CA1175089A

CA1175089A - Modular heated ceiling panel

Info

Publication number: CA1175089A
Application number: CA000391898A
Authority: CA
Inventors: Georges Vasseur
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-12-15
Filing date: 1981-12-09
Publication date: 1984-09-25
Also published as: JPS57124634A; FR2516128A2; FR2516128B2; NO814139L; ES508007A0; EP0055950A1; FI813984L; ES8301309A1; DK552781A

Abstract

ABSTRACT OF THE DISCLOSURE

The invention relates to the field of heated ceilings comprising a heater element layer interposed between a thermally insulating backing and a surface covering.
The technical problem posed is the poor thermal efficiency and difficulty of installation of such ceilings installed on site from separate layers.
The present invention provides a modular panel comprising a heater element layer, and a thermally insulating backing layer secured to the surface covering, which is self supporting, with the backing and surface layers extending laterally beyond the beater element layer.

Description

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Modul_r Heated Ceiling Panel The present invention relates to a modular panel for use in producin~ surfaces heating by radiation, especially for forming suspended heating ceilings, the panel comprising a composite of a heater element energised electrically, interposed between an external decorative surface layer which dissipates the heat by radiation, and a heat impermeable layer. A plurality o~ said panels are ~uxtaposed edge to edge to form a substantially continuous surface and are connected electrically to each other and to the electricity supply.

Heat radiant ceilings have become known with the development of flat heating resistances in the form of heater sheets radiating at a temperature of about 40C over a large 15 area, which enable public or private rooms to be heated economically and safely with comfortable results.
.

Their use has been considerably hindered by difficulties of installation, which involve various craftsmen (specialists in ceiling construction, plasterers, heating engineers and 20 electricians) and must be carefully performed to obtain good quality.

As known hitherto, the installation of heat radiant ceilings comprises the following operations (in résume):

1) electrical mains leads installation

2) putting up a frame or beam

3) stapling up thermal insulation (in strips)

4) stapling up heater sheet ~in strips)

5) soldering supply leads in situ

6) electrical insulation of the edges of the heater sheets

7) electrical connection to supply of each heater 75~

strip

8) putting up a decorative surface layer against the heater sheet without damaging it.

The object of the present invention is to simplify the installation of heated ceilings and provides sets or assemblies of unitary self-supporting panels whose dimensions are suitable for convenient handling (for example 60 X 120cm) which are readily put up without reguiring several craftsmen, but which provide efficient heating of the room in which they are installed.

-The present invention provides a panel for a heated ceiling comprising an electxical element layer interposed between a thermally insulating backing layer and a self-supporting sur~ace covering layer for transmitting heat from said heater element to the room beneath the ceiling r characterised in that before installation said backing and surface layers are secured together in intimate contact with said heater element layer, and extend laterally beyond said heater ele~ent layer whereby said surface covering layer forms a substantially continuous ceiling surface with adjacent layers when installed with juxtaposed similar panels.

Since the layers are in intimate contact, the heating of the decorative surface layer by the heater element is excellent; the contact between the heater element and the heat impermeable layer avoids losses of heat upwards by convection or radiation. These conditions increase the ef~iciency of heat radiation downwards and can be achieved much better than with assembly of the elements ln situ from strip.

30The installation also enables a minimum of heat to be transmitted to the supporting structures and ~o any joints between adjacent panels, which are less subject to linear ..,~

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expansion.

This latter feature is related to the ratio between the thermal resistance of the surface layer in th~ direction of its thickness, and its resistance in the horizontal direction between the active part of the heater element and the edge of the covering.

In an embodiment using plaster board as covering, the transverse thermal resistance is 0,04 and the lateral thermal resistance is 0 r 24 (6 times greater).

The invention leads to high repetitivity in the efficiency and safety of electrical heated ceilings which are suspended or superposed, by avoiding convection losses and thermal blockages which appear when the layers are put up separately on site under the ceiling or roofing by stapling strips, this latter technique producing contact irregularitles.

According to a feature of the invention, the modular panel may have a vapour-proof layer between the underside of the heat insulation being exposed to vapour and/or humidity on the ceiling, the vapour proof layer being of the same width as the heat insulation p~dding.

In accordance with the invention, ~he layers can be secured together by adhesive either over their whole faces or inside border only of the juxtaposed faces, to form self-supporting sub-assemblies.

It is also possible to fix the different layers of the panel together other than by directly adhering one to the other so as to avoid distortion (analogous to a bimetal strip) due to differential thermal expansion of two adjacent layers, either the heat insulator-heater element or the heater element-covering layer. Suitably, when the covering ....

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layer is self-supporting, the heater element can be sand~
wiched between the co~ering layer and the heat insula-tor without being intimately secured to them, for free thermal expansion horizontally.

In a preferred embodiment said heater element layer comprises conductive s~rip buses, and flexible leads for connection to an electrical supply.

The electrical leads may be provided with insulated male and female electrically insulated connector plugs.

In an embodiment of the invention said heater element layer comprises electrical insulator films covering at least one face of said strip buses, and said leads comprising conductors soldered to said buses at their other faces and insulation welded with said insulator film.

In a variant, self stripping electrical connectors may be used for connection to the leads.

In order to ensure electrical insulation at the edges of the heater elements, and at the junctions with the conductors, the edges may be covered with electrically insulating adhesive film and the junctions coated or moulded into an electrically insulating material.

The connection of the conductors to the heater element resistors is obtained by soldering, the flexible core of the conductors passes through the heater element, and the solder joint made like a rivet on the underneath, thus increasing the strength of the joint to pull on the leads. The connection of the leads to the conductors of the heater element can also be obtained by crimping or riveting, directly or through an intermediate member.
~lthough the modules are to be assembled in lines, they ~l75(~
_ 5 _ are preferably connected in parallel, this arrangement enabling each one to be supplied at mains voltage. This arrangement avoids supplying each module through a separate mains cable.

The mains supply to the modules may be obtained from two double-insula~ted electrical cables with the insulation sleeves interrupted at regular intervals for connection to the connectors on the leads of the modules.

The same quick connectors can be used both for connecting the modules together and for connecting the modules to the mains cables.

In accordance with the invention, additional modules without heater elements can also be used, to adjust the overall installed power levels, and for finishing round the edges of the ceiling.

The surface layer may be one of various thin materials used for false cellings, and preferably comprises a sheet of reinforced plaster (staff) either with squared-off edges or with jointed edges. Its width and length may be slightly greater than those of the thermal insulator, which in turn are slightly greater than the size of the heater element.
This arrangement enables the modules to be fixed in place using edge fixings (suspension hooks, reinforced plaster bolsters) commonly used for fixing plaster board, while protecting mechanically the electrically live heater element.
The ends of the heater element foils and the supply leads are electrically insulated using available insula-ting means.

Other features and advantages of the in~ention will appear from the following description, given by way of non-limitative example with reference to the accompanyingdrawings, in which:

~175~g Fig. 1 is a very diagrammatic side elevation of a heater module or modular panel according to the invention;

Fig. 2 is a diagrammatic view of a connector lead used in a ceiling according to the invention;

Fig. 3 shows the method of connecting electrically the heater modules using the connector lead of Fig. 2, in a ceiling in accordance with the invention;

Fig. ~ is a diagrammatic perspective view, partly cut away, of a modular panel in accordance with the invention;

Figs. 5 and 6 are sectional views along the lines II-II and III-III of Fig. 4;

Figs. 7A and 7B are diagrammatic longitudinal sectional views of part of a ceiling including panels of the kind shown in Fig. 4, with support frames respectively hidden and visible;

Fig. 8 is an enlarged detail sectional view of the connection between an electrical lead and a conductive strip of a heater element in the panel of Fig. 4.

In Fig. 1 th~ reference I indicates the surface covering layer, 2 the heater foil, 3 the thermal insulating layer, 4 the flexible electrical supply leads of the modules, 5 and 6 insulated male and female plugs on the supply leads and 7 conductor strip in the foil connecting the leads 4 with the resistor strip in the foil.

Fig. 2 shows a connector lead R comprising an insulated cable, with an insulated male plug 5a at one end and a double insulated female plug 6a at the other end.
Fig. 3 shows the use of connector leads R to connect ~7~

heater modules C together and to the mains supply as described above.

Fig. 4 shows the construction of a modular panel 7 according to this embodiment of the invention. The panel 7 comprises a flat heater element 8 disposed between a self-supporting covering layer or decorative surface 9 and a heat insulating layer of padding 10, for example of glass fibre, as described in the main patent. The heater element 8, formed for example from a resistor or resistors of carbon black in flat sheet or strips comprises conductor strips or buses II, o copper for example, for supplying current, connected to four vertical leads 12 (of which three are shown in the drawing). Furthermore, a vapour-proof layer, in the form of a flat film is inserted between the heater element 8 and the heat insulating padding 10, being secured to the heat insulator by adhesive. In use, in accordance with the invention, the panels are placed side by side in an array as described in the main patent.

The different layers and elements, 9, 10, II and 13 of the panel 7 can all be secured together, for example by adhesive, but in this preferred embodiment, the heater element 8 is mounted freely between the heat insulator 1~
with the vapour-proof film 13, and the surface covering 9, without ~eing secured to the contacting layers, with only the four supply leads 12 going through it. Otherwise, as shown in Figs. 5 and 6, the heat insulator 10 with vapour-proofing 13 has dimensions greater than the heater element 8, to leave a border in which it is secured to the surface covering

9 by patches of adhesive 14 (Fig. 5).

3n Fig. 5 shows a transverse sectional view o a ceiling installed with the panels of Fig. 4, with three neighbouring panels 15, 16, 17 shown at least partially. The covering layers or boards 9 are wider than the heat insulating layers .. ..

1~L75(~39

10 so that they abut underneath support beams or irons 18 o a support structure, to hide the support structure, with the support beams lodged between the facing edges 19, 20 of the heat insulator padding layers 10 of adjacent panels, such as 15-16 and 16-17. The beams 18 are of U-section and shaped blocks 21 of the heat insulating material used for the layers 10 are positioned in the beams 18 and eY~tend to a similar height to the heat insulator layers 10 so as to reduce the sizes of the gaps in the heat insulation to the narrow gaps between the edges 19, 20 of the layers 10 and the facing edges 22 of the blocks 21, so as to reduce or eliminate thermal bridges. Screws 23 fix the self-supporting surface covering 9 of the panels 15, 16 and 17 to the support beams 18.

Fig. 6 shows a longitudinal sectional view of the ceiling and shows the electrical connections between the heater elements 8 of adjacent panels 24, 25 and 26. The connections are effected by self-stripping connectors 27 of non-inflammable material, joining the supply leads 28, 29, 30 and 31 connected to the strip buses II of the heater elements 8 (see Figs. 4 and 8). The same connectors are also used for connecting lines of modules to the supply cables and for insulating electrically the leads of the end modules.

Figs. 7A and 7B are longitudinal sectional views of aajacent modular panels 32, 33 and 34 similar to the panel 7 of Fig. 4 installed in ceilings.

In the ceiling of Fig. 7A, the installation is of the kind shown in Fig. 6, with hidden support beams 18 of U-section supported on the rafters by suspensions 35 to which the panels 32, 33 and 34 are fixed by screws as shown previously. The heat insulator layers 10 are discontinuous, and the gaps are filled as indicated in Fig. 6, the non-insulated borders serving to fix the panels to the beams 18.

~.~L'75(~
_ 9 Fig. 7B shows visible support beams 36 supporting the panels 32, 33 and 34 which themselves are secured to the rafters (not shown) by support mouldings 37 and suspension members 38 shown diagrammatically, such as suspensions threaded rods, nuts and so on. The heat insulating layers 10 reach the edges of the panels so as to leave no significant thermal bridge.
The connection between the leads 12 and the strip buses II of the heater element (see Fig. 1) will now be described. As already described in the main patent, each heater module or modular heater panel is connected electrically by four electrically conducting leads 12 which pass through the thermal insulator formed by the padding 10 (see Figs. 4 to 6), and are secured by soldering, in the edge zones of each heater element 8 to electrically conducting strip buses II.
As shown in Fig. 8, in accordance with the invention, supply leads 39 are used (corresponding to the leads 12, and 28 to 31) which are all similar and comprise dual insulation;
each lead 39 comprises a flexible conductor core 40 surrounded by a first insulating layer or sleeve 41 and a second outer insulating layer or sleeve 42. These leads are non-inflammable and their ends remote rom the strip buses II are stripped of the outer insulator 42 to enable them to be introduced into connectors such as 27 (Fig. 5).
In addition, the leads 39 are soldered perpendicular to the strip buses II of the heater elements 8, traversing the buses at 43. This arrangement, during solderin~, enables the insulator of the leads to adhere to the upper face of the heater element. In particular, the heater element comprises, at least on the parts of its upper and lower faces in the regions of the buses II, upper and lower electrical insulator films 44 and 45. Thus the insulations of leads 33 weld to the film 44 and 46 when the conductors are soldered together, ensuring electrical insulation at the place where s~g the lead passes through the heater element components 44-8-II. Moreover, the welding gives additional mechanical strength against the lead pulling out. In addition, a "rivet" of solder 47 is formed on the underneath face of the heater element 8 with its bus II, which also contributes to the pull-out strength of the lead, the "rivet" being covered by an insulator connecting with the lower insulating film 45.
This embodiment of the invention, due to its design featur~s in modular self-supporting composite form, with the connection modules used during installation of heated ceilings offers in comparison with separate installation of the constituent layers:-a major simplificationan improvement in installation time a reduction in installation cost Its design ensures intimate contact between the layers of the panel, improving the thermal efficiency of the heated celllng .

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A panel for a heated ceiling comprising an electrical heater element layer interposed between a thermally insulating backing layer and a self-supporting surface covering layer for transmitting heat from said heater element to the room beneath the ceiling, character-ised in that said backing layer includes a layer of thermally insulating padding and a vapour proof film be-tween said heater element layer and said padding and that, before installation, said backing and surface layers are secured together in intimate contact with said heater element layer, and extend laterally beyond said heater element layer whereby said surface covering layer forms a substantially continuous ceiling surface with adjacent layers when installed with juxtaposed similar panels.

2. A panel as claimed in claim 1 characterised in that said surface layer extends laterally beyond said thermally insulating backing layer, whereby to accommodate support members.

3. A panel as claimed in claim 2 characterised in that said surface layer comprises squared edges for abutment with the surface layers of adjacent panels.

4. A panel as claimed in claim 1 characterised in that said heater element layer, said backing layer and said surface layer are secured to each other.

5. A panel as claimed in claim 4 characterised in that said layers are all secured together by adhesive.

6. A panel as claimed in claim 1 characterised in that said surface layer comprises reinforced plaster.

7. A panel as claimed in claim 1, 2 or 3 charac-terised in that the edges of said heater element layer are electrically insulated.

8. A panel as claimed in claim 1, 2 or 3 charac-terised in that edges of said surface layer are shaped to mate with a complementary edge of an adjacent similar panel.

9. A panel as claimed in claim 1 characterised in that said heater element layer is disposed for differential lateral thermal expansion between said backing layer and said surface layer.

10. A panel as claimed in claim 9 characterised in that said backing layer is secured to said surface layer.

11. A panel as claimed in claim 1 characterised in that said heater element layer comprises conductive strip buses, and flexible leads for connection to an electrical supply.

12. A panel as claimed in claim 11 characterised in that said leads have male and female plugs for connect-ing adjacent panels with each other and with said electri-cal supply.

13. A panel as claimed in claim 11 characterised in that said heater element layer comprises electrical insulator films covering at least one face of said strip buses, and said leads comprising conductors soldered to said buses at their other faces and insulation welded with said insulator film.

14. A panel as claimed in claim 13 characterised in that the solder joint of said leads to said buses is covered with an insulator, and said heater element layer comprising an insulator film covering at least said other face of said bus.

15. A panel as claimed in claim 13 or 14 character-ised in that the panel is installed with said leads con-nected with corresponding leads of an adjacent panel by self stripping connectors.

16. A panel as claimed in claim 1 characterised in that the panel is installed with at least partially visible suspension means, said thermally insulating layer extending to the edges of said surface layer.

17. A panel as claimed in claim 2 characterised in that the panel is installed with said surface layer at least partially concealing suspension means, with further thermally insulation members on said suspension means sub-stantially filling gasp between said thermally insulating backing layers of adjacent panels.

18. A panel as claimed in claim 1, 2 or 3 character-ised in that said heater element layer comprises a carbon black heater resistor film.