Evening star., 1869-02-06
HEATING AND VENTILATION.

The manifest defects in the present mode of
Nenulsiing and warming schooi-roOms are at
LAST attracting the attention of school author
i,Ies, and the subject is discussed with mucb
inisIlIgence in a late number of the Is,,r,ea,
F'-,I't' Tdl Monthly. 1t is time some thought
was gwen TO this matter. The public are sys
t'u,atIcaily poisoned with bad air m lecture
looms Churches and places of amusement:
ori thst Is their own look out They can
stay OF 20 But the children are compelIad To
breathe the frst-elass article OF carbonic scia
sss provided for them in schooI.rooms for a.
i"sst six hours of each day. The active and
rspidiy developing brains of the pupils are
peculiarly sensitive 10 the benumbing infiu.
enoe OF close and poisoned AIR. ard they are
confined peremptorily TO fixed seats; they have
not the liberty 10 change from one part of
the loom TO another to avoid an unpleasant
draught. or to get into n cool, refres hing breeze
IA 8 relief from the bad air of a foul and stag.
nant school-room. Ii becomes an absolute me-
Cessi,y, therefore. that all portions of the room
should Be evenly warmed; while at the same
time great care must be taken to avoid currents
Of aIT. either hot or cold.
These requirements point directly 10 the ne.
cessity for as great q distribution as possible.
firs,, of the heat; second of the inlets of fresh
sir and third. Of the outlets OF the foul AR.
The physiological requirements are first, that
weshould always keep the feet warmer than
the head; second, that we should keep the back
warmer than the face. With the student the
b-aIn is the most active portion Of the body and
consequently attracts the greatest flow of blood.
while the feet, which are the greatest distance
from the heart and lungs; are more liable 10 be-
come chilled. In moving about we necessarily
zee the current; therefore. for greater protec
lion the prlncIpal nerves and more sensitive nor.
toIs OF the body are placed along the back III
- yery debilitating TO cit with the back 10 a cold
wall, and more especially to a cold window.
But II the back and feet are kept thoroughly
warm, enc can safely have cold air blowing in
his face for breathing. And again. it appears
10 be necessary that there should be- a con sid
-rsb!e difference between the temperature of
our bodies and the temperature OF the air We
oreathe We requirs that difference TO be at
east twenty-eight degrees. As soou as the air
reaches the temperature of seventy degrees we
want II Sept constantly in motion. Any tenn
perature above that is more or less uncomfort-
aOle. OF course we are able to endure a much
h.gner temperature for a short time, but II is
c-bIIitatiag.
cn the other hand the colder the air is or in
other words, the greater the difference, be-
tween the temperature OF the air we brea he aud
thai oi our bodi-s. the more rapidly the blood
c.
ton Of he system. There is twice the quan-
Uty of carbonic acid given of when we are
breathing air from ten to twenty degrees than
when The air is from eighty to ninety degrees
7 be COZ dltIons, then, necessary Cor the SCHOOL
room are that the room should be warmed aud
ventilated In all parts alike; there should De M
peTceptiole current IN any part; the feet O: the
occupants should be kept warmer than their
heads; their backs should be warmer than tneir
faces snd. finally, their bodies should De kent
warm, v hile they have cool. invigoratIng aIr
tor breathing.
To produce these results il is necessary that
We should warm the floor and exterior walls
% a ten Peraturs equal 10 that of our bodies.
Usre,y eight degrees, so as to prevent the ab
soTpnon ef the radiant heat fror our bodies by
the walls We could then afford 10 have cooI
ar Tor breathing, say AIR at a Temperatures OF
Gf'y degrees In a room heated by warm air
ali the air must be hotter than is required for
Breathing II Is very commonly heated up
Vs-ds CT one hundred degrees: the solid OBJ
'"cts IN the room are much colder. and couse-
gusutIy are constantly absorbing the vital hea,
from 'he bodies of the occupants, while they
are bEesihiDg this warm debilItating air Its
shl. condition of things that gives that uuclm-
iOrtSble feeling 90 universally complained of In
al rooms warmed BY hot air On the other
hind. II Is the powerful direct radiation that
comes from the glowing flames OF an open fire.
';ten AZ iemTerature of near three thousand
degrees, hat makes h so nearly correspond
vith the radiation from the sun, aud enables ~
10 produce an artificial warmth uneq ualled fur
comfort and healthfuines<
The requirements Of the school-room. hoU
ever. almost entirely forbid the use OF open
hre-. owing 10 the impo.sibIltty OF maintaining
Uniform temperature over the whole room,
Scd certain other minor difficulties We must
therefore. accept some inferior ARRANGEMENT
Tor that purpose. IL is designed TO heat the
"hoi" building by low-pressure steam from
oUiieT m the cellar. and 20 place the steam
radiators under each window in all the o.
CUpIed rooms. OF course this will not necss-
-arIly warm the whole interior wall. As 4,
would be very desirable TO do; vet by placiuga
radiator under each window, q very consider
able diffusion of the heat Is obtained Besides.
the greatest heat is thus placed Immediately
brow The greatest cold, so that the extremes will
modify each other, and at the same time hs
IrJnrious effects Of sitting with the back toward
cold window are very much overcome
7 he distribution of the inlets of fresh air and
outlets Of foul air is Of not less importance
fresh air should be 50 thoroughly diffused that
While there could BE- no possibility Of .,ag,,-
'"h' there would be no considerable currents
Pe'eephoie any where. The diffusion of fresh
air Is quite well provided for by the intr,duc-
'.on OF air directly under every window and
over the radiators The manner In vhicn ,n,.
10 III ranged Is to place the marble slab COVERING
me ranis'or from two to four inches aboxs ,hs
sO''om OF tne sash. Then, by simply raising
ne window, the fJesh air flows in a. IN. ton os
'ne radiator lu specific gravity being greater
san tnat OF the air within, II fills over the f,.s
CT ,ne raciator, insuring about as perfect a diff.
tusaon OF pure air as it is possible to hsvs
Ihe proper place for the exit of the fou, air
nas been much discussed. A few years aso NO
pne thought Of anything but taking It from the
TOP or the room: then a. soon as it was NJ.
tempted TO warm the room by circulating
warmed air, the ventilators had to be closed.
Now, the tendency is TO run TO the OF aer ex.
treme. and To have the only opening at the bot;
tom Of the room. This also is wrong a. the
excess of the foul air rs at the top PROBABLY
'nTee-iourths of the year. As great q distribu-
'ica OF outlets as possible Is therefore import
SIT Agitation OF the air 10 the great means
oesisneo 10 maintain its purity. In the Salem
scnOo4 i've registers have oeen provided for the
escape OF foul air from each classroom. These
VIII o. equal 10 an opening Of Que square 70 II
eaeh' or about one square foot for every ien
children. The space between the ioists, a der
a. . a -. -.