HOUSE AND GARDEN 
December, ign 
qualities that go to make up the most pleasant, healthful and 
economical method procurable, but at the present time steam¬ 
heating is much superior to hot-water in several particulars, which 
will be noted. 
The “mild, pleasant, summer-like” quality of the heat from hot- 
water radiators so frequently urged in favor of hot-water heating 
has led many people to conclude that this desirable condition is 
due to the water contained in and circulated through the system, 
whereas these agreeable and healthful conditions are due entirely 
to the moderate temperatures of the hot-water radiators, which to 
all intent and purpose might as well be filled with molasses, hot¬ 
air, gas or vapor of the same temperature. The only effect upon 
the air of the room exerted by the hot-water radiator is to warm 
it gradually and steadily, instead of “violently” as with pressure 
steam heating. The water in the system contributes no moisture 
or other element to the air of the room; just temperature. 
The chief objection to hot-water heating consists in the im¬ 
possibility of quickly increasing and reducing the temperature of 
the house; particularly in the latter case, which occasionally en¬ 
tails the necessity of opening windows to allow the excess heat to 
escape. Water is capable of holding so much “heat in suspen¬ 
sion,” that it becomes at once a most intractable medium to 
control. 
For instance, and for the sake of comparison with steam, a 
hot-water apparatus comprising 600 square feet of heating sur¬ 
face in the radiators would contain altogether about 225 gallons 
or 1,880 lbs. of water. If this water were let into the system 
from the street main at 40° and^ heated to an average of 180° 
temperature, the whole quantity would contain about 263,200 
British Thermal Units: B. T. U. (the unit of measure of heat) 
representing under average conditions the burning of about 33 
lbs. of coal. 
A steam-heating apparatus comprising 600 square feet in radi¬ 
ator surface would contain about 50 gallons of water and 25 cubic 
feet (about 1 lb. avoirdupois) of steam. Under atmospheric 
pressure (212 0 ) this amount of water and steam would contain 
55.380 heat units, representing a consumption of about 7 lbs. of 
coal. 
In the hot-water radiators and pipes alone, there would be con¬ 
tained about 230,000 heat units, costing 29 lbs. of coal. In the 
steam radiators and pipes there would be about 1,150 heat units 
costing about 1-6 lbs. of coal. In short, about 180 times as much 
:apital (sinking fund) is invested in the heating medium when 
water is the medium 
as when steam is the 
medium. 
Provided there 
were no s u d d e n 
changes in our cli¬ 
mate, the above facts 
would signify no ad¬ 
vantage in steam¬ 
heating, but as it oc¬ 
casionally happens 
that the outdoor tem¬ 
perature will rise 
twenty to thirty de¬ 
grees in two hours, 
the need of quickly 
cooling the radiators 
becomes apparent. 
With steam-heating 
this can be done 
without loss in a few 
The improved vapor systems bring the steam minutes by closing 
in at the top of the radiator. It flows stead- the valves and al- 
ily and obviates all “knocking in the pipes” lowing the steam to 
condense, but with 
hot-water heating 
the large amount of 
heat in the radiators 
cannot be gotten rid 
of without the loss 
incident to opening 
the windows and al¬ 
lowing it to escape. 
Steam-heating is 
familiarly under¬ 
stood to refer to the 
use of steam de¬ 
livered into the radi¬ 
ators by pressure at 
not less than 212 0 
temperature, and this 
form of steam-heat¬ 
ing is not as desir¬ 
able as hot-water 
heating except in The steam radiator is not placed where ne- 
the one particular cessity demands, but can be located where 
noted above. lt can heat > ncom * n g c °ld air 
For the practical 
purposes of this article, steam may be said to be (as commonly 
understood) the vapor of boiling water which is at 212 0 F. in 
an open vessel at the sea level and at, say 160 0 F. in an open 
vessel at the top of Pike's Peak or any similar altitude where the 
weight or pressure of the earth’s atmosphere is sufficiently re¬ 
duced to let the vapor (steam) get away from the water. 
To make available the lower temperatures possible with the 
production of steam is at once to render steam as a heating me¬ 
dium the equal of hot-water in the mild salubrity of the house 
and economy of fuel, and its superior in flexibility of control. 
The one desideratum in the undertaking is a partial vacuum 
within the heating system, said vacuum corresponding with or 
the equivalent to a reduction of the atmospheric pressure sur¬ 
rounding us and everything about us. Water will boil and 
vaporize in a complete, “perfect vacuum” at about 90° F., but 
a partial vacuum permitting vaporization (the production of 
steam) at from 150° F. to 180 0 F. meets all requirements of 
agreeable and hygienic warming of the house. 
Simple devices bearing quite numerous different trade marks, 
are in practical use at the present time, which make the phe¬ 
nomenon of steam at any temperature from 150° to 212 0 a simple 
accomplishment; likewise devices variously called “graduation, 
modulation,” etc. Valves are today in common vogue which per¬ 
mit a mean temperature of the radiator much lower than 150°, so 
that as wide a range in the temperature of the radiating surface 
is possible with steam as with water, below the advisable maxi¬ 
mum of 180 0 . 
To secure the desirable qualities of hot-water heating as well 
as to avoid its undesirable features, an apparatus should compre¬ 
hend the possibility of an almost continuous state of partial 
vacuum, so that the high temperature of pressure steam in the 
radiators will seldom occur; and any apparatus which contem¬ 
plates the necessity of frequent recourse to steam pressure as a 
means of securing the degree of vacuum necessary to low tem¬ 
perature steam is deficient to the degree of said frequency. 
The prospective builder of the house should understand that 
his interest and comfort as the future dweller therein are not 
conserved by the fact that “smaller radiators will do the work” 
than are required for hot-water heating, when the use of these 
smaller radiators contemplates the use of high temperature steam 
during cold periods of weather, at which times it is the custom to 
exclude as much out-door fresh air as possible. 
(Continued on page 401.) 
