St. Johnsbury Caledonian. [volume] (St. Johnsbury, Vt.) 1867-1919, 1876-11-10
Facts Concerning Hot Air Furnaces
New lORK, Jan. II, 1916.

NEW DIRK, Jan. IL, 1870.
! To the Editor Of the Metal Worker:
DEAR SIR: As the general public are
Interested to Il large extent in the sub
Jcct of hot air furnaces, permit me to
mention some points bearing on this
important topic. The Importance of
| preventing the access of impure air in
our dwellings cannot he uverrated. and
ii is but proper that all defects present
ed 10y the heating apparatus commonly
i'll vogue with us when regarded from
an economic and sanitary view, should
he fully exposed. 1t would appear.
= ""Wcvcr, that ii tendency exists rather
To over estimate than conceal the dan
gers incurred 10y the use of hot air fur
naccs. That this is the fact is Indicated
10y the exaggerated statements fire.
qucntly made i'll this regard, which can
| hardly Ice doubted, have excited un-
necessary alarm i'll the mind of the pub
/ lie. Great prominence has been given
III tins connection to Il series of expert
mcntS made in France in ISti3 aud l-ti4
10y st. Claire Deville and Troost. and
To Il report presented in lS69 to the
| French Academy of Sciences 10y Gen.
| NORM. The results of these investiga-
! tiOns have received unwarranted ap-
/ phcation to furnaces as now construct
/ ed. and have also been WRONGLY quoted
as proving the superiority of wrought
| to east iron for heating purposes. We
will first consider some of the features
exhibited by heated air. and then eX-
anime the results obtained bN the tests
referred to. us regarded by scientific
authorities. The heated air is depri>-
ed of its proper proportion of moisture.
and that noXious gasSes are allowed to
escape and miugle with the air intro
duced into the house
The first objection is fallacious
According to Il high authority on heat
/ (Pecler,) 1.-THE driving of air 10y its CON
tact with the heated metal of the fur
mace is only apparent. its peculiar con-
dition being caused 10y the fact that.
owing to the increased temperature, its
capacity of absorbing aqueous vapor is
greatly augmented, and iron. when heat
ed to the greatest point attainahlc in
our furnaces, will not deprive the sur
rounding air of Il trace of the moisture
contained. The artificial production of
moisture 10y means of water placed in
the hot air-chamber is. however, often
advisable III private dwellings, not on
the score of health, hut for the reason
that air containing an abnormal amount
of moisture Is agreeable to many per
SONS; but i'll churches, theatres and
public halls, where large number of
persons are assembled. the requisite
amount of humidity is abundantly sup
Piled by the constant eXhalations from
the bodies of those present"
The second objection is of far greater
Importance, and merits more extend
ed consideration. The great source of
danger in heating apparatus is the for
nation and escape of carbonic oxide
Carbonic acid was formerly considered
the noxious principle of furnace gases.
but this opinion has been clearly dem
onstrated as erroneous. Carbonic acid
Is infinitely less perniciOus to health than
carbonic oxide.
1t Is safe to assert that corbonic oxide |
does not permeate the fire pots of our