GB2383057A

GB2383057A - Prefabricated underfloor heating tile

Info

Publication number: GB2383057A
Application number: GB0228853A
Authority: GB
Inventors: David Neill
Original assignee: NU HEAT UK Ltd
Current assignee: NU HEAT UK Ltd
Priority date: 2001-12-12
Filing date: 2002-12-10
Publication date: 2003-06-18
Anticipated expiration: 2022-12-10
Also published as: GB0228853D0; GB0129782D0; GB2383057B

Abstract

A prefabricated tile having a base layer 1 of heat insulation material which contains a channel 10 for receiving an underfloor heating element, and a heat diffusion layer 2 of high thermal conductivity which partly covers the base layer.

Description

Nu-Heat UK Limited PREFABRICATED UNDERFLOOR HEATING TILE TECHNICAL FIELD OF THE INVENTION This invention relates to the installation of underfloor heating systems.

BACKGROUND The installation of underfloor heating systems is a skilled job which takes up a considerable amount of time. Such heating systems include one or more heating elements, which could be sections of conduit (pipes or tubing) which carry a heating medium such as warm water, or an electrical heating cable.

Heat diffusion plates are commonly used to conduct heat away from the heating elements and spread the heat over a wider floor area than could be achieved using the heating elements on their own, thereby increasing the potential heat output. During installation it is usually necessary for workers to prepare the floor to receive the heating elements and diffusion plates.

The nature of the preparation work may vary depending, for example, on the nature of the existing floor. In existing solid or timber floors there may already be adequate insulation, and the preparatory work may involve the laying of timber battens at the correct spacing. In other cases it may be necessary to prepare the existing sub-floor to receive sheets of insulation

material, which are generally supplied as large sheets in standard sizes, typically 1200 x 1200 x 50 mm. To assist installation the insulating sheets may be prepared off site with grooves formed at fixed centres to receive the heating elements, but the sheets must still be accurately measured and cut to size, and large sheets are inconvenient to handle and may be difficult to fix to an uneven subfloor.

The present invention seeks to provide a new and inventive form of underfloor heating system which speeds up installation and requires less skill yet is still capable of achieving the required heat output figures.

SUMMARY OF THE INVENTION The present invention proposes a prefabricated tile for use in the installation of underfloor heating systems, the tile including a base layer of low thermal conductivity containing a single upwardly-open channel for locating a heating element therein, and an upper heat diffusion layer of relatively high thermal conductivity which lines the channel and extends over the base layer on opposite sides of the channel.

Unlike the conventional insulation sheets, the tile in accordance with the invention contains only a single channel. Furthermore, the tile preferably has a pair of substantially parallel side faces on opposite sides of the channel. Thus, by butting up the tiles side-by-side the desired spacing between the heating elements can be ensured without any need for cutting or accurate measurement.

The high conductivity layer will usually be of metal. The base layer is preferably of a lightweight cellular structure containing numerous air spaces.

In a preferred form of the tile the heat diffusion layer includes a plurality of contiguous sections along the length of the channel.

BRIEF DESCRIPTION OF THE DRAWINGS The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings: Figure 1 is a general view of an underfloor heating tile in accordance with the invention; and Figure 2 is a similar view showing how a number of the tiles would be installed to receive an underfloor heating conduit.

DETAILED DESCRIPTION OF THE DRAWINGS Referring firstly to Fig. 1, the illustrated tile is substantially rectangular, typically being about 1000 mm long and 200 mm wide. Tiles of different widths could be used (e. g. 150 mm and 250 mm) according to the heat output requirement for a particular floor area. The tile includes a base layer 1 and a heat diffusion layer 2. The base layer may be of a lightweight cellular material which provides low thermal conductivity such as expanded

polystyrene, and has two parallel side faces 3 and 4. Although the end faces 5 and 6 of the tile, preferably extend perpendicular to the sides 3 and 4 they could be rounded or of any other desired shape. In a preferred form of the tile the thickness of backing layer 1 is substantially equal to the diameter of the heating element to be installed so that a tile intended for 1 Omm diameter tube would be about 10 mm thick. The base layer is formed of two separate sheets of substantially equal width which are separated by a small gap to form a straight channel 10 extending longitudinally of the tile between the ends 5 and 6, parallel to the sides 3 and 4. This has the advantage that the installer can lay the tiles directly onto an existing floor which is already adequately insulated, or onto a layer of conventional insulation material which can usually be obtained easily at relatively low cost and requires little skill to install. The bulk of the tiles is thus reduced to a minimum, which reduces the volume of the tiles which must be stocked and has advantages in relation to shipping and storage costs.

The backing layer could alternatively be in the form of a single sheet which is formed with a channel in its upper surface.

The heat diffusion layer 2 is formed of thin sheet of aluminium alloy or other heat-conductive metal, e. g. about 0.3 mm thick, which is preferably slightly brittle. The upper layer 2 extends close to the ends of the tile 5 and 6 and is shaped to line the sides and bottom of the channel 10 with wings 11 and 12 which extend outwardly overthe upper surface of the base layer 1 leaving an exposed area of the base layer 1 on each side of the heat diffusion layer.

Again, the edges of the wings 11 and 12 could be of any desired shape, but the exposed areas of the base layer are useful to allow for trimming the width of the tiles to fit a confined space, for example. The heat diffusion

layer 2 is bonded to the base layer 1 using a suitable heat-resistant adhesive or, if the backing layer is moulded, the bond could be formed in the moulding process.

The heat-diffusion layer 2 is preferably formed from a single sheet to provide thermal continuity and strengthen the tile during handling. However, it is advantageous in many situations if the layer 2 includes a plurality of contiguous sections 2a, 2b and 2c along the length of the channel 10. In order to maintain the structural integrity of the top layer 2 the sections are preferably defined by scored lines 25 and 26, which are preferably straight and extend perpendicular to the sides 3 and 4, forming lines of weakness along which the tile can be snapped. The sections may be of unequal lengths, e. g. dividing the tile into lengths of 500 mm, 300 mm and 200 mm for a 1000 mm tile.

During installation of an underfloor heating system as shown in Fig. 2, the tiles are laid on a suitable heat insulation layer or on to an existing floor as discussed above. A number of the tiles, such as tiles 31 and 32, may be abutted end-to-end so that their channels 10 form a continuous straight run.

In addition, adjacent tiles may be butted up to the sides of each tile, such as tiles 33 and 34, forming a series of parallel rows of tiles, as shown. The tiles may be secured directly to the insulation layer or subfloor, e. g. by means of an adhesive, by nailing or stapling. Since the individual tiles are relatively small and slightly flexible they can easily accommodate small irregularities in the sub floor. An underfloor heating element 15, such as a length of flexible tube through which a heating medium is circulated, is laid in the channels 10 as shown. At the ends of each row of tiles the tube may be looped around to travel back along the next row of tiles to cover the required

floor area.

In order to accommodate reversal of the heating element at each end of the row, additional 900 tiles are provided, 35 and 36. These are similar is structure to the straight tiles but the base layer 1 is substantially square and the channel 10 is curved to exit through two adjacent sides of the tile. The width of the square tiles is substantially equal to that of the rectangular tiles so that they can be butted up closely without intervening gaps. Furthermore, by using two identical tiles it is possible to form a complete 1800 turn between adjacent rows, as shown.

The exposed areas of the base layer, between the outer edges of the diffusion layer 2 and the sides 3,4, form spacers which ensure that the sections of heating tube are maintained at the correct spacing, thereby ensuring that the required heat output is achieved uniformly over the floor area.

Should it be necessary to lay a tile which is shorter than a single tile, e. g. at the end of a row, the till3 can be snapped between two of the sections to form a shorter tile of the required length.

The upper surface of the tiled area is substantially flat allowing the heating system to be easily covered by a layer of timber, chipboard sheeting or a floor screed for example.

It will be appreciated that the features disclosed herein may be present in any feasible combination. Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is

claimed for any inventive combination of the features disclosed herein.

Claims

CLAIMS 1. A prefabricated tile for use in the installation of underfloor heating systems, the tile including a base layer of low thermal conductivity containing a single upwardly-open channel for locating a heating element therein, and an upper heat diffusion layer of relatively high thermal conductivity which lines the channel and extends over the base layer on opposite sides of the channel.
2. A tile according to Claim 1 in which the heat diffusion layer only covers a portion of the base layer on each side of the channel.
3. A tile according to Claim 1 or 2 in which the heat diffusion layer includes a plurality of contiguous sections which are arranged along the length of the channel in mutual end-to-end contact without intervening gaps.
4. A tile according to Claim 3 in which the sections of the heat diffusion layer are defined by lines of weakness in the heat diffusion layer.
5. A tile according to Claim 3 or4 in which the heat diffusion layer includes at least two such sections which are of unequal lengths.
6. A tile according to any preceding claim in which the channel in the base layer is formed by separate bodies of low thermal conductivity material which are spaced apart to form said channel, the heat diffusion layer bridging the bottom of the channel.

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7. A tile according to any of Claims 1 to 5 in which in which the channel in the base layer is formed in a single body of low thermal conductivity material.
8. A tile according to any preceding claim in which the heat diffusion layer is formed of a brittle material which can be snapped by bending.
9. A tile according to any preceding claim in which the base layer has a lightweight cellular structure containing numerous air spaces.
10. A tile according to any preceding claim having a pair of substantially parallel side faces on opposite sides of the channel.
11. A tile according to any preceding claim which is substantially rectangular with a pair of parallel side faces and a pair of parallel end faces,
12. A supply of prefabricated tiles in accordance with any of Claims 1 to 11 for use in the installation of an underfloor heating system, including tiles having channels which are substantially straight and extend between opposite ends of the tile, and tiles having curved channels.
13. A supply of tiles according to Claim 12 in which the tiles with curved channels have a side face and an adjacent end face which are mutually perpendicular and the channel extends between said adjacent faces.
14. A supply of tiles according to Claim 12 or 13 in which the

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widths of the tiles with straight and curved channels, as measured between parallel side faces of each tile, are substantially equal.
15. A supply of tiles according to Claim 14 in which the tiles with curved channels are substantially square.
16. A prefabricated tile for use in the installation of underfloor heating systems which is substantially as described with reference to the drawings.
17. A supply of prefabricated tiles for use in the installation of an underfloor heating system and which are substantially as described with reference to the drawings.