Boston (Mass.). School Committee.

Reports and other documents relating to the ventilation of the school houses of the city of Boston online

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separately or together, as may be desired. (See Ap-
pendix A.)

It is necessary and advantageous to apply some
kind of cap or other covering upon the ventiducts
where they terminate above the roof It is necessary
as a protection from the rain and the down blasts of
wind, and it is also very advantageous to be enabled
in this way to avail ourselves of the power of the
wind to create an active upward current. We used
at first the turncap or cowl invented by Mr. Espy,
and with satisfactory results. It is undoubtedly the
best movable top known ; but is noisy and somewhat
liable to get out of working order. These objections
to the movable tops have long been known, and va-
rious stationary tops have been invented and have
been partially successful. An improved Stationary
Top, or Ejecting Ventilator, as it is called, has been
invented during the past year by Mr. Emerson, and
is the apparatus to which we referred on page 16,
of our first Report. It is shown in the drawing, and
consists of a frustrum of a cone attached to the top
of a tube, open in its whole extent, and surmount-
ed by a fender which is supported upon rods, and
answers the double purpose of keeping out the rain



and of so directing or turning a blast of wind upon
the structure, as that in whatever direction it falls,
the effect, that of causing a strong upward draft,
will be very uniform and constant.


lNJErTI\(; Vn\Tll,ATOR.

Being satisfied that this Stationary Ejector pos-
sessed all the advantages of the best tops hitherto
known, without the disadvantages of either of them,
we have adopted it for several of the houses last ven-
tilated, and find it in all respects satisfactory. We
therefore recommend it for general use.

The Injector may generally be dispensed with, but
in situations unfavorable for introducing air, it may
be sometimes found convenient, or even necessary.




Elevation of Ventiducts.

The discharging ventiducts should
be situated at the part of the rooms
most distant from the stove or reg-
ister of the furnace, and should al-
v^ays, if possible, be constructed in
or upon an interior wall or parti-
tion, and an outer brick wall must
if possible be avoided. They should
be made of thoroughly seasoned
sound pine boards, smoothed on the
inner sides, and put together with
two-inch iron screws. The outside
finish may be of lath and plaster,
or they may be projected back-
wards into a closet or entry, as
^^^ shown in the Section.* They must
be carried entirely to the floor, and
should be fitted at the top and bottom
with a swivel blind, or register,
whose capacity is equal to that of
the ventiduct into which it opens.
This blind may be governed by
stay rods or pulleys. The eleva-
tion in the margin gives a view of
the ventiducts for a building of three
stories, and shows the best mode
of packing them, so as to avoid in-
juring the appearance of the rooms-

These ventiducts must be he^^t
entirely separate to the main dis-
charger at the roof, as any other
arrangement would impair or des-
stroy their utility.


* See page 35.

.^. UfV^^Ji^








n. Cold nir duels.
IT. Smoke flue*.

The size of the ventilators
and ventiducts must corres-
pond to the capacity of the
room, and the number it is
intended to accommodate.

A room containing sixty
Scholars is found to require a
discharo-infi: duct of fourteen
inches in diameter./ A room
for one hundred Scholars re-
quires the tube to be eighteen
inches ; and a room for two
hundred Scholars requires it
to be twenty-four inches.

The fresh air ventiducts
should exceed iJicajMcifj/ those
for carrying off the impure
air by about fiftj/ per cent. ;
so that there will then always
be a surplus or plenum sup-
ply, and the little currents of
cold air which press in at
the crevices of the doors and
windows will be entirely pre-

The Section shown in the
margin exhibits a very con-
venient mode of bringing the
cold air to the ventilating
stoves in a three story build-
-insr in connection with the
smoke flues.

• • • . ^ " / '* ^ •



The following Section and Plans (See page 36)
exhibit at one view an example of a building of two
stories warmed and ventilated by the apparatus and
in the manner recommended.

Jl. Chilson's Furnace.

B. The Boston School Stove.

C. Emerson's Ejector.

a. Cold or Fresh air ductg,

h. Warmed air ducts.

c. Impure air ducts.

d. Smoke flues.



Plans of first and second floors. The letters on
the plans correspond to those in the Section.



A. Furnace.

a. a. a. Fresh air ducta.

b. b. b. Warm air registeri.
e. e. c. Impure air ducts.


In the first Eeport it was estimated that the sum
of j^250 would be sufficient to ventilate each School
house. Our experience has justified this estimate —
but we have found in the basement stories of these
houses Branch or Primary Schools to the number of
twenty-five, all of which have been ventilated. Al-
lowing ^100 each for these, or charging oiF the cost
of supplying and repairing heating apparatus, which
we have been obliged to do, or discontinue our
labors, and we shall still be much within our estimate.
There are a few furnaces which require altera-
tions, and one house, the Franklin, has not been
ventilated, so that we think ^750 more should be
asked for in addition to the ;^2750, the sum which
is required to settle the bills for ventilating the rooms
named above.

We have appended to this Report directions for
the management of the Stoves, Furnaces and Venti-
ducts, to which the attention of the masters of the
Public Schools is requested, in conformity to the
rule of this Board which requires their attention to
the Ventilation of the School houses under their

We request the passage of the accompanying or-

All which is respectfully submitted.


,«, * See Appendix A.


In School Committeey Dec. 9, 1847.

The Committee on Ventilation made a Report —
to which was subjoined the following orders, viz :

Ordered^ That the modes of ventilation and heat-
ing specified in the foregoing Report, be and hereby
are recommended to the City Government for the
use of the Boston Schools.

Ordered., That the City Council be requested to
make an appropriation of ^3500 ; the said sum, or
such part of it as may be necessary to complete the
Ventilation of the School houses, to be subject to the
order of the Sub-Committee of the School Committee
upon the Ventilation of School houses.

Read, accepted, and the orders passed by a unani-
mous vote, and 500 copies ordered to be printed.

Attest, S. F. McCleary, Secretary.



Rules relative to the use of the Stoves, Furnaces and

1. To warm the room. Close the upper, and open the lower
registers of the ventiducts ; close the upper door of the stove or
furnace and open the lower door.

2. After the room is warmed. Eaise the distributing top of
the stove from three to six inches ; close the lower door of the
stove or furnace and open the upper door ; open all the registers
of the ventiducts about half their width.

3. If the room is too warm. Open the registers full width,
and raise the cover of the stove, keeping the upper door of the
stove or furnace open, and the lower door closed.

4. If the room becomes too cool. Close the upper registers, (for
a short time only ;) close the upper door of the stove and open
the lower door ; drop the cover down within two inches of the

5. Never close the top of the stove entirely down, while there
is any fire therein.

6. At night, on leaving the room, let the cover of the stove
down within one inch of the sides ; close the lower door of the
furnace or stove and open the upper one ; place all the registers
open about half their width.

7. The valves in the cold air ducts must never be entirely
closed while there is any fire in the stoves or furnaces to which
they lead.

8. TTie windows must not be opened to cool the room ; but the
fire should be diminished, or the principal door may be opened for
a short time.


B. See pages 14 and 27.

The following extracts are made from a note furnished by Dr.
Wjman* to your Committee at their request, and for which they
desire to express to him their obligations.

The answer to the first question, as quoted here, is a mere
synopsis of that given, but is in the words of Dr. Wyman. The
others are in full.

" Question I. The chemical changes produced in air exposed
in the chamber of a hot air furnace to an iron surface at a red-heat
(800«— lOOO'T.)?

"The changes produced under the circumstances stated in
the query would be, the dryness, and the products of the more or
less perfect combustion of animal or vegetable matter — carbonic
acid and the other constituents of smoke.

" Question II. Would there be any changes in such air which
would render it injurious to the health of persons who depended
upon it to supply their lungs for respiration ?

" The dryness would undoubtedly be injui'ious and produce many
unpleasant sensations, the most prominent of which would be dry-
ness of the lips and skin, and inflammation of the eyes. The pro-
ducts of the combustion of the inpurities of the air, if in sufficient
quantity, would produce the usual effects of carbonic acid gas,
head-ache and drowsiness ; the other products would produce irri-
tation of the eyes, nose and lungs.

" Question III. The consequences of letting into the air cham-
ber of a furnace large quantities of the gases produced by the
combustion of anthracite coal ?

" These consequences must be injurious in proportion to the
quantity of the gases admitted ; they are deadly poisons ; and
when mingled with the air passing through the furnace and as-
cending to the apartments which it supplies cannot but be injuri-
ous to those whose lungs they enter. Not long since a man and
boy in Salem lost their lives from entering a room into which the
gases from burning anthracite had been driven by the wind. Too
much care cannot be taken to prevent the escape of such gases
into the air-chamber.

" I am very respectfully,

" Your obedient Servant,

« Cambridge, Nov. 19, 1847."

* Author of '• Practical Treatise on Ventilation."



The following note has been received from Mr. Hammond, a
Master Mason, who has had more experience in repairing and
setting Furnaces in the Boston School Houses than any other per-

" Sir,

" In compliance with your request, I submit to you what
has come under my observation respecting the use of cast iron
Cylinders (fire pots) in furnaces.

" In the winter of 1845, I was called to put in two new Cylin-
ders at the Mather School House. Last winter, another was re-
quired ; and now it is necessary to put in two more.

" At the Dwight School House, in January, 1847, I set two
new Cylinders, and before the expiration of the winter they were
not fit for use.*

" The expense of a new Cylinder averages about *14.

" I remain, sir,

" Yours, with high respect,


''Nov. 15, 1847."


' See pages 16, 27 and 28.

Extracts from a report on the Mayhew School Furnaces, made
to the School Board, by J. M. Wightman, Esq.

" The furnace of Messrs. Bryent & Herman is entirely of cast
iron — the fire pot is very thick, and armed upon the outside with a
number of projecting points to radiate the heat. The cold air box
and hot air tube are much smaller thap in Mr. Chilson's, and as
the air is admitted near the fire pot, which is generally red hot,
the room is warmed by the diffusion of a comparatively small
quantity of highly heated air passing into it.

" The furnace of Mr. Chilson is of thick plate iron, having a more
shallow fii'e pot of cast iron, lined with soap stone, which efFect-

* The Furnaces here referred to have been «lisplaced by order of the
Committee on Public Buildings.


ually prevents its becoming red hot. The air is let into the fur-
nace chamber, and from thence to the School room, in sufllcient
volume to supply the whole domaiul of the School for fresh air,
the air boxes being much larger than in any other furnace. By
this arrangement, an immense quantity of warmed air is constantly
passing through the School room, and the rapidity with which the
air is changed, and an equal temi)eraturc kept in the School, are
worthy of notice.

'' On Monday, the 27th instant, the weather being very cold, tlie
effect of the two furnaces in warming their several rooms was
very apparent. When the School commenced at 9 o'clock, the
temperature of the upper I'oom, warmed by Mr. Chilson's furnace,
was 68°, while that of the room warmed by the furnace of Messrs.
Bryent & Herman was at 55°. Both the fires were made at the
same time, and had been burning with a full draft. Mr. Chilson's
furnace wjis slightly red on the top ; but as the School was suffi-
ciently warmed, the draft of this furnace was shut off, while that
of Messrs. Bryent & Herman was kept on during the morning to
procure the necessary heat.

" Without entering further into a comparison of these two fur-
naces, the Committee would state that they fully concur with the
views of the " Committee on Ventilation," in giving the preference
to the furnace constructed by Mr. Chilson — and among other
reasons, because experience has shown that there is no danger of
the fire pot being broken or destroyed, so as to let the noxious gas
from the coal into the afr chamber — that they believe plate iron,
sudiciently thick to be durable, will more rapidly transmit the
lieat of the fire than cast iron, which must be much thicker —
and from their observations, the room is warmed much quicker —
the purity of the air is greater — and the Ventilation is more
perfect than with the other."



Elevation of Mr. Ghilson's Furnace referred to on page 27.


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Online LibraryBoston (Mass.). School CommitteeReports and other documents relating to the ventilation of the school houses of the city of Boston → online text (page 3 of 3)