterns we must consider the width of the iron being
used, so as to cut without having much waste. The casing
collar or rim C is usually made about 3 inhces wide so as to fit
the casing ring. Another way is to allow about an inch lap
along the curve C C 1 in the pattern and after the full bonnet
has been riveted together, crimp the bottom edge on a crimper
until it fits the casing ring snugly. The deflected part of the
bonnet is usually filled with sand, but sometimes an additional
sand ring is seamed to the top edge at H, making it about 2
inches high, placing a wire edge along the top. The above
rule applies to any size or pitch of bonnet.

FURNACE FITTINGS 181

Furnace Casings

Casings should be double as indicated in Fig. 115 and care
must be taken that the casing rings are so placed that stock
widths of iron can be used. The rings A, B and C should be
so placed that the distances between will allow using sheets
either 24, 26, 28, 30 or 36 inches wide without waste. When the
casing rings are not correctly placed, it necessitates using short
pieces cut across the sheets, thereby using time and labor and
wasting material, and does not make as neat an appearance, as
when the sheets are rolled up lengthwise. The circumference
of the casing is obtained by the use of a narrow strip of me<r.\
passing it around the ring, holding it snugly, and then allowing
edges for riveting or seaming.

Various Styles of Collars

There are three styles of collars usually employed, viz.: One
joining a pitched bonnet, as shown in Fig. 113, another joining a
straight bonnet as shown in Fig. 116, and the third joining a
flat top casing as shown in Fig. 117. In developing the pattern
for a collar joining a pitched bonnet, as shown in Fig. 113, the
pitch of the collar b is usually made the same as the pitch of
the deflector a, although this is not always done. Some me-
chanics do not develop the collar and opening in the bonnet by
the geometrical rule, but roll up a piece of pipe and trim it to
fit the bonnet at the desired angle and then mark off the open-
ing on the bonnet and trim with the circular shears. While
good results may be obtained in this manner, it is better to de-
velop the patterns accurately, which can be saved for future
use or be slightly modified for different construction.

Patterns for Collar on Pitched Bonnet

The method of developing the patterns for collars on pitched
bonnets is shown in Fig. 118. First draw the center line X B,
upon which establish the hight of the bonnet as C D. From C
and D at right angles to X B draw the lines C 6 and D Y, equal
respectively to the semi-diameters of the casing and top. Con-
nect 6 with Y, extending the line until it meets the center line
at X. Now with radius equal to C 6, from any point, as H,
on the line X B, as center, draw the quarter plan, 6 V, as shown,
and from II in plan draw H J, the center line of the collar. At
the proper angle, draw the elevation of the collar, indicated by
i' E F 5' and in its proper position to the right as shown, draw
the profile of the collar, which divide into equal spaces as shown
from i to 5. With its center at m describe a half profile of the
collar as shown in plan, dividing it as before, being careful in

1 82

FURNACE FITTINGS

numbering the spaces to see that the line i 5 in the profile of the
collar in elevation is perpendicular to the lines of the collar and
parallel to the lines of the collar in plan, all as shown.

Divide part of the quadrant 6 V in plan in equal spaces as
shown by points 6, 7 and 8, from which points draw radial lines
to the center H. From the points 6, 7 and 8 erect vertical lines
cutting the base line of the cone in elevation at 6, 7 and 8 of
1'iat view, from which points draw radial lines to the apex X.

Section on 2

Section on 4-4
Section on 3-3 .

Fig. 1 18 Method of Obtaining Patterns for Collar and Opening to Be
Cut in Pitched Bonnet.

Through the small figures 2, 3 and 4 in the profile of collar in
elevation, draw lines at right angles to X 6 or E F cutting the
radial lines in elevation. Where the line 2 2 cuts the radial
lines drawn from 6, 7 and 8, at a b and c, drop vertical lines in
the plan, until they intersect similar numbered radial lines 6, 7
and 8 in plan also shown by a b and c. A line traced through

FURNACE FITTINGS 183

these points will represent the partial section on the line 2 2 in
elevation. In a similar manner where the planes 3 3 and 4 4 in
elevation cut the radial lines 6, 7 and 8 at d, e and / and at g, h
and the base line at *, drop vertical lines intersecting similar num-
bered lines in plan at d, e and /,_ also at g, h and i. The curved
lines d e f and g h i represent the sections in plan on 3 3 and
4 4 in elevation. Through the points 2, 3 and 4 in the half
profile in plan, draw horizontal lines intersecting the various
section lines in plan, as shown at 2', 3' and 4'. From these inter-
sections, vertical lines can now be erected cutting similar num-
bered section lines drawn through the elevation at 2, 3 and 4.
A line traced these points as shown by i', 2, 3, 4 and 5' will be
the miter line between the collar and bonnet.

The pattern for the collar is now in order and is obtained by
extending the line E F in elevation as F K, upon which the girth
of the collar profile is placed as shown by similar numbers.
Through these small figures, at right angles to F K, lines are
drawn and intersected by lines drawn parallel to F K from cor-
responding numbered intersections i', 2, 3, 4 and 5'. Trace a
line through points thus obtained, then will i S T i be the pat-
tern for the collar, to which laps must be allowed for riveting
and seaming.

The pattern for the opening in the bonnet is obtained as fol-
lows : From the intersections 2, 3 and 4 in the miter line in
elevation, project horizontal lines to the right, intersecting the
outline of the bonnet at 2', 3' and 4'. From X 1 in the diagram
on the right as center with radii equal X Y, X i', X 2, etc., of
the elevation, draw short arcs as shown by similar numbers.
From H in the plan, draw radial lines through the intersections
2', 3' and 4' until they cut the base line as shown at 2", 3" and 4".
As i' and 5' in elevation show the true points of intersections
on the bonnet of lines from points bearing those numbers in the
profile of the collar, these points will be shown at i" 5" (point 6)
on the base line. In the pattern for the opening in bonnet, es-
tablish at pleasure any line, as i" X 1 as a center line, and from
the point i" set off either way on the arc 6" 6", the spaces indi-
cated by the numbered points 4", 2" and 3" in plan, as indicated
by similar numbers in the pattern. From these points draw
radial lines to X 1 , intersecting arcs of similar numbers previously
drawn. A line traced through points thus obtained will be the
desired shape of the opening, which is shown shaded.

Should the collar be placed to one side of the center of the
cone, that is axially oblique as shown in diagram Z at the top
of the cut, the method of procedure will be precisely the same
as that just described, except that the angle of projection upon
the bonnet will be different.

1 84

FURNACE FITTINGS

Patterns for Collar on Straight Bonnet

Fig. 119 shows how the pattern for a collar on a straight bon-
net and the opening in the side of the bonnet are obtained. The
plan and elevation are clearly indicated, as is the method of ob-
taining the miter line from the plan after the proper pitch of
the collar has been shown. It will be noticed that in the draw-
ing the diameter of the collar is out of all proportion to the size

HALF PATTERN
FOR COLLAR,

3 I I 23
454

\HALr ELEVATION.

i|
it

PLAN
i "k '

Fig. 119 Method of Obtaining Patterns for Collar and Opening to Be
Cut on a Straight Bonnet.

of the bonnet. This has been done so as to clearly show how
the points of intersection have been obtained. The method of
obtaining the shape of the opening is so clearly shown at the
left of the elevation, also that of the collar above, as to require
no further description.

Fastening the Collars to the Bonnet

Figs. 1 20, 121 and 122 show how the collars are secured to
the three styles of bonnets previously described. Fig. 120 shows
a view of the finished collar ready to be secured to the pitched
bonnet, which is constructed as shown in Fig. 121, where A
shows the bonnet and B the collar. On the collar itself along
the miter cut a half inch edge a is flanged out, then on the inside

FURNACE FITTINGS 185

a one and one-half inch strip is riveted as shown at b. The
collar is inserted in the opening in the bonnet, and the notched
flange turned snugly around as indicated at c, which secures
the collar. If desired a few rivets can be placed in the flange a.

Fig. 121 Method of Securing
Collar to Bonnet.

Fig. 120 Finished Col- Fig. 122 Finished Col-

lar for Pitched Bonnet. lar for Flat Casing Top.

The same method may be employed for the collars in the straight
bonnet. Where elbows are connected direct to the flat top cas-
ing as shown in Fig. 117, the co^ars are prepared as shown in
Fig. 122, and secured to the casing top as just described.

Elbows

When making the connections from the bonnet to the pipes,
elbows are usually employed, and while adjustable elbows can
be purchased from dealers, it is well to know the short rules for
laying out the various pieced elbows, as odd sizes may be re-
quired, and elbows can be made up in spare time. Fig. 123 shows
the various positions to which a four pieced elbow of this type
can be adjusted to suit any condition which may arise.

When patterns for elbows are to be laid out, a short method
can be employed for finding the rise of the miter line by means
of a protractor, as shown in Fig. 124. This rule is applicable to
any size elbow no matter how many pieces it contains or what
angle it is intended to have when completed. For an example,
we will assume that the rise of the miter line is to be found for
a four piece elbow, whose throat is to be 8 inches, its diameter
6 inches and whose angle is to be 90 degrees when completed.
In diagraming all pieced elbows, each end piece counts one as
a unit of degrees and each middle piece counts as two. Thus
in a four pieced elbow we have I +2 +2+ I =6. Six is then
the divisor. As the completed elbow is to have 90 degrees when
completed, the rise or the degree of the miter line is found by

i86

FURNACE FITTINGS

dividing 90 by 6. Thus 15 degrees is the rise of the miter line
shown in the illustration. This single miter line is all that is
required in developing the full set of patterns. The cut of the
completed elbow is given to show that if the first miter line is
15 dgrees from the base line, the second miter line would be

Fig. 123 Various Positions to Which a Four- Piece Adjustable Elbow

Can Be Set.

45 degrees, the third 75 degrees, and the quadrant shown would
equal 90 degrees, thus providing the rule that each middle piece
contains double the angle of each end piece.

Applying the Rule

In Fig. 125 is shown how this rule is applied in practice to
develop the pattern for a four-pieced 90 degree elbow, regard-
less of its diameter, throat or number of pieces. First draw
any horizontal line as A B. From any point at C erect the verti-
cal line C D. Using C as a center, draw a quadrant of any
size as a. b. If a protractor is handy, place the center of the
protractor upon C and draw the angle of 15 degrees as shown.
If no protractor is at hand this angle of 15 degrees, or any other
angle, can be found as follows : Knowing that Jhe divisor is 6,

FURNACE FITTINGS

divide the quadrant a b into six parts as shown, and through
the first part draw the line C E indefinitely, which represents an
angle of 15 degrees. Now set off on A B, the length of the
throat, as indicated by C i, and from i set off I 7, the diameter

Fig. 124 Finding the Degree of the Miter Line.

of the desired elbow. On i 7 place the semicircle shown, which
divide into equal spaces, from which points erect lines intersecting
the miter line C E as shown. Now take twice the girth of the

NET PATTERNS

2 \\ i/ 6

3^L^5

Fig. 125 Applying the Rule to Developing the Patterns for a Four-
Piece Elbow.

semicircle i to 7 and place it on the line A B from i to 7 to i,
from which points erect perpendiculars, intersecting them by
lines drawn parallel to A B from similar intersections on the
miter line C E. Trace a line through points thus obtained, then

1 88 FURNACE FITTINGS

will i H J K i be the miter pattern for the end piece. The full
set of four patterns can be obtained from one piece of metal
without waste, as follows: H M and K L are each made equal
to twice J 7. H 1 M and K 1 L are made equal to J P 1 , while
H 1 N and K 1 O are equal to H i or K i, which completes the
net patterns.

Elbows Less Than Right Angles

If the elbows were taken from a flat top casing, as shown
in Fig. 117, a pitch would be required in the top piece of the
elbow, and assuming that the elbows were to be completed having
angles of 80 degrees, the rise of the miter line would be obtained
as indicated in Fig. 126, in which the two end pieces as a whole
count 2, and the two middle pieces count 4, making a total of
6. As the completed elbow is to contain 80 degrees, then
80/6=13 1/3 degrees, which is the rise of the miter line.

Seaming the Circular Joints

When the patterns for the elbows have been laid out, allow-
ance must be made for seaming. The method of seaming the
circular joints of the elbow is indicated in Fig. 127. It will be
noticed that one end of each piece has a single edge and the
other end a double edge. When elbows are made in large quan-
tities, special machine outfits can be obtained for making pieced
elbows, which consist of squaring shears, curved shears and
knives for cutting the various sections, press and dies for punch-
ing rivet holes in the longitudinal joints, folder and groover for
lock seams, forming rolls, burring, double edging and seam clos-
ing machine for making the circular joints and a beading and
crimping machine for contracting one end of each elbow.

Oval Elbows

In addition to the round elbows most often used, oval elbows
are sometimes required in the partitions to connect with the warm
air pipes. These oval pieced elbows are sometimes joined to-
gether on the "flat" or on the "sharp." Fig. 128 shows a three
pieced elbow joined together on the "flat." In developing the
pattern for an elbow of this kind, the profile of the elbow must
be placed as indicated in Fig. 129, where the method of develop-
ing a three pieced "oval" elbow on the flat is shown. Draw
any horizontal line, on which locate E, which use as a center
and draw any size quarted circle as shown, representing 90 de-
grees. Divide this in four parts of 22^ degrees each, and from
E draw a line through the 22^ degrees indefinitely as shown
Lay off the throat distance E F, and below this line in the posi-
tion shown place the profile H, and extend lines upward until

FURNACE FITTINGS

189

they cut the miter line at e and /. From this point the method
of procedure is the same as that shown in Fig. 125. This will
produce an elbow on the "flat." Fig. 130 shows a three pieced

Fig. 126 An So-Degree
Four-Piece Elbow.

I *_ _

Fig. 127 Locking
the Circular Joints.

Fig. 128 Three-Piece
Oval Elbow on the
"Flat."

Fig. 120 Placing the
Profile for Develop-
ing the Patterns for a
Three-Piece Oval El-
bow on the "Flat."

Fig. 130 Three-Piece
Oval Elbow on the
"Sharp."

Fig. 131 Placing the Profile for Developing
an Oval Elbow on the 'Sharp."

oval elbow on the "sharp," and in developing an elbow of this
kind the profile must be placed in the position shown by C in

190 FURNACE FITTINGS

Fig. 131, when the method of procedure is the same as before
with only the difference in the position of the profile C from
that of H in Fig. 129. The former produces an elbow on the
"sharp" and the latter an elbow on the "flat."

Developing the Patterns for a Reducing Elbow

Fig. 132 shows a view of a three pieced 90 degree reducing
elbow in which the pipe A is reduced by means of the transition
piece C to the required size B. In working out this problem the
pipes A and B are developed by means of parallel lines, while
the middle transition C is developed by triangulation. How these
three patterns are aid out is shown in detail in Fig. 133. First
draw the center line of the elbow as shown by a 3 8 b, making
the distance 3 8, twice that of a 3 or 8 fr.L Extend 3 a and 8 b
indefinitely 'as shown, upon which establish the centers i and k
respectively and describe the profile of the small pipe F and
large pipe E. at sufficient distances from a and b of both arms
of the elbow. Obtain the miter lines of the elbow by using 3
and 8 on the center line as centers and describe the arcs c d and
/ g respectively. Now, with any desired greater radius and using
c and d, also / and g as centers, describe arcs intersecting each
other at e and at h. Draw lines indefinitely through e 3 and h 8.
Intersect the former by horizontal lines drawn through i and 5
in the profile F, and the latter by vertical lines drawn through
6 and 10 in the profile E. Connect i with 10 and 5 with 6 to
form the middle piece B. Then ABC shows the side elevation
of the reducing elbow.

A
Fig. 132 A Reducing Elbow.

Divide both the half profiles F and E in the same number of
equal parts, as shown from I to 5 and 6 to 10 respectively, and
from these various small figures draw lines parallel to the center
lines of the pipe until they intersect the miter lines as shown by
simliar numbers. The half patterns for the pipes A and C are
developed in the usual manner as shown and need no further
explanation.

FURNACE FITTINGS

191

The pattern for the middle section C will be laid out by tri-
angulation. No sections need be developed on the miter lines
i 5 or 6 10 in elevation, as correct measurements for the sev-
eral spaces can be taken from the miter cuts i' 5' and 6' 10' in
the patterns. Connect points in i 5 with those in 6 10 as shown

1 2 3

DIAGRAM OF TRUE.

Fig. 133 Developing the Patterns for a Pieced Reducing Elbow.

by the dotted lines. These lines then represent the bases of
sections at each end of which prpendiculars will be erected whose
altitudes will equal the various hight in the semi-profiles F and
E as shown in diagram J. For example, to find the true length
of the line 4 8 in B, set off its length as shown from 4 to 8 on

192

FURNACE FITTINGS

any horizontal line as L M in J, and at 4 and 8 erect the per-
pendiculars 4 4' and 8 8' equal respectively to the distances meas-
ured from the center lines to points 4 and 8 in the profiles F and
E. The distance from 4' to 8' in J shows the required length.
In a similar manner are the remainder of true lengths found.

S/DE VIEW
I
I

Fig. 135 T -Joint Between
Pipes of Equal Diameter.

PATTERN

Fig. 134 T-Joint Between
Pipes of Equal Diameter.

The pattern is next in order. As 5 6 in B shows its true
length, set off this distance as shown by 5' 6' in the pattern
at H. Now with radius equal to 6' 7' in the half pattern for
C, and with 6' in H as center, describe the arc near 7', which
intersect by an arc struck from 5' as center and 5' 7' in the true
lengths in J as radius, now with 5' in the pattern H as center and
5' 4 in the pattern A as radius describe the arc shown near 4',
which intersect by an arc struck from 7' as center with
7' 4' in the diagram J as radius. Proceed in this
manner, using alternately, first one of the spaces along the miter

FURNACE FITTINGS

193

cut in half pattern for C, with the proper true length in J to
form the larger end of the pattern; then one of the spaces along
the miter cut in the half pattern for A with the proper length in

Fig. 136 A Round Header.

J to form the smaller end of the pattern, until all spaces have
been used and the pattern has been developed. Laps must be
allowed for seaming as before explained.

454
32123

OPENING
>H\D \

^ V

H-4

Fig. 137 Patterns for T-Joint Between Pipes of Unequal Diameters
at Other Than a Right Angle.

Fig. 134 shows a view of a T joint where the three openings
have equal diameters. The rule employed for developing the
patterns is explained in connection with Fig. 135, in which an
elevation of the joint is shown. When the sizes of the two

194 FURNACE FITTINGS

branches are the same, no projections of points are required
in finding the miter line; all that is required is to intersect the
centers of the two branches as at D and then draw the miter
lines C D E. The pattern for the branch A is obtained in the
usual manner. The girth of A is placed at right angles to the
lines of the pipe as shown, the usual measuring lines drawn and
intersected as shown resulting in the pattern for A.

The shape of the opening to be cut in the main pipe B is
obtained by taking one half of the girth of pipe as indicated by
a b c (or 3 to i to 3 in the profile for A, since both pipes are
similar) and placing it at right angles to B as shown, and then
intersecting the measuring lines from the divisions in the pro-
file, all as shown. This short method can only be followed when
the two branches have the same diameters. Fig. 136 shows a
round header with lead off collars at a and b. The principles
shown in Fig. 135 can be applied to Fig. 136.

T Joint Between Pipes of Unequal Diameters at an Angle

When a branch is to be taken from a main pipe at an angle,
the branch being of smaller diameter than the main, the rule
to follow regardless of what the diameters or angle may be, is
shown in Fig. 137 in which A and A 1 show the profile of the
branch pipe and B the profile of the main. D C shows the side
view of the T, the branch C in this case being placed at an angle
of 45 degrees. First divide both profiles A and A 1 into the
same number of equal parts, placing the numbers in the posi-
tion shown. From the points in A 1 draw lines parallel to the
lines of the pipe until they intersect the profile of the main pipe
as shown, from which vertical lines are drawn and intersected
by lines drawn parallel to the pipe C from the numbered points
in the profile A. Through the intersection thus obtained trace
the miter line shown. The pattern for the branch C is obtained
in the usual manner as indicated. To obtain the opening in the
main pipe D, obtain the girth by using the various spaces in the
end view B, measuring each space separately, as they are un-
equal, and place them at right angles to the line of the main
pipe D in the side view. The usual measuring lines are now
drawn, and intersected by lines from points of corresponding
number shown in the miter line. This gives the opening to be
cut in the pipe D.

In Fig. 138 is shown a view of a reducing T joint such as
is sometimes used in trunk lines of heating. The method of
laying out these patterns is shown in detail in Fig. 139. First
of the illustration, and place on either side of the center line
A B, the widths a l' and b i in their proper positions connect the

FURNACE FITTINGS

195

lines i' I extending them until they meet at C. On the line I I
place the semi-profile H, which divide in equal spaces as shown
from i to 3, from which points draw lines parallel to A B inter-
secting the line I I, From the apex C draw radial lines

Fig. 138 A Reducing T-Joint.

through the points on I I until they intersect the profile of the
large pipe from i' to 3'. From these intersections at right angles
to A B draw lines cutting the side of the tapering pipe at i' 2"
and 3". These points are used in developing the pattern for the
taper joint in the following manner : Using C as center and C
i as radius, draw the arc i 3" ', upon which lay off the girth of
twice the semi-circle H as shown by similar numbers. Through
these small figures draw radial lines from C, extending them
indefinitely and intersecting them by arcs of corresponding num-
ber struck from C as center with radii equal to C i', C 2" and C 3".
A line traced through points thus obtained as show r n by J K L,
together with 3" ' 3" will give the net pattern, to which edges
must be allowed for riveting.

The shape of the opening to be cut in the cylinder is obtained
from the side view, which is projected as follows : Draw any
horizontal line as D E, upon which locate the points C 1 , b' and
i from similar points in the end view. Draw the semi-profile
H 1 and divide similar to H, reversing the numbers as shown.
From the small figures in H 1 draw perpendiculars to 3 3 inter-
secting that line. Through the points on 3 3 draw radial lines
from C 1 , extending them to intersecting lines drawn at right
angles to A B from the similar numbered intersections i' 2' and
3' in the end view of large pipe, which gives the miter line in
the side view. Now upon any line, as F G drawn at right angles
to the line of the main pipe, place the girth of large pipe as ob-
tained from the various divisions i' 2' 3', etc., in the end view,
being careful to measure each space separately, as they are all

196

FURNACE FITTINGS

unequal. From the points thus obtained on F G draw measuring
lines at right angles to F G, and intersect them by lines drawn
parallel to F G from similar points in the miter line. The
shaded portion shows the opening to be cut in the main pipe.

F I' 2' 3' 2' I' G-

QPENING IN
CYLINDER

\ _ _ - -_-rr,r

TJ --- = = *^m~

4 - -- - -x7?5f
^ * - ^ > ///'

c -^

PATTERN FOR

JO//VT:

Fig. 139 Laying Out a Reducing T.

Construction of Riveted Joints in Tees

The method of constructing the joints shown in Figs. 134, 135,
136 and 138 is explained in Fig. 140, which shows how the T
is riveted to the main pipe. A flange a in the diagram is turned
outside on the main pipe, while b shows the flange turned out-
ward on the T through which the rivets are placed, giving an
appearance similar to Fig. 138.

Construction of Cold Air Shoes

When making the cold air connection to the bottom of the
furnace a shoe is required. Two styles of cold air shoes for

FURNACE FITTINGS

197

connections to round pipe are shown in Fig. 141. The first, A,
is beveled, while B is made tapering to suit the round pipe. The
round collar joining the shoe is constructed similar to Fig. 122,
but the connection of the shoes in Fig. 141 with the furnace is

Fig. 140 Method of Riveting Reducing T.

prepared as there shown, in which a in both views indicates the
tiange on the shoe proper, and b is a separate flange riveted
to the inside of the shoe and notched so as to allow it to be bent
inward on the casing. The shoe A is shown in position on a
furnace in Fig. 142, where the round cold air pipe is also con-
nected.

Fig. 141 Shoes for Connections to Round Cold Air Pipes.

In Fig. 143 is shown a cold air shoe for inside air connection.
A is the collar for the hall connection. A wire mesh is placed in
die opening through which the inside basement air is admitted,
Flanges are placed at a a for casing connections. In making up
these shoes the corners are double seamed and the curve at the
farther end of the shoe suits the curvature of the furnace cas-
ings.

Fig. 144 shows a galvanized sheet melal shoe for rectangular
pipe. In placing the collars or shoes on the casing they must
always be put on before the casing is put around the furnace.
A in Fig. 145 shows the shoe in position for rectangular cold
air duct, the method of fastening to the casing being indicated

198 FURNACE FITTINGS

in diagram X, in which A represents the casing and B the base
ring. The outerflange of the shoe collar is placed snugly against
the casing and the inner notched flange a turned tightly against

Fig. 142 Shoe Connected to Round Cold Air Pipe.

the inside of the casing, as shown at b, and riveted. Sometimes
a cast iron shoe is riveted or bolted to the casing proper, as
shown in Fig. 146, holes being drilled along the cast iron flange
to which the cold air duct is bolted.

Fig. 143 Cold Air Shoe for
Inside Air Connection.

Fig. 144 Sheet Metal Cold Air
Shoe for Rectangular Pipe.

Pattern for Shoe Connecting to Center of Furnace

When the cold air shoe is directed toward the center of the
furnace, the pattern for same can be laid out as shown in Fig.

FURNACE FITTINGS

199

147, in which A shows the plan view of the furnace, whose
radius is D. B shows the plan of the duct whose section is
shown at C. Take the girth of the duct C, from i to 2 to 3
to 4 to i and set it off on any horizontal line as shown just below.
Make the length of the collar as desired, as I a, and through a

Fig. J45 Connecting Sheet Metal Shoe to Furnace Casing.

draw the line E F, parallel to i-i. Through the points 2, 3
and 4 draw lines intersecting E F at a, b and b. Using D as
radius, and a and b on both sides of the diagram as centers,
describe arcs intersecting each other in c. With the same radius
and c and c as centers draw the arcs a b and b a, which com-
plete the pattern or layout. When the duct is of such size that

Fig. 146 Cast Iron Shoe for Cold Air Connection.

it cannot be made up of one piece the corners are then double
seamed, making it up in either two or four pieces.

Pattern for Shoe Connecting to One Side of Furnace

When the cold air duct connects to the casing to one side
or off the center, as shown in plan in Fig. 148, the layout or
pattern is obtained as just below. In the cut A is the furnace,
B the duct or shoe, and C its section. Take the girth of C as
before and place it on any straight line, as shown below, and
at the desired distance draw any line as E F. At right angle to the
duct line, from the intersection with the casing at B, draw the

200

FURNACE FITTINGS

line B a. Take the distance from a to b, which represents the
corners 3 and 4 in the section, and set it off on lines drawn

Fig. 147 Layout of Shoe for Concentric Cold Air Pipe.

Fig. 148 Layout of Shoe for Excentric Cold Air Pipe.

FURNACE FITTINGS

201

through 3 and 4, measuring from the line E F, as shown from
a to b'. Now using the proper radius H, and b' and c in the
layout as centers, intersect arcs at d. Then using d and d as
centers with the same radius, describe the arcs c b' as shown.
This gives the layout for a duct, intersecting the shoe or casing
as shown in plan. Flanges must be ollowed for riveting and
seaming.

Fig. 149 Showing How Friction Is Avoided.

Frictionless Cold Air Duct Elbows

When connecting the outside cold air duct all possible friction
should be eliminated. All elbows and bends should be curved
as shown by A and B in Fig. 149. A general rule which can
l)e employed in obtaining the radius for describing the throats

Fig. 150 Rule for Obtaining Radii for Curves.

of the elbows or bends is shown in Fig. 150. Whatever the
width of the pipe may be, that width should be the radius with

2O2

FURNACE FITTINGS

which to describe the throat of the bend as shown by B A. To
this radius is added the width of the pipe which gives the radius
B C for describing the heel C. If the width of the duct is 18
inches, the radius of the throat becomes 18 in. and that of the
heel 36 in.

Seaming Cold Air Duct Elbows

There are two methods of seaming the corners of the elbows
in cold air duct work; the first method is shown by A in Fig.
151, in which the top and bottom of the elbows have a formation

TOP OR
GOT TOM

TOP O/?
BOTTOM

Fig. 151 Seaming the Cold Air Duct Elbows.

as indicated by c, while the sides or elbow curves have a single
edge. The lock is first bent as indicated by x, and after the
sides are inserted in the groove a ''dolly" is held on the inside

Fig. 152 Floor Register Box.

corner c and x turned down with the mallet as indicated by a.
The second method B is the regulation method but requires more
time than the former.

Developing and Constructing Floor Register Boxes

Register boxes are constructed of single and double walls.
Those usually employed are of the single wall type shown in
Fig. 152, and are made in various sizes. The size of the register
box is determined by the size of pipe to which it will be con-
nected. Floor registers are usually connected to round pipes.
To find the proper size box from the round pipe, the following
rule is usually employed :

FURNACE FITTINGS

203

Rule for Determining the Size of the Register Box

Find the area of the given round pipe; then double it and find
the stock size of register near to this area, and make register
box to fit. For example, if the round pipe is 10 inches, its area
is 78.54, which doubled gives 157.08. The nearest stock size
register is 10" X 16", which equals 160, then ioj/6" X 16^6" is
the proper size register box to use. The one-eighth inch added
to the size of the register is for play room.

FLANGE

Fig. 153 Net Patterns for Floor Register Box in One Piece.

Table of Areas of Round Pipes and Registers

The following table gives a safe guide to determine the cor-
rect sizes of registers to use with the standard sizes of round
pipes :

TABLE OF AREAS OF ROUND PIPES AND REGISTERS.

Dimensions
of pipe.

14"
16"
18"

20"
22

24'

Area in square
inches.

Size of register
required.

50 8X12

63 9X14

78 10X16

113 14X16

154 16X20

201 18X24

254 20X26

3M 24X27

380 24X32

452 30X30

2O4 FURNACE FITTINGS

Pattern for Floor Register Box in One Piece

Fig. 153 shows how a floor register box is developed in one
piece when it is of such size that it can be made from one sheet
of tin plate. In laying out register boxes, a slight taper should
be given as shown in Fig. 152. In Fig. 153 the method of de-
veloping the box is as follows: Draw the required size of the
rectangle abed and draw the two diagonal lines intersecting
each other at e, which is the center point with which to describe
the opening to receive the collar. Parallel to the sides of the
rectangle, place the hight of the box as shown, to which allow
a flange. Extend the sides and ends of the box and allow the
taper as indicated by i h and 2 / and draw the miter lines to
the corners a b c and d. Edges must be allowed for double
seaming.

Patterns for Floor Register Box in Four Pieces

When the register box is of a large size the register box can
be made up in four pieces as indicated in Fig. 154, where a b

Fig. 154 Net Patterns for Floor Register Box in Four Pieces.

and b c show respectively the length and width of the register,
while a i and b i show the hight of the sides, the flare being
indicated by i I. To obtain the bottom of the box on each quar-
ter pattern, a rectangular bottom should be drawn on the bench
or elsewhere, of the desired size or as long as a b and as wide
as b c similar to a b c d in Fig. 153. Then with a radius equal
to b e and using a, b, b and c in Fig. 154 as centers, describe
arcs, cutting each other at e and e" . Then using c i in Fig. 153
as radius and e and e" in Fig. 154 as centers draw the arcs i'
and i" as shown, which intersect by the diagonals drawn from
a and b to the center e and from b and c to the center e". Edges
must be allowed for double seaming the corners and bottom.
Sometimes, however, the boxes are made in five pieces that is,
the four sides and a separate bottom.

Quick Method of Joining Collar to Register Box

When the corners of the register box shown in Fig. 153 have
been doubled seamed, the collar can be joined to the bottom

FURNACE FITTINGS

205

by a quick method as shown in Fig. 155, in which the collar is
beaded about one-half inch below the end, using a quarter inch

-. *

Fig. 155 Two Methods of Joining Pipe Collar to Register Box.

bead. ^The half-inch flange above the bead is now notched about
every inch, after which the collar is placed through the bottom

/7/PJr METHOD
I !

& r- r-

J j 1

First \ Second. \ ftnat.

Operation. ^ ^

SECOA/&

156 Quick Method of Joining Collar.

of the register box, as at B, then pressing the bead tightly against
the bottom of the box, the notched flanges are turned down firmly
as at a a.

206

FURNACE FITTINGS

Two Other Methods of Constructing Register Boxes

In Fig. 156 are shown two other methods of joining the collar
to the boxes, each method being shown in three operations. In
the first method A shows a section of a register box with the
edge A turned up around the circular opening in the square
bottom. On the collar B an edge is turned outward on the
burring machine as shown. This collar B is then slipped over
the edge A, as shown in the second operation, the lock closed
with the flat plyers. The box is now set on the square head
stake at a and double seamed with a mallat as shown by d in the
final method. The first operation of the second method an edge
is turned downward around the circular opening in the flat
bottom, and F shows an edge turned inward around the collar.
The collar is now placed inside of the edge E and E turned
over as shown at H in the second operation. The lock is then
turned down and double seamed as shown at b in the third
operation.

A--

Sect -/on on A~&

Fig. 157 Construction of Combination l.eader and Register Box.

Construction of Combination Header and Register Box

In the upper part of Fig. 157 is shown a view of a combina-
tion header and register box. The register box is joined to the
headed oval stack as shown, the box collar being of sufficient
depth to run flush with the finished plaster line of the partition.
The method of joining the collar to the stack is shown in the
cut below which represents a section through A B. Note that
the collar has a doubled flange at a, also a projecting flange b.
The stack is cut out to the required size, the collar inserted and
b turned over as indicated by c.

FURNACE FITTINGS

207

Boots or Wall Pipe Starters

Wall pipe starters are known in some shops as "boots" or
"shoes/' Fig. 158 shows a box-shaped starter connecting to
two registers. There are various styles of starters but those most
generally used on first class jobs are known as "box shaped"
and "frictionless." Care should be taken in designing the starter

Fig. 158 Box-Shaped Starter Connecting to Two Registers.

previous to developing the patterns, that easy, graceful sweeps
are obtained to facilitate the flow of air and avoid friction. Fig.
159 shows nine styles of box shaped starters which cover designs
for almost any case that may arise. In making up these styles
of starters the pattern shape is pricked direct from the drawing
and edges allowed for double seaming, the round collars being
attached as shown in a previous article. A frictionless round
to "oval" starter is shown in Fig. 160. This same style of fric-
tionless starter is also made up for rectangular risers instead of
"oval," as will be explained.

Developing the Pattern for a Round to "Oval" Frictionless

Starter

The method used for laying out the pattern for the round to
oval starter is shown simplified in Fig. 161. According to this
method the lines of the elevation are used as base lines and the

208

FURNACE FITTINGS

Fig. 159 Nine Styles of Box-Shaped Starters.

FURNACE FITTINGS 209

various heighths in the semi-profiles as altitudes, when funding the
true lengths. The first step is to draw the elevation of the starter
or boot as shown by 3, 4, 4", 3", on either end of which place
the semi-profiles of the round and oval or oblong pipes as shown.
As both halves of the starter are alike it is only necessary to

Fig. 160 Round to Oval Frictionless Starter.

develop one-half and duplicate it. The shaded sections in the
drawing show the half profiles. In dividing the half profiles in
practice more spaces must be used than are shown. In this case
the upper and lower quadrants have been divided into two spaces
each, as shown by the small figures I to 3 and 4 to 6. From
these small figures I to 3 at right angles to 3 3" and from points
4 to 6 at right angles to 4 4", lines are drawn intersecting the
lines 3-3" at i' 2' and 4 4" at 5' 6'. Connect these intersections
by lines 6' to i' to 5' to 2' and to 4, which lines will represent
the bases of sections to be constructed, whose altitudes are equal
to the various hights of points of corresponding number in the
semi-profiles. Take the various lengths in elevation from 6' to
i', bases i' to 5', 5' to 2' and 2' to 4 and set them off as shown by
corresponding numbers on the horizontal line A B. From these
points erect lines equal in hight to the corresponding altitudes in
the semi-profiles. As point 4 in the semi-profile has no hight
over the base line 4-4", then 4 remains on the line A B. Con-
nect the various points thus set off, which will show the true
lengths desired. As the seam is usually placed along the ends
3-4 and 3"-4" in elevation, the half pattern can be developed as
follows : Draw any straight line i i in the pattern equal to i i"
in the elevation; then using 1-6 in the true length as radius, and
i and i in the pattern as centers describe arcs intersecting each

210

FURNACE FITTINGS

FURNACE FITTINGS 211

other at 6. With 6 5 in the semi-profile as radius and 6 in the
pattern as center, describe the arcs on both sides at 5 and 5 of
the pattern which intersect by arcs struck from I as centers
and i 5 in the true lengths as radius. With i 2 in the semi-
profile as radius and I and i in the pattern as centers, describe
the arcs 2 and 2, which intersect by arcs struck from 5 and 5 as
centers and 5 2 in the true lengths as radius. Proceed in this
manner, using alternately, first the division in the round profile,
then the proper true length ; the division in the oval profile, then
again the proper true length, until the line 3 4 in the pattern
has been obtained, which equals 3 4 in elevation, its true length.
Trace a line through points thus obtained in the pattern which
will give the layout for the half pattern, to which edges must
be allowed for seaming purposes.

Various Styles of Frictionless Starters

Fig. 162 shows five styles of frictionless starters which can
be used for any condition which may arise. The principles to
be used in developing the patterns for these starters are similar
in every respect to that shown in Fig. 161. Care, however,
must be taken in placing the semi-profiles, as clearly shown in
the diagram in Fig. 163, where the various starters are num-
bered to correspond to those shown in Fig. 162. It will be
noticed that the inlets are round, while the outlets or stack con-
nections are rectangular. This makes the methods of develop-
ment as simple as that shown in Fig. 161. In this case it is
only necessary to measure one altitude as c d in the diagrams
in Fig. 163, whereas in Fig. 161 the altitudes varied, owing to
the curve at i 2 3. After the elevations of the starters have
been drawn, the semi-profiles are placed as shown in Fig. 163.
While the various hights must be taken in the semi-round pro-
files as in the previous development, it is only necessary to take
the hight marked c d in all the diagrams, for the rectangular
profiles. The elbow A is joined to starter number 5 to pro-
duce the starter shown by 5 in Fig. 162. After the patterns
have been developed in Fig. 163, two inches should be added to
the rectangular end of the patterns, to act as a collar, to receive
the slip to which the pipe line is connected.

Offset Boot

Fig. 164 shows a perspective view of an offset boot round to
"oval." In developing the patterns for this style of boot, the
upper and lower pipes are developed by parallel lines, while the
central piece is laid out by triangulation. The principles which

212

FURNACE FITTINGS

will be employed can be applied to this or any other style, re-
gardless of what the profiles of the pipes may be.

Fig. 162 Five Styles of Frictionless Starters.

Developing the Patterns

This is shown in detail in Fig. 165, in which the center line
of the boot is first drawn as shown by a 3' 8' e, making the
angles as desired. Bisect these angles to obtain a true miter

FURNACE FITTINGS 213

line as follows : From 3' as center, with any desired radius, draw
short arcs intersecting the center line at a and b ; then using a
and b as centers, with a radius slightly greater than before, draw
the arcs intersecting at c, and draw the miter line indefinitely
from c through 3' as shown. In a similar manner obtain the
miter line / 6' by means of the arcs d, e and /. Now place the
half profile of the round pipe at the lower end of the boot, on
the line I 5, and the half profile of the "oval" pipe on the upper
end as shewn on the line A B. Space the semi-circles in both
profiles into the same number of parts, as indicated, and at
right angles to I 5 and A B respectively, draw lines from the
various points 2 to 4 and 10 to 6 until they cut the miter lines
i' 5' and 6' 10' as shown. Connect by lines the points i' and 10'
and 5' with 6', which completes the side elevation. The half
pattern for the round and "oval" pipes will be laid out by parallel
lines as follows : Extend the line i 5 in the side elevation as
shown at the right by C D, upon which place the girth of the
half profile of the round pipe as shown. From the small figures
erect lines at right angles to C D, and intersect same by lines
drawn parallel to C D from the various points i' to 5' on the
miter line in elevation. Trace a line through the intersection
thus obtained; then will i" 5" 5 i be the half pattern to which
the edges must be allowed for seaming.

In precisely the same manner is the half pattern for the oval
pipe obtained. B A in elevation is extended as shown by / E,
upon which the girth of the half profile of the "oval" pipe is
placed, as shown by similar letters and figures on / E. The
usual measuring lines are drawn and intersected by lines drawn
parallel to / E from points of corresponding number on the
miter line 6' 10'. This will give the half pattern for the "oval"
pipe, to which edges must also be allowed for seaming pur-
poses.

To develop the middle piece of the offset, connect the various
points 10', 2', 9', 3', etc., as shown. These lines will then repre-
sent the bases of sections to be constructed as shown in the
diagram of true lengths, whose altitudes will equal the various
hights shown by corresponding numbers in the upper and lower
semi-profiles in the side elevation. Draw any horizontal line
as F G, upon which place off the lengths of the several lines
shown in the middle section in the elevation as shown by cor-
responding numbers on F G. For example, to find the true
length of the line 3' 9' in elevation, take this distance and set it
off on F G as shown from 3' to 9', and from these two points
erect perpendiculars, making them equal respectively to the hight
of lines of corresponding number in the half profiles of the side

214

FURNACE FITTINGS

/VOTE: ALLOW
TWO MCH5 FOX
COLLAR OAf ttCr/WGULAK

Fig. 163 Placing the Semi- Profiles.

FURNACE FITTINGS 215

elevation as measured from the lines I 5 and A B, and draw
a line from 3 to 9 in the diagram, which is the desired length.
In this manner all of the true lengths are obtained. It should
be understood that the lines i' 10' and 5' 6' in elevation show
their true lengths, but these two lines also represent the base
of the two sections, whose altitudes at 10' and 6' are equal to A
10 and B 6 respectively, the true lengths of these two invisible
lines being indicated by i' 10 and 5' 6 in the diagram of true
lengths.

Fig. 164 Offset Boot.

It will not be necessary to develop any sections on the miter
lines i' 5' and 6' 10' in elevation as the true lengths along the
miter cuts can be obtained along the miter cuts in patterns of
the straight pieces respectively. The half pattern for the transi-
tion piece can now be laid out as follows : First draw any line
as A i in the pattern equal to 10' i' in the side elevation. With
a radius equal to A 10 in the half profile and A in the pattern
as center, describe the arc near 10, which intersect by an arc
struck from i of the pattern as center and the true length i'
10 as radius. With i" 2" in the half pattern of lower pipe as
radius and i in the pattern as center, describe the arc 2, which
intersect by an arc struck from 10 as center and 10 2 in dia-
gram as radius. With 10' 9' in the half pattern of upper pipe
as radius, and 10 in pattern as center, describe the arc near 9,
which intersect by an arc struck from 2 of pattern as center
and 2 9 in the diagram of true lengths as radius. Proceed in
this manner, using alternately first the divisions along i" 5" in
the pattern for the lower pipe, with the proper true length in
the diagram ; then the divisions along A' B' in the pattern for
the upper pipe, with the proper true length in the diagram, until
all dimensions are used. A line traced through points thus ob-
tained as shown by A B 5 i completes the half pattern, to which
edges must be allowed for seaming and joining. The method
of seaming together the three pieces of the offset is similar to
that shown in Fig. 127, but the wall pipe slips are made as in-
dicated by S in Fig. 164.

216

FURNACE FITTINGS

/ /' + /o' 8' 7' ? J'<3' 6' 9'

r/?V LENGTHS Of 2/rt/LJG A/Utf&eD UA/S /M 5/> VAT/ON.

3 2 /

ffALF PATTERN FOR fiOUA/O P/P.

7 A

Fig. 165 Developing Pattern for Offset Boots.

FURNACE FITTINGS

217

Wall Pipes or Risers

The wall pipes used in warm air heating are also known as
risers, stacks or flue pipes. They are made with single and
double walls. When single wall pipes are used they should
be braced on the inside by soldering a tin brace in the center of
the pipe, as indicated by A in Fig. 166. Where this is not done

Air ce// paper-

Fig. 166 How the Area Is
Decreased in Wall Pipes.

Fig. 167 Method of Securing
Air Tight Joints in Wall Pipe.

the pressure of the plaster when forced through the lathing de-
creases the area of the pipe as indicated by the dotted lines a
The braces A are cut 24 mcn wide and i inch longer than the
width of the pipe. An l / inch hem edge is turned on each of

dsoestos <?// ce//

Galvanized

jheet mete/ corner dng/es

Fig. 168 Protecting Asbestos Covering.

the long sides of the brace, leaving it >^ inch, and a y 2 inch
edge on each end, which is turned at right angles to be used
for soldering purposes as shown. Care must be taken to solder
the brace in edgewise, so as not to interfere with the flow of
the air or decrease the capacity of the pipe.

Covering Single Wall Pipes with Paper

The single wall pipes can be covered with either single paper
or with air cell or corrugated paper. This prevents loss of heat
in the walls, the paper being pasted to the flue pipes as follows :

218 FURNACE FITTINGS

Cut the paper about % inch shorter than the girth required to
go around the pipe. To apply the paper, roll it up, dip in water
and remove immediately and apply the paste. Put the paper
on the pipe while it is soft and pliable. Before bringing the two
edges together in the vertical seam, take a piece of flat, stiff
paper about 3 inches wide, and paste over one edge of the air
cell paper as shown by a in Fig. 167, and then paste down on
the tin pipe at b. Now bring the other edge of the air cell paper
in place as shown by c and paste another strip of stiff paper
over the joint as indicated by d. This secures the covering along
the vertical joints. Do the same with the horizontal joints, and
always have the corrugations next to the tin. When the paper
is dry a good solid air tight covering is obtained,

Double Wall Pipes

Double wall pipes have the advantage over the single wall as
the walls are protected from crushing by means of perforated
angles and corrugations and the air space between the inner and
outer pipes prevents loss of heat in the partitions,

Metal Flues in Brick Walls

When warm air pipes are run up in brick walls as the mason's
work progresses, galvanized iron is generally used, covered with
asbestos air cell covering. The corners of the asbestos covering
is usually protected from injury as shown in Fig. 168, in which
the metal pipe is first covered with asbestos air cell covering .as
previously described, then the corners of the asbestos covering
are protected by galvanized sheet iron angles 3 inches wide on
each side, which prevents the paper from being torn or damaged
by the brick work or studding. These galvanized iron angles
are held in position by thin copper wire twisted around the pipe
at intervals of about 12 inches as indicated in the diagram.

The Various Fittings Used in Furnace Piping

Fig. 169 shows twenty-six styles of single wall furnace fittings,
including every conceivable shape usually met with in practice.
The same style of fittings can also be obtained for double wall
pipe. It will be noticed that the various angles, elbows, offsets,
tees, register boxes, etc., are so constructed that no development
is necessary when laying out the patterns, the shapes being
pricked direct on the metal and edges allowed for seaming and
grooving. This cut should be referred to when any job comes
up, as from these twenty-six styles one or more is sure to sug-
gest itself for practical use.

FURNACE FITTINGS

219

Fig. 169 Twenty-six Styles of Single Wall Furnace Fittinga

i Angle 45 Elbow. 8 Flat Offset Elbow.

2 Elbow of Three Pieces. 9 Two Way Tee.

3 Elbow 90. 10 Flat Angle 45.

4 Regular Elbow 90 Round Heel. 1 1 Through Tee.
5 Flat Elbow 90 Round Heel. 12 Reduced Tee.
6 Offset Elbow. 13 Flat Two Way Tee.

7 Flat Elbow 90 Octagonal Heel. 14 Flat Through Tee.

22o FURNACE FITTINGS

15 Left Compound Tee on the Flat. 21 Through Register Box.
i6-Ri g ht Compound Tee on the Flat. 22 _ Top Register BQX and Riser

17 Left Compound Tee on the ^ ^ .

Sharp. 2 3 T P Register Bex Connected to

Combined. Oval Pipe.

18 Right Compound Tee on the 24 Semi-circular Register Box.

c- 1 -r -n . r 2 5 Double Semi-circular Register

19 Single Top Register Box for . _.

Rectangular Riser. Boxes for Round Rlsers -

20 Double Top Register Box for 26 Double Corner Register Boxes
Rectangular Riser. for Round Riser.

Compound Wall Pipe Offsets

Compound pipe offsets are very often required in furnace
piping. When the partition on the first floor runs in one direc-
tion, and that on the next floor runs at right angles to the lower
one, a compound or double offset is necessary as shown in Fig
170, where the two wall pipes cross one another at right angles,
with equal projection on all four sides as shown. In an offset
of this kind the pattern must be developed, the offset usually
being made up in four pieces, with collar attachment and the
corners double seamed.

The method of developing the pattern for the offset is so
clearly shown in Fig. 171 that little explanation will be required.
The shape of the two pipes is clearly shown in the plan, the
vertical night of the offset is indicated by 2 a in elevation, and
I 2 of the elevation is the slant hight or stretchout to be used
in obtaining the pattern as shown at the right. Allow for a
collar at either end to make connections as shown.

Patterns for a Double Offset

When the upper heat pipe does not come centrally over the
lower one, but offsets to one side, then a double offset is required
as indicated in Fig. 172. The method of laying out the pattern
is shown in Fig. 173, which method can be applied to any style
of offset, regardless of what shape the profiles at either end
may be, whether similar or dissimilar, or whether the upper
pipe is out of center either way or not, providing, however, that
the sides of the upper pipe run parallel to those of the lower
pipe. Referring to Fig. 173, 2, 5, 3, 5 in plan shows the shape
of the lower pipe and i, 6, 4, 6 the shape of the upper pipe, the
two being similar in this case. The amount of offset is equal to
3 i in plan, the narrow side of the upper pipe being set centrally
to the wide side of the lower one. The front and side elevations
are projected from the plan as shown, being careful that the
vertical hight a in the front is equal to a of the side. As the
flare 5 6 in the front elevation is the same as that of the op-
posite side, then will the pattern for one side answer for both.

FURNACE FITTINGS

221

In the side elevation the flares i 2 and 3 4 are unequal ; two
patterns will therefore be required.

To obtain the pattern for the side shown by 5 6 in both front
elevation and plan, proceed as follows: At right angles to the

Fig. 170 Compound Offset.

72 Double Offset.

side 6 in plan draw the line A B, upon which place the girth or
stretch-out of 5 6 in the front elevation as shown. At right angles
to A B, through points 5 and 6, draw the usual measuring lines,
and intersect same from sides of corresponding number in plan
as shown, which will give the pattern for the sides 5 6. Allow
for collars, also edges for seaming at the corners. For the

PLAN Pattern for Sides.

Fig. 171 Developing the Pattern for Compound Offset.

patterns for the sides I 2 and 3 4 in the side elevation, draw
any vertical line as C D below the plan as shown, upon which
place the girth of the flares i 2 and 3 4 in the side elevation.
Through these small figures on C D draw the usual measuring
lines, which intersect by lines projected from points of cor-
responding numbers in plan, all as shown by the dotted lines.
Allow collars, also edges for seaming the corners.

222

FURNACE FITTINGS

Pattern
forS/des /,<?

Allow Edges on &
Patterns for
Double Seaming.

Fig. 173 Patterns for Double Offset.

FURNACE FITTINGS

223

Fittings for Trunk Line Heating Systems.

Where trunk line systems of heating are used, special fittings
must be made up, which are usually round in section. Care,
however, must be taken in designing the branches, tees and forks,
that the main supply pipe is of sufficient area to feed the branches
taken therefrom, as will be explained in problems to follow.

Fig. 175 Short Rule for Reducing Joint.

Five types of trunk line fittings will be shown. Four of the
types will require triangulation in their development, but one
type only will be developed in detail, showing the principles
involved, which can be applied to the balance of the fittings or
any other size or angles which may arise.

Short Rule for Reducing Joint

Fig. 174 shows what is known as a reducing joint. This pat-
tern can be developed by the radial line system, but sometimes
the difference between the large and small diameters is so little
that the radius would become so long as to make it impractical
for use. To overcome this a short rule can be used as shown
in Fig. 175. This is as follows: Draw upon the sheet metal the
outline of the taper joint desired, as shown by a b c d. Now
with a and b as centers, with radius less than a b draw the arcs
e f and e f, crossing the outlines a d and b c at i and i re-
spectively. TT ow using i as center with / e as radius intersect
the arc at /. Do the same in obtaining /'. From a and b draw
lines through / and /' equal in length to a b, as shown by a b'
and b b". In precisely the same manner, using d and c as centers,
draw the arcs g h a-nd g ti and obtain the intersections h and ti

224

FURNACE FITTINGS

by using k and k' as centers with radius equal to k g. From d
and c draw lines through h and h', making them equal in length
to d c, as indicated by d c and c c". Draw lines from b' to c'
and b" to c" . Add to the pattern just described one seventh of
the shape a b c d } as shown by E F. This is obtained by divid-
ing a b and c d each into seven parts and adding one of these
parts as indicated. E. F. b" c" is the desired pattern. When
cutting out the pattern a curved line should be cut along the
top and bottom, carefully allowing edges for grooving the joint
and for seaming to the collars, as indicated by A and B in Fig.
174-

Determining the Unknown Diameter of the Main Pipe

Fig. 176 shows a view of an equal pronged fork fitting, in
a trunk line system of heating. When laying out fittings of

Fig. 176 Equal Fork in Trunk Line Fittings.

this kind, great care should be taken in regard to area, as before
stated. In other words the area of the main trunk line A must
equal the combined areas of the branches B and C, or as many
branches as may be taken from the main.

To avoid computation when fitting the unknown diameter of
the main pipe A, use can be made of a table of Circumferences
and Areas of Circles to be found in chapter 19. Assuming
that the two branches are each 8 inches in diameter, follow the
column of diameters in the table to 8, the area of which will
be found to be 50.26. Double this for the two similar branches,
making a total of 100.52. Now following the column of areas
in the table, the nearest area to 100.52 will be 101.62, which rep-
resents the area of a circle nj^ in. in diameter, as shown in the

FURNACE FITTINGS

225

column of diameters. The main pipe A must be n^j in., which
will then contain the combined areas of the two 8 in. branches
B and C

Pattern for a Fork of Equal Prongs in Trunk Line System

The pattern for this fitting will be developed by triangulation,
as shown in detail in Fig. 177, the principles of which can also
be applied to the other problems on fittings, which will follow

Ztevatt'on w'M //<?//< Pro f//es.

ffaff Potterfl- A //or fc/^es.

Fig. 177 Developing the Pattern for a Two-Pronged Fork.

in regular order. As both branches are to have the same di-
ameter, the pattern for the one will answer for the other. First
draw the elevation of the fork as shown by i, 5, 6, 8", 5', i', 10
(in practice, but one half of elevation will be required, as both
prongs are similar). On the line i 5 in elevation draw the half-
profile A ; on the line 6 8", the half-profile B, and draw the half-
profile on the line 8' 10 as follows : As the hight of the joint is
equal to 8' 10 and the half-depth through 8' equal to 8' 8, place
this distance 8' 8 at right angles to the joint line 8' 10, as shown
by 8' 8", and draw at pleasure a graceful quarter of an elliptical
figure as indicated by 8" 9 10 or C. As the half-profile B and C
are both divided in two equal parts, or a total of four, then divide

226

FURNACE FITTINGS

the half-profile A into four spaces, as shown from I to 5; the
half-profile B has two spaces, as shown from 6 to 8, and the
half-profile C, in two parts, as shown from 8" to 10. From these
various small figures at right angles to their respective base lines,
draw line intersecting the base lines at 2', 3', 4', also at 7' and 9'
Connect opposite points, as shown by the dotted lines. These
lines then represent the base lines of sections which will be con-
structed and whose altitudes will be equal to the various heights
in the half-profiles A, B and C. Therefore on any vertical line,
as DE, place the various lengths of the lines in elevation, as
shown. From the points on DE perpendiculars are erected
whose hights are equal to the altitudes in the various half-sec-
tions, and the points, obtained in F, are then connected by slant
lines, which show the true lengths, all as shown by similar num-
bers.

Fig. 178 Unequal Fork in Trunk Line Fittings.

The half pattern shape H briefly described is laid out as fol-
lows : 5 6 is made equal to 5 6 in elevation. The divisions from

5 to i are obtained from the half-section A, the divisions from

6 to 8 from the half-section B and the divisions from 8 to 10
from the half-section C. The length of the dotted lines in H
are obtained from the true lengths in F, i-io in H being equal
to i-io in elevation. Edges must be allowed for seaming.

FURNACE FITTINGS

227

Determining the Unknown Diameter in an Unequal Two

Pronged Fork

Fig. 178 shows an unequal two pronged fork whose branches
A and B are 7 and 10 inches respectively and it is desired to
know what size the main pipe C must be. This is found with-
out computation by using the table previously referred to. A
7 in. circle has an area of 38.48 sq. in., and a 10 in. circle an
area of 78.54, making a total of 117.02. Now the nearest num-
ber to 117.02 in the column of areas in the table is 117.85, which
suggests a circle 12% in. in diameter, or the size of the main
pipe C.

Fig. 179 Placing the Half-Profiles in an Unequal Pronged Fork.

Placing the Half Profiles Previous to Developing the Patterns

In Fig. 179 is shown how the half-profiles are to be placed
when developing the patterns for an unequal pronged fork.
Draw the outline of the full size fork as shown by A B C D H
E F. Bisect A B and obtain the point J and draw the joint line
J. H. Place semi-circles on the lines A B, C D and E F, which
represent the half-profiles. At right angles to the joint line H J,
from the center J, draw the line J a equal to J A, as shown, and
draw a quarter elliptical figure shown by a H. The profiles
being drawn, they are spaced and the patterns developed as was
shown in Fig. 177.

228

FURNACE FITTINGS

Three Equal Pronged Fork

In Fig. 180 is shown a fork of three equal size prongs in a
trunk line system, so placed that the pattern for one prong can

Fig. 180 Three Equal Pronged Fork in Trunk Line System.

be used for all three. The size of the main pipe would be de-
termined as follows : Following the column of areas in the table,
we find that 8 inch circle has an area of 50.26 sq. in., which

Fig. 181 Method of Drawing Three-Pronged Fork so that the Pattern
for One Will Answer for All.

multiplied by 3 gives a total of 150.78. The nearest number
to 150.78 in the column of areas is 151.20 and suggests a circle
whose diameter is 13% in., the size of the main pipe.

FURNACE FITTINGS

229

Method of Drawing Three Pronged Fork so that the Pattern
for One Will Answer for All Three

Fig. 181 shows how a three pronged fork is drawn, so that
the angles of the miter joints will be similar and the pattern
for one will answer for all. Having determined the size of
the main pipe as a b, bisect it, and obtain c, which use as a center

Fig. 182 Unequal Three-Pronged Fork in Trunk Line System.

and describe the semi-circle a d b. From c draw the perpen-
dicular c m. Now set the dividers equal to c a and starting
from a, step off the points e and /. Using the same space, step
off the points i and h, starting from d. Draw the joint lines
c e and c f and draw lines indefinitely from c through i and h
shown respectively by c I and c n. Now establish the height of
the prong as c o and, using c as center and c o as radius, draw
the arc r s, cutting the radial lines c I and c n at t and u. On
ascertaining the diameter of the prong, set the dividers equal to
one-half the diameter and step off on the arc r s on either side
of the points u o and t, the divisions shown by i 2, 3 4 and 5 6.
Connect these points by lines as indicated, which makes each of
the three prongs similar. As the two halves of each prong are
symmetrical, it is only necessary to develop the pattern for one
half, as indicated by a 6 t c, placing the quadrants for that pur-
pose as follows : With c as center and c a as radius, draw the
quadrant shown shaded, at B. With t as center and t 6 as radius,
draw the quadrant shown by A. Now divide both quadrants in
equal number of spaces and proceed to draw the base lines and
develop the true lengths and patterns as previously described.

230

FURNACE FITTINGS

Unequal Three Pronged Fork

Fig. 182 shows an unequal three pronged fork, each diameter
being different, and each fork leading at a different angle. In
this case the diameters are 6, 8 and 10 in. and represent areas
of 28.27, 50.26 and 78.54, making a total area of 157.07. The
nearest area to this number is 159.48 and represents the area
of a 14^4 i n - pipe, the desired dimensions as shown.

Fig. 183 Finding True Sections and Placing Profiles.

Finding the True Sections and Placing the Profiles in an
Unequal Three Pronged Fork

While the method of developing the patterns for an unequal
three pronged fork is similar to those already described, care
must be taken to draw and place the profiles properly, as is
shown in Fig. 183. In this figure abcdefghij shows the
desired outline of the fork and that it has the desired angles and
proper dimensions and diameters. On the line a j draw the semi-
circle D, and on the lines b c, e f and h i the half-profiles A, B

FURNACE FITTINGS

231

and C respectively. Now at right angles to the joint lines d I
and / g draw the lines / a and / / equal respectively to / a and / /.
Now from the intersections a and / draw the quarter elliptical
figures indicated by a d and / g, or E and F. So that the method
of placing the half-profiles may not confuse the reader, the
prongs have been numbered i, 2 and 3 and have been duplicated
as indicated by i a , 2 a and 3 a , on which the profiles are placed
in their proper positions, being duplicates of similar lettered pro-
files in i, 2 and 3. A little study will make this clear, after
which the spacing of the profiles and obtaining the true lengths
and the patterns are in order.

Finding True Angles in Cold Air Duct Elbows

It is often the case that special elbows must be prepared and
the true angle be found, especially where they pitch in both direc-
tions, as indicated in Fig. 184, where a plan and elevation of a

Cold SAT

Fig. 184 Example in Cold Air Duct Elbows in Furnace Work.

round cold air duct is shown. In this case true angles must be
found, as none of the angles in either plan or elevation show
their true pitch. The height of the elbow from the cellar line
is indicated by A, its projection by B in plan, and it leans away
from the reader as much as is indicated by C. The method of
finding the true length of the middle pipe, also the true angles
of the two elbows, is indicated in the detail drawing in Fig. 185,
in which the heavy dotted lines show the center line of the
pipe, all that is necessary. A B C D represents the center of

232 FURNACE FITTINGS

the pipe in plan, its lean away from the reader being shown by
a D. The same center line is shown in elevation by A 1 B 1 C 1
D 1 , the rise being indicated by b C 1 and the projection by B 1 b,
The first step in finding the true length of B C in plan or B 1 C 1
in elevation is to place the height of b C 1 at right angles to B C
in plan, as indicated by C C 2 , and draw a line from C 2 to B,
the desired length. As A B and C D in plan and A 1 B 1 and
C 1 D 1 in elevation lie in horizontal planes, they then show their
true lengths. Now to find the true angle of A B C in plan, draw
a line from A to C, take this distance and place it on any line
as A C in diagram X and at right angles to A C draw C C 1
equal to b C 1 in elevation. Draw a line from C 1 to A, which is
the true length of C A in plan. Now with the true length C 2 B
in plan as radius and C 1 in diagram X as center, draw the arc E,
which intersect by an arc struck from A as center and A B in
plan or A 1 B 1 in elevation as radius. The dotted line drawn
from C 1 to E to A shows the true angle for the elbows for
A 1 B 1 C 1 in elevation or A B C in plan.

The true angle on B C D in plan is obtained in a similar
manner. The distance from B to D in plan is placed as shown
by B D in diagram Y, perpendicular to which D C 1 is erected
equal to b C 1 in elevation. Then with C D and B C 2 in plan
as radii, and using C 1 and B respectively in diagram Y as cen-
ters, arcs are intersected at H, thus forming the desired true
angle B H C 1 .

Method Employed when Developing the Elbow Patterns

After the true angles have been found the patterns are laid
out similarly to other elbow work. For example, the angle
A E C 1 is bisected, thus obtaining the line c d and the profile F
of the pipe placed as shown, with the center point a placed upon
the line E C 1 . The profile is now divided into equal spaces and
the pattern obtained as usual. Of course it is understood that
the arms of the elbows are usually made about 6 in. long at
the throat, making a slip joint for the center pipe, no matter
how short this may be. This method obviates the labor of find-
ing the amount of twist between the two elbows B 1 and C 1 in
elevation.

True Angles in Warm Air Elbows

When true angles are required in warm air elbows the same
principles are employed. Fig. 186 gives an example of what
is likely to arise in practice. This shows a pipe line connecting
to the first floor register. In elevation the rise is equal to a
and b respectively, while in plan the pipe leans toward the reader

FURNACE FITTINGS

233

^^X"^ S Vay ratn Y

' rrue Jnffe o* 0-C-O //? fVan.

A rrue Any/e on A-B-C in P/an. C

f/evet/on

Pldfl*

Fig. 185 Finding True Angles of Circular Cold Air Duct v

234

FURNACE FITTINGS

as much as indicated by c. This problem has been worked out
in Fig. 187, in which A B C D shows the rise of the center line

Fig. 186 Example in Finding True Angles in Warm Air Elbows.

of the pipe in elevation. The first run of pipe A B has a rise
equal to a B, while the second run B C has a rise equal to b C,

Fig. 187 Finding the True Angles.

the pipe C D being made to suit the connection to the regis-
ter box.

FURNACE FITTINGS

235

A 1 B 1 C* in plan shows similar center line of pipe, leaning
toward the reader a distance equal to d C 1 . The center line of
the pipe C D in elevation is indicated in plan by the dot C 1 D 1 .
Now to find the true length of the run B C and the true angle
of B C D in elevation, proceed as follows : Take the hight from b
to C to D in elevation and place it at right angles to B 1 C 1 in
plan as shown respectively by C 1 to C 2 to D 2 and draw the lines

Fig. 1 88 Finding True Angles with Line and Bevel.

from B 1 to C 2 to D 2 , which will give the true length as well as
the true angle of B C and B C D in elevation. As A 1 B 1 in
plan lies in a horizontal plane, then A B in elevation shows its
true length. To obtain the true angle of A B C in elevation or
A 1 B 1 C 1 in plan, take the distance of A 1 C 1 and place it in X
as shown. From C 1 erect the perpendicular C 1 C 3 equal to the
combined nights of the two runs in elevation, as c b C. Now
with radii equal to A B in elevation and B 1 C 2 in plan and using
A 1 and C 3 in X as centers, intersect arcs at B 2 . A 1 B 2 C 3 then
becomes the true angle desired. The patterns are developed in
exactly the same way as before described.

Finding True Angles with Line and Bevel

A practical way to find the true angles without any drawing
is to do it directly at the job, using only a line and bevel, and is
shown in connection with Fig. 188. The furnace and cold air
inlet c being in position, nail a slat on the inlet sill, as far as the
pipe is to project from the wall, as shown ; also put a nail in the
concrete floor near the furnace where desired. Now drive a

236 FURNACE FITTINGS

nail at the end of the slat and draw a line taut from b to a. It
is now an easy matter to place a bevel at a and b, then take di-
mensions at the inside corners of the bevel legs, after which the
bevel can be closed, and then again opened when the patterns
are laid out in the shop. Before removing the line, the true length
from a to b can be measured.

237

CHAPTER XIX
RULES, TABLES AND INFORMATION

The following pages contain rules, tables and useful in-
formation of value to the sheet metal worker and furnace
man.

This information has been collected from so many sources
that it is next to impossible to give credit to the authors or
compilers of the data and tables published.

The author of this book desires to acknowledge his obliga-
tion to each of those who are in any way responsible for the
data published, believing that no objection will be made to
the use of the information for the benefit of the trade.

2 3 8

WEIGHTS AND GAUGES OF SHEET METALS

Weights of Steel

Approximate

Weight

1 " ~

No.
of Gauge

thickness in
fractions of
an inch

Thickness ir.
decimal parts of
an inch

pet square foot
in pounds
Avoirdupois

per square foot
in pounds
Avoirdupois

Birming-
ham

jof Gauge i

U.S. Standard

U. S. Standard

Iron

Steel

ooooood

L-2

2O.OO

20.4

OOOOOO

15-32

.46875

18-75

19 12$

....

OOOOO

7-16

4375

17.50

17.85

....

oooo

13-32

.40625

16.25

16-575

454

000

3-8

375

I 5.

15.30

425

n -32

34375

13-75

14.025

380

5-16

3125

12.50

12.75

340

0-32

.28125

11.25

H.475

-.300

17-64

.265625

10.625

o 8375

.284

1-4

.25

10.

1O 2

-259

15-64

234375

9-375

9.5625

7-32
18-64

.21875
.203125

8.75
8.125

8.925
8.2875

.220
.203

3-16

1875

7-5

7.65

.180

11-64

.171875

6.875

7.0125

.165

5"~32

.15625

6.25

6-375

,148

9-64,

. 140625

5.625

5-7375

1-8

.125

5 I

.120

7-641

.109375

4-375

4.4625

.109

13
14

3-32
5-64

.09^75
.078125

3-75

3.825
3-1875

.095
.083

13
*4

9-128

.0703125

2^8125

2.86875'

.072

1-16

.0625

2-5

2-55

9-160

.05625

2.25

2.295

'.058

1-20

.05

2.04

.049

7-IOO

.04375

1.785

.042

3-80

0375

.50

1-53

035

II-32O

034375

375

1.4025

.032

1-32

.03125

1-275

.028

9-320

.028125

.125

1-1475.

.025

. 1-40

.025

1.02

.022

'24

7-320
3-160

.021875
.01875

875
-75

.8925
.765

.020
.018

1 1 -640

.0171875

.6875

.70125

.Ol6

1-64

.015625

.625

.6375 '

.014

9-640

.0140625

.5625

57375

.013

1-80

.0125

.012

7-640

.0109375

.4375

.44625

.OIO

13-1280

.01015625

.40625

-414375 '

.OO9

3-320

.009375

375 ,

.3825

.008

11-1280

.00859375

34375

.350625

.007

5-640
9-1280

.0078125
.00703125

.3125

.28125

.3'875
.286875

.005
.O04

17-2560
1-160

.006640625
.00625

. 2/55625

; 2 5

.2709375
255

....

"to

WEIGHTS AND GAUGES OF SHEET METALS

239

GAUGES AND WEIGHTS OF BLACK SHEETS.

No. of
Gauge or
Thickness
of Sheet

Approximate Thickness in Inches.

Weight per Square Foot in Pounds

U. S. Standard,
adopted by U. S.
Government
July 1, 1893

Birming-
ham
Wire
Gauge

American
or
Brown &
Sharpe's
Decimals

U. S.
Standard

Birming-
ham
Wire
Gauge

American
or
Brown &

Sharpe's

fractions Decimals I" Decimals

Steel

5-0's

7-16

437

17 50

0000

13-32

.406

.454

.46

16.25

IS AQ

18.77

000

3-8

.375

.425

.409

15.

17.28

16.71

11-32

.343

.38

.364

13.76

15.45

14.88

5-16

.312

.34

.324

12.50

13.82

13.26

9-32

.281

.30

.289

11.25

12.20

11.80

17-64

.265

.284

.257

10.625

11.55

10.51

1-4

.25

.259

.229

10.

10.53

9.36

15-64

.234

.238

.204

9.375

9.68

8.34

7-32

.218

.22

.181

8.75

8.95

7.42

13-64

.203

.162

8.125

8.25

6.61

3-16

.187

.18

.144

7.5

7.32

5.89

11-64

.171

.165

.128

6.875

6.71

5.24

5-32

.156

.148

.114

6.25

6.02

4.67

9-64

.140

.134

.101

5.625

5.45

4.16

1-8

.125

.12

.09

4.88

3.70

7-64

.109

.08

4.375

4.43

3.30

3-32

.093

.095

.072

3.75

3.86

2.94

5-64

.078

.083

064

3.125

3.37

2.62

9-128

.070

.072

.057

2.8125

2.93

2.33

1-16

.062

.065

.05

2.5

2.64

2.07

9-160

.056

.058

.045

2.25

2.36

1.85

1-20

.05

.049

.04

1.99

1.64

7-160

.043

.042

.035

1.75

1.71

1.46

3-80

.037

.035

.032

.50

1.42

1.31

11-320

.034

.032

.028

.375

1.30

1.16.

1-32

.031

.028

.025

.25

1.14

1.03

9-320

.028

.025

.022

.125

1.02

.922

1-40

.025

.022

.020

.895

.82

7-320

.021

.02

.017

.'875

.813

.73

3-160

.018

.015

.75

.732

.649

11-640

.017

.016

.Q14

.6875

.651

.579

1-64

.015

.014

.012

.625

.569

.514

-9-640

.014

.013

.011

.5625

.461

1-80

.012

.01

.408

7-640

.010

.01

.008

.4375

.363

13-1280

.010

.009

.008

.4062

.326

11-1280

.008

,007

.006

.3437

.257

9-1280

.007

.004

;2812

...

The U. S. Standard Gauge is the one commonly used in the United States.

In figuring weights of Steel Plates add to above the allowances for overweight,
adopted by Association American Steel Manufacturers.

240

WEIGHTS AND GAUGES OF SHEET METALS

GALVANIZED SHEETS.

GAUGES, WEIGHTS AND NUMBER SHEETS IN BUNDLE

Size
of

w t ,

Weight
of

Number
of

Size

Weight
of

Weight

Size
of

wp.

Weieht
of

Number
of

Sheet

Bandlo

Sheets

Sheet

Bundle

Sheet

Bundle

Sheets

No. 14 (3.28 Ibs. sq. ft.) ( No. 16 (2.65 Ibs. sq. ft.) || No. 18 (2.15 Ibs. sq. ft.)

24x72

39.37

157

24x72

31. 87

159

24x72

25.87

155

26x72

42.65

170

26x72

34.5

138

26x72

28.

140

28x72

45.9

138

28x72

37.18

148

28x72

30.18

150

30x72

49.2

147

30x72

39.84

159

30x72

32.34

161

36x72

59.

177

36x72

47.8

143

36x72

38.8

155

24x84

459

137

24x84

37.18

149

24x84

30.18

151

26x84

49.74

149

26x84

40.2

161

26x84

32.68

163

28x84

53.58

161

28x84

43.37

173

28x84

35.2

140

30x84

57.4,

172

30x84

46.48

139

30x84

37.7

151

36x84

68.9

137

36x84

55.78

167

36x84

45.28

135

24x96

52.5

157

24x96

42.5

170

24x96

34.5

138

26x96

56.8

170

26x96

46.

138

26x96

37.36

149

28x96

61.2

183

28x96

49.56

149

28x96

40.23

161

30x96

65.6

131

30x96

53.12

159

30x96

43.12

172

36x96

78.75

157

36x96

63.75

127

36x96

51.75

155

No. 20 (1.65 Ibs. sq. ft.)

No. 22 (1.40 Ibs. sq.ft.)

No. 24 (1.15 Ibs. sq. ft.)

24x72

19.87

159

24x72

16.87

151

24x72

13.87

152

26x72

21.53

151

26x72

18.28

146

26x72

15.03

150

28x72

23.18

162

28x72

19.68

157

28x72

16.18

145

30x72

2484

149

30x72

21.

147

30x72

17.34

156

36x72

29.8

149

36x72

25.3

152

36x72

20.8

145

24X84

23.18

162

24x84

19.68

157

24x84

16.18

145

26x84

25.1

150

26x84

21.3

149

26x84

17.52

140

28x84

27.

135

28x84

22.96

160 7

28x84

18.88

151

30x84

28.97

145

30x84

24.6

148

30x84

20.23

141

36x84

34.78

139

36x84

29.53

147

36x84

24.28

145

24x96

26.5

159

24x96

22.5

157

24x96

18.5

148

26x96

28.7

143

26x96

24.37

146

26x96

20.

160

28x96

30.9

154

28x96

26.24

157

28x96

21.57

151

30x96

33.12

166

30x96

28.12

140

30x96

23.12

162

36x96

39.75

159

36x96

33.75

169

36x96

27.75

166

No. 26 (.906 Ibs. sq. ft.)

No. 27 (.843 Ibs sq. ft.)

No. 28 (.781 Ibs. sq. ft.)

J 24x72

10.87

152

24x72

10.12

151

24x72

9.37

149

26x72

11.78

153

26x72

10.96

153

26x72

10.15

152

28x72

12.68

152

28x72

11.81

153

28x72

10.93

153

30x72

13.57

149

30x72

12.65

151

30x72

11.71

152

36x72

16.3

146

36x72

15.18

151

36x72

14.06

155

24x84

12.68

152

24x84

11.81

153

24x84

10.93

153

26x84

13.73

151

26x84

12.78

153

26x84

11.84

153

28x84

14.79

148

28x84

13.77

15,1

28x84

12.75

153

30x84

15.85

152

30x84

14.76

147

30x84

13.67

150

36x84

19.03

154

36x84

17.7

159

36x84

16.4

148

24x96

14.5

145

24x96

13.5

148

24x96

12.5.

150

26x96

15.7

157

26x96

14.62

146

26x96

13.53

148

28x96

16.9

152

28x96

15.74

157

28x96

14.57

146

30x96

18.12

145

30x96

16.87

152

30x96

15.62

156

36x96

21.75

152

36x96

20.25

162

36x96

18.75

150

WEIGHTS AND GAUGES OF SHEET METALS

241

SHEET COPPER

TABLE OF WEIGHT PER SQUARE FOOT, AND THICKNESS, PER STUBS'

WIRE GAUGE.

Stubs'
Guage
(nearest
No.)

Thickness
in decimal
parts of
1 inch

Ounce
per
square
foot

14x48

ibs.

24x96
Ibs.

30x60

Ibs.

24x72
Jbs.

30x96
tba.

36x96
tbs.

30x120
Ibs.

.00537

1.16

3.12

6.24

.00806

1.F5

4.68

4.50

7 50

9.36

.0107

2.33

6.25

10.

12.

12.50

.0134

2.91

7.81

7.50

12.50

15.

15.62

.0161

3.50

9.37

15.

18.

18.74

.0188

4.08

10.93

10.50

17.50

21.

21.86

.0215

4.66

12.50

12.

20.

24.

25.

.0242

5.25

14.06

13.50

22.50

27.

28.12

.0269

5.83

15.62

15.

25.

30.

31.24

.0322

18.75

18.

30.

36.

37.50

.0430

9.33

25.

12.

40.

48.

50.

.0538

11.66

31.25

30.

50.

60.

62.50

.0645

14.

37.50

36.

60.

72.

75.

.0754

16.33

43.75

42.

70.

S4.

87.50

.0860

18.66

50.

48.

80.

96.

100.

.095

55.

52.50

87.50

105.

110.

.109

63.

61.

101.25

121.50

126.

.120

70.

67.

111.50

133.50

140.

.134

100

. . .

100

78.

75.

125.

150.

156.

.148

110

86.

82.50

137.50

165.

172.

.165

123

96.

92.

153.75

184.50

192.

.180

134

105.

100.50

167.50

201.

210.

.203

151

118.

113.50

188.75

226.50

236.

.220

164

128.

123.

205.

246.

256.

.238

177

138.

133.

221.25

265.50

276.

.259

193

151.

144.

241.25

289.50

302.

.284

211

165.

158.

263.75

316.50

330.

.300

223

174.

168.

278.75

334.50

348.

.340

253

198.

190.

316.25

379.50

396.,

These weights are theoretically correct, but variations must be expected in
practice.

242 WEIGHTS AND GAUGES OF SHEET METALS

APPROXIMATE WEIGHT OF SHEET ZINC.

Zinc
Numbers

Weight per
Square Foot,

Thickness in
decimals of an, 1
Inch.

American or
U. S. Gauge.

Average weight
per sheet 36x84
Pounds.

.37

.010 ( T ta)

7.77

.45

.012

9.45

.52

.014

.29

10.92

.60

.016

12.90

.67

.018

14.32

.75

.020 to)

17J6

.90

.024

20.00

.05

.028

22.84

.20

.032

25.20

.35

.036

28.52

.50

.040 ( 2 ' 5 )

31.50

.68

.045

35.28

.87

.050

39.27

2.06

.055

45.55

2.25

-060 GV)

16'

47.25

2.62

.070

55,02

3.00

.080

63.00

3.37

.090

13 1

70.77

3.75

.100 to)

78.75

4.70

.'125 (H)

98.70

9.40

.250 (K)

197.40

14.10

.375 (y 8 )

000

296.10

18.80

.500

0000000

37.60

1.000

WEIGHTS OF GALVANIZED PIPE AND
ELBOWS

SMOKE PIPE JOINTS 26* LONG.

24 GAUGE

7" Diam. Lock Seam 4 Ib. 8 oz.
8* Diam. Lock Seam 5 Ib. 2 oz.
9* Diam. Lock Seam 6 Ib. 2 o*.

26 GAUGE

7* Diam. Lock Seam 3 Ib. 9 o*,
8* Diam. Lock Seam . 4 Ib. 3 o.

ELBOWS 4 PIECE.
24 GAUGE

7* Diam.
8* Diam
9* Diam.

V Diam.
8* Diam.
9* Diam.

26 GAUGE

1 Ib. 11 oz.

2 Ib. 9 oz
.3 Ib. 8 oz.

1 Ib. 8 oz.

1 Ib: 14 o

2 Ib. 6 09.

WEIGHTS AND GAUGES OF SHEET METALS

243

NET WEIGHT PER BOX TIN PLATES.

Basis, 10x14, 225 Sheets; or, 14 x 20, 112 Sheets.

TRADE TEIJIM ......... 80 Ib 85 Ib

APPROXIMATE WIRE \ No. No.

GAUGE. . . .......... 33 32

Wt. pr. Bo*, Ibs ____ .' 80. 85

Size of Sheets Sheet* Ojor box. '

10 x!4. .. ......225 , 80 85

14 x20 ......... 112 80, 85

20 x28.... ..... 112 160 170

10 x20 ..... '....225 114 ,121

11 x22 ...... ...225 138 147

11^x23. ..:.'.. .225 151 161

12 x24... ......112 82 87

13 x!3. ...... .\225 97 103

13 x26. .. ... .. .112 97 103

14 x28 ........ .112 112 119

15 x!5 ......... 225 129 137*

16 x!6... ...... 225 146 155

17 x!7 ........ .^225 165 175

18 x!8.... ..... 112 93 98 ,

19 x!9 ..... ____ 112 103 110

20 x20. ........ 112 114 121

21 x21... .... . 112 126 134

22 x22... ..... 112 138 147

23 x23. .. ..;,.. 112 151 161

ll 164 175

112 193 205

112- 75 80
89
94

16 x20 ...... ...112 .91 97

14 x31 ......... 112 124 132

108

90 Ib 95 Jh 100 Ib 1C JXt IX IXX 1XIX IXXXX

No. No. No. No. No. No. No. No. No.

3; 31 30 30 28 28 27 26 25

90 95 100 107 128 135 155 175 195

24 x24...., .
26 x26...... .

14 x21.

112

14 x22..... .. ..112

84
88

90 95

180 190

129 136

156 164

170 179

93 98

109 115

126 133

145 153

165 174

186 196

104' 110

116 122

129" 136

142 150

156 164

170 179

185 195

217 229

85 89

95 100

99 105

103 109

140 147

115 121

100 107

200 214

143 153

172 184

189 202

103 110

121 129

140 150

161 172

183 196

206 221

116 124

129 138

143 153

158 169

172 184

189 202

204, 220

241 258

94 100

105 112

110 118

114 122

155 166

127 136

128 135

256 270

183 193

222 234

242 255

132 139

154 163

179 189

206 217

234 247

264 279

148 156

165 174

183 193

202 213

221 234

242 255

263 278

309 326

155 175 195

310 350 390

221 250 279

268 302 337

293 331 368

159 180 201

187 211 235

217 245 273

249 281 313

283 320 357

320 361 403

179 202 226

200 226 251

221 250 279

244 276 307

268 202 337

295 333 370

320 360 40 L

374 422 471

-COST OF TIN FOR STANDING SEAM ROOFING.

Size, 20x28 inches.
Price per box, per square foot and per hundred square feet.

When

8.3.

S. S.

When

S. S.

When

S. S.

Tin
Costs.

Roofing
Costs.

Roofing
Coets.

Tin

Costs.

Roofing
Costs.

Tin
Costa.

Roofing
Costs.

Box.

Sq. Ft.

Sq.

Box.

Sq. Ft.

Sq.

Box.

Sq. Ft.

Sq.

$ 6.00

.0162

$1.62

$12.50

.0337

$3.37

$19.00

.0513

$5.13

6.50

.0175

1.75

13.00

.0351

3.51

19.50

.0526

5.26

7.00

.0189

1.89

13 50

.0364

3.64

20.00

.0540

5.40

7 50

.0202

2.02

14.00

.0378

3.78

20.50

.0553

5.53

8.00

,0216

2.16

14.50

.0391

3.91

21.00

.0567

5.67

8.50

.0230

2.30

15.00

.0404

.04

21.50

.0580

5.80

9.00

.0243

2.43

15.50

.0418

.18

22.00

.0594

5.94

9.50

.0256

2.56

16 00

.0432

.32

22.50

.0607

6.07

10.00

.0270

2.70 ,

16.50

.0446

.46

23.00

.0621

6.21

10.50

.0283

2.83

17.00

.0459

.59

23 50

.0634

6.34

11.00

.0297

2.97

17.50

.0473

24.00

.0648

6.48

11.50

.0310

3.10

18.00

.0486

.86

12 00

.0324

3-24

18.50

.0500

5.00

The above estimates do not include cost of laying material

244

WEIGHTS AND GAUGES OF SHEET METALS

20x28 STANDING SEAM TIN ROOFING.

Table showing quantity of 20 x 28 tin required to cover a given number of
square feet with Standing Seam Tin Roofing.

In the following estimates all fractional parts of a sheet are treated as a full
sheet. Full size of sheet, 20 x 28, locked at ends. Covering surface, 474.9 square
inches, or 3.3 square feet.

Sheets
required

-I

Sheets
required

Sheets
required |

4ft

Sheets
| required |

Sheets
1 required |

1 Sheets
required

145

270

150

280

75"

155

290

160

300

165

310

170

320

175

330

100

180

340

103

185

350

106

100

190

360

109

105

195

370

112

110

200

115

210

120

220

125

230

130

240

135

250

140

260

...

A full box, 20 x 28, 112 sheets, will cover approximately 370 square feet.

SHEET
20-JC23"

29"x29J

STOCK SIZES HEATER PIPE TIN.
ROUND

V 4*x9*

8* 4*xlO|

9* 4*xl2

10* 4*xl4*

12* 4*xl7

SIZE OF SHEET NECESSARY TO MAKE 4 PC. ELBOWS
7* 12x23
8* 14x26
9* 14x29*
10* 15x32*
W 10*3*

MISCELLANEOUS TABLES

245

r l ?l ff "3" -T * iO iO <O O

P- i i 1 i 1 1 1

Cl lO T - I 1 1- O fO '-O Cl Cl I*

S Cl C> O CO .-O "* 1< S O ^ tO

'-O -H -*< t- O CO tO C>
'fj ?Z t- f- ' O O "TOO
Ot-t-OOKOO>0

f-^c*C'icicocoi-* < Tni3otootbt.~-t-GOQOC?*

**a

SSsiSSIlSSSll

oo oo t- o in ift

O O -f 30 CJ

to to t- t- t- eo

g s ?, s s ,t ri 5 fs r. o

i-ii-<Mc^ceoco-i<ii<oft

(o S to E- t-

O'-O

ci oo eo d 7" o to >- i^icir-jo

o 5 t-
to to to ;

lOCCCOcOCJICOt O -i* CO * lO
COOOgi^30COl^OCOt^O

o <ri to

IJ fl

cc vo

2isasSISIS315

11 : : :

^ 00

8SSoS?S^22

r1iH^-(C<(?jnClCOCOCO'<l< *<

: : : :

2 J

H 5

ClOOOO^*C1-^C*it-^OCOr- )

r-t-?iooc<m>oco-ocici

>-lp-li-li-(C4C4C)COCOCO?5'l>

: : : . . .

o d

a *

gSS5'SScoS3S ! " '

r-tiHi-li-lCSCMeMeNCOCOCO

H . .

O e =
2 too

W -

t- Cl O O O CO t- Cl O ;

CJ Cl -r< t- O -* to d i-l

; | ; i * * ;

w ,Hr-lrti-lCNC>^c1

: : ' : : : : :

10 tO

3 S g "* 5S L 2 * ' ' : : : : : : : : '' : :

** *" " "* rt ** C1 : t : :::::::

^w^coSSSo

-T tO

g^gw^g::::::;;:::;:::

S r-l

CO tO

IOtOt-0

-*oto

:*::::,'.

<*tO

J5 5 I:::"::::::

CO i

1 o 1

a a 4 a a a

to to <o to to to
*; . *; +j *? -J ^ *^ j

a a a a

to to to to

d d d d d. d d d d

COCOC0<^00

.s
I

246

MISCELLANEOUS TABLES

r-l<NCNJC^<MOJCOCO'*iOU><O

Q r-| 09 ^H GO rH

C<J M O-l <N CX| CO

r-l iH <M <N (N CO CO

!N C^l <N W IN CO

i-l (M <N <N

COCCO>--^'-lOOO<NCiOCOO
WCO^^WSWCOt-OOOOOSOrH

MISCELLANEOUS TABLES 247

TABLE OF DIAMETERS OF WIRE 1

IN DECIMAL PARTS OF AN INCH
As Represented by the Various Standard Gauges.

.No. of Wire>

Washburn and
Moen or
A. S. & W. Co.

X! .

American or
Brown and Sharpe

Birmingham, Stut
Peck. Stow AW.,
or British Standa

D. 8. Standard.*

[

000000

.46

.46875

00000

.43

.4375

0000

.393

r .454

.46 '

.454

.40625

.400

000

.362

.425

41ft

.425

.375

.372

.331

.38

-.365

.34375

.348

.307

.34

.324

.34

.3125

.32'

1.1

.283

.289

.28125

.300

,263

i284

.258

(284

.26562

.276

.244

.259

.229

.269

.25

.252

225

.238

.204

.238

.23437

.232

,207

.22

.182

.21875

,212

,192

.203

.162

1203

. ?0312

.192

177

.18

.144

.18

,1875

,176

.162

.165

.128

.165

.17187

,160

.148

.114

.148

. 15625

.144

.135

.134

.102,

.134

.14062

.128

.12

.091

.12

,125

.116

.105

.109

.081 :

.109

.10937

.104

.01)2

.095

.072

.095

.09375

.092

.08

.083

.064

.083

.07812

.080

.072

.057 !

.072

.07031

.072

.063

.065

.051

.065

.064

.054

.058

.045

.058

'.05625

.056

,047

.049

.040

.049

.05

.04B

.041

.04

.036'

.042

.04375

.040

.035

.032

.035

,0375

.036

.032

-.0315

.028

.032

.03437

.032

.028

.0295

.025

.028

.03125

.028

.025

.027

.023

.025

.02812

.024

.023

.025

.020

.022

.025

.022

.02

.023

.018

.02

.02187

.020

.018

.0205

.016

,018

.01875

.018

.017

.01875

.014

.016

.01719

.0164

.016

.0165

.01264

.014

.01562

.0149

.015

.0155

.01126

.013

.01400

.0136

\014

.0137.5

.01002

.012

.0125

.0124

.0135

;0122

,00893

,01

.01094

.0116

.013

.01125.

^00795

.009

.01016

.0108

,OJ1

.01025

,00708

.008

.00937

.0100

,01

.0095'-

'.-00630

.007

.00859

.0092

.0095

.009

/00561,

; ;005.

,00781

.0081

.009

.0075

.005

.<J04

.00703

.0076

.0085

.0065

.00445

.00664

.0068

.008

.0057

,00396

.00625

.0060

.0075

.005

.00353

.0052

.0045

.00314

M.t "i

J.0048

2 4 8

MISCELLANEOUS TABLES

.393

.362.

Fig. 189 Stubb's Wire Gauge.

MlSCELLA N EOUS TA IJLES

249

WEIGHT, STRENGTH AND SIZE OF WIRE.

Gauge

Diatn.

Approximate
Size.

Length
of 63 tbs.

Length

of 100

tbs.

Length

of 2000

tbs.

Length
of one
carload,
20,000
tbs.

Weight
100
feet

Weight
one
mile

Tensile
Strength

000

Ins.
.362
.331
.307
.283
.263
.244
.225
.207
.192
.177
.162
.148
.135
.120
.105
.092
.080
.072
.063
.054
.047
.041
.035

Inches.
3-8 in. scant
11-32
5-16
9-32

1-J
7-32

full

3-16 "
5-32 a

1-8 in. scant
3-32 "

1-16
1-32 full

Feet.
181
217

228

296

343

399

470

555

647

759

905

1,086

1,304

1,649

2,168

2,813

3,728

4,598

6.000

8,182

10,862

14,000

19,687

Feet.

288

344

361

471

545

634

747

881

1,028

1,205

1,437

1,724

2,070

2,618

3,425

4,464

5.-917

7,299

9,524

12,992

17,241

22,222

31,250

Feet.

5.759

6,886

7.320

9,425

10,905

12,674

14,936

17,621

20.555

24,096

28,734

34,483

41,408

52,356

68,493

89,286

118,343

145,985

190,476

259,740

344,827

444,444

fi25,OCO

Miles.

100

130

169

224

277

360

492

653

841

1,185

Lbs.

34.73

29.04

27.66

21.23

18.34

15.78

13.39

11.35

9.73

8.30

6.96

5.80

4.83

3.82

2.92

2.24

1.69

Lbs.

1,834

1.533

1,460

1.121

968

833

707

599

514

439

367

306

255

202

154

118

Lbs.

9,755

8,290

6.880

5,650

4,930

4,250

3,620

3040

2,510

2,220

1,840

1,560

1,280

1,000

800

668

456

352

264

208

160

128

104

Melting Points of Different Metals

Antimony 951 degrees

Bismuth 470 degrees

Brass 1900 degrees

Bronze 1692 degrees

Copper 2548 degrees

Glass 2377 degrees

Gold (pure) 2590 degrees

I ron (cast) 3479 degrees

I ron (wrought) 3980 degrees

Lead 504 degrees

Platinum 3080 degrees

Silver (pure) 1250 degrees

Steel 2500 degrees

Tin . 421 degrees

Zinc 740 degrees

Boiling Points of Various Fluids

Ether 100 degrees

Alcohol 173 degrees

Sul. Acid 240 degrees

Refined Petroleum 316 degrees

Turpentine 304 degrees

Sulphur > 570 degrees

Linseed Oil 640 degrees

Water 212 degrees

Water in Vacuum 98 degrees

2 5

MISCELLANEOUS TABLES

STANDARD SIZES OF REGISTERS.

Size of
Opening.
4x6
4x8
4x10

Size of
Opening.!
6 x 30
6 x 32
7x7

Size of
Opening.

12 X 14
12 X 15
12 X l6

Size of
Opening.
18x27
18 x 30
18x36

4x12

7x10

12 X 17

20 x 20

4x13
4x15

7x12
7X 14

12 X 18
12 X 19

2O X 23
20 X 24

4 x 18

8x8

12 X 2O

20 X 26

4 x 21

8x10

12 X 24

20 X 28

4x24
5x8

c v o

8x 12
8x14
8x 16

12 X 30
12 X 36
I4X 14

20 x 30
20 x 36

21 X 2Q

3 A y

r v T O

8x18

14 x 16

22 X 22

5 A 1U
SXI2

8x 20

I 4 X 18

22 X 24

s x 14

8x21

14 x 20

22 X 26

3 *

c x 16

8 x 24

14 X 22

22 X j8

5x18
6x6

8x30
9x9

14 x 24

16 x 16

22 X JO

24 x 24

6x8
6x9

9x12
9 x 13

16 x 18
16 x 20

24 X 27

24X30

6x10
6x 12
6 x 14
6x16

9x14
9x16
9x18

IO X IO,

16 X 22

16 x 24

16x28

16 x 30

24 x 32
24 x 36

27X27
27X38

6 x 18

10 X 12

16 x 32

30X30

6 x 20

10 x 14.

16 x 36

30 x 36

6 X22

6 x 24
6x28

10 x 16

10 x i8f

I X 20\
12 X 12

18 x 18
i8x 21
i8x 24

30x42
30x48

36 x 36

38x43

Made to order.

DIMENSIONS OF REGISTERS

Size of
opening,

Nominal

areaof
opening.

Effective
area of
opening,

Galv. Iron or

Extreme
dimensions of

Inches

Square
Inches

Inches

6x10

6/i x 10 e /ie

7 1 Viex llHia

8x10

8%/x 10%

9%x 11%'

8x12

8% x 12 5 / 8

9^*xl3%

8x15

120

8%xl5%

9^4xl6Hi

9x12

108

9'We x 12*7*6

10 7 /8Xl3 7 /8

9x14

126

9'Vi6xl4Hi6

10 7 /8Xl5 7 /8

10x12

120

10*710 x!2Hie

H lr /i6x 13 I5 /i

10x14

140

10 1 Wxl4 1 We

ll^/iexl^U

10x16

160

107

LOHix 16*^6

H lf >i6xl7 7 /

12x15

180

120

1294x15%

14Mox 17

12x19

228

152

12 3 /i x 1.9%

1 4 Vie- x 21

14x22

308

205

14 T /s x 22 T /s

16^x24^

15x25

375

250

15 7 /s x 25 7 /s

17tfx27K

16x20

320

213

16% x 20 7 <8

18 5 /iox22 5 /U

16x24

384

256

16 7 /8 X 24 7 /9

18^iex26%

20x20

400

267

20 15 /i6 x 20 lr >lo

22% x 22%

20x24

480

320

20 lf >io x 24 15 /ia

22% x 26 s /*

20x26

520

347

20 15 /ie x 26 ir >io

22^8 x 28%

21x29

609-

403

21 16 /iex29 15 /io

23%x31%

27x27

729

486

27 lc /i6x27 t5 /io

29% x 29%

27x38

1026

684

27 t( Ko x 38 16 /xo

29'% x 40%

30x30

900

600

30 1B Ae x 30 1B /m

32% x 32-%

Dimensions of different makes of registers vary
slightly. The above are for Tuttle & Bailey Mfg.
Co.'s manufacture.

MISCELLANEOUS TABLES

251

TABLE FOR SIZE OF CONDUCTORS.

Roof Area

Discharge per Dia. of Pipe

Area in

Insq. ft

sec. in cu. ft.

inches.

in. required.

I2,OOO

2.25

63.61 . . .

10,000

8 4 8

52-5 ...

9,000

50.26. ..

9,000

47-2 ...

8,000. . . .

42 ...

7,250. . . .

38.48...

7,000. . . .

3^-7 ...

6,000

3^-5 ...

5,250....

28.28...

5,000....

0.92

26.2 ...

4,000

0.74 ,.

21 , . . .

3,500....

0.70

19.63...

3,000. . . .

0.55 v ...

15.9 ...

2,500

0.45 .,...;

12.56...

2,000

0.37 ,

10.5 ...

1,225....

0.25

7.06...

1,000

O.l85

5-25...

900. . . .

0.166

47 ...

800. ...

0.15

4.2 ....

700....

O.I2

3-7 ...

600....

O.I I

.3-2 ..,

, 3

500. ...

O.O92 ,...

2.6

400. ...

0.074

2.1

300. ...

0.055

1.6 ...

200

0.037

1.0 ...

100,...

0.018

0.5 ...

Square

Feet of Surface in Round Grates

of Different

Diameters.

Inches.

Feet.

Inches.

Feet.)

13$..,..,.

26/, ...

27 ...

164

28 ...

4*.

28| ...

19 T 3 s

29$ ...

20&

3tVV ...

21$

31$ ...

22$

33 T 3 - ...

23]

34$ ...

244

35}|

25 / 6

2 5 2

MISCELLANEOUS TABLES

WEIGHTS AND MEASURES

Troy Weight.

'24 grains = I pwt.
20 [ .vis. = i ounce.
12 ounces r= I pound.

Used for weighing gold, silver
...id jewels.

Apothecaries' Weight.

20 grains = i scruple.
3 scruples = i dram
8 drams = I ounce.

12 ounces = i pound.

The ounce and pound in this
-are the same as in Troy weight.

Avoirdupois Weight.

2 7 IJ -32 grains = i dram,,
1 6 drams = i ounce.
1 6 ounces i pound.
25 pounds = i quarter.
4 quarters = i cwt.
2.000 Ibs. = i short ton.
2,240 Ibs. = i long ton. /

Dry Measure.

2 pints = i quart.
8 quarts =: i peck.
4 pecks = i bushel.
36 bushels = i chaldron.

Liquid Measure.

4 gills = i pint.
2 pints = i quart.
4 quarts = i gallon.

gallons = i barrel,
barrels = i hogshead;

Circular Measure.

60 seconds = i minute.
6o~minutes =r^ degree.
30 degrees = i sign.
90 degrees ~ i quadrant.
4 quadrants =12 signs.
360 degrees = i circle.

Long Measure.

12 inches = i foot.

3 feet = i yard.

5^2 yards = i rod.
40 rods = i furlong.

8 furlongs = i sta. .mile*

3 miles = i league.

Square Measure.

<T44 sq. inches = 'I sq. ft,
9 sq. feet = I sq. yard.

- - .

4OsSq. rods=-i rood.
/ 4 roods = i acre.
640 acres i sq. mile.

lime Measure.

60 seconds = i minute
60 minutes = i hour.
24 hours = i day.
7 days = i week.
28. 29, 30 or 31 days = I "cal-
endar- month (30 days = i
month* in computing interest)

365 days = i year.

366 days = i leap year.

MISCELLANEOUS TABLES

253

TABLE OF MILLIMETERS AND
DECIMALS,

Millimeter

Decimal
.02952
.03937
.04687
.04921
.05900
.06250
.07812
.07874
.08858
.09375
.09843.
.11811
.125
.12795
.1378
.14062
.157-18
.17717
.18750
.19685
.21654
.23622
...25

Millimeter

8
9.

10
11

13
14
15

19
22
25.

Decimal
.25591
.27559
.28125
.3125
.31496
.35433
.375
.3937
.43307
.4375
.47244
.5

.51181
.55118
.59055
.59375
.625
.74803
.75

.86614
.875
'.98425

Capacity in Gallons and Barrels of Round Tanks or Cisterns

of Different Diameters 12" Deep.
Diameter of Tank. Gallons. Barrels.

2 feet 23.4 .....

2* " 36.72 H

3 " 52.87 If

3* " 71.96 2

4 " 94.00 3

4* " 118.97 3

5 " 14G.88 4$

5J " 177.72 5f

6 " 211.50 6$

6* " 248.22 7$

7 " 287.85 9

7 " 330.48 lOfc

8 " 376.00 12

8J " 424.46 , 13J

9 " 475.87 15^

9J " 528.75 16|

10 " 587.04 18f

11 " 710.88 22J

12 " . ...846,00.., ...26*

254

MISCELLANEOUS TABLES

Horse Power of Belting

A simple rule for ascertaining transmitting power of belting without first computing speed
r per minute that it travels, is as follows:

Multiply diameter of pulley in inches by its number of revolutions per minute, and thia
product by width of the belt in inches; divide the product by 3,300 for single belting, or by
2. 100 for double belting, and the quotient will be the amount of horse power that tan be safely
transmitted.

TABLE FOR SINGLE LEATHER, FOUR-PLY RUBBER AND FOUR-PLY

COTTON BELTING, BELTS NOT OVERLOADED

1 Inch Wide, 800 Feet per Minute = 1 Horse Power,

Speed

WIDTH OF BELTS IN INCHES

in feet

per
Minute

H. P

H. P.

H P.

H. P.

H, P.

H. P.

400

\\/ 2

600

2ki

73^

.ion

13/^

800

2 *

1000

3?4

6V 4 '

7)^

12}4

\iy 2

22H

1200

3 ^

4. l /2

1500

5?'4

7X2

l?i*

U VS

18%

22 H

26 H

33%

1800

\y t

6^4

13j^

22^

31/^

403^

2000

7^2

12 J^

2400

2800

10 V 2

\iy^

3000

7 t

ilk'

18%

22^

37^

52^

67'H

3500

\iy 2

52*^

-79

4000

io' 4

100

4500

11*4

22 y 2

102

114

5000

37H

62^

87 y 2

100

112

125

Double leather, six-ply rubber or six-ply cotton belting will transmit 50 to 75 per cent, more
power than is shgwn ia Ibis table. (One incti wide, 550 feet per minute = one horse power.)

MISCELLANEOUS TABLES

255

TABLE OF COMMON FRACTIONS 1
AND DECIMALS.

Fraction

Vie
%4
%2

%-i

%4
5 /32

J %4

2 %4

27 /64

Decimal
.015625
.03125
.046875
.0625
.078125
.09375
.109375
.125
.1*0625
.15625
.171875
.1875 '
.203125
.21875
.234375
.25

..265625
.28125
.296875
.3125
; 328125.
.34375
.359375
i.375
1.390625
,40625
.421875
.4375
.453125
.46875 '
.484375

Fraction

33 /64
17 /32
3 %4

19 /32
; 3 %4

4 iL
4 %I

JJie
23 /32*'

47,4.

49 /64
23 /32

13 /i6

57 /64
29 /32
5 %4
15 /16
>V 6 4
81 /32

Decimal
.515625
.53125
.546875
.5625
.578125
.59375
.609375
.625
.640625
.65625
.67*1875
.6875
.703125
.71875
.734375
.75

.765625
.78125
.796875
.8125
.828125
.84375
.859375
.875
.890625
.90625
.921875
.9375
.953125
.96875
.984375

256

MISCELLANEOUS TABLES

TABLE OF A~REAS AND CIRCUMFERENCES OF CIRCLES

Diam. Cir. Area
Inches Inches Sq. In.

Diam. Cir. ^."Area
[nches Inches q. In.

y s .393 .012

16 50.26 201.06

54 169.6 2290.2

X .785 .049

16X 51.83' 213.82

55 172.7 2375.8

H 1-178 .110

17 53.40- 226.98

56 175.9 2463.

X 1.570 .196

17X 54.97 240.52

57 179. 2551.7

% 1.963 .307

18 56.54 254.46

58 182.2 2642.

X 2.356 .442

18X 58.11 268.80

59 185.3 2733 9

Y 8 2.748 .601

19 59.69 283.52

60 188.4 2827.4

1 3.141 .785

19X61-26 298.64

61 191.6 2922.4

\Ys 3.534 .994

20 62.83 314.16

62 194.7 3019.

IX 3.927 1.227

20X 64.40 330.06

63 197.9 3117.2

\Ys 4.319 1.484

21 65.97 346.36

64 201. 3216.9

IX 4.712 1.767

21X 67.54 563.05

65 204.2 3318.3

iy s 5.105 2.073

22 69.11 380.13

66 207.3 3421.2

IK 5.497 2.405

22X 70.68 397.60

67 210.4 3525.6

IJi 5.890 2.761

23 72.25 415.47

68 213.6 3631.6

2 6.283 3.141

23X 73.82 433.73

69 216.7 3739.2

2X 7.068 3.976

24 75.39 452.39

70 219.9 3848.4

2X 7.854 4.908

24X 76.96 471.43

71 233. 3959.2

2K 8.639 5.939

25 78.54 490.87

72 226.1 4071.5

3 9.424 7.068

26 81.68 530.93

73 229.3 4185.3

3X 10.21 8.295

27 84.82 572.55

74 232.4 4300.8

3X 10.99 9.621

28 87.96 615.75

75 235.6 4417.8

3K 11.78 11.044

29 91.10 660.52

76 238.7 4536.4

4 12.56 12.566

30 94.24 706.86

77 241.9 4656.6

4X 14.13 15.904

31 97.38 754.76

78 245. 4778.3

5 15.70 19.635

32 lOO.o 840.24

79 248.1 4901.6

5X 17-27 23.578

33 103.6 855.30

80 251.3 5026.5

6 18.84 28.274

34 106.8 907.92

81 254.4 5153.

6X 20.42 33.183

35 109.9 962.11

82 257.6 5281.

7 21.99 38.484

36 113. 1017.8

83 260.7 5410.6

7X 23.56 44.178

37 116.2 1076 2

84 263.8 5541.7

8 25.13 50.265

38 119.3 1134.1

85 267. 5674.5

8X 26.70 56.745

39 122.5 1194 5

86 270.1 5808.3

9 28.27 63.617

40 125.6 1256 6

87 273.3 5944.6.

9X 29.84 70.882

41 128.8 1320.2

88 276.4 6082. 1>

10 31.41 78.539

42 131.9 1385.4

89 279.6 6221.1

10X 32.98 86.590

43 135. 1452.2

90 282.7 6361.7

11 34.55 95.033

44 138.2 1520.5

91 285.8 6503.8

11X 36.12 103.86

45 141.3 1590.4

92 289. 6647.6

12 37.69 113.09

46 144.5 1661.9

93 292.1 6792.9

12X 39.27 122.71

47 147.6 1734.9

94 295.3 6939.7

13 40.84 132.73

48 150.7 1809.5

95 298,. 4 7088.2

13X 42.41 143.13

49 153.9 1885.7

96 301.5 7238.2

14 43.98 153.93

50 157. 1963.5

97 304.7 7389 8

14X 45.55 165.13

51 160.2 2042.8

98 307.8 7542,9

15 47.12 176.71

52 163.3 2123.7

99 311. 7697.7

15X 48.69 188.69

53 166.5 2206.1

100 314,1 7853.9

MISCELLANEOUS TABLES 257

Rules Relative to the Circle

To Find Circumference:

Multiply diameter by 3.1416.
Or divide diameter by 0.3183.

To Find Diameter:

Multiply circumference by 0.3183.
Or divide circumference by 3.1416.

To Find Radius:

Multiply circumference by 0.15915.
Or divide circumference by 6.28318.

To Find Size of an Inscribed Square:

Multiply diameter by 0.7071.

Or multiply circumference by 0.2251.

Or divide circumference by 4.4428.

To Find Side of an Equal Square:

Multiply diameter by 0.8862.

Or divide diameter by 1.1284.

Or multiply circumference by 0.2821.

Or divide circumference by 3.545.

Square:

A side multiplied by 1.4142 equals diameter of its cir-
cumscribing circle.

A side multiplied by 4.443 equals circumference of its
circumscribing circle.

A side multiplied by 1.128 equals diameter of an equal
circle.

A side multiplied by 3.545 equals circumference of an
equal circle.

Square inches multiplied by 1.273 equals circle inches of
an equal circle.

To Find the Area of a Circle:

Multiply circumference by one-quarter of the diameter.
Or multiply the square of diameter by 0.7854.
Or multiply the square of circumference by 0.07958.
Or multiply the square of one-half diameter by 3.1416.

To Find the Area of an Ellipse:

Multiply the product of its axes by .785398.

Or multiply the product of its semi-axes by 3.14159.

Contents of cylinder area = area of end X length.

Contents of wedge = area of base X one-half altitude.

Surface of cylinder length X circumference -f- area of both
ends.

Surface of sphere = diameter squared X 3'I4!6, or = diame-
ter X circumference.

Contents of sphere = diameter cubed X 0.52.36.

Contents of pyramid or cone, right or oblique, regular or
irregular = area of base X one-third altitude.

Area of triangle = base X one-half altitude.

Area of parallelogram = base X altitude.

Area of trapezoid altitude X one-half the sum of parallel
sides.

258

MISCELLANEOUS TABLES

CUBICAL CONTENTS OF ROQMS

HAVING CEILINGS OF THE FOLLOWING HEIGHTS

.Floor Area

8 ft.

8% ft.

Oft.

Ofc.ft.

10 ft.

10V& it.

11 ft.

12 ft.

108

105

110

115

120

102

108

114

120

126

132

144

108

115

122

128

135

142

148

162

120

128

135

142

150

158

16,5

180

132

140

149

156

165

173

18-1

198

144

153

162

171

ISO

189

198'

210

3V6

104

110

116

123

129

'134'

147

3y 2

112

119

126

133

140

147

154

168

126

134

142

149

158

165'

173

189

140

149

158

166

175

184

192

210

154

164

173

182

193

202

211'

231

168

179

ISO

199

210

221

231

252

3V 2

6M.

182

193

205

216

22S

239

250

273

196

208

221

232

245

257

2G9

294

128

136

144

152

100

168

176

192

144

153

162

171

ISO

189

19$

216

160

170

ISO

190

200

210

220

240

5V6

176

187

198

209

220

231

242

264

192

204

216

228

240

252

264

288

6y a

208

221

234

247

260

273

2S6

312

224

238

252

266

250

294

308

336

7.%

240

255

270

285

300

315

330

360

256

272

288

304

320

336

352

3S4

4y a

162

172

182

192

203

213

2^)9

243

4y 2

180

191

203

213

225

236

247

270

4%.

198

210

223

235

248

260

272

297

4y 2

216

230

243

2.56

270

2S4

297

324

4y 2

ey 2

234

249

263

277

293

307

321

351

4y 2

252

268

284

299

315

331

346

378

.7%

270

287

304

320

338

354

371

405

4y 2

288

306

324

342

360

378

396

432

iy 2

8Ms

306

325

344

363

383

402

420

459

4y 2

324

345

384

405

425

445

4S6

200

212

225

237.

250

263

275

300

.6%

220

234

248

261

275

289

302

330

240

255

270

285

300

315

330

360

260

276

293

308

325

341

357

390

280

297

315

332

350

368

3S5

420

7V6

300

319

338

358

375

394

412

450

320

340

360

380

400

420

440

480

sy 2

340

361

3S3

403

425

446

467

510

360

382

405

427

450

473

495

540

380

404

428

451

475

499

522

570

400

425

450

475

500

525

550

600

242

257

272

287

303

318

332

363

264

281

297

313

330

347

363

396

5tf

286

304

322

339

358

375

393

429

308

327

347

365

385

404

423

462

330

351

371

391

413

433

453

495

5y 2

352

374

396

418

440

462

4S4

523

374

397

421

444

468

491

514

561

sy 3

396

421

446

470

495

520

544

504

418

444

470

496

523

549

574

627

MISCELLANEOUS TABLES

259

CUBICAL CONTENTS OF ROOMS

HAVING CEILINGS OF THR FOLLOWING HEIGHTS

Floor Area

8 ft.

8% ft.

9ft.

9% ft.

10ft.

10% ft

lift.

12ft.

440

468

495

522

550

578

605

660

10%

462

491

520

548

578

606

635

693

4&4

514

545

574

605

635

665

726

288

306

324

342

360

378

396

432

312

332

351

370

390

410

429

468

336

357

378

399

420

441

462

604

360

383

405

427

450

473

495

540

384

408

432

456

480

504

528

576

408

434

459

484

510

536

561

612

432

459

486

513

540

567

594

648

456

485

513

541

570

599

627

684

480

510

540

570

600

630

660

720

10 y 3

504

536

567

598

630

662

693

756

528

561

594

627

660

693

726

792

11%

552

587

621

655

690

725

759

828

576

612

648

684

720

756

792

864

338

359

380

401

423

444

464

507

364

387

410

432

455

478

500

546

390

414

439

463

488

512

636

685

416

442

468

494

520

546

572

624

6y 2

442

470

497

524

553

580

607

663

468

497

527

555

585

615

643

702

494

525

556

586

618

648

679

741

520

553

585

617-

650

683

715

780

10 y 2

546

580

614

648

683

717

750

572

608

644

679

715

751

786

S58

11%

598

035

673

710

748

785

822

897

624

663

702

741

780

819

858

956

i2y 2

650

691

731

771

813

853

893

975

ey 2

676

718

761

802

845

887

929

1014

392

417

441

465

490

515

539

588

420

446

473

498

525

651

677

630

8 .

448

476

504

532

560

688

616

672

476

506

536

5.65

50G

654

714

504

536

557

59-8

630

662

693

756

532

565

599

631

665

698

731

798

560

595

630

665

700

736

770

840

10%

588

625

662

698

735

772

808

882

616

655

693

731

770

809

847

924

11%

644

684

725

764

806

845

885

966

672

714

756

798

840

882

924

1008

12%

700

744

788

831

875

919

962

1050

728

774

819

864

910

956

1001

1092

13%

756

803

851

945

992

1039

1134

784

833

882

931

980

.029

1078

1176

450

478

506

534

563

591

618

675

480

510

540

670

600

630

660

720

510

642

574

005

638

669

701

766

540

574

608

641

675

709

742

810

570

606

641

676

713

748

783

855

600

638

675

712

750

788

825

900

10%

630

669

709

748

788

827

866

945

660

701

743

783

825

866

907

990

11%

690

733

776

819

863

906

948

1035

260 MISCELLANEOUS TABLES

CUBICAL CONTENTS OF ROOMS

HAVING CEILINGS OF THE FOLLOWING HEIGHTS

Floor Area

8 ft.

8V^ ft.

9 ft.

9Vfe ft.

10 ft.

10% ft.

lift.

12ft.

720

765

810

855

900

945

990

1080

12%

750

797

844

890

938

984

1031

1125

780

829

878

926

975

1024

1072

1170

13 1/ 2

810

861

911

961

1013

1063

1113

1215

l/o

840

893

945

997

1050

1103

1155

1260

l /2

14%,

870

924

979

1033

1088

1142

1196

1305

V 2

000

956

1013

1068

1125

1181

1237

1350

512

544

576

608

640

672

704

768

8y 3

544

578

612

646

680

714

748

816

576

612

648

684

720

756

792

864

608

646

684

722

760

798

836

912

640

680

720

760

800

840

880

960

ioy 2

672

714

756

798

840

882

924

1008

704

748

792

836

880

924

968

1056

11 /2

736

782

828

874

920

966

1012

1104

768

816

864

912

960

1008

1056

1152

12%

800

850

900

950

1000

1050

1100

1200

832

884

936

988

1040

1092

1144

1248

is y 2

864

918

972

1026

1080

1134

1188

1296

896

952

1008

1064

1120

1176

1232

1344

14%

928

986

1044

1102

1160

1218

1276

1392

960

1020

1080

1140

1200

1260

1320

1440

is y 2

992

1054

111G

1178

1240

1302

1364

1488

1024

1088

1152

1216

1280

1344

1408

1536

578

614

650

686

723

759

794

867

612

650

689

726

765

803

841

918

646

686

727

767

808

848

888

969

680

723

765

807

850

893

935

1020

8y 2

iov

714

759

803

847

893

937

981

1071

748

795

842

888

935

982

1028

1122

11%

782

831

880

928

978

1026

1075

1173

8y 4

816

867

918

969

1020

1071

1122

1224

8V 2

12%

850

903

95$

1009

1063

1116

1168

1275

8V 2

884

939

995

1049

1105

1160

1215

1326

13%

918

975

1033

1090

1148

1205

1262

1377

sy 2

952

1012

1071

1130

1190

1250

1309

1428

sy 2

14%

986

1048

1109

1170

1233

1294

1355

1479

sy 2

1020

1084

1148

1211

1275

1339

1402

1530

sy 2

15%

1054

1120

1186

1251

1318

1383

1449

1581

sy 2

1088

1156

1224

1292

1360

1428

1496

1632

8y 2

16%

1122

1192

1262

1332

1403

1473

1542

1683

sy 2

1156

1228

1301

1372

1445

1517

1589

1734

648

689

729

769

810

851

891

972

684

727

770

812

855

898

940

1026

720

765

810

855

900

945

990

1080

10%

756

803

851

897

945

992

1039

1134

792

842

891

940

990

1040

1089

1188

11%

828

880

932

982

1035

1087

1138

1242

864

918

972

1026

1080

1134

1188

1296

12%

900

956

1013

1068

1125

1181

1237

1350

936

995

1053

1111

1170

1229

1287

1404

13%

972:

1033

1094

1154

1215

1276

1336

1458

1008

1071

1134

1197

1260

1323

1386

1512

14%

1044

1109

1175

1239

1305

1370

1435

1666

MISCELLANEOUS TABLES

261

CUBICAL CONTENTS OF ROOMS

HAVING CEILINGS OF THE FOLLOWING HEIGHTS

Floor Area

8 ft.

8% ft.

9 ft.

9& ft.

10 ft.

10 Vz ft.

H ft.

12 ft.

1080

1148

1215

1282

1350

1418

1485

1620

15 %

1116

1186

1256

1325

1395

1465

1534

1674

1152

1224

1296

1368

1440

1512

15S4

1728

ioy a

1188

1262

1337

1410

1485

1559

1633

I7t>2

1224

1301

1377

1453

1530

1607

1683

1836

17 y a

1200

1339

1418

1496

1575

1654

1732

1890

1206

1377

1458

1539

1620

1701

1782

1944

9y 2

722

767

812

857

903

948

992

1083

760

808

855

902

950

998

1045

1140

9y 2

10 y 2

798

848

898

947

998

1047

1097

1197

836

888

940

992

1045

1097

1149

1254

9y 2

11%

874

929

983

1038

1093

1147

1201

1311

9y,

912

969

1026

1083

1140

1197

1254

1368

12 y 2

950

1009

1069

1128

11S8

1247

1306

1425

988

1050

1111

1173

1235

1297

1358

1482

9V 2

i3y a

1026

1090

1154

1218

1283

1347

1410

1539

1064

1131

1197

1263

1330

1397

1463

1596

9y 2

14 y 2

1102

1171

1240

1308

1378

1446

1515

1653

1140

1211

1282

1353

1425

1496

1567

1710

15%

1178

1252

1325

1398

1473

1546

1619

1767

1216

1292

1368

1444

1520

1596

1672

1824

9y 2

16 y a

1254

1332

1411

1489

1568

1646

1724

1881

9y 2

1292

1373

1453

1534

1615

1696

1776

1938

9v 2

17%

1330

1413

1496

1579

1663

1746

1828

1995

9y 2

1368

1454

1539

1624

1710

1796

1S81

2052

9y 2

18Va

1406

1494

1582

1669

1758

1845

1933

2109

9y 2

1444

1534

J.625

1714

1805

1895

1985

2160

800

850

900

950

1000

1050

1100

1200

10%

840

893

945

997

1050

1103

1155

1260

880

935

990

1045

1100

1155

1210

1320

11%

920

978

1035

1092

1150

1208

1265

1380

960

1020

1080

1140

1200

1260

1320

1440

i2y a

1000

1063

1125

1187

1250

1313

1375

1500

1040

1105

1170

1235

1300

1365

1430

1560

13%

1080

1148

1215

1282

1350

1418

14H5

1620

1120

1190

1260

1330

1400

1470

15*40

1680

14%

1160

1233

1305

1377

1450

1523

1595

1740

1200

1275

1350

1425

1500

1575

1650

1800

15 y a

1240

1318

1395

1472

issa

1628

1705

1800

1280

1360

1440

1520

1600

1680

1760

1920

16%

1320

1403

14S5

1567

1650

1733

1815

1980

1360

1445

1530

1615

1700

1785

1870

2040

17 y 2

1400

148S

1575

1662

1750

1838

1925

2100

1440

1530

1620

1710

1800

1890

1980

2160

18%

1480

1573

1665

1757

1850

1943

2035

2220

1520

1615

1710

1805

1900

1995

2090

2280

19%

1560

1658

1755

1852

1950

2048

2145

2340

1600

1700

1800

1900

2000

2100

2200

2400

968

1029

1089

1149

1210

1271

1331

1452

1056

1122

1188

1254

1320

1386

1452

1584

1144

1216

1287

1358

1430

1502

1573

1716

1232

1309

1386

1463

1540

1617

1694

1848

1320

1403

1485

1567

1650

1733

1815

1980

1408

1496

1584

1672

1760

1848

1936

2112

262

MISCELLANEOUS TABLES

CUBICAL CONTENTS OF ROOMS

HAVING CEILINGS OF THE FOLLOWING HEIGHTS

Floor Area

8 ft.

sy 2 ft.

9ft.

9% ft.

10ft.

10% ft.

11 ft.

12ft.

1496

1590

1683

1776

1870

1964

2057

2244

1584

1683

1782

1881

1980

2079

2178

2376

1672

1777

1881

1986

2090

2195

2299

2508

1760

1870

1980

2090

2200

2310

2420

2640

1848

1964

2079

2194

2310

2426

2541

2772

1936

2057

2178

2299

2420

2541

2662

2904

1152

1224

i29e

1368

1440

1512

1584

1728

1248

1326

1404

1482

1560

1638

1716

1872

1344

1428

1512

1596

1680

1764

1848

2016

1440

1530

1620

1710

1800

1890

1980

2160

1536

1632

1728

1824

1920

2016

2112

2304

1632

1734

1836

1938

2040

2142

2244

244S

1728

1836

1944

2052

2160

2268

2376

2592

1824

1938

2052

2166

2280

2394

2508

2736

1920

2040

2160

2280

2400

2520

2640

2880

2016

2142

2268

5394

2520

2646

2772

3024

2112

2244

2376

-2508

2640

2772

2904

3168

2208

2346

2484

2622

2760

2898

3036

3312

2304

2448

2592

2736

2880

3024

3168

3456

1352

1437

1521

1605

1690

1775

1859

2028

1456

1547

1638

1729

1820

1911

2002

2184

1560

1658

1755

1852

1950

2048

2145

2340

1664

1768

1872

1976

2080

2184

2288

2496

1768

1879

1989

2099

2210

2321

2431

2652

1872

1989

2106

2223

2340

2457

2574

2808

1976

2100

2223

2346

2470

2594

2717

2964

2080

2210

2340

2470

2600

2730

2860

3120

2184

2321

2457

2593

2730

2867

3003

3276

2288

2431

2574

2717

2860

3003

3146

3432

2392

2542

2961

2840

2990

3140

3289

3588

2496

2652

2808

2964

3120

3276

3432

3744

2600

2763

2925

3087

3250

3413

3575

3900

2704

2873

3042

3211

3380

3549

3718

4056

1568

1666

1764

1862

1960

2058

2156

2352

1680

1785

1890

1995

2100

22J05

2310

2520

1792

1904

2016

2128

2240

2352

2464

2688

1904

2023

2142

2261

2380

2499

2618

2856

2016

2142

2268

2394

2520

2646

2772

3024

2128

2261

2394

2527

2660

2793

2926

3192

2240

230

2520

2660

2800

2940

3080

3360

2352

2499

2646

2793

2940

3087

3234

3528

2464

2618

2772

2926

3080

3234

3388

3696

2576

2737

2898

3059

3220

3381

3542

3864

2688

2856

3024

3192

3360

3528

3696

4032

2800

2975

3150

3325

3500

3675

3850

4200

2912

3094

3276

3458

3640

3822

4004

4368

3024

3213

3402

3591

3780

3969

4158

4536

3136

3332

3528

3724

3920

4116

4312

4704

1800

1913

2025

2137

2250

2363

2475

2700

1920

2040

2160

2280

2400

2520

2640

2880

2040

2168

2295

2422

2550

2678

2805

3060

2160

2295

2430

2565

2700

2835

2970

3240

2280

2423

2565

2707

2850

2993

3135

3420

2400

2550

2700

2850

3000

3150

3300

3600

MISCELLANEOUS TABLES

CUBICAL CONTENTS OF ROOMS

HAVING CEILINGS OF THE FOLLOWING HEIGHTS

Floor Area

8 ft.

8V6 ft.

9 ft.

9% ft.

10 ft.

10% ft.

11 ft.

12 ft.

2520

2678

2835

2992

3150

330&

3465

3780

2640

2805

2970

3135

3300

3465

3630

3960

2760

2933

3105

3277

3450

3623

3795

4140

2880

3060

3240

3420

3600

3780

3960

4320

3000

3188

3375

3562

3750

938

4123

4500

3120

3315

3510

3705

3900

4095

4290

4680

3240

3443

3645

3847

4050

4253

4455

4860

3360

3570

3780

3990

4200

4410

4620

5040

3480

3698

3915

4132

4350

4568

4785

5220

3600

3825

4050

4275

4500

4725

4950

5400

2048

2176

2304

2432

2560

2688

2816

3072

2176

2312

2448

2584

2726

2856

2992

3264

2304

2448

2592

2736

2880

3024

3168

3456

2432

2584

2736

2888

3040

3192

3344

3648

2560 .

2720

2880

3040

3200

3360

3520

3840

2688

2856

3024

3192

3360

3528

3696

4032

2816

2992

3168

3344

3520

3696

3872

4224

2944

3128

3312

3496

3680

3864

4048

4416

3072

3264

3456

3648

3840

4032

4224

4608

3200

3400

3600

3800

4000

4200

4400

4800

3328

3536

3744

3952

4160

4368

4576

4992

3456

3672

3888

4104

4320

4536

4752

5184

3584

3808

4032

4256

4480

4704

4928

5376

3712

3944

4176

4408

4640

4872

5104

5568

3840

4080

4320

4560

4800

5040

6280

5760

3968

4216

4464

4712

4960

5208

5456

5952

4096

4352

4806

4864

5120

53T6

,'5632

6144

2592

2754

2916

3078

3240

3402

3564

3888

2880

3060

3240

3420

3600

3780

3960

4320

3169

3366

.3564

3762

3960

4158

4356

4752

3456

3672

3888

4104

4320

4536

4752

5184

3744

3978

4212

4446

4680

4914

5148

5616

4032,

4284

4536

4788

5040

5292

5544

6048

4320

4590

4860

5130

5400

5670

5940

6480

4608

4896

5184

5472

5760

6048

6336

6912

4896

5202

5508

5814

6120

,6426

6732

7344

5184

5508

5832

6156

6480

6804

7128

7776

3200

3400

3600

3800

4000

4200

4400

4800

3520

3740

3960

4180

4400

4620

4840

5280

3840

4080

4320

4560

4800

5040

5280

5760

4160

4420

4680

4940

5200

5460

5720

6240

4480

4760

5040

5320

5600

5880

6160

6720

4800

5100

5400

5700

COOO

6300

6600

7200

5120

5440

5760

60SO

6400

6720

7040

7680

5440

5780

6120

6460

6800

7140

7480

8160

5760

6120

6480

6840

7210

7560

7920

8640

6080

6460

6840

7220

7600

7980

8360

9120

6400

6800

7200

7600

8000

8400

8800

9600

264

CHAPTER XX
RECIPES AND MISCELLANEOUS DATA

To Clean Brass.

Mix in a stone jar one part of nitric acid, and one-half part
of sulphuric acid. Dip the brasswork into this mixture, wash
it off with water, and dry with sawdust. If greasy, dip the
work into a strong mixture of potash, soda and water, to re-
move the grease, and wash it off with water.

To Clean Zinc.

Dissolve a teaspoonful of oxalic acid in a half pint of water,
and wash the zinc with the solution, after which the zinc
should be washed off with water, and polished witha woolen
cloth and dry whiting.

To Clean Out Water Front That is Filled With Rust.

Take the water front out and place it in a forge or in a
furnace, and heat it. This will bake the deposit that has col-
lected in the water front, and will loosen much of it.

After being sufficiently heated, it should be removed, and
tapped with a hammer to dislodge the rust that clings to the
surface. In this way the water front may be entirely cleaned.

To Remove Lime Deposit in a Water Front.

After disconnecting the range, take out the water front, and
immerse it in muriatic acid, where it should remain two or
three hours, according to the amount of deposit and the
strength of the acid. On removing the water front from the
acid, plunge it into water and wash thoroughly.

Government Recipe for Cleaning Brass.

The following is said to be the method used in government
arsenals for cleaning brass. Use two parts of common nitric
acid to one part of sulphuric acid. The acid should be kept
in a stone jar. Articles that are to be cleaned should be first
dipped into the acid, then into clear water, and then dried
with sawdust. This cleaning process will change the brass
at once to a brilliant color. If the metal to be cleaned is

RECIPES 265

greasy, the grease should be first removed, by dipping the
article in a strong solution of potash and soda in warm water.

To Prevent Rusting of Iron and Steel.

Cover the surface with a mixture made of I Ib. melted lard,
I oz. camphor, and black lead to give it the desired color.
By covering the surface with this mixture, the metal will be
protected for an indefinite length of time, and it may be
cleaned off with naptha or benzine.

To Prevent Polished Iron From Rusting.

Cut a small amount of beeswax with benzine, and supply
it to the surface of the polished iron. This has long been in
use in protecting Russia iron through the damp season, and
has been found very effective.

To Clean Zinc.

Zinc is generally cleaned by scouring it with fine sand and
pumice. A bath of two parts of nitric acid, and one part
sulphuric acid will also give results. The bath should be
followed by a water bath.

After cleaning zinc, a permanent bright surface may be
obtained by giving it a coat of transparent varnish.

How to Clean Steel Tapes.

Cover the tape with crude oil and rub down with No. O
steel wool. This will clean the rust from the tape without
injury to the etching. If the tape is not very rusty it may
be brightened up by rubbing with powdered pumice or dry
cement.

To Paint Galvanized Iron.

There is very often difficulty in making paint stick to gal-
vanized iron. The galvanized iron should first be cleaned
with a solution of ammonia and water. When the iron has
dried off, it is ready for the paint, which will then adhere
without any difficulty.

To Keep Plaster of Paris From Setting Too Quickly.

Sift the plaster into the water, allowing it to soak up the
water, without stirring, which would admit air and cause
the plaster to set quickly. If desired to keep the plaster
soft for a much longer time, add to every quart of water,
one-half teaspoonful of common cooking soda. This will gain
all the time necessary.

266 RECIPES

To Solder Galvanized Iron.

Be sure to have a very hot soldering copper in soldering
galvanized iron, even though it has to be returned often.
When the copper is not sufficiently hot, it simply solders to
the surface of the zinc, which is liable to peel off. In having
the iron hot, the soldering gets to the iron, and the solder
and zinc are more thoroughly fused together and to the iron.

A Flux for Tin Roofing.

A good roofing flux is made of two parts of binnacle oil,
and one part of rosin. Rosin, cut with alcohol, and applied
with a swab, also is very satisfactory.

Fluxes for Various Metals.

For cast and malleable iron and steel, borax and sal-am-
moniac. For brass, gun metal and copper, chloride of zinc,
sal-ammoniac or rosin. For zinc, chloride of zinc. For tinned
iron, chloride of zinc or rosin. For lead, tallow for coarse
solder, and rosin for fine solder. For pewter, gallipoli oil.

To Keep Soldering Coppers in Order While Soldering With

Acid.

In a pint of water dissolve a piece of sal-ammoniac about
the size of a walnut. Whenever the copper is taken from the
fire, dip the point into the liquid, and the zinc taken from the
acid will run to the point of the copper and can then be shaken
off, leaving the copper bright.

A Good Soldering Acid.

In i Ib. muriatic acid, dissolve all the zinc it will take up,
thereby forming zinc chloride. Add to the zinc chloride I
ounce of sal-ammoniac. Reduce with the same amount of
water there is of the acid.

A Non-Corrosive Soldering Paste.

An excellent paste for soldering purposes can be made of
one part by weight, of chloride of zinc, and sixteen parts of
some such grease as vaseline, thoroughly mixed together.
The chloride of zinc is known to every tinsmith, and is made
by dissolving in muriatic acid, as much zinc as the acid will
eat up.

RECIPES 267

Waterproof Glue.

Use one part India rubber, and three parts gum shellac,
by weight.

Dissolve each in separate vessels, in ether, and under a
mild heat.

After being completely dissolved, mix the two, and keep
in an air-tight vessel. This mixture will withstand both hot
and cold water, and nearly all kinds of acids.

Common glue, mixed with varnish or linseed oil, applied
to the parts to be glued after they have been warmed, will
be permanent and with stand water.

How to Make Putty.

Mix dry whiting with raw linseed oil. For glazing, add
about 10 per cent, of white lead to increase durability. In
hot climates a little cottonseed oil should be added to prevent
the putty from drying too quickly.

Fireproof Cement for Furnaces.

A cement or mortar that will close up cracks in furnaces
to keep the gas from escaping can be made as follows: Mix
together seventy-five parts of wet fire clay, three parts of
black oride manganese, three parts of white sand and one part
of powdered asbestos. Thoroughly mix by adding enough
water to make a smooth paste. Apply over the cracks and
when dry it will be as hard as iron and stick like glue.

Rust Joints.

To make a good rust joint, use 5 Ibs. iron filings, and I oz.
each of sal-ammoniac and flour of sulphur. Do not use a
greater amount of sal-ammoniac as it is likely to generate
heat, and thereby cause expansion. A stronger but slower
setting cement may be made by using the following propor-
tions of ingredients: 12 Ibs. iron filings, 2 ozs. sal-ammoniac,
and i oz. flour of sulphur.

Friction of Water in Passing Through Pipes.

Friction of Water in pipes is approximately equal to the
square of the velocity at which it is flowing.

Therefore the greater the velocity, the greater the friction
will be. The friction of water in passing a 90 degree bend is
as great as the friction of a length of such pipe 38 times as
great as the diameter. The friction of water in small pipes is
much greater than in large pipes, as in the small pipe a much
larger proportion of the water comes in contact with the sides
of the pipe.

268 RECIPES

Heating Capacity of Stove and Furnace Coils.

When a stove or furnace heating coil is so placed as to be
covered by the fire, it is estimated that it will take about one
square foot of heating surface in the coil to heat fifteen gallons
of water in the boiler.

If the coil is to be of J4 inch pipe, it will require 45 inches
of pipe for each 15 gallons of tank capacity. If a I inch coil
is to be used, it will require 3 feet of pipe for 15 gallons.

In the case of furnace coils that are placed in the combus-
tion chamber, above the fire, the heating power of the coil
will not be so great, for the reason that when the feed door
is opened, or fresh coal is thrown onto the fire, the heating
of the coil is checked. Under these circumstances it would
not generally be safe to figure on heating much over 10 gal-
lons per square foot of heating surface.

INDEX I

Furnace Heating

Air, Amount Required for Ventilation Ill

Air, Amount Moved by Fan 115

Air, Composition of 109

Air Filter 55

Air Moistening and Humidity 121

Air Moistening, Investigation of Results Obtained 124

Air Moistening, Methods of 125-129

Air Moistening, Methods of Testing 129

Air Moistening, Reduction of Fuel 123

Air, Recirculation of 132

Air, Vitiation of no

Apparatus for Controlling Drafts 161

Application of Heating Rules 80

Appliances for Fuel Saving 147

Area and Height of Chimney Flue 12-14

Area of Cold Air Duct 32, 33

Automatic Air Damper 82, 83, 84

Automatic Draft Regulators 159

Auxiliary Heaters, Types of 140

Auxiliary Heating, Arrangement of 141-143

Auxiliary Heating from Furnaces 138

Auxiliary Heating, Methods of 139-145

Auxiliary Heating, Methods of Installation 144

Bends 100

Black Sheets, Weights of 239

Boiling Point of Fluids 249

Brass, Government Recipe for Cleaning 264

Brass, To Clean 264

Capacity of Exhaust Fans 1 18

Carbonic Acid Gas, Parts in the Air 109, in

Casing and Top of Furnace 24- 26, 98

Cement Construction, Determining Quantities 176

270 FURNACE HEATING

Cement Construction for Furnace Men 173

Cement Construction, Methods Used 177

Cement Construction, Tools Required 175

Cement for Furnaces, Fire-Proof 267

Character and Size of Chimney Flue 9

Character and Size of Furnace 23, 24

Chimney Flue 9

Chimney Flue, Area and Height 12, 14

Chimney Flue, Character and Size 9

Chimney Flue, Construction 10, 1 1, 12

Chimney Flue, Draft Gauge 15, 16

Chimney Flues, Location 17, 18

Chimney Flues, Sources of Trouble 18, 19

Chimney Flues, Table of Sizes 17

Chimney Flue, Table of Velocities 16

Chimney Flue, Tests of 15, 17

Chimney Flue Troubles 19, 20

Circle, Areas of 256

Circle, Circumferences of 256

Circle, Rules Relative to -. 257

Coal, Composition of 165

Coal, The Universal Fuel 171

Coke Air Moistener 125

Coke, How Produced 165

Cold Air, Methods of Supplying 29

Cold Air Duct, Area of 32, 33

Cold Air Filter 31

Cold Air Pit for Furnace 27

Cold Air Supply for Furnaces 29, 33

Combustion of Fuel 163

Composition of Air 109

Composition of Coal 165

Concrete Mixtures 173

Conductors, Table of Sizes 251

Construction of Chimney Flue 10, 1 1, 12

Construction, Practical Methods of 85

Correct Tests of Chimney Flue IS" 1 /

Cost of Hard Firing 101

Cost of Heat Regulation 156

FURNACE HEATING 271

Cubical Contents of Rooms 258-263

Draft Gauge for Testing Chimney Flue 15, 16

Draft Regulators 159

Ducts for Recirculation of Air, Method of Connecting. . . 136

Dust Discharge 97

Effect of High Winds 135

Efficiency of Exhaust Fans 117

Estimate, Form for 77, 78

Estimating Furnace Work 70, 77, 79

Estimating Sizes of Pipe 47

Example of Good Furnace Work 103, 107

Exhaust Fans, Efficiency of 117

Exhaust Fans, Horse Power Required 1 18

Exhaust Fans, Speed and Capacity 1 18

Exhaust Fans, Table of Capacities 119

Expansion Tank, Size and Location 144

Factors of Good Furnace Work 97

Fan-Blast Heating 61

Fan-Blast Heating with Trunk Line Piping 65

Filter for Cold Air 31

Filtering Chamber 55

Fittings for Furnace Heating 37, 38

Flues, Location of 42

Fluids, Boiling Points of 249

Fractions and Decimals 255

Fuel 163

Fuel, Air Required for Combustion 166

Fuel, Analysis of 165

Fuel, Chemical Components and Combustion 163

Fuel Saving Devices 146

Furnace, Auxiliary Heating from 138

Furnace Casing and Top 24, 26, 98

Furnace, Character and Size 23, 24

Furnace, Coil in Fire Pot 139

Furnace Coils, Heating Capacity of s 268

Furnace, Cold Air Pit 27

Furnace, Cold Air Supply 29, 33

Furnace Fittings 37, 38

Furnace, Foundation for 97

272 FURNACE HEATING

Furnace Heating, Arguments for 22, 23

Furnace, Heating Surface 101

Furnace Heating, History of 21

Furnace, Installation of 44

Furnace, Location of 26

Furnace, Methods of Setting 26, 30

Furnace Pipe 36, 37, 99

Furnace Ratings 34, 35

Furnace, Size Required 33~35

Furnace, The 21

Furnace Work, Estimating 70

Furnace Work, Factors of Good 97

Furnace Work, Importance of High Class IO2

Galvanized Iron, to Solder 266

Galvanized Iron, to Paint 265

Galvanized Pipe and Elbows, Weights of 242

Galvanized Sheets, Gauges and Weights 240

Glue, Water Proof 267

Grates, Diameter of 251

Grates, Square Feet of Surface 251

Heater Pipes, Stock Sizes of Tin for 244

Heating, Fan-Blast 61

Heating Rules, Intelligent Application of 80

Heating, Trunk Line 57

Heat Regulation, Cost of 156

Herr Humidifier 126

High Class Work, Importance of IO2

History of Furnace Heating 21

Horse Power Required for Exhaust Fans Il8

Humidity and Air Moistening 121

Hygrometer, The 129

Importance of High Class Furnace Work IO2

Installation of the Furnace 44

Iron, to Prevent Rusting 265

Location for Rotating Register ioo

Location of Chimney Flue 17, 18

Location of Furnace 26

Location of Registers 40, 41

Melting Points of Metals. -. 249

FURNACE HEATING 273

Metals, Fluxes for 266

Metals, Melting Points of 249

Method of Estimating Furnace Work 70

Methods of Setting Furnace 26, 30

Methods of Ventilating ill

Millimeters and Decimals 253

Miscellaneous Data and Recipes 264-268

Mixing Concrete 174

Opposition to Re-circulation of Air 134

Origin of Thermostats 148

Plaster of Paris, To keep from Setting 265

Practical Methods of Construction 85

Propeller Fan, Use for Ventilation 114

Putty, How to Make 267

Radiator, Size of 138

Ratings of Furnaces 34, 35

Recipes and Miscellaneous Data 264-268

Re-circulation of Air 132

Re-circulation of Air, Method of Connecting Ducts for. 136

Rectangular Tanks, Capacities in U. S. Gallons 245

Registers, Dimensions oi ...._, 250

Registers, Location of 40, 41

Registers, Side Wall 38, 39

Registers, Size of 42, 43

Registers, Table of Standard Sizes 250

Regulators, Electric 149

Regulators, How to Attach 156

Regulators, Non-Electric 150

Rooms, Cubical Contents of 258-263

Rotating Register, Location of 100

Round Tanks, Capacities in Gallons 246

Rules, Tables and Information 237

Rust Joints, How to Make 267

School House Warming and Ventilating 91

Sheet Copper, Weights and Thickness . : 241

Sheet Zinc, Weight of 242

Side Wall Registers 38, 39

Size of Furnace Required 33, 35

Size of Registers 42, 43

274 FURNACE HEATING r

Size of Warm Air Pipes 40

Soldering Acid 266

Soldering Coppers. To Keep in Order 266

Soldering Paste 266

Speed of Exhaust Fans 118

Stack for Ventilating 1 12, 1 13

Standing Seam Roofing, Table of Costs 243

Standing Seam Roofing ; Tin Required 244

Steel Sheets, Weights of 238

Steel Tapes, To Clean 265

Steel, To Prevent Rusting 265

Stove Coils, Heating Capacity of 268

TABLES :

Air Moved by Propeller Fan 115

Areas and Circumferences of Circles 256

Cost for Standing Seam Roofing 243

Diameters of Wire 247-248

Gallons in Round Tanks 246

Gauges and Weights of Black Sheets 239

Gauges and Weights of Galvanized Sheets 240

Horse Power of Belting 254

Exposures 74

Common Fractions and Decimals 255

Millimeters and Decimals 253

Chimney Flues, Sizes 17

Pipes, Flues and Registers, Sizes 74

Weights and Measures 252

Size of Conductors 251

Size of Registers 43

Stock Sizes Tin for Heater Pipes 244

Tin Required for Standing Seam Roofing 244

U. S. Gallons in Rectangular Tanks 245

Weights of Copper Sheets 241

Weights of Galvanized Pipe and Elbows 242

Weights of Sheet Zinc 242

Weights of Steel 238

Weight of Tin Plates 243

Weight, Strength and Size of Wire 249

Wire, Diameters of 247-248

FURNACE HEATING 275

Tanks, Capacity in Gallons and Barrels 253

Temperature Regulation 146

Temperature Regulation, Cost of 156

Temperature Regulation, Electric Regulators 149

Temperature Regulation, Non-Electric Regulators 150

Temperature Regulation, Value of 154

Thermostats, How to Sell 155

Thermostats, Method of Attaching 156

Thermostats, Origin of 148

Tin Plates, Weight Per Box 243

Tin Roofing, Flux for 266

Trunk Line Heating 57

Velocity in Chimney Flues 16

Ventilation 22, 23, 108

Ventilation by Use of Propeller Fan 144

Ventilation, Fresh Air Required in

Ventilation, Methods of 1 1 1

Ventilating Stack 1 12, 1 13

Warm Air Pipes, Size of 40

Warming and Ventilating School Houses 91

Water, Friction in Passing through Pipes 267

Water Front, to Clean Out Rust 264

Water Front, to Remove Lime Deposit 264

Weights and Measures, Table of 252

Weights of Black Sheets 239

Weights of Galvanized Pipe and Elbows 242

Weights of Galvanized Sheets 240

Weights of Sheet Copper 241

Weights of Sheet Zinc 242

Weights of Steel 238

Weight of Tin Plates per Box 243

Wire, Diameters of 247, 248

Wire, Weight, Strength and Size 249

Zinc, To Clean 264, 265

INDEX II

Furnace Fittings

Adjustable Elbows, Positions for Setting 186

Air Tight Joints in Wall Pipes 217

Angle of Collar Determined by Deflector 179

Angles in Warm Air Elbows, Methods of Finding. . . .232-236

Area in Wall Pipes, How it is Decreased 217

Areas of Round Pipes and Registers, Table of 203

Asbestos Covering in Wall Pipe, Protecting 217

Bonnet and Deflector 179

Bonnets or Hoods, Conical 179

Boots, Offset 21 i -216

Boots or Wall Pipe Starters 207

Box-Shaped Starter Connecting Two Registers 207

Box-Shaped Starters, Nine Styles of 208

Casings, Furnace 180, 181

Casing Rings, Spacing - 180

Cast Iron Shoe for Cold Air Connection 199

Circular Joints, Locking , . . . 189

Circular Joints, Seaming 188

Cold Air Duct Elbows, Finding True Angles in 231

Cold Air Duct Elbows, Frictionless 201

Cold Air Duct Elbows, Seaming 202

Cold Air Shoe Connection, Cast Iron for 199

Cold Air Shoe for Inside Air Connection 198

Cold Air Shoes 196

Collars Joining a Flat Top Casing 180

Collar on Pitched Bonnet 181

Collar on Straight Bonnet 184

Collar to Register Box, Joining 204

Collars, Various Styles of 181

Collar Joining a Straight Bonnet 180

Combination Header on Register Box 206

Compound Wall Pipe Offsets 220222

FURNACE FITTINGS 277

Conical Bonnets or Hoods 179

Connecting Sheet Metal Shoe Casing 199

Connecting Shoes to Center of Furnace 198

Connecting Shoes to Round Cold Air Pipes 197

Covering Wall Pipes with Paper 217

Deflector on Conical Bonnet 179

Degree of Miter Line for Four-Piece Elbow 187

Determining Size of Register Box 203

Diameter of Main Pipe, Determining Unknown 224

Double Offset 220, 222

Double Wall Pipes 218

Elbow, Frictionless Cold Air Duct 201

Elbow, Oval, on the Flat 189

Elbow, Oval, Three-Piece on the Sharp 189

Elbow Patterns, Methods Employed 232

Elbow, Reducing 190

Elbows 185, 186, 187

Elbows, Cold Air Duct, Finding True Angles in 231

Elbows Less Than Right Angles 188

Elbows, Oval 188

Elbows, True Angles in, Finding 232-236

Equal Fork in Trunk Line Fitting 224

Fastening Collar to Straight Bonnet 184

Finding True Angles in Cold Air Duct Elbows 231

Finished Collar for Flat Casing Top 185

Finished Collar for Pitched Bonnet 185

Fittings for Trunk Line Heating Systems 223

Fittings Used in Furnace Piping 218

Flat Casing Top, Finished Collar for 185

Flat Top Casing, Collars Joining 180

Floor Register Box in Four Pieces 204

Floor Register Box in One Piece 204

Floor Register Boxes 203

Flues, Metal, in Brick Walls 218

Fork, Equal, in Trunk Line Fitting 224

Fork of Equal Prongs in Trunk Line System 225

Fork, Unequal, in Trunk Line Fittings 226

Forks for Trunk Line Systems 224-231

Four-Piece 90 Degrees Elbow, Rule for 186

278 FURNACE FITTINGS

Frictionless Cold Air Duct Elbows 201

Frictionless Starters 207-212

Furnace Casings 181

Furnace Fittings, Single Wall, Twenty-Six Styles of... 219

Furnace Piping, Fittings Used in 218

Header, Combination, on Register Box 206

Header, Round 193

Joining Collar to Register Box 204

Locking Circular Joints 189

Metal Flues in Brick Walls 218

Methods of Finding True Angles in Cold Air Elbows. . .232-236

Miter Line for Four-Piece Elbow, Finding Degree of. 187

Obtaining Radii for Curves 201

Offset Boots 211-216

Offset, Double 220, 222

Oval Elbow on the Sharp, Three-Piece 189

Oval Elbows 188

Pitched Bonnet, Collar for 181, 185

Positions for Setting Four-Piece Adjustable Elbow 186

Pronged Fork, Three Equal in Trunk Line System 228, 230

Pronged Fork, Three Unequal in Trunk Line System... 229

Protecting Asbestos Covering in Wall Pipe 217

Radii for Curves, Rule for Obtaining 201

Reducing Elbow 190

Reducing Joint, Short Rule for . . 223

Reducing T, Riveting 197

Reducing T-Joint 195

Risers, Wall Pipes or 217

Riveted Joints in Tees 196

Riveting Reducing T 197

Round Header 193

Round Pipes and Registers, Table of 203

Round to Oval Frictionless Starter 207

Rule for Developing Four-Pieced 90 Degree Elbow 186

Rule for Reducing Joint 223

FURNACE FITTINGS 279

Seaming Circular Joints 188

Seaming Cold Air Duct Elbows 202

Setting Four-Piece Adjustable Elbows 186

Shoe, Cast Iron, for Cold Air Connection 199

Shoe, Cold Air, for Inside Air Connection 198

Shoe Connecting to One Side of Furnace 19^)

Shoe, Sheet Metal for Rectangular Pipe 198

Shoes, Cold Air 196-201

Shoes, Connecting to Furnace Casing 199

Shoes, Connecting to Center of Furnace 198

Shoes for Round Cold Air Pipes, Connecting 197-198

Short Rule for Reducing Joint 223

Single Wall Furnace Fittings, Twenty-Six Styles of. . 219

Straight Bonnet, Collar on 184

Spacing the Casing Rings 180

Starter, Box Shaped, Connecting Two Registers 207

Straight Bonnet, Collars Joining 180

Straight Bonnet, Fastening Collar on 184

T-Joint Between Pipes of Equal Diameter 192

T- Joint Between Pipes of Unequal Diameter 193, 194

T-Joint, Reducing 195

Table of Areas of Round Pipes and Registers 2*03

Tees, Riveted Joints in 196

Three Equal Pronged Fork in Trunk Line System 228

Three-Piece Oval Elbow on the Flat 189

Three-Piece Oval Elbow on the Sharp 189

True Angles in Cold Air Duct Elbows, Finding 231

True Angles in Warm Air Elbows, Finding 232-236

True Angles in Warm Air Elbows, Finding with Line

and Bevel 235

Trunk Line Fittings, Equal Fork in 224

Trunk Line Fittings, Unequal Fork in 226

Trunk Line Heating Systems, Fittings for 223

Two-Pronged Fork for Trunk Line System 225

Two-Pronged Fork, Unequal, Determining the Unknown

Diameter in 227

Unequal Fork in Trunk Line Fittings 226

Unequal Three-Pronged Fork in Trunk Line System. . . . 229

Unknown Diameter of Main Pipe, Determining 224

280 FURNACE FITTINGS

Wall Pipe Offsets, Compound 220-222

Wall Pipe Starters 207

Wall Pipes, Covering with Paper 217

Wall Pipes, How Area is Decreased in 217

Wall Pipes or Risers 217

Wall Pipes, Securing Air Tight Joints in 217

SHEET METAL

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Efficiency of the Exhaust Fan.

Use of the Two-Way Mixing Valve and the Automatic Damper.
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Chapter i. Terms and Definitions 15 pages.

Chapter II. Drawing Instruments and Materials 13 pages.

Chapter III. Linear Drawing 6 pages.

Chapter IV. Geometrical Problems 35 pages.

Chapter V. Principles of Pattern Cutting 25 pages.

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Tools and Methods of Obtaining Pattern 3-26

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Index 263-267

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