OA13083A - Energy efficient window. - Google Patents

Description

013083

ENERGY EFFICIENT WINDOW

TIELI) OP THE INVENTION 5 The présent invention relates to an energy efficient window and, in pardcular, to a desiocation System for energy efficient Windows.

BACKGROUND OF THE INVENTION

Windows or glass areas are a significant weakness in heat insnlation schemes forbuildings in hot or cold climates. A basic insulating window that is well-known is 10 constructed from two panes of glass within a rigid trame. The air space between the panes provides heat insolation. ït is also known to evacuate die air space or to fîD the air space witha gas of lower thermal conductrvity than air such as argon. One iurther method of erihancmgthe insulating value of such a window is to provide transparent partitions between the outerglass panes to reduce convective heat transfer within the unit This may increase the air 15 volume within the unit wfaich may cause pressure-related difficulties to develop if die air volume is not vented. If the air volume is vented, a means of desiccatmg the air entering theunit must be provided.

Other technologies include providing selectively reflecting or low-emissivity coatings' 20 to reduce radiant heat transfer through the window. As well, there hâve been significant improvements in the window frame, both in. the union of the glass panes and the design andmateriel of die frame. The layers of glazing in an insulating unit must be held apart at theappropriate distance by spacers. Eecause of rts excellent structural properties, windowmanufacturera hâve used aluminum spacers. Unfortunately, aluminum is an excellent 25 conductor of heat and the aluminum spacer used in most standard edge Systems represented asignificant thermal "short circuit" at the edge of the insulating glass unit, wliich reduces thebenefits of improved glazings. In addition to the increased heat loss, the colder edge is moreprone to condensation. 30 InU.S. PatentNo. 4,563,843 (assigner!to SulzerBros.Limited), aheatinsulating 013083 window is described which includes outer glass panes and transparent partitions within the airspace to suppress convective air flows. The frame includes opposing metallic frame memberswhich are structarally joined together and separated by non-metallic webs to avoid thermalbridging between the inner and outer frame menibers. A thermoplastic piece serves as aspacer between the glass planes and to retain the transparent partitions. Other connectingwebs define a drying chamber between the frame members which is filled with a desiccant.The outside of the frame is sealed with hot melt butyl and thin métal foils which hâve lowthermal conductance and provide eSective vapour barriers. It is necessary to vent the airspace because of the large volume of air within these Windows. If not vented, internaiwïndow pressures would increase to unacceptable levais, sufficient to break frie glass inexterne instances, as a resuit of températures changes created by solar radiation. Becausewater vapour within the air space may resuit in condensation which impairs the transparencyof the window unit, the air being vented into the aïrspace must be desiccated.

The drying chamber formed in the Sulzer patent is defined by the web and framemembers and sealed within the window unit. Therefore, the desiccant is pennanentlyinstalled within the window unit and cannât be replaced without destructively dïsmantiing thewindow.

Therefore, there is a need in the art for an energy efficient window unit which includesa spacer configuration and desiccant System mitigating the difficulties posed by the prior art.

SUMblARY OF THE INVENTION

The présent invention is directed at energy efficient Windows having an advanceddesiccant system. Therefore, in one aspect, the invention comprises a heat insuîation windowcomprising: (a) a pair of outer panes defming an air space tharebetween; (b) a spacing member disposed between the outer panes which maintain the panesin a spaced-apartrelationship, the spacing member being hoîlow and defîningopenings permitting gas communication between the air space and the interiorvolume of the spacing member; -2- 013083 (c) a desiccant material contained within the spacing member; and (d) a frame suirounding a perimetex of the window, wherein ihe fiame comprises: (i) at least one desiccant concealing member wfaich is hollow anddétachable from the fiame; (ii) a desiccant cartridge removably disposed witbin the desiccantconcealing member and (iii) conduit means for providing gas communication between the air spaceand the desiccant cartridge.

The conduit means provides gas communication between die interior volume of the spacingmember and the desiccant cartridge and may preferably be a tube. The desiccant cartridgepreferably comprises an elongated cylindrical tube winch fits wifhin the desiccant concealingmember, which.is preferably elongated and has a substantially U-shaped cross-sectionalprofile.

In one embodiment, the fiame comprises an outer chaxmel member, an inner channelmember, a web member disposed between the outer and inner channel members, and thedesiccant concealing member îs detachably connected to the inner channel member.

BRIET DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of an exemplary embodiment with 'reference to the accompanying simplified, diagrammatic, not-to-scale drawmgs. In thedrawings:

Figure 1 is a perspective view of one embodiment of the présent invention.

Figure 2 is a cross-section of one embodiment of a window unit of the présentinvention along line 2-2 in Figure 3.

Figure 3 is a cross-section of lhe embodiment of Figure 2 along line 3-3 in Figure 2. -3- 013083

DETAJOLED DESCRIPTION OF THE INVENTION

The présent invention provides for an. energy efficient, heat insulating window design.When describing fhe présent invention, ail tenns not defined herein hâve their conmon art-recognized meanings.

Figure 1 shows an interior view of a window unit comprising dual glass panes (10,12)and a trame (14).

Figures 2 and 3 show cross-sections of the glass panes (10,12) spaced apart hy aspacer (16) and held togefher by the fiame (14). The cross-sectional plane of Figure 2 isnormal to the cross-sectional plane of Figure 3. Although for référencé proposes, Figure 2will be described as a vertical cross-section and Figure 3 is a horizontal cross-section, thoseorientations are not essentiel and may be reveised.

The trame comprises an outer charmel member (18), an inner channel niember (20)and dual mtermediate web members (22) which join the inner and outer channel members..The inner channel member may include an installation flange (24) which proiects outwardlyand will ahut a window jamb (not shown) when installed into a wall fiame. A removabledésiccant concealing member (26) is attached to the inner channel member (20) opposite theinstallation flange (24) which serves to retain the glass unit but does not serve any otherstructural fonction. The désiccant concealing member (26) is tube-shaped defming a singleelongate channel (28). One edge of the charmel defines a first lip (30) while the other edge ofthe channel defines a second lip (32). The two lips (30,32) mate with coiresponding grooves(31,33) fonned in the inner channel member (20).

The glass planes are positioned and retained by résilient seals (34, 38). Seal (34) isattached to the outer channel member (18) while seal (36) is attached to the inner channelmember (20). Air seal (38) is attached to the désiccant concealing member (26). The sealsare preferably formed fiom a material having low thermal conductivity and relativelyimpervious to moisture, such as neoprene, epdm or silicone iuhher..

In aprefeired embodiment, a dual désiccant System is employed. The spacer is a -4- 013083 hollow rectangular member which is filled with a suitable desiccant (40). The spacer defrnespores which allow air to circulate hetween the air space between fhe glass panes (10,12) andihe interior volume of the spacer which contains fhe desiccant. As well, a small conduit (42)connecte the interior space of the spacer to a sealed tube (44) within the desiccant concealing 5 member (26) which is filled with desiccant (40). The sealed tube (40) has a cap (46) whichreceives the conduit (42) thereby providmg gas communication between the spacer interiorvolume and the desiccanttube (44).

As is apparent, the desiccant concealing member (26) may be removed fiom the ftame 10 (14) by disengaging the lips (30,32) fiom the inner charnel member (20), thereby exposing the desiccanttube(44). The desiccanttube (44) canthenbe easily disconnected fiom theconduit (44) and replaced with a fiesh desiccant tube if necessary. hi one alternativeembodiment, the desiccant in the desiccant tube may be different from the desiccantcontained in the spacer and has a higher affinity for water than the desiccant in the spacer. As 15 will be appreciatedby those skilled in the art, air which is drawn into the air space must pass through the replaceable desiccant tube, thereby preserving the dry atmosphère within thewindow unit

Desiccant tubes (44) may be placed in one, two, three or ail four desiccant concealing 20 members (26) m any orientation.

The outer, intermediate andirmer channel members which comprise the ftame (14)may be foimed from a thennoplastic material having low thermal conductivity such aspolyvinylchlori.de or polyamide. Altematively, fhe inner and outer channel members may be 25 metallic members such as aluminum while the intennediate member is non-metallic, avoidinga thermal bridge between the two. The desiccant concealing members may be any suitablematerial such as a métal or a plastic, provided that it is résilient to facilitate its installation andremoval fiom the hmer channel member. 30 As will be apparent to those skilled in the art, various modifications, adaptations and variations of the foregoing spécifie disclosure can be made without departing fiom the scopeof the invention claimed herein. The various featoes and éléments of the described invention -5- Û 1 3083 may be combined in a marner different from ibe combinations described or claimed hereïn,without departing from the scope of die invention. -6-

Claims (8)

013083 WHATIS CLÀJMEDIS:

1. A beat insulation window comprising: 10 15 (a) a pair ofouter panes defining an air space therebetween; (b) a spacing member disposed between the outer panes which maintain the panesin a spaced-apaxt relationship, the spacing member being holîow and definingopenings penmrtting gas communication between the air space and the interiorvolume of the spacing member; (c) a desiccant material containsd within lhe spacing member; and (d) a fiame surrounding a pèrimeter of the window, wherein fhe fiame comprises: (i) atleastone desiccant concealing member which ishollow anddétachable from the frame; (ii) a desiccant cartridge removably disposed within the desiccantconcealing member and (iii) conduit means for providing gas communication between the air spaceand the desiccant cartridge.

2. The window of claim 1 wherein the conduit means provides gas communication between the interior volume of the spacing member and the desiccant cartridge.

3. The window of claim 1 wherein the desiccant cartridge comprises an elongatedcylindrical tube.

4. The window of claim 1 wherein the desiccant concealing member is elongated and hasa substantially U-shaped cross-sectional profile. 30

5. The window of claim 6 wherein the cross-sectional profile comprises two linear segments joining at a substantially right angle. -7- 013083

6. The window of claim 1 wherein the frame comprises an outer charnel member, aninner channel member, a web member disposedbetweenthe outer and inner channelmembeis, wherein the desiccant concealing member is detachably coimected to the innerchannel member.

7. The window of claim 6 wherein the desiccant concealing member is comprised of arésilient matériel and comprises a first lip and a second lip which each engage an undercutgroove in the inner channel member.

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