US3064110A - Heated frame element for door and window constructions - Google Patents

Description

Nov. 13 1962 ow CONSTRUCTIONS Filed Feb. 19, 1960 /4 OR DOOR AND WIND FIG.

y 5m WI/W United States Patent Ofitice 3,064,110 HEATED FRAME ELEMENT FOR DOOR AND WINDOW CONSTRUCTIONS Jacques Vogler, Downsview, Ontario, Canada, assignor, by mesue assignments, to R.M.P. Industries Limited Filed Feb. 19, 1960, Ser. No. 9,830 2 Claims. (Cl. 219-19) This invention relates to a heated frame element for door and window frame structure adapted to effect heating of the interior surfaces of a window or door to obviate moisture condensation and ice formation thereon.

Insulation is ordinarily provided in window glass area by creating a dead air space such as by applying a storm window exteriorly or by mounting two panes of glass in predetermined spaced relation sealed at their edges in fixed relationship. A dead air space between two panes of. glass tends to permit the inner plane to achieve a temperature near to room temperature thus avoiding condensation of moisture thereon.

Prefabricated window and door frames of recent years, particularly of the all metal type such as extruded aluminum box door and window frame constructions, allow the rapid conduction of heat to the outer atmosphere tending, in the area of the interior metal, to maintain the window glass surfaces sufficiently cool in many cases to result in the substantial condensation of moisture thereon. This condition may be intensified in modern oflice building construction where glass areas are required substantially from ceiling to floor or where the exterior wall is formed entirely of a metal sheeting of high conductivity, as for example, aluminum.

It is accordingly the main object of this invention to provide a frame element for window and door frame structures adapted to generate a sufficient quantity of added heat to maintain the temperature of the inner surfaces of the window and door at a temperature greater than the condensation temperature of moisture in the room served thereby.

Other objects of the invention will be appreciated by a study of the following specification taken in conjunction with the accompanying drawings.

In the drawings:

FIGURE 1 is a partial perspective elevation of a relatively standard window construction embodying the invention; and,

FIGURE 2 is a sectional view on the line 2-2 of FIGURE 1.

Referring to the drawings, window structure is illustrated in place in a building wall 11. The window construction itself comprises a box frame 12 adapted to be seated within the wall opening 13. The box frame is adapted to carry a sash or window frame 14 supporting one or more panes of glass 15, said window panes being of either single pane or double pane construction.

According to this invention the box frame or sash frame 12 embodies at least one frame element such as the frame element 16 carrying therewithin heating elements of the invention as revealed in more detail in FIGURE 2 and indicated generally therein by the numeral 17.

Heating element 17 is of known metal encased construction having, according to this invention, a predetermined rate of heat generating capacity per foot of length. The heat generating rating of such a heating device depends upon the necessary heat energy to replace that lost from an interior room through a heat loss section one foot wide extending for substantially the height of the room or at least the height of the window opening having regard to the maximum heat loss which could occur through the window construction over such area and the minimum outside temperature expected in the locality of 3,064,110 Patented Nov. 13, 1962 the installation. It is only necessary, however, to compensate for that heat losswhich would allow the temperature of the interior surfaces of the window construction. to drop to condensation temperature of moisture of the interior room having regard to the temperature of the latter and to humidity conditions. Less than 50 watts per foot will supply many times the added heat energy normally required in cold exterior conditions and severe conditions of heat loss. It has been found that a heater of a rating of the order of about 10 watts per foot is of highly satisfactory nominal value for a wide range of condensation-preventing installations, particularly when same are provided in two foot length units adapted to be connected inparallel or electrically in series. A series connection will cut the heat generation to one-half or less depending upon the number of heating units of the invention so connected, and in this way the installer can control the. heat generation by the electrical connection even after the window assembly is completed. The installation of two heater units or rods in parallel indicated in FIGURE 2 further facilitates the range of heat generation which the installer could accomplish.

The heater units or rods of the invention must have a low surface temperature for concealment within the building or window structure. The surface area of the heating units therefore must be such as to dissipate heat at a surface temperature less than will be observed that the heating element 18 is supported within a metal body 19 adapted to serve as the glazing stop for the glass pane 20' and having substantial surface areas, the temperature of which should be approximately room temperature and which may be regarded herein as comprising the surfaces of the heating unit itself, the structure being such that the glazing stop forms a part of the heating unit. Thus the invention contemplates a heating element supported within a radiating enclosure such as enclosure 19 or the enclosure 20, which latter is adapted to ensure the necessary safety requirements and which also serves as a frame portion or element of the window or door frame construction.

The application of the present invention to a door frame construction embodies the same structural essentials more conveniently applied to a door sill structure. It will be apparent that a door construction normally em bodies a door box frame of which the sill structure forms the lower member.

If preferred, the frame element 20 may embody a conveniently located electrical switch 21 connected by wire 22 to heating element 17 through a conventional electrical wiring box 23 from which a wire cable 24 extends exteriorly of the enclosing frame member 20.

In use, when moisture begins forming on a window pane, the switch 21 may be switched to the on position to cause heat to be added to the room exposed surfaces of the window structure. In particular where the window structure is of the all-metal glass type covering substantially the full height of an exterior wall, the formation of ice will be prevented. In countries where there is a season of very low temperature it has been found that the cost of supplying additional heat to raise the temperature of inner window Surfaces to above condensation temperature over a period of some years may be less than the cost of providing substantially thermally insulated multiple glass window structures in the first instance. In any event, the prevention of ice on metal window structures extending over large areas in Spite of expensive insulation precautions is rendered possible by the more simplified and less expensive construction afforded by this invention.

It will be apparent from the foregoing that the invention generally concerns a frame element for door and window frame structures comprising: an electric-a1 resist- F. In this respect itance heating element of the strip type embodied within a totally enclosing metal casing, said heating element having a rating of the order of about 10 Watts per foot of length; and an enclosure for said heating element extending thereabout and having a radiating Surface of an area per foot of length of said heating element controlling the temperature of said surface to less than about 135 F.

It is intended that the present disclosure should not be considered in any limited sense other than that included by the following claims having regard to the teachings of the prior art.

What I claim is:

1. An electrically heated frame structure for window constructions or the like, comprising: a'metallic bottom frame element having a horizontally disposed top surface, an outer glazing stop fixed to said surface and projecting upwardly therefrom, an inverted metal channel member fixed to said surface inwardly of and parallel to said outer glazing stop and spaced relatively thereto to clamp the lower edge of a glazing unit and glazing strip means between said outer glazing stop and the outer face of said channel member serving as an inner glazing stop, and a metal-sheathed electric heating unit disposed longitudinally within a conduit defined by said inverted channel member and closed by said top surface of said bottom frame element.

2. Structure according to claim 1, said metallic bottom frame element being hollow and having an auxiliary metal-sheathed electric heating unit longitudinally disposed therein.

References Cited in the file of this patent UNITED STATES PATENTS 1,633,451 McLaughlin et a1. June 21, 1927 1,665,031 Herman Apr. 3, 1928 1,822,884 Creighton Sept. 15, 1931 1,848,337 Franzen Mar. 8, 1932 1,885,127 Milette et a1. Nov. 1, 1932 2,548,363 Gray Apr. 10, 1951 2,594,465 Lovfald Apr. 29, 1952 2,803,734 Germon Aug. 20, 1957 2,858,408 Barroero Oct. 28, 1958 FOREIGN PATENTS 329,513 Switzerland June 14, 1958

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