The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1893-02-04
House Ventilation.


State Medical Association Here are
some extracts from DIR. Van Rensselaer's
article
Were people killed outright by foul air,
its dangers would be carefully guarded
against, but its effects are slow and insidi-
GUS, and often ascribed to other causes.
We are careless of its results because, as
its effect at any one time is slight, we grow
accustomed to it and disregard its risks,
and after being in its presence few min
utes our senses become dulled and do not
warn us of the danger.
But while the Immediate effects seem
trifing, yet it is true that any prolonged
vitiation of this source of supply interferes
with the proper working of our organiza-
tions and depresses our vital functions.
Statisticians have shown that of the causes
of mortality the most important and far
thest reaching is impure air.
We keep our windows closed great
part of the year-during the winter to
keep out the cold and in the heated term
in summer to exclude the heat-so that
the circulation and renewal of air in our
houses are at these times slight The in-
coming air introduced for ventilation may
be vitiated or not, according to our sur
roundings; but once in, it may be contain
mated in several ways, and unless we take
special pains to remove this foul air it
rapidly accumulates, becomes offensive and
is menace to health
The primary condition for ventilation is
that the incoming air shall be pure; it
must be pure external atmosphere. Air
that is drawn from small, closed courts, or
from between back to back buildings, or
that has blown over refuse or that rises
from cellar is unfit for continuous breath
ing. The sun rarely or never visits these
spots and the wind gets no chance to sweep
through them. Especially bad is the cellar
air, as cellars are apt to be damp, mouldy
and dark, and are frequently polluted by
decaying vegetables and the ash heap, and
currents of air are constantly passing
through them from the soil below, so that
sewer air from defective drainage in the
neighborhood may easily enter and be suck
ed through the house. This danger is
particularly great if the house is heated by
furnace whose wooden air box passes
through the cellar.
In providing inlets number Of things
have to be taken into consideration. The
inlets must be so placed that the air can
not blow directly on the occupants of the
room, and they must be of such size that
sufficient incoming air is obtained without
a high velocity, for if the movement is
greater than two or three feet per second
drafts are experienced, and besides slow
current is more favorable for uniform diffu-
sion than a rapid one.
If it can be avoided air should not enter
through openings at the level of the floor,
as dust readily falls into the openings and
fouls the air. and if the incoming air is
cooler than the temperature of the room it
ehills the feet. The place of admittancc of
cool air should be above the heads of the
occupants, and means should be taken to
diminish the current if too rapid, and the
flow should be directed upward, as there,
meeting the warmer air Of the ceiling, it
mingles with it, becomes warmer and
gradually spreads through the room. The
external openings of the inlets should give
air in place where the air suncontaminat-
ed They should be short and so arranged
that they admit of ready cleansing. They
should be numerous and small, rather than
large and single, as they are thus less liable
to cause drafts.
When the conditions are such that the
window cannot be freely opened, it can be
arranged in one of several ways to provide
sufficient fresh air. Hinckes-B Birds meth
cd consists of placing movable block of
wood under the entire length of the lower
window sash, thus raising the top of the
lower sash above the bottom of the up
per- By this procedure considerable space
between the two window frames is left.
through which the incoming air freely
passes, and being impelled in an upward
direction it causes no draft.
In Tobin's tube the air from outside en-
ters through hole in the wall and is cor
Quoted by an upright tube into the room.
The opening of the tube is above the heads
of the occupants, and the air escaping as
cends toward the ceiling,
Cooper's ventiator consists of series Of
apertuIes in a window pane arranged in a
circle, which can be partially or entirely
closed by glass disk, movable on a pivot,
with corresponding apertures. In private
honses during parties the rooms often be-
come insuferably hot and close. These
unpleasant features can to great extent
be avoided by having temporary Shering-
ham valve, constructed of wood and can
vas and inserted above the upper sash Of
the window, which is lowered for the pur-
pose
The sheringham valve consists Of an
opening through the wall for the air to
pass, the euterance being usually guarded
by strainer of some sort to keep out dust
On the inside is Waived iron plate with
closed sides and hinged at the bottom. An
attachment is arranged to more or less
completely change it. The entrance should