WO2009031132A2

WO2009031132A2 - A heat transfer system

Info

Publication number: WO2009031132A2
Application number: PCT/IE2008/000085
Authority: WO
Inventors: James Carolan; Gregory Flynn
Original assignee: Kingspan Research And Developments Limited
Priority date: 2007-09-04
Filing date: 2008-09-03
Publication date: 2009-03-12
Also published as: GB0816052D0; WO2009031132A3; GB2452612A; GB2452612B

Abstract

A heat transfer system comprises a plurality of insulating panels (60) used to construct at least part of a building. Each of the panels (60) has a plurality of air passageways (7) therein. The system comprises plenum chambers defined by housings (61) into which air from the panel passageways (7) is drawn. The housings (61) have outlets (62) for discharge of air. Plenum housings (61) of varying lengths (dependant on building design) span across connecting passageways (65) between the air passageways (7) and the housings (61). The plenum chamber (61) comprises a panel side sub-chamber (70) and a room side sub-chamber 71 which are divided by a partition wall (72). A fan (73) is mounted to the partition wall (72) and draws air from the panel air passageways (7) into the panel side sub-chamber (70) and into the room side sub-chamber (71) for discharge through the outlets (62). The system comprises control means for controlling the operation of the fan (73) and hence the flow of air from ihe panels (100) into the room.

Description

"A heat transfer system^"

Introduction

With increasing energy costs there is a need for optimizing heat transfer to and from a building.

This invention is directed towards providing an improved insulating panel system which will address this issue.

Statements of Invention

According to the invention there is provided a heat transfer system comprising an. insulating panel having a first sheet, a second sheet, and an insulating material therebetween, the insulating panel having a plurality of air passageways located adjacent to at least one of the sheets for heat transfer between the sheet and air in the passageways and a plenum chamber connected to the panel, the air passageways having an exit opening into the plenum chamber, and the plenum chamber having an outlet for discharge of air which has passed through the air passageways in the panel.

In one embodiment the panel has connecting passageways between the panel air passageways and the plenum. The panel air passageways may be located adjacent to a first sheet and the connecting passageways extend through the foam from the panel air passageway through the second sheet. The plenum may be attached to the second sheet. The plenum may be sealingly attached to the second sheet.

In one embodiment the plenum chamber is defined by a plenum housing extending across the exit openings. In one case the plenum housing comprises a number of plenum housing sections which are interengagable or interlockable together. In one embodiment the housing sections comprise an insulation material. The housing sections may comprise a metal facing with an insulation material bonded thereto. The insulation material may comprise an insulating foam board.

In one embodiment each plenum housing section comprises a first end engagement feature and a second end engagement feature. The end engagement features may be complementary for inter-engagement of adjacent plenum housing sections.

In one embodiment the system comprises air drawing means for drawing air into the plenum chamber from the panel air passageway.

In one case the plenum chamber comprises a panel side sub-chamber and a room side sub-chamber and the drawing means draws air from the panel air passageways into the panel side sub-chamber, and air from the panel side sub-chamber into the room side sub-chamber for discharge from the plenum chamber. The plenum chamber -may be divided into the sub-chambers by a partition wall and the air drawing means is mounted to the partition wall.

In one case the air drawing means comprises a fan.

The system may comprise control means for controlling the operation of the air drawing means. In one case the control means comprises a panel air inlet temperature sensor, an air exit temperature sensor and a controller for controlling the operation of the air drawing means in response to the differentia] between the air inlet and air exit temperatures. The system may have a thermostat for activating and/or de-activating the air drawing means.

In one embodiment the system comprises an insert for an air passageway. In one case the insert is a push fit in one end of the passageway. The insert may provide an input mesh. Alternatively the insert provides a filler. The invention also provides a system comprising a plurality of insulating panels each having a plurality of air passageways therein and the plenum chamber is connected to a number of adjacent panels. There may be a plurality of plenum chambers. The plenum chambers may be separated.

In one embodiment the air passageways extend longitudinally of the panel.

In one aspect there is a barrier between the passageway and the insulating foam. The barrier may comprise a membrane such as a foil or tape. In one case the barrier is not planar.

The barrier may comprise a pair of longitudinally extending transversely spaced-apart sides defining a plane therebetween and the barrier extends outside of said plane.

In one embodiment the barrier extends into the foam.

The barrier may extend inwardly of the first sheet or inwardly of the second sheet.

In one embodiment between adjacent air passageways the foam is in direct contact with the sheet(s). Adjacent barriers may be spaced-apart.

In one case the first sheet is profiled. The second sheet may be profiled. In one case the profile defines a profile recess and the recess forms part of the passageway. The passageway may be larger than the profile recess. The passageway may comprise the profile recess part and a foam recess part. In one case, the foam recess part is oppositely directed with respect to the profile recess part. The foam recess part may be of a shape which is substantially a mirror image of the profile recess part.

In one embodiment the first sheet comprises a plurality of longitudinally extending profiled crowns, at least some of the crowns defining the passageway. One of the crowns may define an underlap for jointing with an adjacent like panel and the underlap crown is filled with foam.

The panel may be a roof panel, a wall panel, or a floor panel.

^• 5

Brief Description of the Drawings

The invention will be more clearly understood from the following description thereof 10 given by way of example only, in which :-

Fig. 1 is a perspective view of an insulating panel of the invention;

Fig. 2 is a cross sectional view of the panel of Fig. 1; 15

Fig. 2(a) is an enlarged view of a barrier used in the panel.

Fig. 2(b) is an enlarged view of a detail of the panel of Figs. 1 and 2;

20 Figs. 3 and 4 are cross sectional views of illustrating an overlap joint between adjacent panels of Figs. 1 and 2;

Fig. 5 is a perspective view of an apparatus used to manufacture panels of the invention;

25

Figs. 6(a) to 6(e) are cross sectional views illustrating various steps used in the manufacture of the panels;

Figs. 7(a) to 7(c) are perspective views of an external sheet part of a panel at 30 various stages during the manufacturing process; Fig. 8 is a cross sectional view of another panel according to the invention;

Fig. 9 is a cross sectional view on an enlarged scale of portions of the panel of Fig. 8:

Fig. 10 is a cross sectional view of a further panel according to the invention;

Fig. 11 is a cross sectional view on an enlarged scale of portions of the pane] of Fig. 10;

Figs. 12 to 31 are cross sectional views of various examples of pane's according to the invention;

Fig. 32 is a pian cross sectional view of building comprising a plurality of panels of the invention; • . ^{■ ■}

Fig. 33 is a cross sectional view of a top comer of the building of Fig. 32; and

Fig. 34 is a cross sectional view of another corner of the building ofFig. 33. ^■

Fig. 35 is a perspective view of an insulating panel system of the invention;

Fig. 36 is a perspective view of a plenum chamber detail of the pane] system of Fig 35:

Figs. 37 and 38 are elevationaJ views of the plenum of Figs. 35 and 36;

Fig. 39 is a transverse cross sectional view of a plenum chamber and panel;

Fig. 40 is an enlarged cross sectional view of the insulating panel and plenum svst em: Fig. 41 is a perspective view of another insulating panel system of the invention;

Fig. 42 is a perspective view of a plenum chamber detail of the panel system of

Fig. 41

Fig. 43 is an elevational view of the plenum system of Fig. 42;

Fig. 44 is a cross sectional view of the plenum chamber of Figs. 41 to 43;

Fig. 45 is a cross sectional view of a roof panel plenum system of the invention;

Fig. 46 is a cross sectional view on the line x-x in Fig. 45;

Fig. 47 is an enlarged view of detail A in Fig. 45;

Fig. 48 is an enlarged view of detail B in Fig. 45.

Fig. 49 is a cross sectional view of a wall panel plenum system of the invention;

Fig. 50 is a cross sectional view on the line x-x in Fig. 49;

Fig. 51 is an enlarged cross sectional view of one conduit of an insulating panel of the invention;

Fig. 52 and 53 are perspective views of an insert for the conduit of Fig. 37; and Figs. 54 and 55 are perspective views of another insert for the conduit of Fi^

5.

Detailed Description

Referring to the drawings and initially to Figs. 1 and 2 thereof there is illustrated an insulating panel 1 according to the invention comprising a first sheet 2, a second sheet 4 with an insulating body, in this case an insulating foam.5 therebetween. The foam may, for example be a polyisocyanurate foam or a phenolic foam. In this case the panel 1 is a roof panel 1 comprising a. profiled external sheet 2 which may be of painted galvanized steel. The profile in this case comprises a plurality of projections, in this case raised crowns 3. The crowns 3 in this case are of generally trapezoidal form and extend longitudinally along the length of the panel. The panel also comprises an inner metal liner sheet 4.

The foam defines a plurality of longitudinally extending conduit means 7 through which a suitable heat exchange medium such as air is circulated. The panel thus has an integral heat collecting means provided in some of the crowns 3 of the external sheet which are devoid of insulation 5. The conduits 7 extend through the crowns 3 and air is circulated through the conduits 7. The conduits 7 run through the roof and/or wall in the external envelope of the building and the air absorbs solar energy. Conduits 7 may alternatively or additionally be provided in floor panels for heat circulation. The warmed air may be pumped back into the building to provide heat to the building space. Once the heated air passes through the building and transfers its energy, it may flow back to the conduit in the roof and/or wall and/or floor panels and the process may be repeated in a closed loop.

Barriers, in this case in the form of a membrane such as a tape or foil 10 are located below the crowns 3 to prevent foam entering the crowns 3 and in this case also to create additional foam-free voids below the crowns 3. This. creates an. enlarged void space through which air may be circulated to enhance the solar collecting efficiency of the panel. Referring in particular to Figs. 2(a) the barriers 10 in this case have projecting side portions or legs 1 1 which may be attached, for example by adhesive to the inner face of the outer skin 3 of the panel. There is a free area 12 between individual barriers 10 to which the foam may directly bond to ensure direct foam bonding to the skin 3. The barriers 10 may be any suitable material such as foil or tape.

In the invention, the barrier 10 is not planar and can be used to define conduits of any desired size and/or shape. The barrier 10 has a pair of longitudinally extending transversely spaced-apart sides, 11 defining a plane therebetween and the barrier extends outside of said plane. The barrier can therefore be extended into the main body of the foam. The barrier can extend inwardly of the first sheet 2 and/or the second sheet 4 to provide a conduit of any desired size and shape. The first and/or second sheets may be profiled and at least some of the profile recesses may form- a conduit. To increase the heat transfer capabilities the conduit may be larger than the recess defined by the profile of the sheet. There may be a foam recess part and a profile recess part of the conduit. These may be oppositely directed to enlarge the size of the conduit. In one case the foam recess part is of a shape which is substantially a minor image of the profile recess part.

It will be noted that the cross sectional area of the void space 7 created between the crowns 3 and the barriers 10 is relatively large for optimisation of air flow and heat transfer. Utilising barriers of different size, the void area can be adjusted to suit the particular requirements of a building.

In this case an underlap crown 8 is filled with insulation foam so that when overlapped on assembly with an overlap hook 9 of an adjacent panel (see especially Figs. 3 and 4), the panels at the joint can be readily jointed or stitched together. The compressive strength at the joint is enhanced. Composite panels may be manufactured on a continuous production line by leading the outer sheet 2 along a flat bed with the recesses defined by the crowns 3 facing upwards. The sheet 2 may be of metal such as thin gague steel. The profiled sheet 2 is led to a lay-down area at which liquid foam reactants are spread across the sheet 2 • using a lay-down poker or the like. As the foam rises a backing sheet is applied over the foam and the sandwich thus formed is then led through an oven and subsequently cut to length. The backing sheet 3 may be of metal such as thin gague steel. The manufacturing technology is described in our UK-A-2227712, UK-A-2257086, and UK-A-2325640, the entire contents of which are herein incorporated by reference.

In the panels of the invention longitudinal conduit means 7 are defined by the foam. Referring in particular to Figs 5 to 7 a panel according to the invention is manufactured by leading an external sheet 2 along a flat bed defined .by a conveyor ^{< '}ι having rollers 20. A transverse support 21 is mounted by brackets 22 above the bed. ^■*^■ In this case, four anchor blocks 23 are mounted to the support -21 and a former 25 is ^' mounted to each block 23 by screw threaded rods 26. The longitudinal extent of a "• former 25 may be adjusted by moving the rod 26 relative to the associated anchor block 23. The formers 25 remain static with respect to the moving profiled sheet 2. Barriers which in this case comprise foil strips 10 are applied over the formers 25 and in this case are bonded to the inside face of the sheet 2 on each side of the profiled recess. Adhesive 30 is applied to the inner sheet face by nozzles 31 which are supplied from a supply tank 32. In this case a suitable lubricant 35 is applied to the underside of the barrier strips 10 by brushes 36 supplied from a supply tank 37.. The lubricant assists the movement of the barrier strips 10 on the- static formers 25. Shaping rollers 40 shape the strips 10 to conform with the exposed profile of the formers 25. ■

After application of the strips 10 over the formers 25, liquid foam reactants are laid down over the applied barrier strips 10 and the upper face of the sheet 2. A backing sheet 4 is applied and the foam is allowed to expand to fill the space between the sheet

2, barriers 10 and the sheet 4. In this case, the formers 25 only extend for. a length . sufficient to allow the foam to at least partially set whilst supporting the barrier 10. The panel with the conduit means defined in the foam continues through an oven to cure the foam. The panels may then be cut to a desired length and various further operations may be performed.

The formers 25 may be of any size and shape and may be located anywhere along a sheet 2 (whether profiled or not). Thus, the method can be utilized to produce a very wide range of panels, including those illustrated by way of example in Figs. 8 to 31. The panels of Figs. 8 to 31 are similar to those of Figs. 1 and 2 and like parts are assigned the same reference numerals.

The panel 100 of Figs. 8 and 9 with two conduits 101 will have the ability to collect and circulate energy but will not be as efficient as the panel of Figs. 1 and 2.

The panel 110 of Figs. 10 and 11 is similar to that of Figs. 1 and 2. In this case the panel has engagement formations in the form of recesses 111 and projections 112 for engagement of adjacent like panels. Interengagement features may be provided on any of the panels of the invention.

The panels of the invention may or may not have projections/crowns on their external face. These projections/crowns may or may not be used to provide conduits 7. Using the technology of the invention conduits 7 may be provided in any desired shape at any desired location of the panel.

In the panel 120 of Fig. 12 and the panel 130 of Fig. 13 conduits 7 extend inwardly from the face of the external sheet of the panel. Because the face against which solar energy impinges is generally flat the collection efficiency is likely to be diminished.

The panel 140 of Fig. 14 is similar to that of Fig. 2 except that the crowns/projections 141 are of curvilinear - such as accurate - shape. In the panel 150 of Fig. 15 the crowns/projections 151 are of triangular shape The panels 160, 170. 180, 190, of Figs. 16 to 19 are of similar profile and are generally flat with external sheets 2 and/or internal sheets 4 with or without small formations such as micro ribs.

Referring to Fig. 20, in this case a panel 200 is a roof tile panel with an external sheet of undulating or corrugated form. Panels of this type are described in UK-A -2384500. The panels 210 and 220 of Figs. 21 and 22 respectively are roof panels of different types incorporating conduits 7.

The panels 230 to 310 of Figs. 23 to 31 respectively again illustrate the application of the invention to a wide range of panel types with different joint details and/or internal sheet and/or external sheet detailing/profiles.

The panels may be used to construct part of or all of the building envelope including the roof, walls and floor. One such building is illustrated in Figs. 32 to 34. Each of the walls and the roof of the building comprise a plurality of the panels 50. Air circulating through the conduit means defined by the foam is directed into ducting 51. The flow or air may be controlled using one or more fans 52. The ducting may have venting system 53 which may be motorized to facilitate ease of operation and control. The circulating air is again heated by solar energy. This hot air is captured and may be passed into the heating/ ventilation ductwork of the building, again assisting in heating the building. The heated air may also or alternatively be circulated through a heal exchanger for transfer of solar heat to another heat collector. The system may be set to take air from the warmest or coldest elevations depending on the internal and external temperatures. The system can be used for heating and/or cooling.

Referring especially of Figs. 33 and 34 suitable insulated cappings 55 may be provided. The building may also have insulated flashings 56. Examples

We have found that the panel of Fig. 2 is particularly suitable for roofs, walls and for floors. The panel has a large exposed surface area and a high large internal void space whilst maintaining structural and insulation properties. The width L of the panel in this case is 1 meter. For optimum thermal efficiency there may be at least three and preferably at least four crowns 3. Each of the crowns 3 defines an area which is devoid of foam.

Referring to Fig. 2(b) the faces that are exposed to the external environment comprise an outer face x and two side faces which diverge inwardly from the outer face x. The angle α between the faces x, y is preferably 115 ° to 125°, most preferably 1 18° to 123° and in this case about 121°.

The width wl of the exposed face x is from 50mm to 60mm, most preferably in this case about 54mm. The height hi is from 30mm to 40mm, in this case about 36mm. The total cross sectional area above the dashed line in Fig. 2(b) is about 0.002906m². In this case the cross sectional area is further enlarged by providing an additional recessed section extending into the foam. This additional section has an inner face v and side faces z of which diverge outwardly from the inner face v. The angle α between the faces v and z is preferable 115° to 125°, most preferably 3 18° to 123°, and in this case about 120°. ^{• •} '.

The inner face v has a width w2 that may be from about' 50mm to about 100mm, preferably about 65mm to 75mm, in this case about 70mm.

The maximum width w3 of the cavity is in this case about 80mm to 120mm, preferably about 90mm to 110mm and in this case about 97mm.

The depth h2 of the recessed section is typically from 10mm to 40mm, preferably 20 to 35mm, and in this case about 27mm. The cross sectional area of the recessed section below the dashed line is about 0.00236m².

The total cross sectional area of the cavity (void area) is 0.002906 + 0.00236 = 0.005266m²

The efficiency is calculated based on an air velocity through the cavity of 4.3m/s. operating through an elevation of 6m xlOOm.

The ASHRAE Standard 93-2003-equation for efficiency of a solar collector

η =

A:I

Test data generated using the panel of Fig. 2 indicates an approximately 9.5 deg C air temp rise at 500W/m²

The energy production possible the panel was calculated using RETscreen

International Clean Energy Project Analysis software available at www.retscreen.net. The following assumptions were made:

Building Location: North West England

Building Size: 10m x 100m x 100m = 10,000m² floor space. South Facing Wall : 100m (W) x 1 Om (H)

Fan Air Speed: 7m / sec. Using the panels of Figs. 1 and 2 to construct the south facing wail of the building and circulating air through the foam-free passageways results in the following energy production:

Renewable heating energy delivered in one year 183.08 MWhrs based on local wather data.

Referring to Figs. 35 to 40 there is illustrated a heat transfer system according to the invention comprising a plurality of insulating panels 60 which in this case are similar to the panels described above with reference to Figs. 1 to 4 and like parts are assigned the same reference numerals. A building is at least partially constructed from a plurality of the panels 60. Each of the panels 60 has a plurality of air passageways 7 therein. The system comprises plenum chambers defined by housings 61 into which air from the panel passageways is drawn. Only one such housing 61 is illustrated however several such housings may be provided at appropriate locations associated with the same or different groups of panels 60. Some of the plenums have been omitted in Fig. 35 for illustrative purposes. The housings 61 have outlets 62 for discharge of air.

In this case the backing sheet 4 of the panel and the foam 5 have connecting passageways 65 therein through which air is drawn from the panel passageways 7 into the housing 61 which in this case is attached to the backing sheet 4.

Plenum housings 61 of varying lengths (dependant on building design) span across the passageways 65. Expandable foam tape is applied around the perimeter of the plenum housing 61 to ensure sealing between the plenum and profiled liner tray 4. The plenum 61 may be pop riveted to the liner tray 4. Alternatively or additionally the housing 61 may be braced to support the steelwork, if required. The plenum chamber 61 comprises a panel side sub-chamber 70 and a room side sub- chamber 71 which are divided by a partition wall 72. Drawing means in this case a fan 73, is mounted to the partition wall 72 and draws air from the panel air passageways 7 into the panel side sub-chamber 70 and into the room side sub-chamber 71 for discharge through the outlets 72.

The system comprises control means for controlling the operation of the fan 73 and hence the flow of air from the panels 50 into the room. The control means comprises a panel air inlet temperature sensor, an air exit temperature sensor and a controller for controlling the operation of the fan 73 in response to the differential between the air inlet and air exit temperatures. There is also a thermostat for activating or deactivating the fan 73.

When the fan 73 is activated it creates a uniform negative pressure across the sub- chambei 70, ensuring that an equivalent/balanced air flow through each passageway 7 is achieved. Warm air entering the sub-chamber 70 is drawn into the room side sub- chamber 71 creating an overall positive pressure. There is a pressure differential between the room side sub-chamber 71 and the internal building environment, forcing air to flow out of the plenum through gravity backdraught vents 75.

A thermostat communicates to the fan control system when the internal building temperature falls outside the desired range. This will in turn activate the fans 73 which will draw air through the crowns/heat exchanger passageways 7 into the plenum 61 delivering heated fresh air to the building. In the event of low levels of solar radiance, whereby the surface temp of the panel is not adequate to heat the air to the required temp, an internal sensor encapsulated in the plenum senses the cold air drawn into plenum and deactivates the fan 73.

Referring to Figs. 41 to 44 there is illustrated another heat transfer system of the invention which is similar to that described with reference to Figs. 35 to 40 and like parts we assigned the same reference numerals. In this case a plenum chamber is defined by a plurality of channel section housings 77 which are interengagable and interlockable together. The housing 77 has a male projection 78 at one end for engagement with a corresponding recess 79 of an adjacent housing 77 may be readily assembled. A fan 73 is housed in a fan housing 80 which is fixed to the housing 77. In this case side outlets 81 are provided for discharge of air from the fan housing 80.

This system is particularly useful as it is modular, lightweight and easy to fit. The plenum housing sections 77 comprise an insulation material to insulate the plenum and prevent cold bridging. Each section 77 may comprise a metal (such as steel) facing with an insulation material (such as an insulation foam board) bonded thereto. Alternatively the housing section 77 may be formed from a unitary material such as plastics which may be vacuum formed.

A roof panel plenum system is illustrated in Figs. 45 to 48. This incorporates the modular assembly system as described with reference to Figs. 41 to 44 and like parts are assigned the same reference numerals. The panels 60 and modular housing sections 77 are used to build up a heat transfer system, as illustrated. Ends of a run of housings 77 may be closed off with an end wall 83.

Figs. 49 and 50 illustrate a wall plenum system of the invention which is similar to the roof plenum system described above and like parts are assigned the same reference numerals. In this case fan housing outlets 84 are provided on a front wall of the fan housing 80. Using wall panels is preferred because they provide for efficient solar energy collection, even in winter months when the sun is low.

Two temperature sensors are incorporated into the control system one in the plenum, measuring air intake temperature, and one externally measuring the temperature of the air entering the panel. This temperature differential dictates the speed at which the fan/fans 73 operate. For example in the morning when the sun is rising the surface temperature of the metal begins to heat up, subsequently warm air is drawn through the system slowly to ensure maximum heat transfer, hence is delivered to the building at a slow rate. As the temperature of the metal increases so to does the fan speed until the fan reaches full power.

The fans 73 continue to run at an optimal speed, dictated by the temperature differential, until either the thermostat or low levels of radiation deactivate the system.

It will be appreciated that the heat exchange system can be used in association with any suitable panel containing air passageways. Several non-limiting examples are illustrated in Figs. 8 to 31.

Referring to Figs. 51 to 55 there are illustrated various details and components for a panel of the invention. Fig. 51 shows an enlarged view of one conduit 90 of a panel 91 which is similar to the panel of Figs. 1 to 4. Figs. 52 and 53 illustrate an insert piece 92 which may be inserted at an end of the conduit 90 to provide an input mesh to allow air to pass but to prevent ingress of debris or vermin into the conduit 90. The insert 92 is of the same profile as that of the conduit 90 and may be a push-fit. The insert 92 in this case has an outer generally flat outer face with a suitable mesh 93. Side walls 94 depend from the outer face and these side walls 94 have engagement / sealing fins 95 which tightly engage with the conduit walls to sealingly engage therewith. A sidewardly projecting handle part 96 may be provided to assist in case of removal of the insert 92 from the conduit 90.

Referring to Figs. 54 and 55 there is illustrated a cavity filler 98 which can be used to close off one or both ends of a conduit 90, either to manage air-flow and/or to close off the conduit if it is not in use. The filler 98 may be a block of any suitable material such as an EPDM rubber or the like. The filler 98 may have similar details to the insert 92.

It will be appreciated that while we have illustrated input mesh insert and cavity fillers of a particular shape and form these may be modified to correspond to any suitable sizp and shape of conduit. , . _ Referring back to Figs. 35 to 50 it will also be appreciated that if the passageways 65 are not required they may be closed off with a suitable filler or insert piece.

Many variations on the embodiments described will be readily apparent. Accordingly the invention is not limited to the embodiments hereinbefore described which may be varied in detail.

Claims

1. A heat transfer system comprising an insulating panel having a first sheet, a 5 second sheet_,, and an insulating material therebetween, the insulating panel having a plurality of air passageways located adjacent to at least one of the sheets for heal, transfer between the sheet and air in the passageways and a plenum chamber connected to the panel, the air passageways having an exit opening into the plenum chamber, and the plenum chamber having an outlet 10 for discharge of air which has passed through the air passageways in the panel.

2. A system as claimed in claim 1 wherein the panel has connecting passageways between the panel air passageways and the plenum.

J 5

3. A system as claimed in claim 2 wherein the panel air passageways are located adjacent to a first sheet and the connecting passageways extend through the foam from the panel air passageway through the second sheet.

20 4. A system as claimed in claim 3 wherein the plenum is attached to the second sheet.

5. A system as claimed in claim 4 wherein the plenum is sealingly attached to the second sheet.

25 ■

6. A system as claimed in any of claims 1 to 5 wherein the plenum chamber is defined by a plenum housing extending across the exit openings.

7. A system as claimed in claim 6 wherein the plenum housing comprises a 30 number of plenum housing sections which are interengagable or interlnckable together. . .

8. A system as claimed in claim 7 wherein the housing sections comprise an insulation material.

5 9. A system as claimed in claim 8 wherein the housing sections comprise a metal facing with an insulation material bonded thereto. ^■ . .

10. A system as claimed in claim .9 wherein the insulation material comprises an insulating foam board. . . . .

10

11. A system as claimed in any of claims 7 to 10 wherein each plenum housing section comprises a first end engagement feature and a second end engagement feature.

jl5 12. A system as claimed in claim 11 wherein the end engagement features are complementary for inter-engagement of adjacent plenum housing sections.

13. A system as claimed in any of claims 1 to 12 comprising air drawing means for drawing air into the plenum chamber from the panel air passageway.

20

14. A system as claimed in any of claims 1 to 13 wherein the plenum chamber comprises a panel side sub-chamber and a room side sub-chamber and the drawing means draws air from the panei air passageways into the panel side sub-chamber, and air from the panel side sub-chamber into the. room side

25 sub-chamber for discharge from the plenum chamber.

15. A system as claimed in claim 14 wherein the plenum chamber is divided into the sub-chambers by a partition wall and the air drawing means is mounted to the partition wall.

30

16. A system as claimed in any of claims 13 to 15 wherein the air drawing means comprises a fan.

17. A system as claimed in any of claims 13 to 16 comprising control means for controlling the operation of the air drawing means.

18. A system as claimed in claim 17 wherein the control means comprises a panel air inlet temperature sensor, an air exit temperature sensor and a controller for controlling the operation of the air drawing means in response to the differential between the air inlet and air exit temperatures.

19. A system as claimed in claim 17 or 18 comprising a thermostat for activating and/or de-activating the air drawing means.

_: 20. A system as claimed in any of claims 1 to 19 comprising an insert for an air passageway.

21. A system as claimed in claim 20 wherein the insert is a push fit in one end of the passageway.

22. A system as claimed in claim 20 or 21 wherein the insert provides an input mesh.

23. A system as claimed in claim 20 or 21 wherein the insert provides a filler.

24. A system as claimed in any preceding claim comprising a plurality of insulating panels each having a plurality of air passageways therein and the plenum chamber is connected to a number of adjacent panels.

25. A system as claimed in claim 24 comprising a plurality of plenum chambers. . . . . . . „- . ..

26. A system as claimed in claim 25 wherein the plenum chambers are separated.

27. A system as claimed in any of claims ! to 26 wherein the air passageways extend longitudinally of the panel.

28. A system as claimed in any of claims 1 to 27 comprising a barrier between the passageway and the insulating foam.

29. A system as claimed in claim 28 wherein the barrier comprises a membrane such as a foil or tape.

30. A system as claimed in claim 28 or 29 wherein the barrier is not planar.

31. A system as claimed in any of claims 28 to 30 wherein the barrier comprises a pair of longitudinally extending transversely spaced-apart sides defining a plane therebetween and the barrier extends outside of said plane.

32. A system as claimed in any of claims 28 to 31 wherein the barrier extends into the foam.

33. A system as claimed in any of claims 28 to 32 wherein the barrier extends inwardly of the first sheet.

34. A system as claimed in any of claims 28 to 32 wherein the barrier extends inwardly of the second sheet.

35. A system as claimed in any of claims 28 to 34 wherein between adjacent air passageways the foam is in direct contact with the sheet(s).

36. A system as claimed in Claim 35 wherein adjacent barriers are spaced - apart.

37. A system as claimed in any of claims 1 to 36 wherein the first sheet is profiled.

38. A system as claimed in any of claims 1 to 37 wherein the second sheet is profiled.

39. A system as claimed in claim 37 or 38 wherein the profile defines a profile recess and the recess forms part of the passageway.

40. A system as claimed in claim 39 wherein the passageway is larger than the profile recess.

41. A system as claimed in claim 39 or 40 wherein the passageway comprises the profile recess part and a foam recess part.

42. A system as claimed in claim 41 wherein the foam recess part is oppositely directed with respect to the profile recess part.

43. A system as claimed in claim 42 wherein the foam recess part is of a shape which is substantially a mirror image of the profile recess part.

44. A system as claimed in any of claims 1 to 43 wherein the first sheet; comprises a plurality of longitudinally extending profiled crowns, at least some of the crowns defining the passageway.

45. A system as claimed in claim 44 wherein one of the crowns defines an underlap for jointing with an adjacent like panel and the underlap crown is filled with foam, . .;

46. A system as claimed in any of claims 1 to 45 wherein the panel comprises a roof panel.

47. A system as claimed in any of claims 1 to 45 wherein the panel comprises a wall panel.

48. A system as claimed in any of claims 1 to 45 wherein the panel comprises a floor panel.

40. A system substantially as hereinbefore described with reference to the drawings.