WO2002070957A1

WO2002070957A1 - Heating panel

Info

Publication number: WO2002070957A1
Application number: PCT/AU2002/000258
Authority: WO
Inventors: Barry Ernest Pillinger
Original assignee: Barry Ernest Pillinger
Priority date: 2001-03-08
Filing date: 2002-03-08
Publication date: 2002-09-12
Also published as: AUPR358201A0

Abstract

A heating panel (10) comprises a laminate of a first sheet (12), a second sheet (16), and a bonding medium (18) adapted to bond together the first sheet (12) and the second sheet (16). The bonding medium (18) is a rapid cure resin, and has embedded in it a heating pad (20) which, when it is supplied with electrical energy, heats the first sheet (12) such that heat is able to be transferred from the first sheet (12) to the atmosphere or to any other substance in contact with or close to the panel (10). The heating element (20) may be in the form of an electrical resistance heating element or a polyester substrate printed with a conductive ink, in the latter case with electrical energy to the heating element (20) supplied through upper (68) and lower (26) bus bars. A thermostat (54) or a voltage regulator may be provided to control the supply of electrical energy to the heating element (20) to regulate the temperature of the heating panel (10).

Description

HEATING PANEL

This invention relates to heating apparatus, and more particularly relates to heating panels.

Fixed heating systems usually take the form of ducted heating and/or airconditioning systems, with outlets in the floor or ceiling. Such systems, which circulate heated air, which air may be contaminated with dust, pollens, dust mites, bacteria and the like. Those systems may be considered to be "unhealthy" systems. Underfloor heating, using electric resistance coils or hot water circulated in pipes in a slab, have also been used, although with such systems there is a lag between switching the heating off and heat ceasing to emanate from the floor.

Hydronic heating is very popular, although at least in retro-fitted systems the radiator units are located adjacent to perimeter walls, and not in areas away from such walls. There are high costs involved in the installation, operation and maintenance of conventional heating systems, and such systems also occupy a great deal of space. Of course, movable heating units such as fan heaters, column and pad or panel heaters, may be used in domestic, commercial and industrial applications, but such arrangements are usually neither efficient or economical.

There is also a need for an effective and economic heating system for such articles as aquariums, vivariums, plant seedling trays, incubators and the like.

It is an object of this invention to provide an improved heating. system and a heating panel for use in such a system.

The invention provides a heating panel including first sheet means, second sheet means, and a bonding medium adapted to bond together said first sheet means and said second sheet means, said bonding medium being associated with heating means, said heating means being adapted to heat at least part of said assembly.

The invention also provides a method of producing a heating panel, characterised by the steps of: assembling first sheet means and second sheet means with a gap between said first sheet means and said second sheet means;

locating heating means in said gap and/or adjacent to said first sheet or said second sheet; and

filling at least part of said gap with a bonding medium, such that said first sheet means and said second sheet means are bonded together, and such that said heating means is embedded in said bonding medium.

The invention further provides a panel including first sheet means, second sheet means, and a bonding medium adapted to bond together said first sheet means and said second sheet means, said bonding medium being associated with infrastructure means such that said infrastructure means occupies at least part of the region between said first sheet means and said second sheet-means.

Embodiments of the invention, which may be preferred, will be described in detail hereinafter, with reference to the accompanying drawings, in which:-

Fig. 1 is a side elevation of a heating panel, in accordance with an embodiment of the present invention;

Fig. 2 is an exploded view of the panel of Fig. 1 ;

Fig. 3 is a plan view of one form of electrical connection which may be used with the panel of Figs. 1 and 2; and

Fig. 4 is a plan view of one form of heating element arrangement for use in the panel of Figs. 1 to 3.

The present invention has for its aim a panel which is able to double as a heating panel and as a building partition or wall, or ceiling panel. Turning firstly to Fig. 1 , the illustrated embodiment of a panel 10 includes a first sheet of material. A second sheet of material 16 is located adjacent to first panel 12. Sheets 12 and 16 are bonded together by a bonding medium 18, in which a heating element 20 is located.

The panel 10 in its simplest form, that shown in Fig. 1, may be seen as a lamination of two sheets of material (12, 16) by a bonding agent 18, thus forming a laminated panel 10 of material, which includes a heating element 20 embedded in the bonding medium.

Fig. 2 shows in exploded form a more detailed view of the panel 10 of Fig. 1. In Fig. 2, the three sheets, the first sheet 12, the second sheet 16, and the bonding medium 18 (in a solidified form) are shown in a preferred situation in which at least the external dimensions of the sheets 12, 16 are substantially identical.

Bonding medium 18 bonds sheets 12, 16 together. It is to be understood that sheets 12, 16 may be formed from any suitable material, but that glass is preferred. It may well be that at least sheet 16 may be made from an alternative material. Preferably, the bonding medium 18 is a semi-translucent rapid cure resin material. The thickness of the bonding medium 18 in the assembly 10 may accordingly be within the limits of the manufacturer's specifications.

It may be possible, during the manufacture of a panel 10, to pour the resin liquid between sheets 12, 16 at intervals, and allow it to set between each layer. The resin may have a dye therein, to provide a multi-colour effect. The layers do-not need- to be parallel, as the glass fabrication may be tilted as required.

The heating means for the panel 10 is preferably in the form of an electrical resistance heating element 20, depicted by broken lines in Fig. 2. More preferably, the heating element 20 is of a type which incorporates a polyester film substrate printed with a conductive vinyl baked ink with one or more bus_bars (preferably of copper, which may be tinned, but alternatively of solder or silvered, or of conductive foil) located near the outer edges of the opposite sides of the conductive ink, which may be covered by an insulation layer (not shown), similar to the substrate, with a selvedge (not shown) protruding beyond the bus bars. A particular example of such a heating element 20 is shown and will be subsequently described in relation to Fig. 4.

The heating element 20 will preferably be prepared prior to the lamination process by suitably affixing (preferably by soldering) electrical leads 22 and 24 (Fig. 3) to a bus bar 26 (Figs. 3 and 4). The thickness of the heating element 20 will be minimal, particularly in relation to the thickness of the sheets 12, 16 and the bonding medium 18; the thickest section is anticipated to be near the bus bars 26, 68.

Alternative heating elements may be used, in which other conductive media such as foil conductive material may have terminal connections similarly closely positioned.

Alternatively, conductive ink or another equivalent conductive substance may be applied, by, for example, printing, to a surface of sheet 12 and/or sheet 16. The preferred surface for the location of such an ink or substance, is the rear surface of sheet 12. The conductive ink or substance may be connected to copper strips or the like for the supply of electricity to the heating element. Bus bars may be secured to the appropriate pane(s) on either side of the (carbon) electro-conductive lines of the printed element to complete the electric circuit. The dimensions of the heating element 20 may be varied, and may be in the form of a singular sheet in the form of multiple sheets suitably connected for satisfactory connection to electrical power, and satisfaction of assembly.

One form of heating element of the foil type does not require a bus bar, and has a "maze" pattern, and as a consequence the terminal points for the connection of the element to a source of electrical energy may be located in any position, although a preference would be for a connection along any one outer edge of the pattern. The use of such an alternative heating element would enable the position of the electrical connection to be altered from the position shown in the embodiment of Figs. 3 and 4.

The type of glass sheet which may be suitable for use as sheet 12 and/or sheet 16 is termed "low-E glass", one manufacturer of which is CIG, the. Commercial Insulating

Glass Company of the United States of America. Low-E glass is also made by Pilkington: the Pilkington web site www.low-eqlass.com. operated by Pilkington Building Products of the United states of America, describes low-E glass as being produced by a pyrolytic coating system which applies a consistent, effective layer of tin-oxide to a glass surface, through chernical vapour deposition. The low-E glass is toughened by a heat treatment process, and both the glass and the electro- conductive surface thereon are translucent. A translucent bonding medium, in the form of a rapid cure resin, is available for use as bonding medium 18.

The bus bar used on the low-E glass is a silk-screening application of liquid metallic fluid which is electro-conductive. The sheet may have such an electro-conductive surface on one entire face of the sheet. A tool is then used to scribe a channel to isolate the perimeter of the sheet, and a bus bar is applied to opposite sides of the remaining electro-conductive facing. It may not be necessary for leads from the bus bars to be physically close together. It is likely that the bus bars will be connected with leads individually, and to have each lead exit from respective ends of what may be the "active" area, that is the lower area, to be described in the next paragraph.

It is proposed that a sheet of low-E glass be "sandwiched" between two panes of mirror glass, to provide a mirror surface on both sides of the assembly. The reflective surface is only required on the lower part of opposite sides, and that is the only part to be heated, and accordingly the internal low-E glass pane has an area scribed within that lower area where the mirroring will be retained and be "active". Preferably, the mirror sheets will be sandblasted to remove the mirroring from the upper parts thereof.

The bonding medium is preferably tinted and semi-traήslucent, is located between sheet 12 and the central or internal low-E glass sheet, and between the low-E glass sheet and sheet 16. The heat of the low-E glass sheet may preferably be controlled by a voltage regulator, similar to a dimmer switch used to control lighting levels in dwellings, and no thermostat is used.

Alternative heating panel arrangements include a laminate of one mirrored or partially-mirrored sheet, and one sheet of low-E glass, the latter providing the heat, as described in the preceding five paragraphs. The panel assembly 10, which has been stated is in the form of a laminate, may be produced in any suitable manner. One method of producing the laminate is to locate sheets 12, 16 a predetermined distance from each other, with sheet 16 to the rear of sheet 12. Heating pad 20 is located in the gap between sheets 12 and 16, and is held in registration in that position by the location of part of a junction facility 30, to be described hereinafter, in aperture 34 in sheet 16.

Three sides of the preliminary assembly of sheets 12 and 16 and heating pad 20 may be closed, for example by placing adhesive tape along three sides of the gap between the sheets 12 and 16 to close off the gap along those sides, with the open side at the top of the preliminary assembly. A preferred tape may be narrow-width 3M (Trade Mark) double-sided adhesive tape. The bonding material 18, in the form of a liquid rapid-cure resin material such as Synolite 40-6519, produced by Dulux Resins, may then be poured in through the top, until it reaches a predetermined level. The top gap may also then be sealed with adhesive tape or the like, and the preliminary assembly is then laid flat until the resin cures, at which time the assembly 10 is created. A hardener may be necessary to cure the resin material.

In an alternative embodiment, the element 20 is fixed in position with the same type of double-sided adhesive tape as that which surrounds the perimeter between sheets 12, 16. The double-sided tape is positioned on the rear of the mirror pane in (in use) vertical strips, arranged at intervals. The element 20 is then stretched across the vertical strips and pressed on to the tape, forming a small gap between the element 20 and the sheet to which it is attached. By way of an example, the double-sided tape which is located around the perimeter of the-assembly of the two sheets 12, 16 may be 3 or 4 layers thick, while that retaining the element 20 in place may only be two thicknesses. This keeps the element 20 in place, while creating a gap between the element and the mirror sheet for the bonding medium to surround the element 20. The nature of the double-sided tape in question is such that its material is infiltrated by a bonding medium 18, particularly the resin referred to earlier in this specification, such that the tape becomes, virtually, a continuation of the mass of the bonding medium 18 and no weakness occurs within the assembly 10. In Fig. 2 an exposed section 28 of heating element 20 is shown, which section includes sections 60, 62 of bus bar 26 (Fig. 4). A junction facility 30, which may be a preferred form of connecting heating element 20 to a source of electrical power, is also shown. A flanged base portion 32 of junction facility 30 is intended to be attached to the exposed portion 28 of heating element 20. The base portion includes a planar part and a cylindrical part, the latter being adapted to protrude, in the final assembly 10, through a circular aperture 34 in translucent sheet 16. The junction facility 30 may be formed from any suitable material from which a similar unit, such as an electrical terminal block, may be formed. One preferred material may be polyvinyl chloride (PVC).

Base portion 32 is preferably attached to exposed portion 28 of heating element 20 by means of pressure sensitive adhesive means 38 or by any other suitable method. The electrical connection will be described with reference to the description relating to Figs. 3 and 4. In the panel assembly 10, a cover 36 will be placed on that part of base portion 32 which protrudes through the aperture 34 in sheet 16.

Fig. 3 shows one form of junction facility 30 for electrically connecting heating element 20 to a source of electrical power. A power cord 40 supplies electrical power, and may be physically clamped to the junction facility 30 by a "saddle" or other cord anchor 70. The wires 42, 44 of power cord 40 are connected to a terminal connecting device 46. Lead 22, which is connected to wire 44 through block 46, is connected to terminal 48 on one section of bus bar 26. Lead 50, which is electrically connected to wire 42 through block 46, is connected to terminal 52 of thermostat 54. Lead 24 connects terminal 56 of thermostat 54 to terminal 58 on another section of bus bar 26.

In some instances a junction facility such as junction facility 30 may be omitted. An arrangement may be such that wiring exits from between sheets 12, 16 and is connected externally of the panel 10 to a source of electricity. Alternatively, a connecting device may be sandwiched between sheets or panes 12, 16 in the form of two "spade" terminals (male or female), to permit a "plug-in" arrangement. The exemplary heating element 20 of Fig. 4 is suitable for use with the assembly of Figs. 1 and 2, and with the junction facility 30 of Fig. 3. It may have the specifications of the "Flexel Model Mk 4" produced by Flexel International Limited of the United Kingdom. The element 20 includes the aforementioned printed vinyl ink portion 66, which has a preferred pattern of vertical lines, and which is connected to upper (68) and lower (26) bus bars, which as has been stated previously, are preferably formed from copper. Bus bar 26 has a portion cut out at 64, preferably around the centre thereof. That facilitates the connection of leads, in a manner to be described hereinafter, to the bus bar 26 at respective locations thereon. This results in the flow of electricity through the bus bar 26 to one side of the cutout 64, there being a void section between the printed lines of the ink 66, the void section being directly above the cutout 64, to the opposite bus bar 68, and then through the other portion of ink 66 to the other part of bus bar 26. An alternative heating element may include three bus bars, instead of two. Such an arrangement would enable the heating element to be operated at the Australian/UK voltage of 220V/240V AC, or the United States (and other countries) voltage of 110V AC.

Terminals 48, 58 are on separated portions 60, 62 of bus bar 26 of heating element 20, the separated portions 60, 62 having been electrically separated from each other, by cutting or otherwise separating bus bar 26 at 64 (Fig. 4). Separated portions 60, 62 are revealed by exposed portion 28 of heating element 20. The exposed portion 28 of heating element 20 is accessible through the open end of the flanged junction facility 30. This method of connecting power to a heating element is known as a "2- in-series" connection.

It is to be understood that the particular means by which the wiring connection for providing power to one or more heating elements may be varied according to the type of element or elements used. In addition, a second access point to heating element 20 may be provided.

Thermostat 54 is a non-essential feature of junction facility 30. A basic assembly 10 may not include a thermostat 54, in which case lead 42 may directly connect to terminal 58, and lead 44 may connect directly to terminal 48. However, a thermostat such as thermostat 54 is preferred. The thermostat 54 is adapted to be attached to heating element 20 such that the temperature of the element 20 activates the thermostat 54. When the temperature of the element 20, at the point where it is connected to thermostat 54, reaches a predetermined level, the electric circuit powering the element 20 will be opened, switching off the electrical power until the temperature drops below the predetermined level. At that time, the bi-metal contacts (not shown) of thermostat 54 will close to again allow electricity to flow to the heating element 20.

The thermostat 54 may be of the self-enclosed heat sensing type or may have an external sensor which may extend to another section of heating element 20 or of the assembly 10, such as the sheet 12. In such an arrangement, the thermostat 54 does not need to be affixed to the surface of the heating element 20.

As an alternative to thermostat 54, a voltage regulator, similar to a dimmer switch of the type used in dwellings to control light levels, may be used as a heat control mechanism for assembly 10.

A further embodiment of the invention, which may be preferred, includes the provision of a fuse, either of a conventional fuse-wire type or of a circuit-breaker type, which when overloaded will cut the supply of electricity to the heating element 20. Another embodiment of the invention envisages allowing the temperature of the heating element 20 to change (in particular rise) at the same rate as the ambient temperature, by the use of a self-regulating element which has a high resistance to prevent overheating, and which may accordingly result in a thermostat not necessarily being fitted to the assembly 10.

Removable cover 36 of junction facility 30 is preferably fashioned to permit the two- core power cord 40 to enter the junction facility 30. Furthermore, if a fuse is to be used, it may be integrated into the circuit, and housed within the junction facility 30.

The final panel assembly 10, in the form of a laminate, is designed to be used as or in a wall, ceiling, partition or the like, or as a heating panel for use with or as part of articles such as aquariums and the like, as will be described hereinafter. When the heating pad 20 is energised, it will heat the panel assembly 10, in particular the sheet 12. When the sheet 12 is so heated, it will in turn heat the air in the space in which the panel 10 is located. Alternatively, if the panel 10 is in contact with part of an aquarium, vivarium or the like, for example the base thereof, or is incorporated into such an article by forming one or more of the base, side walls and like, the panel 10 will transfer heat directly to the article, and/or to the contents of the article, such as the water (in the case of an aquarium), soil, rocks and the like (in the case of an aquarium or a vivarium), soil or potting mix (in the case of a seedling tray) or the like.

The panel of the present invention, including the panel 10 of the described embodiment of the invention, is suitable for use as, or as part of, a partial wall, a partition, a complete wall, a ceiling or the like. It is felt that the panel of this invention may be unsuitable for use as a floor heating panel, should the preferred material (glass) be used. Such panels may form a single wall (or part thereof), multiple walls and/or dividing walls (or parts thereof) between rooms, or may be conjoined one to the other to border two or more walls of a room or a similar area. They may also be used as ceiling panels, to radiate heat from above.

A wall, partition or ceiling panel contemplated by the present invention may effectively be a panel such as panel 10, or may include one or more such panels 10. The number and size of panels such as 10 would be selected in accordance with the size of the room/space/enclosure, such that the required amount of heat would be provided by element 20 in the panel or panels 10.

If the wall consisting of or including one or more panels such as 10 is a dividing wall or partition, heat will be transmitted in both directions and would be a particularly efficient - and energy-saving - means of heating the areas on both sides of the wall.

In an arrangement in which a wall consisting of or including a panel such as 10 is used as a boundary wall or as a ceiling panel, it may be desirable for one of the sheets 12, 16 to be insulated or heat-reflecting, so that heat from the element 20 only emanates from one side of the panel 10. That may also be preferred when the panel 10 is used to heat an article, as described hereinbefore. It is a preference for panels such as 10 to have the sheets 12, 16 formed from glass, which means that as the sheets 12, 16 are bonded together by bonding medium 18 a laminate is formed, one which will not shatter into dangerous shards of glass if broken. The outer edges of the sheet may be clean cut, smooth-edged or bevelled, and the panel 10 may be enclosed in a frame or the like in a suitable manner. The latter arrangement may involve, in a boundary wall situation, where one of the sheets 12, 16 may be formed from an insulating material, the addition of a layer of insulation, at one side of the panel assembly 10. Access to the junction facility 30 should, however, be able to be maintained.

By way of a preference, it is felt that laminated heating panels 10 may be located in a frame such as a moulding, for example an extruded moulding. It may be that mouldings of plastics material, such as PVC, may be suitable for the location of the base and/or one or more sides and/or the top of a panel such as panel 10. In other words, extruded PVC mouldings may be fitted to be fitted around the sides, corners, doorways and so on, to construct walls for an enclosed area. It may also be possible to use such mouldings or channelling which incorporate wiring, or bus bars or power stripping, to supply power to the elements 20 embedded in the panels 10 forming at least part of such a wall.

One option, where substantially clear glass is used for sheets 12, 16, is to obscure element 20 by using a pigment in the rapid cure resin 18 bonding the sheets 12, 16 together. Alternatively, a form of etching on the glass of the sheets 12, 16 may be used, or the use of surface paint suitable for use on glass, may be used to obscure the element 20.

The area of panel 10 which has no element 20 embedded therein may use the natural (semi-translucent) colour of the rapid-cure resin, or may contain a pigment or the like for decoration, which may provide partial privacy or total privacy if viewed from the other side of a wall formed from the panel 10. The division of the two colours (or more if further variations are required) may be achieved by allowing one area of resin to cure before adding another amount of resin of another colour to complete another layer or section of the bonding medium 18. The form of heating provided by a wall, partition, ceiling panel or the like formed by or including a panel such as panel 10 uses little energy, and the temperature of the heated section of the wall/panel may be maintained at a moderately low temperature which will nevertheless provide adequate heating and comfortable warmth for a habitable room or area. The temperature of such an area may be regulated by a thermostat which may be suitably situated, and will operate to automatically switch on electrical current to the embedded element 20 and consequently heat the enclosed area as required.

Other items may be located between the two sheets of a panel in accordance with the present invention, in addition to a heating element. Alternatively, such item(s) may be present even though a heating element is not.

One example of a class of such an item are cables, conduits and the like, for example electrical cables, telephone cables, audio/visual cables, data cables and the like, which may be located in the region between the two sheets, and embedded within the bonding medium. Such cables may exit at the top, bottom or sides of a panel and from there may be placed in the aforementioned tracks used to secure the panels in place, and/or other features relating to the panels such as frames therefor. Another example of such an item is the provision of lighting between the two sheets of a panel. It is envisaged that lighting means, preferably although not exclusively for room illuminatioh, may be located in the same general manner as described in relation to the heating element 20 of Fig. 1.

It is felt that decorative or informative lighting lends itself best to such an. application, and it may well be that low-voltage (for example 12V) lighting may be suitable, and/or with low-wattage bulbs. LED lighting may be even more suitable. It is envisaged that such lighting, which may be visible through one or both of the sheets of a panel, may be used simply in a decorative manner, as a kind of wallpaper formed from lights, and/or may be used to convey a message, fixed, flashing, changing or the like. The lighting may be used to provide an analogue or digital clock visible from one or both sides of a panel. It would even be possible to run news stories on an arrangement of lights on one or more panels. One embodiment which would be of importance in a fire situation involves the placing of lighting within panels, visible from one or each side, and located in use close to the floor, for use as emergency lighting such as that used in aircraft.

Of course, the power supply, control means and the like necessary for such items may all be located elsewhere, for contact with cabling, bus bars or the like associated with the item(s) in the panel.

It is further envisaged that an area of a panel which utilises one transparent or translucent sheet, may be provided with a coloured bonding medium, for example white, which would enable the panel to be used as a projection screen for film, video, computer, slide presentations and the like.

The panels could also be decorated with etching, or may be painted, or the like, to produce a picture, design, lettering or the like which may be visible from one or both sides. That is in addition to the previously-described use of layers of multi-coloured bonding media.

The heating panel of the present invention may also be used as an equivalent of a heated towel rail. Heated towel rails are widely used, and consist of one or more generally cylindrical, horizontally-disposed rails, as part of a structure which is freestanding or wall-mounted. Heating elements within the rails heat the material of the rails, such that damp towels draped over the rails may be heated, and dried as a result.

Conventional towel rails have disadvantages. The small area of contact between a rail and a towel draped over it, means that much reliance has to be placed on heat transfer from the rail to the towel by convection, rather than by direct transfer. In addition, there are safety aspects. The heated rails are quite hot, and when contact with such rails is made by a person, especially a child, discomfort and possibly burns may occur. Children may also wish to climb up the rails of a towel rail arrangement, as they tend to do with railings in general.

A towel heater utilising a heating panel in accordance with the present invention would be more efficient than a conventional heated towel rail, and would be safer. The larger surface area of the panel in contact with, or close to a towel draped over such a panel, means that heat transfer is carried out more efficiently. In addition, because a towel warmer including a heating panel according to this invention would be, in use, a substantially flat, vertical sheet, children are unlikely to wish to climb on it. And the fact that the panel is effectively a safety laminate means that even if glass sheets are used, there is no danger to users of the warmer.

A towel warmer including one or more heating panels according to the present invention, may be free-standing or wall-mounted. Earlier in this specification, there has been described the use of a frame in which a heating panel may be mounted, and it is felt that that sort of arrangement would be suitable in a towel warmer utilising a heating panel according to the present invention. It is felt that the "plug-in" power connection arrangement described earlier in this specification may be suitable for the "towel warmer" embodiment of the present invention.

The heating panel of the present invention may also be used in other applications. Such a heating panel may be used anywhere where heated surfaces are required. EΞxamples are heated glass shelves, heated glass doors, such as used in refrigerators, and installations for warming and/or dehumidifying, such as food and beverage warmers. A cabinet or other structure for heating, warming or keeping items heated or warmed may have at least one side comprised of a heating panel according to this invention, as well as or in place of upper or lower surfaces in the form of heating panels, or shelves in the form of heating panels.

It can be seen that this invention provides an improved system for heating a room, area or the like, one which is efficient and cost-effective, and which is more healthy than air-circulating conventional heating systems. As has been stated, the panel and system may be used, not only for heating a room or other area to make the area comfortable for human occupants, but may be used to warm any article, but for effectively and economically heating such articles as seedling trays for the propagation and growth of plants, and incubators for incubating eggs and the like.

The heating panels of this invention may have one or both sheets, forming the sides thereof, mirrored or partially-mirrored. The entire contents of the specification and drawings of Australian provisional patent application no. PR3582 are hereby incorporated into this specification.

The claims form part of the disclosure of this specification.

Claims

1. A heating panel characterised by first sheet means, second sheet means, and a bonding medium adapted to bond together said first sheet means and said second sheet means, said bonding medium being associated with heating means, said heating means being adapted to heat at^" least part of said assembly.

2. A heating panel according to claim 1, characterised in that said heating means is adapted to heat at least one of said sheets, which in turn is adapted to provide heat to an area.

3. A heating panel according to claim 1 or claim 2, characterised in that said heating means is embedded within said bonding medium.

4. A heating panel according to any preceding claim, characterised in that said heating means is an electric resistance heating element.

5. A heating panel according to claim 4, characterised in that said electric resistance heating element is in the form of a film substrate with a conductive ink or other conducted substance applied thereto, for example by printing.

6. A heating panel according to claim 4, characterised in that said conductive ink or substance may be applied to one surface of said first sheet or said second sheet.

7. A heating panel according to any one of claims 4 to 6, characterised in that said electric resistance heating element is of a foil type with a "maze" pattern.

8. A heating panel according to any one of claims 1 to 3, characterised in that one of said sheets has an electro-conductive layer applied to one surface thereof, which layer may be scribed to form said heating element.

9. A heating panel according to claim 8, characterised in that said one of said sheets is a sheets of low-E glass.

10. A heating panel according to any preceding claim, characterised in that said heating panel is in the form of a laminated sheet assembly.

11. A heating panel according to any preceding claim, characterised in that electrical power is supplied to said heating element through a junction facility.

12. A heating panel according to any preceding claim, characterised in that a thermostat is located in the electrical circuit supplying electricity to said heating element, said thermostat monitoring the temperature of said heating element, directly or indirectly.

13. A heating panel according to any one of claims 1 to 11 , characterised in that a voltage regulator is located in the electrical circuit supplying electricity to said heating element such that the temperature of said heating panel may be regulated.

14. A heating panel according to claim 2 or claim 13, characterised in that a fuse is located in the circuit supplying electrical power to said heating element.

15. A heating panel according to any preceding claim, characterised in that said heating panel is adapted to constitute all or part of a wall, ceiling, partition or the like.

16. A heating panel according to any preceding claim, characterised in that said heating panel is located in a frame or support.

17. A heating panel according to any preceding claim, characterised in that

Infrastructure means may be located between said first sheet means and said second sheet means, such that said infrastructure means occupies at least part of the region between said first sheet means and said second sheet means.

18. A heating panel according to claim 17, characterised in that said infrastructure means may be embedded in said bonding medium.

19. A heating panel according to claim 17 or claim 18, characterised in that said infrastructure means is lighting means, and is adapted to be visible through at least one of said first sheet means and said second sheet means.

20. A heating panel according to any one of claims 17, 18 and 19, characterised in that said infrastructure means may be cabling or the like, which may be adapted for use as a means to supply power, telephone, data or like services.

21. A device for warming objects, characterised in that said device includes at least one heating panel according to any preceding claim.

22. A device according to claim 21, characterised in that said device is for warming objects such as clothes, towels and manchester.

23. A method of producing a heating panel, characterised by the steps of:

assembling first sheet means and second sheet means with a gap between said first sheet means and said second sheet means;

24. A method according to claim 23, characterised in that at least one of said sheet means is a glass sheet.

25. A method according to claim 23 or claim 24, characterised in that both of said sheet means are glass sheets.

26. A method according to any one of claims 23 to 25, characterised in that prior to the filling of the said gap with bonding medium, said heating means is secured to and spaced from one of said first sheets means or said second sheet means by double-sided adhesive tape.

27. A method according to any one of claims 23 to 26, characterised in that prior to the filling of the said gap with bonding medium, said first sheet means and said second sheet means are secured to and spaced from each other by double-sided adhesive tape.

28. A panel including first sheet means, second sheet means, and a bonding medium adapted to bond together said first sheet means and said second sheet means, said bonding medium being associated with infrastructure means such that said infrastructure means occupies at least part of the region between said first sheet means and said second sheet means.

29. A panel according to claim 28, characterised in that said infrastructure means are lighting means, and are adapted to be visible through at least one of said first sheet means and said second sheet means.

30. A panel according to claim 28 or claim 29, characterised in that said infrastructure means may be cabling or the like, which may be adapted for use a power, telephone, data or like services.