GB2521604A

GB2521604A - Insulative panel

Info

Publication number: GB2521604A
Application number: GB1322720.2A
Authority: GB
Inventors: Neil Mullarkey; Mark Tickle
Original assignee: POLYFAB COATINGS AND SYSTEMS Ltd
Current assignee: POLYFAB COATINGS AND SYSTEMS Ltd
Priority date: 2013-12-20
Filing date: 2013-12-20
Publication date: 2015-07-01
Anticipated expiration: 2033-12-20
Also published as: GB201322720D0; GB2521604B

Abstract

An underfloor insulative panel 300 comprises at least one channel 309 provided in a surface of said panel for accommodating a conducting element 310. The channel comprises a heat transfer material 324 extending from within said channel to the surface of said panel. The thickness of the heat conducting material increases along the side walls from the base of the channel to the surface of the panel, it may be cement-based and preferably extends over the entire surface of the panel. A fibre glass mesh may be embedded in the cement to reinforce the panel. The channel is preferably shaped with two convex curves before being filled with the cement. The channel preferably also has expansion strips 328 to ensure contact. Tiles 322 and adhesive 320 can be placed directly on the panel. Also claimed is a method of manufacturing an underfloor insulative panel a temperature control system, and kit of parts. In use the panel is used in an underfloor heating system to insulate the subfloor, carry the pipes and transfer heat evenly across the floor.

Description

Insulative Panel

Field of invention

This invention relates to a panel and to a method of manufacturing a panel for underfloor temperature control. The invention also relates to a corresponding kit of parts and to a temperature control system using said panels.

Background

Underfloor heating can take a number of forms which all follow the same general principle of heating a room by installing conducting elements undemeath the floor finish.

The two most common forms are electrical, where resistive heating elements placed under the floor heat up the floor surface, and hydronic (water based) systems where heated water is passed through a series of pipes under the floor to transfer heat to (or from) the floor and thereby the room.

Underfloor heating systems may be preferable to other forms of heating as they can be more efficient, safer (no exposed hot elements), aesthetically pleasing (being hidden under the floor), and more comfortable (it is pleasing to walk on a warmed surface).

However, there are many technical problems to overcome to achieve any or all of the above advantages. Foremost, there is the potential for a significant amount of energy to be dissipated downwards, which would heat up floor cavities or structural parts of the building, thus wasting energy by heating areas which do not need to be heated.

Insulating material is often placed below the heating elements to minimise such heat losses. However, this can result in increased bulk, effectively raising the level of the floor, reducing available space and potentially interfering with other above-floor elements and boundaries with areas without such underfloor heating.

Electrical underfloor heating is most popular in refurbishment projects in existing properties where it can be installed one room at a time with minimal disruption. The total installation cost can be much lower than hydronic systems, but the cost of energy can be higher than the water based systems heated by modern gas fuelled boilers or renewable heat sources (such as solar water heating systems).

Thermally insulating backerboards' may be incorporated into electrical underfloor heating installations, particularly when the final floor finish is tiled. The boards are typically bonded to concrete floor slabs or screwed to timber floors. The electrical heating element is then laid on top before tiling. On concrete subfloors, installations without this insulation can take many hours to reach final temperature, whereas with the insulation warm up times are greatly reduced. Most electrical underiloor heating systems come supplied with an electronic controller which sets the floor temperature and the times when the heating is to be switched on and off. Without these insulating boards the effectiveness of the heating system and accuracy of the timer is greatly reduced leading to significant customer dissatisfaction.

Hydronic systems involve a water based fluid (which may include additives such as antifreeze) being used as a heat-transfer agent flowing through pipes laid under the floor.

Hydronic underiloor heating systems are more likely to be used in new build properties or significant property extensions as their installation cost are significantly higher than electrical based systems and the installation methods generate significant disruption in the property. They are particularly appropriate for some of the modern renewable heating systems where the water can be heated via heat pumps or solar systems and can therefore be significantly cheaper to run.

A typical hydronic system, as illustrated in Figure 1, comprises of a series of plastic pipes 110, laid in a serpentine' pattern underneath the floor, which are connected to the heat source 102 through a thermostatically controlled manifold 104. The temperature in each heating loop can be independently controlled by thermostatic valves 106 at the manifold 104.

A section (through line A-A' of Figure 1) of an example prior-art underfloor heating system is shown in Figure 2. The pipes 110 are typically laid onto sheets of polystyrene insulation 112, which may include a pre-printed patterned grid to assist in the correct spacing of the pipes 110. Plastic brackets or clips 113 may be provided so as to hold the pipes in the correct position.

A thick sand/cement screed 114 (typically around 75mm) is then applied over the pipes to create a thermal mass (heat sink) and create a robust floor structure. The time required to heat this thermal mass to the desired temperature setting can be considerable.

Furthermore, the build-up in the floor height may make such systems impracticable for single room installations. Another disadvantage of this screed 114 is that it takes a long time to set properly, meaning that laying the heating pipes and subsequently tiling is not possible in a single day.

To overcome these problems some manufacturers have attempted to create a system which does not require the thick screed layer 114. An example section 200 of such a system is shown in Figure 3. This comprises a thinner sheet of insulation 212 (possibly with pre-machined channels 209 to locate the water heating pipes 210) with a top surface and the pre-machined channel lined with a thin foil of aluminium 216 placed over the channel. If the final floor covering is to be ceramic or a natural stone tile, due to the incompatibility of the tiling adhesives and the aluminium foil, this system must first be covered with a compressed cement board or plywood 218 before fixing the tiles 222 (using tile adhesive 220). Tiling contractors may be concerned about applying ceramic tiles to such a floating floor'. The high risk of movement in such floating floors could result in delamination and cracking of the tiles.

An improved panel is hereby described which attempts to alleviate some or all of the problems associated with the aforementioned underfloor heating systems.

In one aspect of the invention there is provided an underfloor insulative panel comprising: at least one channel provided in a surface of said panel for accommodating a conducting element; the channel comprising a heat transfer material extending from along the side-walls of said channel to the surface of said panel; wherein the thickness of the heat transfer material along the side-walls of the channel increases from the base of the channel to the surface of said panel.

The thickness of the heat transfer material along the side-walls of the channel may conform to a convex curve from the base of the channel to the surface of said panel.

The heat transfer material may further extend over the entire surface of the panel.

The panel may further comprise expansion strips in said channel so as to ensure contact between a conducting element accommodated within said channel and said heat transfer material.

The heat transfer material may comprise a cement-based compound.

The panel may further comprise reinforcement on a surface of the panel in which said channel is provided.

The panel may further comprise reinforcement on a surface of the panel opposite to the surface of the panel in which said channel is provided.

The reinforcement may comprise a coating extending over substantially the entire surface of the panel; and preferably wherein the coating is the heat transfer material.

The coating may comprise a cement-based compound.

The reinforcement may comprise a reinforcing mesh disposed on a surface of the panel.

The reinforcing mesh may be alkaline-resistant.

The reinforcing mesh may comprise fibre glass.

The heat transfer material may be adapted to have tile adhesive applied directly thereto.

The channel may be suitable for accommodating a pipe.

The base of the channel may be curved so as to conform to the shape of a pipe.

The panel may further comprise at least two channels for a conducting element joined by a further channel.

In another aspect of the invention there is provided a kit of parts comprising a plurality of the aforesaid panels, each provided with channels in different configurations such that when placed together the channels coapt to form a serpentine track for accommodating piping.

In another aspect of the invention there is provided a kit of parts comprising a panel as aforesaid and at least one pipe.

The kit of parts may further comprise a heating manifold.

The kit of parts may further comprise flooring material, such as ceramic tiling, laminate flooring, wooden flooring.

In another aspect of the invention there is provided a method of manufacturing an underfloor insulative panel, comprising: providing a trough in a surface of the panel; said trough having a narrower base than opening; providing a heat transfer material within said trough.

The method may further comprise: providing a further trough, parallel to said trough, having a narrower base than opening; and providing a heat transfer material within said further trough.

The method may further comprise: removing the material disposed between said parallel troughs thereby forming a channel suitable for accommodating a conducting element.

The method may further comprise providing expansion strips along side-walls of said channel so as to ensure contact between a conductor locatable within said channel and said heat transfer material.

The heat transfer material may be a cement-based material.

The panel may further comprise providing reinforcement on a surface of the panel on which said channel is provided.

The method may further comprise providing reinforcement on a surface of the panel opposite to the surface of the panel on which said channel is provided.

The reinforcement may comprise a reinforcing mesh.

The reinforcing mesh may comprise fibre-glass.

The reinforcing mesh may be alkaline-resistant The reinforcement may comprise a coating of a cement-based compound; and preferably the coating is the heat transfer material.

In another aspect of the invention there is provided a temperature control system comprising a plurality of the aforesaid panels, a conducting element and a temperature controller.

The temperature controller may include a manifold and the conducting element is piping.

The temperature controller may include an electrical controller and the conducting element may be resistive wiring.

The invention also extends to an underficor insulative panel substantially as herein described and/or as illustrated with reference to the accompanying figures.

The invention also extends to a kit of parts for an underfloor heat temperature control system substantially as herein described and/or as illustrated with reference to the accompanying figures.

The invention also extends to a method of manufacturing an underfloor insulative panel substantially as herein described and/or as illustrated with reference to the accompanying figures.

The invention also extends to a temperature control system substantially as herein described and/or as illustrated with reference to the accompanying figures.

The invention extends to any novel aspects orfeatures described and/or illustrated herein.

Further features of the invention are characterised by the other independent and dependent claims.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa.

Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

In this specification the word or can be interpreted in the exclusive or inclusive sense unless stated otherwise.

The invention extends to methods and/or apparatus substantially as herein described with reference to the accompanying drawings.

Purely by way of example, the present invention is illustrated by the accompanying drawings in which: Figure 1 is a schematic diagram of an underfloor heating system; Figure 2 is a cross-section of a prior-art underiloor heating system; Figure 3 shows a cross-section of another prior-art underfloor heating system; Figure 4 shows a cross-section of an underfloor insulative panel according to one embodiment of the present invention; Figures 5(a) to (f) show the various steps involved in the construction of the underiloor insulative panel of Figure 4; Figure 6(a) shows a perspective cross-sectional view of the underiloor insulative panel of Figure 4; Figure 6(b) shows a perspective cross-sectional view of the undertloor insulative panel of Figure 4 including piping; Figure 7(a) shows a further perspective view of an underfloor insulative panel of Figures 4and6; Figure 7(b) shows a further perspective view of an underfloor insulative panel of Figures 4 and 6 including piping; and Figures 8(a) to (e) show a number of alternative underfloor insulative panel arrangements.

Detailed description

Figure 4 shows a cross-section of an exemplary undertloor insulative panel 300. The conducting elements 310 (in this case, pipes) sit in pre-machined channels 309 formed of troughs 307 in a polystyrene core 312 which are opened up so as to allow the deposition of a heat transfer material 324.The heat transfer material 324 extends from within the channel 309 to the face of the heating panel 300. The thickness of the heat transfer material 324 increases from the base of the channel 309 to the top face of the panel. The heating panel is then coated ith a mesh reinforced cement coating 326 (see Figures 5(a)-(f)). This facilitates both lateral and upward conduction of heat from the pipe to the floor; the example shown of the thickness conforming to a curved, convex surface, tapering outwardly from the base of the channel to the surface of the panel being particularly suited to this.

Expansion strips 328 are situated on the inner side-walls of the channel 309 so as to ensure contact between the pipe 310 and the heat transfer material 324 regardless of whether the pipe 310 is in a state of expansion or contraction. This ensures optimum heat transfer from the pipe 310 to the heat transfer material 324, and thus to the floor. Tile adhesive 320 is then placed directly onto the mesh reinforced cement coating 326 and pipe 310 so that tiles 322 can be installed. Alternatively, other floor coverings such as laminate flooring or wooden boards may be applied with or without adhesive.

The heat transfer material 324 has a high thermal conductivity (compared to the insulative core 312 or traditional screed 218) thus transferring the heat from the pipe 310 to the surface of the panel 300 between adjacent pipes. The heat transfer 324 material is preferably a cement-based material. Coupled with the mesh reinforced cement coating 326, this provides more efficient heat transfer to the floor surface thus heating up the floor faster and consequentially introducing thermodynamic efficiency gains in the system by minimising the heat loss of the return flow temperature. These features are advantageous for all applications of hydronic underfloor heating, but particularly those which run on a tirner (rather than those that are always on) as there is less lag in the floor reaching the required temperature. This means the timer would accurately reflect the period in which the floor is actually heated.

The mesh reinforced cement coating 326 also provides additional strength to the panel 300 thus reducing the need for thick layers of screed or an additional cement board to protect the insulation layer from point loading. Furthermore, the coating 326 provides a surface upon which tile adhesive can be placed directly, unlike previous systems utilising a foil layer.

In a particularly advantageous embodiment, the coating 326 is also applied to the underside of the panel 300 to improve the overall strength of the panel 300.

A preferable material for the coating 326 is a cement-based coating (preferably the same material as the heat transfer material), due to its compressive strength and thermal properties. Placing such a coating 326 on the surface(s) of the panel 300 also improves adhesion to the tile adhesive, greatly increases the tensile strength and improves resistance to impact.

The reinforcement mesh contained within coating 326 is preferably fibre glass as this provides good tensional and compressional strength without adding significantly to the weight or bulk of the panel 300. Furthermore, this mesh is preferably alkaline-resistant so as to not degrade when the cement coating is applied.

The tile adhesive 320 and tiles 322 do not form part of the underfloor heating panel 300 but are shown for context. In practice, the entire surface area to be heated would be covered with panels 300, then pipes 310 installed and connected to a manifold 104 (as shown in Figure 1) prior to tiling (or another floor covering) being applied.

Figures 5(a)-(f) show a method of constructing the underfloor heating panel 300 of Figure 4. Figure 5(a) shows the extruded polystyrene core 312 with the underside coated with the mesh reinforced cement coating 326.

Figure 5(b) shows the extruded polystyrene core 312 with a machined trough 307. The trough 307 is shown to be formed of two parallel troughs, each having a narrower base than opening, separated by a rectangular section of insulative material. The edges of each trough 307 are curved so that they can be filled with a heat transfer material which conducts heat both outwardly and upwardly in an efficient and effective manner.

The trough 307 is shown to extend in a curved, convex manner from the base of the trough to the surface, but in alternative embodiments it may extend as a slanted line. This alternative embodiment may be easier to manufacture. An alternative method would be to extrude a single trough, having a base narrower than opening, and forming a channel for a pipe by filling only a portion of the trough (for example, by using a mask).

Figure 5(c) shows the trough 307 having been filled with a heat transfer material 324 level with the surface of the extruded insulative (e.g. polystyrene) core 312. The heat transfer material 324 is preferably pumped in to the trough 307 but may also be poured, sprayed or painted, depending on the composition, viscosity and intended thickness of the material. To facilitate the accurate placement and extent of the heat transfer material 324, a mask or stencil (not shown) may be utilised.

The mesh reinforced cement coating 326 is then applied to the upper face of the panel, as shown in Figure 5(d). The coating 326 adds to the rigidity of the panel, and, on the upper surface, has a further purpose of aiding the conduction of heat from the pipe.

The cement coating permeates through the mesh and fixes it to the extruded polystyrene core 312. Alternatively it may be affixed to the extruded polystyrene core 312 by a suitable fixing means such as glue or epoxy resin.

In one embodiment, the coating layer on the upper (or lower) layer is between 0.5mm and 5mm thick, more preferably between 1mm and 3mm and even more preferably 2mm thick.

Figure 5(e) shows the final manufacturing step of producing a machined channel 309 by removing the rectangular section separating the parallel troughs 307, and creating expansion strips 328 along the side-walls of the channel 309. These strips 328 make the channel slightly thinner than the width of the pipe (when cold) so that the pipe is in constant thermal contact with the heat transfer material 324. The panel 300 shown in Figure 5(e) is in the form it would take prior to installation or in situ, but before any piping -10-or floor covering has been provided, and Figure 5(f) shows the panel with piping 310 and tiling 322 in place.

The choice of piping size would be influenced by a number of factors including: the size of the area that is to be heated, the available space under the floor, the power of the pumping system, and the power of the heating system. Table 1 below illustrates example dimensions of the panel when using particulardimensions of piping: Diameter of piping Thickness of panel (insulative (mm) core + coating) (mm) 16 12 18 21 16 22 Table 1 -Example dimensions of pipe and panel Although the panels 300 are adapted to reduce overall thickness of a hydronic underiloor heating system, the panels described and illustrated herein would also be available in a range of different thickness to suit different floor heights. This would be advantageous in retro-fit situations where there is a larger area of space to fill so as to match the level of the adjacent room (for example). Thicker panels comprise a thicker insulation layer 312, so would have a greater insulative effect. In one example, the panel may be up to 100mm thick, but more preferably it is up to 70mm thick.

Figures 6(a) and 6(b) show perspective cross-sections of the underfloor heating panel with and without pipes respectively. The heat transfer material 324 is shown extending down through the channel 309, forming a square-sided channel into which a pipe 310 is placed. This heat transfer material 324 extends to the surface of the panel 300 where the mesh reinforced cement coating 326 is placed.

Figures 7(a) and (b) show entire panels 300 corresponding to Figures 6(a) and (b). The panels are adapted to coapt with neighbouring panels such that they can be pre-fabricated off-site and fitted alongside one-another to fill the desired area and provide a serpentine path for piping. The pipes 310 then snake back and forth through the channels 309, afforded by connecting channels 330 between parallel channels 309.

Figure 8 shows a number of different panels which afford flexibility in the design of the heating system. Figure 8(a) shows a panel intended to be placed at the edge of the heated area, where the pipes may snake back in the opposite direction.

Figure 8(b) shows the heating panel previously shown in Figures 7(a) and (b). This panel may be used as an edge panel extending further into the area to be heated.

Figure 8(c) shows a panel arranged to coapt with either panel (a),(b) or panel (d) so as to extend across the floor area. An example arrangement using these three different types of panel with an example flow path is shown in Figure 8(e). In this figure, additional channels (designated (d)) may be cut in-situ so as to allow the pipes to come from I return to the manifold.

Figure 8(d) shows a set of close-parallel channels, such a panel would be used where the heating source needs to be connected to multiple zones that are required to be independently controlled.

Alternatives and modifications The terms underiloor heating', heating', heated', heats' are used throughout this specification, but the system could equally be used as an undefloor cooling' system by using a fluid of lower-than-ambient temperature. Similarly, the term underfloor' should be read to incorporate not only use underneath a typical floor but also any surface where heat transfer is required and the associated advantages of the system still apply.

The term hydronic' has been used to describe water-based heat transfer' systems, but a person skilled in the art would understand the advantages detailed above could equally be afforded by using any other suitable fluid, depending on the application. For example, oil or air could be used if a lower heat transfer coefficient is desired.

Various other modifications will be apparent to those skilled in the art including making the square-sided channels conform to the shape of a pipe; if such a modification were provided, the channel might be flexible so as to allow the insertion of a pipe.

It will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims. -12-

Claims

Claims 1. An undeifloor insulative panel comprising: at least one channel provided in a surface of said panel for accommodating a conducting element; the channel comprising a heat transfer material extending from along the side-walls of said channel to the surface of said panel; wherein the thickness of the heat transfer material along the side-walls of the channel increases from the base of the channel to the surface of said panel.
2. The panel of claim 1 wherein the thickness of the heat transfer material along the side-walls of the channel conforms to a convex curve from the base of the channel to the surface of said panel.
3. The panel of any preceding claim wherein the heat transfer material further extends over the entire surface of the panel.
4. The panel of any preceding claim further comprising expansion strips in said channel so as to ensure contact between a conducting element accommodated within said channel and said heat transfer material.
5. The panel of any preceding claim wherein the heat transfer material comprises a cement-based compound.
6. The panel of any preceding claim further comprising reinforcement on a surface of the panel in which said channel is provided.
7. The panel of any preceding claim further comprising reinforcement on a surface of the panel opposite to the surface of the panel in which said channel is provided.
8. The panel of claim 6 or 7 wherein the reinforcement comprises a coating extending over substantially the entire surface of the panel; and preferably wherein the coating is the heat transfer material.
9. The panel of claim 8 wherein the coating comprises a cement-based compound.
10. The panel of any of claims 6 to 9 wherein the reinforcement comprises a reinforcing mesh disposed on a surface of the panel. -13-
11. The panel of claim 10 wherein the reinforcing mesh is alkaline-resistant.
12. The panel of claims 10 or 11 wherein the reinforcing mesh comprises fibre glass.
13. The panel of any preceding claim wherein, in use, said heat transfer material is adapted to have tile adhesive applied directly thereto.
14. The panel of any preceding claim wherein the channel is suitable for accommodating a pipe.
15. The panel of claim 14 wherein the base of said channel is curved so as to conform to the shape of a pipe.
16. The panel of any preceding claim comprising at least two channels for a conducting element joined by a further channel.
17. A kit of parts comprising a plurality of panels according to claim 16, each provided with channels in different configurations such that when placed together the channels coapt to form a serpentine track for accommodating piping.
18. A kit of parts comprising a panel of any of the preceding claims ito 16 and at least one pipe.
19. The kit of parts of claim 18 further comprising a heating manifold.
20. The kit of parts of claim 18 or claim 19 further comprising flooring material, such as ceramic tiling, laminate flooring, orwooden flooring.
21. A method of manufacturing an underfloor insulative panel, comprising: providing a trough in a surface of the panel; said trough having a narrower base than opening; and providing a heat transfer material within said trough.
22. The method of claim 21 further comprising: providing a further trough, parallel to said trough, having a narrower base than opening; and providing a heat transfer material within said further trough.
23. The method of claim 22 further comprising: removing the material disposed between said parallel troughs thereby forming a channel suitable for accommodating a conducting element. -14-
24. The method of claim 23 further comprising providing expansion strips along side-walls of said channel so as to ensure contact between a conductor locatable within said channel and said heat transfer material.
25. The method of any of claims 21 to 24 wherein the heat transfer material further extends over the entire surface of the panel.
26. The method of any of claims 21 to 25 wherein the heat transfer material is a cement-based material.
27. The method of any of claims 21 to 26 further comprising providing reinforcement on a surface of the panel on which said channel is provided.
28. The method of any of claims 21 to 27 further comprising providing reinforcement on a surface of the panel opposite to the surface of the panel on which said channel is provided.
29. The method of claim 27 or 26 wherein the reinforcement comprises a reinforcing mesh.
30. The method of claim 29 wherein the reinforcing mesh comprises fibre-glass.
31. The method of claim 29 or 30 wherein the reinforcing mesh is alkaline-resistant
32. The method of any of claims 27 to 31 wherein the reinforcement comprises a coating of a cement-based compound; and preferably the coating is the heat transfer material.
33. A temperature control system comprising a plurality of panels according to any of claims 1 to 16, a conducting element! and a temperature controller.
34. The temperature control system of claim 33 wherein the temperature controller includes a manifold and the conducting element is piping.
35. The temperature control system of claim 33 wherein the temperature controller includes an electrical controller and the conducting element is resistive wiring.
36. An underfloor insulative panel substantially as herein described and/or as illustrated with reference to the accompanying Figures 4-8. -15-37. A kit of parts for an underfloor heat temperature control system substantially as herein described and/or as illustrated with reference to the accompanying Figures 4-8.38. A method of manufacturing an underfloor insulative panel substantially as herein described and/or as illustrated with reference to the accompanying Figures 4-8.39. A temperature control system substantially as herein described and/or as illustrated with reference to the accompanying Figures 4-8.