teachers open their windows in buildings equipped with the
ordinary type of modern heating and ventilating apparatus.
Nor can one always blame the teacher if she feels that the
regulation against opening windows is a useless imposition.
One of the most frequent difficulties encountered with
modern types of artificial ventilating apparatus is that the
heat supplied to all the classrooms is at the same tempera-
ture. Classrooms on the north side of the building, which
are naturally cold when exposed to the wind, need more
heat than do those on the southern side of the building, where
the sun pours into the room all day long. Often there is a
difference of as much as five or ten degrees between the two
rooms, but the heat supplied in each case is practically the
same.
Contrary to the general belief, it is possible to construct
buildings with modern apparatus so that the windows in
any room may be opened without interfering with the heat-
ing and ventilating of other rooms. This is made possible
by substituting for the old common-duct arrangement either
the double-duct system or the individual-duct system. In
both these latter systems the air for each room is individu-
ally regulated according to its need. Under the ordinary
system there is a heating chamber in the basement where all
the air supplied to the building is warmed and driven up
HEATING AND VENTILATING 149
through one huge duct, which has branches connecting with
each room. The double-duct system is built on the same
plan, but under every branch carrying warm air into the
room there is a second branch carrying cool air. At the base
of each flue there are dampers, which are connected with a
thermostat. When the temperature of the room falls, the
thermostat acts so that the warm-air damper is open and
the cool-air damper is partly closed. As the room becomes
too hot, the warm-air damper is closed and the cool-air
damper is opened. In this way the temperature of the air
admitted to each room is regulated by the thermostat in the
room, and is not affected in any way by the temperature of
other rooms.
The most desirable, but also the most expensive, system
has an individual duct for each room leading directly to the
heating chamber. Arrangements are made whereby cool air
and warm air are each supplied to the duct, and the propor-
tion of each is controlled by dampers connected with ther-
mostats in each room, as is the case with the double-duct
system just described.
It is probable that in the near future we shall see many
and interesting experiments with new methods of indirect
heating. Dr. Bass, for example, has made some interesting
experiments in Minneapolis, in which, instead of having
large flues in the walls of the classrooms, he has supplied
individual air inlets at each desk. On the other hand, some
of our leading school architects have come out strongly in
favor of doing away with all forms of indirect ventilation
and depending solely on direct radiators and open windows.
Fans. When systems of indirect heating were first intro-
duced, it was customary to rely upon the difference in weight
between hot and cold air to produce proper circulation.
Later it was found that the so-called "gravity" system
worked well only when the difference between the outdoor
150 HEALTHFUL SCHOOLS
temperature and that of the air inside was very marked.
In spring and summer, when the outdoor temperature was
very mild, ventilation inside the building became increas-
ingly less adequate, and even when windows were open,
very little fresh air entered, because the pressure of the air
outside was not heavy enough to force it in. In order to
secure adequate circulation of air at all times it has recently
become the custom to install fans which force the air
through the rooms, regardless of its temperature.
There are two methods for using fans. One method is to
suck the foul air out of the classroom, and thus create a
vacuum which fresh air rushes in to fill. This is known as
the "exhaust" method. The fan is placed either in the attic
or in the basement. The exhaust method was widely in
favor at one time, but its popularity rapidly waned. When
the fans were placed in the basement, it was found difficult
to make them work properly; when placed in the attic, the
vibration of the machinery was unpleasantly noticeable.
Moreover, it was found that when the foul air was drawn
out of the classrooms, its place was taken not only by fresh
air from windows and flues, but by foul air from corridors,
basements, and toilets. Air rushed in from all available
quarters, and it was very difficult to regulate its quality.
The plenum fan works on exactly the opposite principle.
Here, instead of drawing foul air away from the classroom,
fresh air is pumped into the room and drives the foul air
out through pressure. The plenum system makes it possi-
ble to regulate the quantity, quality, and warmth of the air
supplied to each classroom. Occasionally a combination of
plenum and exhaust fans has been used successfully in
school buildings.
Plenum fans are usually located in the basement, and air
intakes lead from outdoors directly to a large, enclosed
chamber. The fan placed at the opening of this chamber
HEATING AND VENTILATING 151
draws the air from it and forces it up through the various
ventilating flues throughout the building. The location of
the air inlet is a matter of supreme importance. All too
frequently it is either actually below the level of the ground
outside, or else just even with it. This means that when the
fan is working the air which is being drawn in from outdoors
continually carries with it small particles of dirt, and unless
there is some form of air-cleaning apparatus, this dirt is
carried up into the classrooms for children to breathe.
Frequently, also, the air inlet is placed on the north or
exposed side of the building. Few people realize the differ-
ence in the temperature of air directly outside the different
walls of a building. In some cases it is said that there is as
much as thirty-seven degrees Fahrenheit difference between
the air on the north and the south sides of the same building
in winter. During cold weather sometimes as much as a
seventh of the entire fuel bill could be saved were the air
inlet on the south side, where the incoming air had already
been warmed by the sun. In planning the air inlet, then,
care should be taken to place it high on the school wall on
the southern side of the building. The air chamber should
be kept clean and empty. It should never be used for stor-
age. The fan should be enclosed in a fan chamber. It is not
uncommon to find school fans, placed on the floor of the
basement near the boilers, energetically pumping basement
air into the classrooms.
Recently a distinctly new method has been used for
school ventilation by means of fans. Instead of installing
one large fan in the basement to supply air for all parts of
the building, a small electric fan is placed in every classroom.
This fan either draws warmed air up from the basement air
chamber or cold air directly from outdoors, depending upon
the way in which it is installed; and the air supply for each
classroom may be controlled without affecting that of any
152 HEALTHFUL SCHOOLS
other. The fans are practically noiseless; and may be run
without causing unpleasant draughts or interfering with
classroom work.
Air cleaning. Reference has already been made to the
danger of locating the air inlet near the ground, because it
picks up dirt and spreads it by means of the fan throughout
the building. Even where the intake is located high upon
the wall the air frequently is found to be very dirty. This is
particularly true in smoky cities, or in communities where
the ground is dry and dusty. Our better school buildings
are now installing apparatus whereby air taken into the
building can be strained and cleaned of all the dirt it carried
before it is sent into the rest of the building. This cleaning is
either done by forcing the air to pass through cheesecloth
bags, or similar dry strainers, or else by causing it to pass
through streams of water which literally wash the dirt out.
Air-moisteners. If recent experiments furnish reliable
evidence, it seems to be true that it is even more important
to have the air moist than it is to have it clean. The problem
of moistening air is a most perplexing one, and does not
seem as yet to have been satisfactorily solved. Many differ-
ent forms of apparatus have been devised, most of which
are easy to install and simple of operation. The greatest
difficulty encountered is that most of the successful air-
moisteners are costly to run. Apparently the most success-
ful and also the most expensive types are those which utilize
the steam spray. Steam from the boilers is allowed to mix
with the air which is being blown into the room by the fan.
Although at times people complain that the air so mixed
carries with it an unpleasant odor, it seems entirely possible
to remedy the defect. The chief trouble with the system is
that large amounts of steam are necessary in order ade-
quately to moisten the air. This air is carried into the school-
rooms at high rates of speed, and is immediately forced out
HEATING AND VENTILATING 153
through the foul-air flues into the outside air in order to
make room for the large volumes of heated air which follow
it. This means that the steam from the boilers is being con-
stantly used up, and the fuel cost for doing this is very
heavy.
There are many other forms of air-moisteners. For exam-
ple, sometimes tanks of water are placed underneath the
fan. Again, the air is forced through streams of water, which
moisten and wash it at the same time. Sometimes sheets of
porous cloth are kept constantly wet by sprays of water
and the air is forced through them. These devices work
with varying degrees of success. Usually it is necessary to
combine the water with the steam, or to provide hot pipes
which raise the temperature of the water. The chief diffi-
culty encountered is to make the air take up moisture fast
enough as it passes up into the room.
Thermometers. Every classroom in the country should
be supplied with a thermometer. Every teacher and every
child should be taught how to read it, and what to think
about the results it shows. The thermometer should be of
large size and of good make. Small thermometers are diffi-
cult to read and frequently get out of order. In placing the
thermometer care should be taken not to place it too near
the window, nor, on the other hand, too near radiators or
fresh-air inlets. Probably the fairest place in the room for
hanging a thermometer is in the exact center, halfway
between floor and ceiling. If it must hang on the walls the
teacher should experiment to find out which particular
location will most accurately record the average temper-
ature of the room.
Thermograph. Better than a thermometer is the ther-
mograph, which not only shows the degrees of heat in the
room, but also registers the findings in the office of janitor
or principal. It is strongly desirable that the janitor should
154 HEALTHFUL SCHOOLS
be able to tell the condition of heat in each of the classrooms
without having to make a personal visit. Thermographs
can be installed at moderately low cost, and will be of
immense help to the janitor.
Thermostats. The thermostat is an instrument which
is installed in each room, and is so arranged that it auto-
matically regulates the supply of steam to the radiators in
that room. It regulates heat, not ventilation. Complaints
are constantly made that thermostats get out of order.
Where buildings are properly constructed, however, with
the double or individual system of fresh-air flues, thermo-
stats render excellent service. They take responsibility for
heating classrooms from the shoulders of both teacher and
janitor and make it an automatic matter.
Humidostats. The humidostat is similar in principle to
the thermostat, except for the fact that it registers the
amount of moisture in the air rather than the temperature.
When the classroom air becomes too dry, the humidostat
automatically turns more steam into the fresh-air flue.
When the moisture becomes too great, the heat is auto-
matically turned off again. As yet humidostats are rarely
found in public school buildings, but it is probably true that,
as the importance of securing the proper degree of humid-
ity is recognized by ventilating authorities, the humidostat
will take its place beside the thermostat as an important
and necessary part of school equipment.
Re-circulation. Probably the most significant of all the
recent experiments in ventilating and heating problems are
those already mentioned which were carried on by Dr.
McCurdy in his Springfield, Massachusetts, gymnasium,
and by Dr. Bass in a public school in Minneapolis. Both of
these gentlemen investigated physiological and psycholog-
ical results of re-circulating air. The results of these experi-
ments in re-circulation seem to show that if air is properly
HEATING AND VENTILATING 155
washed, moistened, and kept in motion, it can be used over
and over again with amazingly satisfactory results. It seems
possible to eliminate all objectionable odors. The air seems
fresh and clean throughout the building, and students
working in rooms where re-circulation is used frequently
say that they prefer that atmosphere to that found in
buildings where the air is supplied fresh from the outside.
Careful psychological tests all give the same evidence, that
students working in re-circulated air do exactly as good
work and as much of it as students working in fresh-air
rooms.
There is, however, one important point on which evidence
has not yet been made public. The New York Ventilation
Commission has recently discovered that where air is kept
cool, moist, and in motion in experimental chambers, the
amount of carbon dioxide and other gases present seems
to have no measurable effect either upon physiological or
psychological responses. Only one important effect of foul
air has been discovered, but that is an extremely significant
one. The commission has succeeded in demonstrating so
clearly that it cannot be successfully controverted that
foul air tends to diminish appetite, and that the amount of
food consumed each day by students in fresh-air chambers
is materially greater than that consumed by students in
foul-air chambers. Results of this study at once raise a most
important question with regard to the plan for re-circulating
air in buildings. Does washing foul air remove its appetite-
destroying properties? Does mixing ozone with foul air
have any such effect upon it? If it can be successfully
demonstrated that re-circulation has no undesirable effect
upon appetite, it will probably mean that most of our large
public buildings, including school buildings, of the future
will be built so that re-circulation is possible.
Re-circulation provides exceedingly clean air to the class-
156 HEALTHFUL SCHOOLS
room because it is washed on every round, and whatever
dust escapes the first washing is sure to be caught in the
second. Air-moistening is accomplished with very small
expense because very little heat and moisture are lost in the
process. The chief saving, however, — and it is an enormous
saving, — comes in the amount of fuel necessary to heat
the building. Since most of the air is kept in the building
there is very little loss of heat. The desirable elements of
re-circulation are so large and the undesirable elements so
few that further experiments concerning the effects of re-
circulation upon appetite seem of paramount importance.
If re- circulated air can be shown to have no undesirable
effect upon appetite, it will be difficult not to agree with
Dr. Gulick when he calls re-circulation "the ideal ventila-
tion for school buildings."
What shall schoolmen do? After studying carefully all
the articles and books which have been written on the
subject of heating and ventilating, superintendents and
members of school boards find themselves in a curiously un-
satisfactory position. They read of many interesting ex-
periments. They learn that most of the old theories of ven-
tilation have been proved false. They learn of many new
principles which apparently are in the process of being
established. But when the town has to build a new school
building, to be ready for occupancy within a year, the
question of what is the most satisfactory type of heating and
ventilating apparatus to install is apt to meet with a very
indefinite and unsatisfactory answer. One architect says
dispense with all artificial ventilation, rely simply on direct
heating by radiators, and open the windows. Another goes
to the opposite extreme and recommends the most com-
plicated system of fans, strainers, and moisteners. A few
of the most enthusiastic engineers believe that re-circula-
tion solves the problem, and strongly recommend that
HEATING AND VENTILATING 157
a re-circulation system be established in all new school
buildings.
For superintendents and school board members who are
actually facing the problem of erecting new buildings within
the coming year, and who cannot wait to find out what con-
clusions are eventually to be reached by experts, we suggest
the following plan : —
First, employ not only a competent architect, but a
competent heating and ventilating engineer, and if possi-
ble have the two men work together in devising their plans
for the buildings.
Second, ask the engineer if it is not possible to construct
the building in such a way that one of several different plans
of ventilation might be used. For example, if the building
is piped throughout, direct ventilation might be used with
window ventilation. Inlet and outlet flues could be placed
in the walls, as is usual with indirect heating and ventilating,
and space could be left in the basement where a fan might
be installed. At the same time the building could be so
constructed that outside air could be shut out and the air
of the building re-circulated. In a building erected in such
a way it would be possible to shift, with minor changes,
from one system of heating and ventilating to another, de-
pending upon the findings of those who are now experiment-
ing with the subject.
It is probably true that new buildings are not being
planned in this way, but it is also true that the skillful
heating engineer, working in cooperation with a competent
school architect, could devise a system which could be
readily adapted to meet changes in theory. Many of our
newest and finest buildings are being constructed of steel
and cement in such a way that they may be expected to
be standing and in good condition after perhaps a hundred
years of service. Even the buildings which are not of mono-
158 HEALTHFUL SCHOOLS
lithic construction are expected to last for twenty or thirty
years at least, and we may be sure that within this time
methods of heating and ventilating will be radically im-
proved. Anything which can be done to forecast possible
changes and construct buildings so that they may easily
be made when the time comes, will be a wise investment of
time and money.
QUESTIONS FOR STUDY AND DISCUSSION
1. In certain schools steam cocks on radiators are left open, pans of
water are placed on radiators, or water tanks are attached to stove
or furnace. How valuable are such devices for humidifying the air?
If a water pan is provided in the classroom, why is it that children's
faces may become flushed and dry before the water has been notice-
ably evaporated?
2. Why is it that damp air seems hotter than dry in summer and colder
than dry in winter?
3. If suffocation is really caused by inability of the body to throw off
heat, why are people able to lie comfortably completely immersed in
water of a hot bath for many minutes at a time?
4. What, if any, changes would have to be made in the laws of your
State to permit an ideal system of ventilation to be installed in a
school building?
5. What are the comparative advantages and disadvantages of the dif-
ferent types of steam boilers now commonly used?
6. Make a special study of ventilating flues, noting number, size, loca-
tion, equalizing chambers, automatic control, legal provisions, costs,
etc. What are your conclusions as to the most desirable type?
7. Outline a course of study of ventilation for janitors. What should
teachers know about the subject?
8. Make a schedule for a heating and ventilating survey 6f a school
system.
9. The theory of re-circulation has ardent advocates and bitter opponents.
If it can be proved desirable it will effect amazing changes in school
practice. On the basis of all the evidence you can gather, what are
your own conclusions?
SELECTED REFERENCES
International Y.M.C.A. College, Springfield, Massachusetts. Ventilation
Studies. Reprinted from the American Physical Education Review,
December, 1913.
Authoritative account of re-circulation experiments at Springfield, with bibliography.
HEATING AND VENTILATING 159
New York State Commission on Ventilation, College of the City of New
York.
See various papers and reports published from time to time by members of the Com-
mission.
Journal of Industrial and Engineering Chemistry. Files and current numbers,
especially that for March, 1914.
Thorndike, Edward L., Ruger, G. J., and McCall, W. A.: "Effects of Out-
side Air and Re-circulated Air upon Intellectual Achievement and
Improvement"; in School and Society, May G, 1916.
The printed material on this subject is enormous in amount, and even
a carefully selected list of the most important references would be too
long to include here. The student is urged to look through the files
of the heating and ventilating journals, and to refer to the card in-
dexes at public libraries under the headings of heating, ventilating,
air, atmosphere, etc.
CHAPTER IX
PROTECTING SCHOOLHOUSES FROM FIRE
Fire protection unpopular. Fire protection is a distinctly
unpopular subject. Most people are naturally optimistic.
They do not like to believe that danger threatens, and they
would rather take chances than spend time and money
for various forms of insurance. In the United States as a
whole at least one school is burned or partially destroyed
by fire every school day in the year. But as most school -
houses are only open five hours a day and five days a
week, most of these fires occur when schools are not in ses-
sion, and therefore very few school children are burned to
death.
Occasionally, however, a terrible tragedy occurs; the
communities which have followed the policy of taking
chances are shocked out of their previous indifference, and
for a few brief months undertake drastic reforms in the
building of their schoolhouses. The burning of the Lake
View School at Collinwood, just outside of Cleveland, on
March 4, 1908, was directly responsible for placing Ohio
at the head of all the States of the Union so far as concerns
fire protection legislation. The recent tragedy at Peabody,
Massachusetts, aroused waves of popular agitation in the
New England press, but neither Collinwood nor Peabody
nor the other lesser tragedies has any great permanent
effect on the popular attitude toward fire protection. Safe-
guarding public buildings is an expensive process. School
boards are beset on every side with applications for in-
creased funds. Building costs already seem prohibitive, and
the addition of thousands of dollars to secure prevention
PROTECTING SCHOOLHOUSES FRCM FIRE 1C1
against loss of life which in all probability will not occur
seems almost an official extravagance.
Fire-retarding. If there is not sufficient money to erect
a completely fireproof building, slow burning or fire-retard-
ing buildings may be erected which will, at Least, give the
children sufficient time to escape. Corridors and stairs may
be made of fireproof material, and cut off from the rest of
the building by fireproof walls. Throughout the building,
wherever possible, metal furring or tiled linings should be
used. Where wood furring is necessary, it should be stopped
off by plaster at the floor and ceiling and midway between.
Even metal furring should be fire-stopped, to prevent the
spread of fire by draughts of superheated air or flaming
gases. In some of the earlier forms of construction the
hollow spaces between inner and outer walls furnished flues
whereby draughts might draw the flames from basement
to attic. Again, the semi -fireproof building should avoid