Evening star. [volume] (Washington, D.C.) 1854-1972, 1883-11-07
MOISTURE In ROOMS.
SOine Practical Suggestions with Refer.
ence To Its Regulation.


Prof, C. F. Bracket of Princeton president
the New Jersey state board of health, gives, in
the sixth annual report Of the state board of
health OF New Jersey, brief paper, entitled
Hints with Reference to the Regulation Of
Moisture in Rooms" from which the following
extracts are taken:
Under conditions ordinarily favorable to
health, it is found that - per cent of the heat
given OFF by the body escapes by radiation, AS
by evaporation from the skin, 72 by eyapora-
ton from the lungs, 2.5 By heating the air from
breathing and 1.S by the solid and liquid ex-
creta. Ii is thus seen that about % per cent of
all the heat which leaves the body passes off by
evaporation. IT, now, such conditions super
vene as shall tend to Increase or diminish this
evaporation, corresponding disturbances in the
system result and. though it possesses powers
OF compensation which are calel into action bv
such disturbances. their exercise NAV greatly
interfere with our vocations comfort and
health Now. the quantity of water which is
required to completely Saturate given space
with vapor is dependent upon the temperature
OF the space alone. it being exactly the same
whether air be present or not.
Moreover. the amount is for every given de-
gree OF temperature, definite. so that. having
once been reached. no more can be taken up.
Thus. If one pound of air at 800 Fair.
We're saturated with moisture it would contain
-0039 pounds of water. If. now, the whole
We're heated to 42o Fair. il would no longer be
saturated since at this temperature pound of
air would be capable of holding 00J6l pounds.
Merely heating the pound of air. together with
the yapor contained in it, has changed it's hy-
grometrlc state from complete satGratiOn to one
which is only 6S per cent saturated In like
manner, if the temp TaiuTe We're successfully
raised !" b.. 62o and To- Fair, the correspond
Ing degrees of saturatiOn would be 46 80 and
20 per cent. If we assume that the tempera-
ture of our living rooms is to be maintained at
say, go Fair. our sense of comfort will depend
on two factors jOinty-the warmth OF the air
and It's condition as regards dryness. If we
rely on open fires. which radiate their heat
without warmiD" the air directly but do so by
1irSt warming the walls of the ROOM which after
ward warm the air moderately, we shall be
obliged to admit SO much moist air from with
out that there will be little danger of too much
dryness.
But if we employ stoves. the case is altered
Their more advantageous positions and dull ra-
diatiOnS enable them to sufficiently raise the
tenperature~WithOut the expenditure of large
amount of fuel. and. therefore. with little ne
ceSsity for admitting large amounts of fresh air
and 1t hence results that on the temperature
being raised the degree of saturatiOn with
moisture falls very low. and most uncOmfOrta-
Die dryness results. This is obviated by placing
a vessel of water on the stove in such a position
That 1t may be heated and give Off vapOr more
or less c0DiOuSly. In order to present the prin-
clpes involved clearly. let us suppose we
have a stove in which we have to
burn 40 pounds of coal in the course of 10
hours in order to maintain temperature of g.
Fair when the outside air is at 32o Fair. Now
four pounds of coal per hour will require 1900
1eet cf ar Tor It's combustion. This will weigh
about 81 3 pounds aud will contain, at 81 Fahr,
$40 pounds Of vapor This would be intoeraby
dry. tor the degree of saturation would be only
230. Let vessel of one foot area contain water
and be SO placed on the stove that it will be kept
at a temperature of 1922 Fahr. This vessel will
yield .53S pounds of yapOr
I've shall have then. altogether. 1854 pounds
OF vapor brought into the room every hour
But 9l.3 pounds of air at So would require for
complete saturaton 1864 pounds Of water. We
thus have an atmosphere too damp. About 50
per cent SaturatiOn. Ii We reduce the SiZ,. OF
the cooperating vessel one-half we shall add.
other things being constant, about 1863 pounds
OF yapOr to that brought i'm from without and
secure degree OF saturation of about 81 per
cent.
Tins May re called a ory atmosphere. since
IL could sustain much more vapOr; accord
lngIy. every article that is exposed to it will
continually give oil such moisture as it Eiay
contain. The same will be more emphatcallv
true OF less degrees of satutation. 1t appears.
then. that with the conditions supposed We
may, if We would secure a moderately dry and
healthy atmosphere. so place an eVaporating
vessel az to secure the evaporation of somewhat
less than half pound of water in an hour (be-
tween StJ ahd .a3Sl pounds This may form
a basis for regulating the amount of water that
Is to be eyapOrated on stoves. II we are to con-
sider the case of furnaces where large amount
of fresh air is to be heated AMI thrown into the
dwelling. the case is complicated with the mum
circus details of construction. the rate At which
the air is admitted to the heating chamber etc
No doubt the most satisfactory plan is to have
recourse to observation Of the wet and dry bulb
thermometers, and by their indications regulate
the exposed surface as to extent and proX unity
10 the fire pot till the proper amount of eeapo-
ration is secured"