Patent Publication Number: US-2009236074-A1

Title: Composite Insulating Panel

Description:
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 which will address this issue. 
     STATEMENTS OF INVENTION 
     According to the invention there is provided a composite insulating panel comprising a first sheet, a second sheet, insulating foam between the first and second sheets, and heat collecting means within the panel for transfer of heat from one source to another. 
     In one embodiment the heat collecting means comprises conduit means for containing a beat transfer medium. The conduit means may comprise a plurality of tubes extending through the panel. The conduit means may be located adjacent to the first sheet and/or adjacent to the second sheet. 
     In one case the first sheet is profiled to define a plurality of recesses, the heat collecting means extending through at least portion of at least some of the recesses. Alternatively or additionally the second sheet may be profiled to define a plurality of recesses, the heat collecting means extending through at least portion of some of the recesses. 
     Preferably at least some of the recesses contain the heat collection means. 
     Conduit means may extend through at least some of the recesses. 
     In one embodiment at least some of the recesses define a pathway for air circulation. 
     The recess defined by at least some of the profiles may be substantially free of insulating foam. 
     In one case the profile is formed in an external sheet of the panel. The external sheet may comprise a plurality of laterally spaced-apart crowns. 
     In a preferred embodiment the recess has a cross sectional area of at least 0.002 m 2 , most preferably at least 0.0025 m 2 , and about 0.003 m 2 . 
     In one embodiment the recess has an exposed surface, the width of the exposed surface being from 150 mm to 200 mm, preferably from 160 mm to 180 mm, and about 170 mm. 
     In one embodiment the exposed surface comprises an outer face and a pair of side faces which diverge inwardly from the outer face. 
     The angle between the outer face and each side face may be from 115° to 125°, preferably from 118° to 123°, and about 121°. 
     In one embodiment the width of the outer face is from 50 mm to 60 mm. The width of the outer face may be about 55 mm. 
     In one embodiment the width of each side face is from 50 mm to 60 mm. The width of each side face may be about 57 mm. 
     Preferably, the panel comprises at least 3 crowns. The panel may comprise at least 4 crowns. 
     There may be a barrier between the recess and the insulating foam. The barrier may extend across the inwardly facing opening of the recess. The barrier may be a seal, a tape, or the like. 
     In one case the panel comprises a roof panel. 
     In another case the panel comprises a wall panel. 
     The panel may also be a floor panel. 
     The invention also provides a heating or cooling system comprising at least one panel of the invention. 
     In one embodiment a heat transfer medium is circulated through the panel. The heat transfer medium may be air. 
     The system may comprise duct means for collecting and directing air which is passing through the panel. The system may have air circulating means such as a fan for circulating air to or from the panel or duct. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more clearly understood from the following description thereof given by way of example only, in which:— 
         FIG. 1  is a cross sectional view of an insulating panel of the invention; 
         FIG. 2  is an enlarged view of portion of the panel of  FIG. 1 ; 
         FIG. 3  is a cross sectional view of an insulating panel according to another embodiment of the invention; 
         FIG. 4  is a cross sectional view of a further panel according to the invention; 
         FIG. 5  is a cross sectional view of a composite insulating panel according to the invention; 
         FIG. 5(   a ) is a cross sectional view of another composite panel; 
         FIG. 5(   b ) is an enlarged view of a crown of the panel of  FIG. 5 ; 
         FIGS. 6 and 7  are cross sectional views illustrating an overlap joint between adjacent panels of  FIG. 5 ; 
         FIG. 8  is a plan cross sectional view of a building comprising a plurality of panels of the invention; 
         FIG. 9  is a cross sectional view of a top corner of the building of  FIG. 8 ; and 
         FIG. 10  is a cross sectional view of another corner of the building of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings and initially to  FIGS. 1 and 2  thereof there is illustrated an insulating panel according to the invention which in this case is a roof panel  1 . The roof panel  1  comprises a first sheet which in this case is a profiled external sheet  2  which may be of painted galvanized steel. The profile defines recesses. The profile in this case comprises a plurality of raised crowns  3  which in this case are of generally trapezoidal form and extend longitudinally along the length of the panel. The panel also comprises a second sheet which in this case is an inner metal liner sheet  4 . There is insulating foam  5  between the inner and outer sheets  2 ,  4 . 
     The panel has an integral heat collecting means for transfer of heat from one source to another. In this case the heat collecting means are provided in the crowns  3  of the external sheet which may be devoid of insulation  5 . Conduits  8  in this case extend through the crowns  3  and a heat transfer medium such as water is circulated through the conduits  8 . In this way solar heat illustrated diagrammatically as  9  is transferred and used, for example, to provide hot water for washing and the like. The heat transfer medium may be any suitable fluid such as water, refrigerant or anti-freeze solution. The conduits  8  run through the roof in the external envelope of the building and the medium absorbs solar energy. The warmed medium may be pumped back through the system into the building to provide heat to the building space. Once the medium passes through the building and transfers its energy, it flows back to the roof conduit and the process is repeated in a closed loop. 
     Referring to  FIG. 3  there is illustrated another panel  20  according to the invention. In this case the heat collecting means is in the form of conduits  21  through which a heat transfer medium is circulated. The conduits  21  are in this case located adjacent to the internal liner  4 . The system may be used to extract heat  22  rising from the building, especially in environments where equipment and machines give off heat, causing the internal temperature to rise. This system can be used to help keep the building cool in summer and heat it up in winter. In the summertime, a coolant may be circulated. A valving system may be provided to switch from heating to cooling cycles. Extracted heat can be used as described above to heat a supply of hot water. 
     Referring to  FIG. 4  there is illustrated another panel  17  according to the invention which is similar to the panels of  FIGS. 1 to 3  and like parts are assigned the same reference numerals. In this case there are inner conduits  21  through which a beat transfer medium is circulated (for example to extract heat from inside a building) and outer conduits  8  for collection of solar heat  9 . Such a system may be used as part of a heating/cooling/ventilation system for a building. 
     Referring to  FIGS. 5 ,  5   b,    6  and  7  there is illustrated another panel  29  according to the invention which is similar to the panel of  FIGS. 1 and 2  and like parts are assigned the same reference numerals. In this case the recess is defined by the crowns. Air is circulated through crowns  3  which are not filled with insulating foam and thereby define passageways  19 . The circulating air is again heated by solar energy. This hot air is captured and may be blown by small fans 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 heat exchanger for transfer of solar heat to another heat collector. Another panel of this type is illustrated in  FIG. 5(   a ) but with smaller crowns  3 . 
     Air is circulated through the crowns  3  which are not filled with insulating foam. Such panels are usually manufactured by leading the profiled outer sheet  2  along a flat bed with the recesses defined by the crowns  3  facing upwards. The profiled sheet is let to a lay-down area at which liquid foam reactants are spread across the sheet using a lay-down poker or the like. As the foam rise the backing sheet is applied over the foam and the sandwich this formed is then led through an oven and subsequently cut to length. The manufacturing technology is described in our UK-A-2227712, UK-A-2257086, and UK-A-2325640. 
     In the panels of the invention foam is excluded from at least some of the recesses defined by the crowns  3 . This may be achieved in a number of ways. For example, a seal or tape  25  may be laid across the recesses defined by the crowns  3  prior to foam lay-down. Alternatively a lost core may be inserted into the recesses defined by the crowns  3  and subsequently removed leaving the recesses substantially fee of foam. 
     We have found that the panel of  FIG. 5  is particularly suitable for roofs, walls and for floors. The panel has a relatively large exposed surface area and a relatively high large internal void space whilst maintaining structural and insulation properties. The width L of the panel in this case is 1 metre. For optimum thermal efficiency there should be at least 3 and preferably at least 4 crowns  3 . Referring especially to  FIG. 5(   b ), each of the crowns  3  defines an area which is devoid of foam. The void area A is preferably at least 0.002 m 2 , most preferably greater than 0.0025 m 2 , and in this case about 0.003 m 2 . 
     The faces of the crown  3  which are exposed to the external environment comprise an outer face x and two side faces y which diverge inwardly from the outer face x. The angle α between the faces x, y is preferably 115° to 125°, most preferably 118° to 123° and in this case about 121°. 
     The width of the exposed surface of each crown  3  is from 150 mm to 200 mm, most preferably 160 mm to 180 mm, and in this case about 170 mm. the outer face x has a width Wx of from 50 mm to 60 mm, in this case about 55 mm. Each side facing has a width Wy of from 50 mm to 60 mm, in this case about 57 mm. 
     In the panel of  FIG. 5  each of the foam-free crowns has a cross sectional area of 0.002906 m 2 . 
     By way of comparison, in the panel of  FIG. 5(   a ) the foam-free crowns each have a cross sectional area of 0.001603 m 2 . 
     The energy production possible using panels with crowns of this type was calculated using RET screen International Clean Energy Project Analysis software available at www.retscreen.net. The following assumptions were made: 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 Building Location: 
                 North West England 
               
               
                 Building Size: 
                 10 m × 100 m × 100 m = 10,000 m 2  floor space 
               
               
                 South Facing Wall: 
                 100 m (W) × 10 m (H) 
               
               
                 Fan Air Speed: 
                 10 m/sec 
               
               
                   
               
            
           
         
       
     
     Using the panels to construct the south facing wall of the building and circulating air through the foam-free passageways results in the following energy production: 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 Panel of FIG. 5(a) with two crowns: 
                 125,569 kWh per year based on 
               
               
                   
                 local weather data. 
               
               
                 Panel of FIG. 5 with four crowns: 
                 347,647 kWh per year based on 
               
               
                   
                 local weather data. 
               
               
                   
               
            
           
         
       
     
     Using a panel with enlarged foam-free crowns greatly enhances energy production. 
     The panels may be used to construct part of or all of the building envelope including the roof, walls and/or floor. One such building is illustrated in  FIGS. 8 to 10 . Each of the walls and the roof of the building comprise a plurality of the panels such as the panels  29  of  FIG. 5 . Air circulating through the passageways defined by the crowns  3  is directed into ducting  30  as shown by the arrows. The flow of air may be controlled using one or more fans  31 . The ducting may have a venting system  32  which may be motorized to facilitate ease of operation and control. The circulating air is 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 alternatively be circulated through a heat exchange 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 to  FIGS. 9 and 10  suitable insulated cappings  35  may be provided. The building may also have insulated flashings  36 . 
     May 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.