February, 1912 
HOUSE AND GARDEN 
35 
case if such rooms were heated by warm air through registers. 
Any of the three types of heating apparatus, steam, hot-water 
or hot-air, will serve the end of indirect heatingsuccess being 
dependent upon the ability of the engineer to realize the inherent 
disabilities of each and to design the apparatus along lines which 
will favor such disabilities arid give advantage to the plan of the 
strong points in each. 
Whichever type of apparatus is selected the expense for fuel 
in indirect heating remains about the same. The efficiency of the 
best examples of the different types of heaters will vary but little, 
and considerations of durability and first cost are the principal 
ones. There are some points of difference between steam or hot- 
water and furnace heating that are worth considering. 
In the former the radiators or source of heat may be placed 
near the registers and losses by radiation from long warm air 
pipes avoided, also the delivery of heat through short pipes con¬ 
necting the indirect radiators with the registers is more to be de¬ 
pended upon than in the case 
of the hot-air furnace cen¬ 
trally located in the cellar 
with pipes of greatly varying 
length and some of the regis¬ 
ters necessarily quite remote 
from the source of heat, viz., 
the furnace. 
As previously noted, toilet 
and bathrooms should be 
heated by direct radiators; 
likewise pantries, back halls, 
kitchens (when a gas range 
is the type used) and many 
rooms not occupied by any 
number of hours consecutive¬ 
ly by persons physically in¬ 
active, can with considerable 
economy in fuel be heated by 
direct radiation. 
In short, the heating of the 
entire house by the indirect 
method is from any consid¬ 
eration unnecessary and will 
not be as satisfactory as the 
composite of direct and in¬ 
direct as indicated. 
The cause of failure in 
heating apparatus, in almost 
every case, arises from the 
the same misconceptions on 
the part of the house-builder 
as result in the production of an architectural blot when the 
architect s services are “economized” and the carpenter who takes 
the contract designs ( ?) the house. 
A house built along the lines of stock sizes of lumber and 
window frames may be habitable, but if competition among the 
heating contractors is to decide the selection of heating appa¬ 
ratus it is almost a certainty that the acceptance of the lowest bid 
will result in a condition which will render the house 
uninhabitable. 
The design of the heating apparatus should be dissociated 
from the scramble for the heating contract, and this can only be 
accomplished by the selection an engineer per se: one who has 
his professional reputation at stake only. 
In indirect heating, the introduction of outdoor air through 
the cold and warm air pipes entails the entrance of dust from 
the street, unless special provision is made for the filtration of 
the air through screens of cheesecloth or deflecting the air cur¬ 
rents so as to promote the deposit of dust in a chamber before 
the air is allowed to enter the ducts located in the basement. 
Elaborate mechanisms called air-washers would hardly come 
within the investment scope of the average house, but simple 
inexpensive devices will prove very effective and require but a 
few minutes of the engineer’s time in the planning. 
The importance of removing the dust from the air is at once 
apparent to anyone who has noted the results of medical investi¬ 
gation of disease germs. 
Humidity of the air is next in importance to dust removal, and 
here again the simplicity of method that would be in keeping with 
the running expense of the average house is to be sought. What¬ 
ever expedient may be resorted to in this connection, no receptacle 
containing water for evaporation should go longer than forty- 
eight hours without a thorough cleaning; this is hygienically of 
greater importance than fresh water with which to make the tea. 
In mechanical detail, as to that part of the indirect heating 
apparatus above the basement, it is important for the house 
builder to reach an early decision to adopt it in order that his 
architect may, while the plans are still in embryo, provide spaces 
for the proper heating flues, 
with all registers in the walls 
and none in the floors where 
they become receptacles for 
dust which will be dessicated 
by heat and menace the ol¬ 
factories. 
Should the term indirect 
heating here used lack defini¬ 
tion in the mind of the lay 
reader, a word along this line 
may not be amiss in closing. 
The two processes of Nature 
by which heat is dispensed 
from a heated body are con¬ 
vection and radiation, the for¬ 
mer signifying the absorption 
of heat by air brought into 
direct contact with a heated 
body and the latter the com¬ 
munication of heat from a 
heated body or substance to 
another by means of invisible 
rays which do not affect the 
temperature of the air 
through which they pass. 
Indirect heating is accom¬ 
plished by the exclusive means 
of convection or the medium 
of air brought into contact 
with heated surfaces (either 
radiators or furnaces placed 
in the basement). It is one of the best methods known. 
A radiator, stove or fireplace in an inhabited room constitutes 
the means of direct heating, although in case of the former two, 
both convection and radiation obtain. 
The points noted might be amplified by reference to the inter¬ 
esting facts that the open fire heats almost exclusively by radia¬ 
tion, while a stove burning freely heats by radiation about 90 per 
cent, and by convection 10 per cent. A radiator at about 170° 
Fahrenheit heats by radiation about 45 per cent, and by convection 
55 per cent. 
The laws governing light and radiant heat are the same: the 
intensity decreases as the square of the distance from the source 
increases. With these laws of heating engineering proved and 
accepted it will be readily seen that the heating question is not a 
matter of guesswork or experiment, and the engineer previous to 
installing a system can compute its needs and make provision for 
them. The materials considered are all of constant efficiency, so 
there is no reason why the indirect system should not, if installed 
by competent engineers, meet the heating problem in an ideal 
manner. 
Where steam or hot-water radiators are used in indirect heating they 
may be placed as near the registers as desired and thus secure uniform 
temperatures 
