Improved Means for the Prevention of Condensation on Windows.
Year: 1893

page_text: Date of Application, 16th Feb., 1893
Complete Specification Left, 6th June, 1893-Accepted, 15th July, 1893
PROVISIONAL SPECIFICATION.
Improved Means for the Prevention of Condensation on Windows.
I FREDERICK HORNE of Heath Bank Wilmslow in the County of Chester
Gentleman, do hereby declare the nature of this invention to be as follows:-
The condensation of moisture upon windows causes considerable inconvenience
and loss, and this is more especially with shop windows, not only on account of the
view of articles exhibited for sale being intercepted, or in very cold weather
entirely hidden by the windows becoming frosted, but also goods of various
descriptions are in many cases irretrievably damaged by coming into contact with
the moisture on the glass.
This condensation (as is well known) is caused by the warm moist atmosphere of
the room or shop coming into contact with the cold glass of the window, causing it
to gradually part with its moisture which becomes condensed upon the glass, and
in cold weather frozen thereon.
The object of my invention is to entirely prevent this condensation and
"frosting" which I propose to effect by passing a continuous column or sheet of
hot air over the interior surface of the window in the following manner.
On the inside of the window (say for example a shop window) I place a second
sheet of glass preferably thin and separated from the existing glass of the window
by a space of about two or three inches, extending to about three inches from the
bottom of the outside sheet.
In the space between the two sheets of glass at the bottom of the window I fix
a gas pipe fitted with burners along its entire length, or if a system of heating the
shop or room by means of hot air, steam or hot water pipes exists, I cause one or
more of these pipes to supply the necessary heat, or in places where neither of the
above means are available I employ a lamp or lamps or other known sources of
heat, so as to cause a constant current of warm air to pass upwards between the
two glass surfaces.
in
The inside sheet of glass may extend to the top of the window or it may vary
depth (from near the bottom upwards) to suit the requirements of the various
trades, such as for example whether the whole window is to be kept clear of
condensation, or only that part which is within the line of sight of passers by.
The second or inner sheet of glass is preferably so mounted in a hinged frame,
or frames, or otherwise, that it can readily be removed for cleaning and other
purposes when required.
The constant current of heated air passing up between the two glasses will cause
the inner thin glass to be kept at a temperature warmer than the atmosphere of the
shop or room and thus effectually prevent the condensation of the moisture in the
air of the shop or room upon the window, and this condensation being prevented
no "frosting" of the window can take place.
Dated this 15th day of February 1893.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improved Means for the Prevention of Condensation on Windows.
I FREDERICK HORNE of Heath Bank Wilmslow in the County of Chester,
Gentleman, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:
The condensation of moisture upon windows, causes considerable inconvenience
and loss and this is more especially the case with shop windows, not only on
account of the view of articles exhibited for sale being intercepted or in very cold
weather entirely hidden by the windows becoming "frosted," but also goods of
various descriptions are in many cases irretrievably damaged by coming into
contact with the moisture on the glass.
This condensation, (as is well known) is caused by the warm moist atmosphere of
the room or shop coming into contact with the cold glass of the window, causing it
to gradually part with its moisture which becomes condensed upon the glass and
in cold weather frozen thereon.
The object of my invention is to entirely, prevent this condensation and
"frosting" (or to remove the same if already formed) which I propose to effect by
passing a continuous column, of heated air, over the interior surface of the window.
The manner in which my said invention is to be performed, or carried into
practical effect will be readily understood on reference to the sheet of drawings
hereunto annexed and the following explanation thereof.
The drawings represent, for the sake of illustration the application of my inven-
tion in the case where gas is used as a source of heat for warming the air but other
sources of heat may also be employed (as hereinafter explained) for the purposes
of my invention.
Fig. 1 on the drawings represents in elevation part of a shop or other window
as seen from the inside with my invention shown as applied thereto.
:
Fig. 2 is a vertical section and Fig. 3 a horizontal section of the same.
a is part of the window frame and b is the ordinary window glass.
On the inside of, the window I place a second sheet of glass c preferably. thin
and separated from the existing glass of the window by a space of from two to
three inches, and (when gas or lamps are employed as a source of heat) extending
to about two inches from the bottom of the outside sheet, if. hot air. pipes.are used,
then the glass can extend to the bottom of outside sheet, if hot water, pipes. are
employed, then the glass can extend to one inch from the bottom of outside sheet.
In the space between the two sheets of glass at the bottom, of the window, I fix
a gas pipe d fitted with burners equidistant (say two and a quarter inches) along
its entire length (those burners known as "Brays Patent." answer very well). and
also a band e of wire gauze (or other suitable material) bent in such a manner as
to enclose the flame, thereby causing a greater quantity of air to be mixed with the
gas, and producing a greater heat, with less consumption of gas but if desirable 'to
utilize the gas for illuminating purposes, then the gauze can be dispensed with.
If hot air be available, then I pass a pipe or pipes, from the apparatus (in the.
place of the gas pipe d) and having pierced the same at intervals, allow a
sufficient quantity of hot air to pass upwards between the two sheets of glass b
and c.
If hot water be the source desired to give.. the. heat. necessary, then a pipe or
pipes of such form and capacity, as are found most convenient, to the particular
trade, can be used.
If in country places, lamps are the only means available then I should adopt
such lamps as would give a wide flame parallel to the window.
The inside sheet of glass c may vary in width, a piece six inches wide being
sufficient (under ordinary conditions as to draught etc.) to maintain from two feet

page_text: six inches to three feet of the window perfectly clear of condensation this would
generally be equal to the "line of sight" of a man of medium height, standing on
the pathway outside.
The second or inner sheet of glass c is preferably so adapted to the frame of
the window, with buttons or other fastenings f, or hinged or otherwise so arranged
that it can readily be removed for cleaning or other purposes when required.
The continuous current of heated air passing up between the two glasses b and c
will cause the inner one to be kept at a temperature above that of the shop or
room, and also will so effectually ventilate that section (immediately inside the
window glass proper) as in itself to prevent moisture in the air of the shop or room
from coming into contact with or condensing upon it, and "frosting" cannot then.
occur, if such does form during the night or during cessation of using the
"improved means a very few minutes will suffice to evaporate all, and the window
will be left clear and bright us a mirror. This improved means is almost.
imperceptable to persons outside.
"
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The improved means for the prevention of condensation on windows consisting in
the combination with the glass of the window of an inner piece of glass parallel
thereto, and the admission into the space between the two of a continuous current
of heated air substantially as herein before described and illustrated by the drawings
annexed.
Dated this 5th dan of Tune 1902