GB2240618A

GB2240618A - Electric space heater

Info

Publication number: GB2240618A
Application number: GB9101784A
Authority: GB
Inventors: Daniel Martin Brand; Thomas Gilmour Graham
Original assignee: Thermaflex Ltd
Current assignee: Thermaflex Ltd
Priority date: 1990-01-31
Filing date: 1991-01-28
Publication date: 1991-08-07
Anticipated expiration: 2011-01-28
Also published as: GB9101784D0; GB2240618B

Abstract

An electric space heater of a convector/radiator type which is compact and useful where available space and/or power is limited, eg. in caravans provides a sheet steel casing consisting of a first, front panel 10, a second, rear panel 12 and a third, rearmost panel 14 connected by end walls to define a first convector space 20 between the first and second panels 10, 12 and a second convector space 22 between the second and third panels 12, 14. First and second planar electric heating elements 24, 26 are affixed to the rear surface of the first panel 10 and the front surface of the second panel 12 such that they face one another. Optionally one or more further planar heating elements are spaced, parallel to the first and second elements, within the first space 20. <IMAGE>

Description

Electric Space Heater The present invention concerns electric space heaters of the convector/radiator type.

There is a need for compact, high efficiency electric space heaters in many situations, particularly where the available space and/or power supply is restricted. One such example is in caravans, particularly of the static, residential type, where space is obviously at a premium and the power supply current is commonly limited to 5 amps. The lowest wattage convector/radiator currently available is rated at 500W, so that only two such heaters could be run from a 5 amp supply.

It is an object of the present invention to provide an improved electric space heater which gives a higher heat output for a given power rating and which is more compact than existing heaters.

An electric space heater in accordance with a first aspect of the present invention comprises a first, front panel and a second, rear panel with a space defined therebetween, each of said panels having a generally planar electric heating element disposed on its surface such that the elements face one another across said space.

This construction provides radiant heat from the front panel whilst the opposed elements provide an improved convective heating effect between the panels.

Preferably, the heater includes a third panel disposed rearwardly of the second panel with a second space defined therebetween such that heat radiated from the second panel creates a further convective heating effect in the second space. The top edge of the rear panel may also be extended upwardly and forwardly to create a baffle for deflecting heated air forwardly from the heater.

The electric elements are preferably of the flexible, impregnated type or, alternatively, of the etched or screenprinted type.

The heater may be adapted to be free-standing or to be suspended or otherwise mounted on a wall or other support, and may also include safety cut-out devices, temperature controls etc as required.

An electric space heater in accordance with a second aspect of the present invention comprises a first, front panel and a second, rear panel with a space defined therebetween, each of the panels having a generally planar electric heating element disposed on its surface such that the elements face one another across the space, there being further provided within the space at least one further planar electric heating element such that adjacent elements face one another within the space.

This construction provides radiant heat from the front panel whilst the adjacent elements within the space provide an improved convective heating effect between the elements.

Preferably the at least one further electric heating elements are spaced from one another and from the elements on the front and rear panels by means of a plurality of spacer elements.

The heater may further be adapted such that in use one or more of the elements can be independently controlled in order that the heater may give a variable heat output.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a front perspective view of a first embodiment of an electric space heater according to the present invention; Fig. 2 is a sectional end view of the heater of Fig. 1; Fig. 3 is a front perspective view showing a section through one end of a second embodiment of an electric space heater according to the present invention.

Referring to Figs. 1 and 2 there is provided a first embodiment of a panel-type electric convector/radiator comprising a casing, typically fabricated from sheet steel, consisting of a first, front panel 10, a second, rear (or intermediate) panel 12 and a third, rearmost panel 14 connected by end walls 16 and 18 to define a first space 20 between the first and second panels 10 and 12 and a second space 22 between the second and third panels 12 and 14.

The heater further includes first and second generally planar electric heating elements 24 and 26 affixed to the rear surface of the first panel 10 and to the front surface of the second panel 12 such that they face one another across the first space 20. The elements 24 and 26 cover substantially the whole surfaces of the first and second panels 10 and 12.

It is particularly preferred that the elements 24 and 26 are of the flexible, impregnated type, such as "Flexel", available from the present applicants, which comprises sheets of woven, carbon impregnated glass fibre material having copper foil busbars stitched to opposite edges thereof for connection to a power supply. Such elements can be made in almost any required size and may be manufactured in a wide range of resistances, power ratings and operating temperatures. Alternatively, etched or screen-printed elements could be used or, less desirably, laminated, planar, wire-wound elements.

The above-described construction provides a highly efficient, compact heater wherein the heat output for a unit of a given size and power-rating is significantly improved in comparison with existing heaters. Radiant heat is provided from the front of the first panel 10, whilst the opposed elements 24 and 26 create an improved convective heating effect within the first space 20. Heat radiated from the rear surface of the second panel 12 also provides supplementary convective heating in the second space 22.

The top and bottom of the first space 20 are preferably covered by grilles 28 and 30, and the top edge of the rear panel 14 is extended upwardly and forwardly to form a baffle 32 for deflecting heated air out into the space being heated. The elements 24 and 26 are connected to a power supply via an on-off switch 34 mounted on one of the end walls and a cable 36. A thermal safety cut-out 38 is located centrally between the elements in the first space 20 and is set to disconnect the power supply if a predetermined temperature (eg 1200C) is exceeded. Additional temperature controls or the like may be added as required, however such features, being well known in the art, are not further described herein.

The heater may also be readily adapted to be freestanding, wall-mounted or suspended from some other fixture.

The heater may conveniently be constructed from two basic units: a rectangular casing comprising the first and second panels 10 and 12 and including all of the electrical components; and the third panel 14 which is attached to the rear of the rectangular casing. Besides enhancing the convective heating effect of the heater, the third panel 14 further serves to facilitate the adaptation of the heater for wall mounting.

Referring to Fig. 3 there is provided a second embodiment of a panel-type electric convector/radiator comprising a casing, typically fabricated from sheet steel, consisting of a first, front panel 10a and a second, rear panel 12a connected by end walls 16a (not shown) and 18a to define a first space 20a between the first and second panels 10a and 12a.

The heater includes first and second generally electric heating elements 24a and 26a affixed respectively to the rear surface of the first panel 10a and to the front surface of the second panel 12a such that the elements 24a, 26a face one another across the space 20a. The elements 24a and 26a cover substantially the whole surface of the first and second panels 10a and 12a.

Further provided within the space 20a are one or more electric heating elements 40a. In the present embodiment there are provided three such elements 40a. The elements 40a are aligned substantially parallel to the first and second elements 24a and 26a, and are of substantially the same size and shape as the first and second elements 24a and 26a.

The elements 40a are further equally spaced from one another and from the first and second elements 24a and 26a by means of a plurality of spacer elements 42a. In the present embodiment there are provided three substantially equally spaced spacer elements 42a at or near each side edge of each element 24a, 26a, 40a between adjacent elements 24a, 26a, 40a.

There is further provided a spacer element 42a at or near the centre of the upper edge of each element 24a, 26a, 40a between adjacent elements 24a, 26a, 40a.

In this way the elements 24a, 26a, 40a are substantially equally spaced apart from, and retained in association with, one another.

In use radiant heat is provided from the front of the first panel 10a, whilst the elements 24a, 26a, 40a, facing one another create an improved convective heating effect within the space 20a.

The top and bottom of the space 20a are preferably covered by grilles 28a and 30a. Further, a rearmost panel 14a (not shown), similar to that provided in the first embodiment of the invention disclosed herein, may be provided. The provision of the panel 14a would facilitate the adaptation of the heater for wall-mounting.

Alternatively, the heater may be provided with feet and/or legs (not shown) to allow free-standing of the heater.

A 200 Watt heater constructed in accordance with the present invention provides adequate heat for a typical room in a static caravan, and five such units could be run off a 5 amp supply as compared with only two 500 Watt heaters.

Thus, the use of the present invention would allow virtually every room in a typical caravan to be provided with at least one heater, which has not hitherto been practical with existing heaters. The invention is of course equally applicable to larger heaters having higher power-ratings to provide economical heating of domestic or commercial premises.

Finally, it should be appreciated that the embodiments of the invention described hereinbefore are given by way of example only, and are not in any way meant to limit the scope of the invention. Accordingly, various modifications and/or adaptations may be envisaged. In particular it should be appreciated that the elements may be covered in a coating, for example, of micra.

Claims

1. An electric space heater comprising a first, front panel and a second, rear panel with a space defined therebetween, each of the panels having a generally planar electric heating element disposed on its surface so that the elements face one another across said space such that in use radiant heat is provided from the front panel whilst the opposed elements provide a convective heating effect between the panels.

2. An electric space heater comprising a first, front panel and a second, rear panel with a space defined therebetween, each of the panels having a generally planar electric heating element disposed on its surface such that the elements face one another across the space, there being further provided within the space at least one further planar electric heating element so that adjacent elements face one another within the space such that in use radiant heat is provided from the front panel whilst the adjacent elements within the space provide a convective heating effect between the elements.

3. An electric space heater as claimed in claim 2, wherein the at least one further electric heating elements are spaced from one another and from the elements on the front and rear panels by means of a plurality of spacer elements.

4. An electric space heater as claimed in claims 2 or claim 3, wherein control means are provided to independently control one or more of the elements in older that the heater can give a variable heat output, in use.

5. An electric space heater as claimed in any preceding claim, wherein the heater further includes a third panel disposed rearwardly of the second panel with a second space defined therebetween such that in use heat radiated from the second panel creates a further convective heating effect between the second and third panels.

6. An electric space heater as claimed in claim 5, wherein a top edge of the third panel extends upwardly and forwardly to create a baffle for deflecting heated air forwardly from the heater.

7. An electric space heater as claimed in any one of claims 1 to 6 inclusive; wherein the electric elements are of a flexible impregnated type.

8. An electric space heater as claimed in any one of claims 1 to 6 inclusive, wherein the electric elements are of an etched or screen-printed type.

9. An electric space heater as claimed in any preceding claim, wherein the heater is adapted to be free-standing.

10. An electric space heater as claimed in any preceding claim, wherein the heater is adapted to be mounted on a wall or other support.

11. An electric space heater as claimed in any preceding claim, wherein the heater further includes a safety cut-out device.

12. An electric space heater as claimed in any preceding claim, wherein the heater further includes a temperature control.

13. An electric space heater substantially as described hereinbefore with reference to Figs. 1 and 2 or Fig. 3.