GB2492146A

GB2492146A - Composite panel for use in underfloor heating

Info

Publication number: GB2492146A
Application number: GB1110674.7A
Authority: GB
Inventors: Brian Robertson
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-06-23
Filing date: 2011-06-23
Publication date: 2012-12-26
Also published as: GB201110674D0

Abstract

The composite panel comprises a first layer 240 comprising a thermally insulative material in which at least one channel 241 is provided; and a second layer 220 provided on the first layer and comprising a thermally conductive material, the second layer including a means for providing access to the at least one channel. The means may comprise a hinge (325a-b, see figure 2) that allows a movable portion of the second layer to rotate relative to the first layer between open and closed positions, or a moveable portion of the second layer that may be completely removed from the first layer. A heat conductive and generally T-shaped cover 510 may be provided that resiliently engages with indentations 224 provided in walls 283 of the channel. The panel may include a third layer of insulator-backed reflective foil 260, a second channel (242, see figure 2) that is perpendicular to the at least one channel, and tongue and groove formations for joining similar panels together.

Description

I

Sflflaci The present invention relates to a heating panel, a method for installing a heating panel, a heating system comprising the heating panel and associated parts thereof. In particular, the invention relates to a composite heating panel for an underfloor heating system, a method for instaffing the composite heating pan&, and an underfloor heating system comprising the heating paneL Underfloor heating systems are increasingly being chosen as a means to heat indoor spaces, as they offer numerous advantages over alternalive heating methods, Placing heating pipes within the floor obviates the need for radiators, which can be considered to be aestheticafly undesirable, and which encroach on space in a room, possibly preventing optimum placement of furniture or equipment.

Also, undertloor heating provides even heating of indoor spaces, and can heat a room more quickly than using radiators. Furthermore, a heated floor can provide a pleasant experience for the user, especially when used in combination with hard flooring.

Instaflation of underfloor heating systems typicaliy involves a complex and time consuming process involving significant work on the part of a skifled insta Her. The need for the time of a skiiled instafler adds significantly to the costs of instaHing the underfloor heating system.

The present invention seeks to provide a heating panel, a method for installing a heating pan&, and a heating system that overcomes or at least alleviates the above issues.

An aspect of the present invention provides a composite panel for an underfloor heating system, the panel comprising a first layer in which at least one channel is provided for receiving a fluid carrying conduit of the underfloor heating system, and a second layer, provided on the first layer, comprising a thermally conductive material.

An aspect of the present invention provides a composite panel for an underfloor heating system, the panel comprising a first layer comprising a thermally insulative material in which at least one channel is provided for receiving a fluid carrying conduit of the underfloor heating system, and a second layer, provided on the first layer, comprising a thermafly conductive material, and means for providing access to the at least one channel whereby to aVow receipt of a fluid carrying conduit into the channel, A third layer comprising a thermally reflective layer may be provided on the first layer, the first layer may be disposed between the second layer and the third layer.

The access providing means may comprise at least one opening provided in the second layer to allow said fluid carrying conduit to be inserted into said channel during installation of said heating system The channel may be configured for releasable engagement with a cover portion for covering the channel.

The channel may comprises at least one recess for receiving a corresponding projection in said cover portion whereby to allow said releasable engagement of said cover portion.

The channel may comprise at least one projection for engaging with a corresponding recess in said cover portion whereby to allow said releasable engagement of said cover portion.

The access providing means may comprise a movable portion of the second layer that is movable between a closed position in which the channel is covered by the moveable portion and an open position in which the channel is accessible to allow said fluid carrying conduit to be inserted into said channel during installation of said heating system.

The movable portion may be hingedly connected to a fixed portion of said second layer and may be moveable between said closed and open positions about said hinged connection.

The movable poron may be configured for complete removal from the composite panel to achieve said open position and for placement or replacement on the composite panel to achieve said closed position.

The second ayer may comprise a portion that extends at east partiafly into said channeL The second layer may further comprise a means for engaging wth at least one further paneL The means for engaging with a second pan& may comprise a tongue for engaging with a corresponding groove on the at least one further paneL The means for engaging with a second panel may comprise a groove for engaging wfth a corresponding tongue on the at least one further paneL The second layer may comprise a plurailty of channSs for receiving the or at least one further fluid carrying conduit of the underfloor heating system.

The second ayer may further comprise a first and second channel arranged substantially perpendicular to one another.

The chann& may further comprises a base portion configured to conform at least partiafly to the shape of said fluid carrying conduit.

The channel may further comprise substantiaily straight wails extending from the base portion to the second layer.

An aspect of the present invention provides a cover portion for the composite pan& of any of the above aspects, the cover portion being configured for releasable engagement with the at least one channel of said composite panel to secure the cover portion in position covering said chann& and comprising means for thermally connecting the cover portion to a surface of said fluid carrying conduit when said fluid carrying conduit is in position in said channel.

The means for thermally connecting the cover portion to said surface of said fluid carrying conduit may comprise a thermally conductive portion of the cover portion configured to at least partially conform to said surface of said fluid carrying conduit when said fluid carrying conduit is in position in said channel whereby to form an area of thermal contact between the fluid carrying conduit and the cover portion.

The cover portion may further comprise means for thermauy connecting the cover portion to a surface of said second layer of said composite panel The means for thermafly connecting the cover portion to the surface of said second layer of said composite pan& may comprise a thermafly conductive element configured such that when the cover portion is engaged in the at least one channel a surface of the thermaliy conductive element is in contact with said surface of the second layer whereby to form an area of thermal contact between said surface of the second layer and the cover portion.

The cover portion may have a generally shaped crosssection, wherein a base of the shaped crosssection is configured for engagement against a surface of said fluid carrying conduit when said fluid carrying conduit is in position in said channel and said cover portion is engaged in position covering said channel, and/or wherein a top portion of the T shaped crosssection is configured to engage against a surface of said second layer.

An aspect of the present invention provides an underfloor heating system comprising a composite panel as described above.

The underfloor heating system may comprise at least one cover porUon as described above.

An aspect of the present invention provides a method of installing an undertloor heating system comprising providing at east one composite panel as described above, inserting a fluid carrying conduit of the underfloor heating system into the channel of said at least one composite panel and connecting said fluid carrying conduit to a source of heated fluid.

The method may further comprise covering said channel of said at least one composite panel after said inserting step with a cover portion as described above.

An aspect of the present invention provides a kit comprising a plurality of composite panels as described above.

The kit may further comprise a plurality of cover portions as described above.

Embodiments of the invention wifi now be described by way of example only with reference to the attached figures in which: Figure 1 shows, in overview, a typical system in which an underfloor heating pan& would be instaUed; Figure 2 shows a simplified exploded view of an embodiment of the underfloor heating panel of Figure 1 induding a movable portion; Figures 3A and 3B show simplified sectional views of an embodiment of the underfloor heating panel and a removable heat plate; Figure 4 shows a simplified isometric view of the removable heat plate; Figures 5A to 5G show alternative arrangements in which the heat plate of Figure 4 may be used; Figure 6 shows a simplified plan view of a plurality of the underfIoor heating panels forming part of an underfioor heating system; Figure 7 illustrates a further embodiment of the system in which the undertloor heating panel would be installed; and Figures 8A and SB illustrate a further embodiment of the heating panel.

Figure 1 shows an underfIoor heating system 10 comprising a boiler 120, pump 110, expansion vessel 105, temperature sensor 130, flow control 150, air vents 160, drain points 165, underfloor heating pipes 140 and underfloor heating panels 180, all connected via piping 100.

The boiler 120 receives water from water input 115, along with water from underfloor heating pipe egress point 125. The received water is heated by the boiler and subsequently flows towards the underfloor heating pipes 140 via the pump 110, expansion vessel 105, temperature sensor 130, flow control 150 and airvent 160, Pump 110 maintains water flow throughout underfloor heating system 10. The expansion vessel 105 regulates pressure within the system 10. Temperature sensor 130 is configured to measure the temperature of water flowing through the o piping 100, and this measurement can be transmitted, for example, to the boiler 120, a user or to an external device.

Flow control 150 can be opened or dosed, to either increase or decrease the volume of water flowing through the heating system per unit time. The flow control can be operated manuafly or automatically.

Drain points 165 are provided at an underfloor heating ingress point 135 and at water input 115.

The underiloor heating panel of the present embodiment is configured to accommodate a copper pipe of 10mm diameter. However, it will be appreciated that the panel could be configured to accommodate a different pipe diameter, for example a diameter in the range 5mm to 100mm, or more commonly a heating pipe diameter in the range 12mm to 24mm (e.g. 15mm or 22mm in the case of standard copper pipes), In the present embodiment the panel is generally rectangular, with dimensions of 1000mm x 500mm and a thickness of 18mm +/ 3mm, However, the boards can be manufactured in a range of sizes, with side lengths ranging from 100mm to 5000mm. Typical rectangular length and width dimensions, for example, are 1800mm x 1200mm and 2400mm x 1200mm.

It wifl be appreciated that where the panel is configured to accommodate pipes of different diameters, the thickness of the panel can be chosen appropriately, for example in the range of 6mm to 200mm. Thicker boards are suitable for accommodating larger pipe sizes, for example pipes used in industrial settings.

Typical board thicknesses, for example, include 15mm, 20mm, 25mm and 30mm.

Figure 2 shows an exploded view of a preferred embodiment of the present invention. In the present embodiment, the undertloor heating panel 20 is a generally rectangular composite panel comprising an upper layer 220, central layer 240 and lower layer 260.

Central layer 240 comprises channels 241244 that are recessed into the central layer 240 and that are configured to receive one or more underfloor heating pipes. Channels 241 and 242 are substantially straight and extend in directions perpendicular to one another. Straight channels 241 and 242 intersect at intersection point 247 and each extend longitudinally and transvers&y from one side of central layer 240 to an opposing side.

Channels 243 and 244 are curved channels, originating on opposing sides of straight channel 241 and terminating at straight chann& 242 either side of intersection point 247. This channel configuration beneficially allows an underfioor heating pipe to be passed along the entire length of either of the straight channels or, alternatively, from one straight channel into the other straight channel via a curved channel, undergoing a change in direction of 90 degrees.

Central layer 240 is a poorer heat conductor that upper layer 220. The central layer comprises an insulating material having a relatively high thermal mass so that heat energy which is transferred into it from the underfloor heating pipe is retained within the underfloor heating panel and gradually transfers into the surroundings via upper layer 220. This means that the boiler, after an initial heating period, does not need to continuously heat water to the same temperature as residual heat held within the central layer 240 gradually transfers into the surroundings and contributes to heating the room, Central layer 240 is preferably manufactured from a gypsum based material, and may be formed by injection moulding, other moulding process, or the like. The channels may be formed as part of the injection moulding process or may be routed into the panel.

Central layer 240 further comprises a tongue 347 disposed on a side face of the underiloor heating panel 20, extending longitudinally parallel to channel 241. A corresponding tonguereceiving groove 347 is disposed on an opposing side face of the central layer 240. The tongue and tonguereceiving groove are configured such that, in operation to install a plurality of such underfloor heating panels 20, the tongue of one underfloor heating panel 20 may be received into the groove an adjacent panel to form a generally continuous surface. It will be appreciated that the adjacent underfloor heating panels may be substantially identical to one another or may be different, for example having different construction or channel patterns to provide alternative routing patterns. A plan view of a typical arrangement of 12 underfloor heating panels is shown in Figure 6.

The upper layer 220 comprises a heat conductive material which, in this embodiment, comprises a 0.5mm copper sheet. In this embodiment, upper layer 220 comprises two separate parts 220a and 220b, positioned either side of chann& 241. The separate parts 220a and 22Db are separated by an opening which is in general alignment with the channel 241.

Each of the upper layer parts 220a and 22Db comprise a fixed portion 323 and a movable portion 321. Fixed portion 323 and movable portion 321 are connected by a joint 325 configured to allow the movable portion 321 to rotate about the joint 325 as indicated by the arrows X, in the manner of a flap, between an open position in which the curved channels 243 and 244 and transverse channel 242 are uncovered and hence accessible, and a closed position in which the channels 243, 244 are covered and the copper sheet forming the upper layer is substantially planar. The joint 325 may! for example, comprise a hinged portion comprising a series of perforations, or an indentation in an upper or lower surface of the upper layer, such that the movable portion can preferentially fold about the joint 325.

The arrangement of the fixed and movable portions 323, 321 advantageously allows an installer of an underfloor heating system comprising the paneLs 20 to gain access to the curved channels 243 and 244 by opening the movable portions 321a and 321b such that curved channels 243 and 244 are accessible.

The arrangement thus allows the pipes to be curved to fit the channel (and if necessary soldered or otherwise fixed together), and the provision of a movable portion allows this to be done with relative ease without having to completely remove upper layer 220.

The fixed and movable portions of upper layer parts 220a and 22Gb each comprise a lip, 327a, 327b, 329a and 329b which partially descends into the channel 241, as illustrated in Figures 3A and 3B.

Upper layer 220 is discussed in further detail in relation to Figure 3, below.

Lower layer 260 comprises an insulatorbacked reflective foil. The lower layer 260 minimises heat loss through the base of the heating panel 20 into materials upon which the heating panel 20 is placed, such as a concrete floor, floor joists, or underlay material. Lower layer 260 is adhered to the central layer 240 such that it remains in contact with the composite panel before, during and after instaUation.

In addition to making installation easier and hence quicker, having the lower layer adhered to the central layer 240 is beneficial in that any gaps between the lower layer and central later are minimised, even when the lower layer is directly placed S upon a non-continuous support, such as joists.

The composite nature of the underfloor heating panel 20 provides quicker installation times, as the installer does not need to position, cut and fix multiple layers separat&y.

The composite underfloor heating panel 20 may be constructed such that it can support loads large enough that it can be used as part of the floor construction and placed directly in joists, without the need for floorboards or the like.

Flooring materials, such as tfles, may be placed directly on top of the upper layer 220. This is advantageous over existing systems where intermediate layers need to be installed on top of underfloor heating panels, such as a screed layer, which is time consuming and prevents easy access to heating pipes for maintenance.

Figures 3A and 38 illustrate a sectional view of channel 241.

Channel 241, considered in cross section, comprises a generally semicircular base 281 for supporting a heating pipe 230. The channel further comprises substantially straight walls 283 extending from the semi-circular base portion 281 to the upper layer 220.

Also shown in Figures 3A and 38, and illustrated in more detaU in Figure 4, is a generally T' shaped removable heat plate 510 for securing the pipe 140 of the underfloor heating system 10 in place and for improving the thermal conduction path between the pipe 140 and the thermally conductive upper layer 220. The removable heat plate 510 comprises a thermally conductive curved portion 516 at the base of the central column of the configured to conform generally to the outer surface of the heating pipe 140 such that after installation the pipe 140 is in contact with the curved portion 516 (either directly, or via a heat conducting gel or the like). In this embodiment, a plate portion 512 forms the top (or 8cross') of the 1' shaped removable heat plate 510, as shown in Figures 3A and 3B, for providing improved thermal conduction away from the heating pipe 140 thereby helping to provide an improved thermal distribution and avoiding hot-spots'. The curved portion 516 provides better thermal contact with the pipe 140 than would be the case for a flat surface, because the pipe 140 has a r&atively large thermal contact area with the curved portion 516. This relatively large thermal contact area with the pipe provided by the curved surface of the removable heat plate also helps to provide improved thermal conduction to, and a more even distribution of heat over, the upper layer 220.

Removable heat plate 510 further comprises projections 514 (on either side of the central column of the T), adapted to engage with complementary recesses 282 formed in the channel 241 of central layer 240 to hold the removable heat plate 510 in position when installed. The walls on which the projections 514 are formed and/or the projections themselves may have some resilience to allow the removable heat plate 510 to be snapped into place. As shown in Figure 313, in this embodiment, the projections 514 of the removable heat plate are not in direct contact with the recesses 282 of the central layer. Instead, the lips (327a, 327b, 329a, 329b) of the upper layer 220 are indented into the recesses 282 to form indentations 224 configured to receive the projections 514. This arrangement has the potential to improve thermal conductivity between the heat plate 514 and the upper layer 220.

The projections 514 thus allow the removable heat plate to be secured in place without the need for additional fixing means such as nails, They also allow the removable heat plate to be removed in order to inspect, perform maintenance or otherwise gain access to the heating pipes.

Accordingly in this embodiment, after installation, a lower surface of the plate portion 512 is received against the upper surface of the upper layer 220, thereby forming a relatively large area of thermal contact.

During installation, a thermally conductive gel is applied to the contact area between the heat plate 510 and the upper layer 220. The thermally conductive gel can also be applied at the contact area between curved surface 516 and underiloor heating pipe 230.

The three remaining channels 242 to 244 not illustrated in Figures 3A and 313, when considered in cross section perpendicular to their sides, have substantially identical properties to channel 241 described above.

In operaflon after instaflaUon, therefore, heat energy carried by the water in heating pipe 140 is transferred to the upper layer 220, This can occur via a number of mechanisms, for example by conduction via the heating pipe wafi (iflustrated in Figure 3B) and the heat plate 510 (where fitted). Also, heat can be transferred to the upper layer 220 via the pipe waU 231 and an air gap, or heat stored in the central layer can pass into the upper layer 220. Within the upper layer 220, heat energy is conducted away from underfloor heating pipe 140, and transmitted into the surroundings.

Figure 6 illustrates an exemplary arrangement of a pluralfty of underiloor heating panels including panels 20 as described previously, and panels 650 comprising only a single channel. As seen in Figure 6, the underfioor heating system 10 is beneficially modular and therefore scalable due to the regular nature of the channels and the presence of a tongue 347 and a tonguereceiving groove 345 on each underfloor heating panel 20.

Installation of a plurality of underiloor heating panels as described above would typically consist of the following steps: A roll form overlay may be laid prior to laying the heating panels, and in the situation where the panelling is being placed directly on joists, insulation may be placed between joists.

The plurality of identical or nonidentical panels, such as those illustrated in Figure 6, are laid on the floor surface, employing the tongue 345 and corresponding tonguereceiving groove 347 of each panel for engagement with an adjacent panel. The panels can be cut to appropriate sizes and shapes, particularly at corners and edges of a room.

The movable portion 321 of each panel is postoned such that the installer can gain access to channels of the panel, in particular curved channels 243 and 244.

Heating piping is then placed within the appropriate channels of the panels, for example as illustrated in Figure 6. Where panels are located near the edge of a floor, pipes are typically placed along curved channels 243 and 244, in order that the piping can be redirected in a direction away from the edge of the flooring. The heating pipes can be soldered (if necessary), bent and the like to form a continuous piping network within the plurality of panels.

Once the heating pipes are installed, the movable portions can be positioned to cover the channels of their respective panel. In the case where a removable heat plate is employed, these can be placed in the gap provided. A thermally conductive gel may be used to improve the thermal contact between the heat plate and the upper layer.

Boards can be fixed to the material on which they are placed (such as wooden joists) using any suitable means (e.g. screws, nails) Accordingly, it can be seen that the configuration of the heating panel beneficially provides a composite panel for quicker installation. The tongues 345 and tongue-receiving grooves 347 allow a plurality of the modular panels to engage with adjacent panels during and after installation. The opening provided in upper layer 220 allows the installer access to the channels, for placing heating pipes connected to the underfloor heating system. The movable portion 321 of upper layer 220 can be positioned to allow access to curved channels 243 and 244, for placement of piping, in particular when redirecting piping away from the edge of a floor. The removable heat plate 150 improves the thermal conduction path between the pipe 140 and the thermally conductive upper layer 220, and additionally allows access to at least one of the channels.

Modifications and alternatives A number of detailed embodiments and variations have been described above.

As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above embodiments and variations whilst still benefiting from the inventions embodied therein. Figures 5A to 5G, for example, illustrate further embodiments of the upper layer, central layer and removable heat plate.

In Figure 5A recesses 246 are provided in the central layer 240, either side of the channel, into which the plate portion 512 of the removable heat plate 510 may be received, during installation, such that the upper surfaces of the heat plate 510 and central layer 240 are generally coplanar. In this arrangement the upper layer 220 to comprises a generally continuous layer rather than comprising two separated parts 220a and 220b. In this embodiment the upper layer would still comprise a joint 325. In this embodiment the thermal contact between the upper 1.3 surface of the heat plate 510 and the lower surface of the upper layer 220 is relatively large (along the entire upper surface of heat plate 510), which is advantageous in terms of heat transfer. To provide further access to the channel in this embodiment, an additional movable portion (or 1ap) may be hingedly connected to the fixed portion 323 which is movable between an open position in which the channel is accessible and a dosed position in which it is covered. This embodiment may benefidafly be employed for curved chann&s 243, 244.

Figure SB shows removable heat plate 510 substantiafly flush with the surface of upper layer 220. This is achieved by providing recesses 226 formed in the upper layer, either side of channel 241. The recesses 226 are adapted to receive the plate portion 512 of heat plate 510. In this embodiment the upper layer may or may not comprise lips.

Figure SC iflustrates another embodiment in which upper layer does not comprise lips, and in which upper layer parts 220a and 220b are arranged to leave a section 248 of the central layer 240 uncovered, into which section 248, the plate portion 512 of the heat plate 510 may be received during installation such that its upper surface is to generally planar with the upper surface of the upper layer 220.

Figure 50 shows an embodiment in which the central layer 240 comprises recesses 246 formed either side of channel 241. Recesses 246 are configured to receive deformed portions 227 of upper layer 220. The deformed porons 227 are adapted to receive plate portion 512 of the heat plate 510 during installation such that its upper surface is to generally planar with the upper surface of the upper layer 220.

Figure 5E illustrates an alternative embodiment in which the lips of upper layer 220 are not are indented into the recesses 282 to form indentations. The complementary recesses 282 formed in the channel 241 of central layer 240 are positioned below the lips of the upper layer.

Figure SF shows an alternative heat plate embodiment, wherein the heat plate does not comprise a plate portion 512. The heat plate 510 is in thermal contact with the lips of the upper layer 220 and therefore conducts heat away from the pipe via the lips.

Figure 5G Ulustrates an embodiment in which the lips (327a, 327b, 329a, 329b) of upper layer 220 do not comprise indentations 224 configured to receive the heat plate projections 514. In this embodiment, such indentations 224 may be formed during instaflation due to deformation of the upper layer.

The above described embodiments, as iflustrated in figures SA to 5G, may incorporate any of the features from previous embodiments, In particular, a thermafly conductive gel may be apphed to the contact area between the heat plate 510 and upper layer 220. Also, in the embodiments above the three remaining channels 242 to 244, when considered in cross section perpendicular to their sides, may have substantially identical properties to channel 241.

It will be appreciated that curved versions of the heat plates may be provided for the curved channels 243 and 244. These may be slightly recessed into the central layer 240 such that the upper surfaces of the central layer 240 and heat plate 510 are generally co-planar and such that a lower surface of each movable portion 321 of the upper layer 220 may be positioned flush against the upper surfaces of the central layer 240 and the heat plate 510 when closed, for a large area thermal contact, as illustrated in Figure 5A. In this case, the configuration of the longitudinal and transverse channels, and the heat plate for them, may also be as shown in Figure 5A, or may be as shown in Figures 3A, 38 or SB to 5G.

The underfloor heating panels can be provided as part of a kit, comprising a plurality of undertloor heating panels 20 as described in the embodiments above and optionally comprising associated removable heat plates. A kit comprising a plurality of underfloor heating panels may comprise panels of dimensions suitable to be transported on a pallet. Furthermore, the kit may comprise a plurality of identical heating panels, or may comprise nonidentical panels. For example, Figure 6 shows an arrangement which may comprise six panels as described the first embodiment, and six panels comprising only a single channel. Providing simpler, single channel panels is advantageous as the cost of the kit can be reduced.

Figure 7 illustrates a further embodiment of an underiloor heating system comprising an undertloor heating panel. In this embodiment, the flow control is automatically controlled by an electronic actuator 710 connected to a programmable room thermostat 720. These two elements are configured such that a user can enter configuration data into the programmable room thermostat 720, for example entering a chosen air temperature for a particular time period of the day. Based on this data, the thermostat 720 causes the flow at flow control to be automatically controlled, by sending a signal to electronic actuator 710 which causes the actuator to adjust the flow control 150. In addition, a motion sensor 730 or a pressure sensor 740, or both, can be connected to the programmable room thermostat, The motion sensor 730 is positioned in a room such that a person entering or moving within the room is within the motion sensor's range of perception. Typically, the motion sensor and thermostat will be configured to reduce or terminate heating of the room when no motion has been sensed by the motion sensor for a period of time.

In the present embodiment, the pressure sensor 740 is located beneath an underfloor heating panel 20. Alternatively, the pressure sensor 740 can be placed in between the upper and central layers, or provided on the upper layer. The panel 20 as described above is suitable for use with pressure sensor 740 as the panel is able to make direct contact with flooring material, such as tiles, without the need for an intervening layer for example, screed. Therefore, small displacements of flooring caused by a person stepping on it will be transmitted to the pressure sensor 740 via the panel 20. Typically, the pressure sensor and thermostat will be configured to reduce or terminate heating of the room when no change in pressure has been sensed by the pressure sensor for a period of time.

Figures 8A and 88 illustrate an alternate embodiment of the underfloor heating panel in which the upper layer 220 comprises a single layer of a conductive material such as copper. The depth of the channel, i.e. the distance between the base 281 and the upper layer 220, is chosen such that when heating pipe 140 is placed in the channel 241, the outer surface 234 of the heating pipe is either in contact with or in close proximity to the upper layer 220. Therefore, in this embodiment, no removable heat plate is used to aid the transfer of heat from the heating pipe to the upper layer 220. Although the removable heat pate is advantageous because it provides an improved thermal distribution away from the heating pipe and therefore avoids hotspots', the present embodiment allows a more basic construction of the upper layer and does not require a heat plate, and is therefore sknpler and cheaper than the embodiments requiring a heating plate.

Further, referring in particular to Figure 1, the piping 100 can be of any suitable design and manufactured from any suitable material, for example copper.

Flexible plastic pipes can also, for example, be used.

While in the above embodiments water is passed through the underfioor healing system in order to transport heat energy from the boiler to the underfloor heating pipes, any fluid can be used for this purpose, such as steam.

The boiler may comprise any boiler type, for example a condensing boiler or a soUd fuel boiler, or alternatively may be replaced with any suitable water heating means, for example a ground source heat pump. Further! unlike conventional underfloor heating systems, the underfloor heating system described herein may beneficially be connected to a solar heated water system. Any of the elements shown in Figure 1 can be combined, for example the expansion vessel and pump can be provided as part of boiler 120.

Pump 110 may comprise, for example, a centrifugal pump.

Referring in particular to Figure 2, alternative channel arrangements to the one depicted may be used. The central layer 240 may comprise additional or fewer channels. Curved channels 243 and 244 could be replaced with substantiafly straight ones, or curved channels 243 and 244 could be dispensed with altogether.

Upper layer 220 may comprise a single, continuous layer comprising the joint 325. Additionally, upper layer 220 may not comprise a joint, and may instead be removable in its entirety. The upper layer may comprise any heat conductive material, such as copper or aluminium. Additionally, upper layer 220 may have any suitable thickness typically, for example, within the range of 0.2mm to 10mm, Hinge 325 may be replaced with any connection means which allows the movable portion 321 to be moved with respect to the fixed portion 323.

The tongue 345 and complementary tongue-receiving groove 347 can be replaced with any engaging means.

Central layer 240 is preferably manufactured from a gypsum based material, and may for example be made from gypsum and paper. Using a gypsum based material to manufacture the central layer is advantageous as it results in a fire and heat resistant paneL Therefore, the underfloor heating panel described in the above embodiments can be used as a fire barrier between floors of a buding.

Other fire resistant materials can be used in the construction of the panel in addition to or in place of the gypsum based materiaL The gypsum based central layer has the further advantage of being water resistant, which is beneficial in maintaining structural integrity in the situation where a leak or flood has occurred.

Lower layer 260 may comprise any means for reflecting heat towards upper layer 220. Also, the lower layer may optionafly only be attached to the central layer during installation, or may be dispensed with altogether.

Referring in particular to Figure 3, thermally conductive gel may be replaced with another thermaily conductive materiaL or may be dispensed with entirely.

Also, central layer 240 may comprise projections in place of recesses 282, and the other elements altered accordingly, in particular heat plate 510 may comprise recesses in place of projections 514.

Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

Each feature disclosed in this specification (which term includes the claims) and/or shown in the drawings may be incorporated in the invention independently (or in combination with) any other disclosed and/or illustrated features. In particular but without limitation the features of any of the claims dependent from a particular independent claim may be introduced into that independent claim in any combination or individually.

Statements in this specification of the "objects of the invention" relate to preferred embodiments of the invention, but not necessarily to all embodiments of the invention falling within the claims.

The description of the invention with reference to the drawings is by way of

example only.

The text of the abstract filed herewith is repeated here as part of the specification.

An under floor heating system is described in which a number of composite panels are used. The composite panels comprise a first layer that is of a thermafly insulative material in which at least one channel is provided for receiving a pipe of the underfloor heating system. A second layer is provided on the first layer, comprising a thermafly conductive material, and means for S providing access to the at least one channel whereby to allow receipt of a fluid carrying conduit into the channel.

Claims

Claims 1. A composite panel for an underfloor heating system, the panel comprising: a first layer comprising a thermally insulative material in which at least one channel is provided for receiving a fluid carrying conduit of the underfloor heating system; and a second layer, provided on the first layer, comprising a thermally conductive material, and means for providing access to the at least one chann& whereby to allow receipt of a fluid carrying conduit into the channel.
2. The panel of claim I wherein a third layer comprising a thermaUy reflective layer is provided on the first layer, the first layer being disposed between the second layer and the third layer.
3. The panel of any preceding claim, wherein the access providing means comprises at least one opening provided in the second layer to allow said fluid carrying conduit to be inserted into said channel during installation of said heating system.
4. The panel of any preceding claim wherein the channel is configured for releasable engagement with a cover portion for covering the channel.
5. The panel of claim 4, wherein the channel comprises at least one recess for receiving a corresponding projection in said cover portion whereby to allow said r&easable engagement of said cover portion.
6: The panel of claim 4 or 5, wherein the channel comprises at least one projection for engaging with a corresponding recess in said cover portion whereby to allow said releasable engagement of said cover portion.
7. The panel of any preceding claim, wherein the access providing means comprises a movable portion of the second layer that is movable between a closed position in which the channel is covered by the moveable portion and an open position in which the channel is accessible to allow said fluid carrying conduit to be inserted into said channel during instaUation of said heating system.
8. The panel of claim 7 wherein the movable portion is hingedly connected to a fixed portion of said second layer and is moveable between said closed and open positions about said hinged connection.
9. The panel of daim 7 wherein the movable portion is configured for complete removal from the composite panel to achieve said open position and for placement or replacement on the composite panel to achieve said closed position.
10. The panel of any preceding claim, wherein the second layer comprises a portion that extends at least partially into said channel.
11. The panel of any preceding claim, wherein the second layer further comprises a means for engaging with at least one further panel.
12. The panel of claim 11 wherein the means for engaging with a second panel comprises a tongue for engaging with a corresponding groove on the at least one further panel.
13. The panel of daim 11 or 12 wherein the means for engaging with a second panel comprises a groove for engaging with a corresponding tongue on the at least one further panel.
14, The pan& of any preceding claim, wherein the second layer comprises a plurality of channels for receiving the or at least one further fluid carrying conduit of the underfloor heating system.
15. The panel of claim 14, wherein the second layer further comprises a first and second channel arranged substantially perpendicular to one another.
16. The underfioor heating panel of any preceding claim, wherein the channel further comprises a base portion configured to conform at least partially to the shape of said fluid carrying conduit.
17. The panel of claim 16. wherein the channel further comprises substantially straight walls extending from the base portion to the second layer.
18. A cover portion for the composite panS of any preceding daim, the cover portion being configured for releasable engagement with the at least one channel of said composite panel to secure the cover portion in position covering said channel and comprising means for thermally connecting the cover portion to a surface of said fluid carrying conduit when said fluid carrying conduit is in position in said channel.
19. A cover portion as claimed in claim 18 wherein the means for thermally connecting the cover portion to said surface of said fluid carrying conduit comprises a thermally conductive portion of the cover portion configured to at least partially conform to said surface of said fluid carrying conduit when said fluid carrying conduit is in position in said chann& whereby to form an area of thermal contact between the fluid carrying conduit and the cover portion.
20. A cover portion as claimed in claim 18 or 19 further comprising means for thermally connecting the cover portion to a surface of said second layer of said composite panel.
21. A cover portion as claimed in claim 20 wherein the means for thermally connecting the cover portion to the surface of said second layer of said composite panel comprises a thermally conductive element configured such that when the cover portion is engaged in the at least one channel, a surface of the thermally conductive element is in contact with said surface of the second layer whereby to form an area of thermal contact between said surface of the second layer and the cover portion.
22. A cover portion as claimed in claim 18 wherein the cover portion has a generally tT shaped cross-section; wherein a base of the T' shaped cross-section is configured for engagement against a surface of said fluid carrying conduit when said fluid carrying conduit is in position in said channel and said cover portion is engaged in position covering said channel; and/or wherein a top portion of the 1' shaped cross-section is configured to engage against a surface of said second layer.
23. An underfloor heating system comprising a composite panel according to any of claims I to 17.
24. An underfloor heating system according to ckiim 23 further comprising at least one cover portion according to any of c'aims 18 to 22.
25. A method of instafling an underfloor heating system comprising: providing at least one composite panel according to any of claims 1 tol7; inserting a fluid carrying conduit of the underfloor heating system into the channel of said at least one composite panel; and connecting said fluid carrying conduit to a source of heated fluid.
26. A method according to claim 25 further comprising: covering said channel of said at least one composite panel after said inserting step with a cover portion according to any of claims 18 to 22.
27. A kit comprising a plurality of composite panels according to any of claims Ito 17.
28. A kit according to claim 27 further comprising a plurality of cover portions according to any of claims 18 to 22.