BUILDING PANEL Field of the Invention This invention relates to improvemfen~fts in building panels used in the construction of walls and similar structural elements. 5 Background of the Invention Prefabricated building panels are generally constructed as a pair of sheets, one internal and the other external, joined at regular intervals by elongate prefabricated steel studs. The interior and exterior sheets are generally made from fibre cement and are joined to the steel studs by adhesive. The cavities formed between the exterior and 10 interior sheets are generally infilled with concrete and the studs have apertures through which the concrete can move between the various partitions formed by the vertical studs between the sheets. This then forms the complete wall panel. However, instead of using concrete between the fibre cement sheets, insulation can be infilled whereby prefabricated precision cut, solid polystyrene foam insulation is 15 formed and is able to be joined to adjacent foam panels through the use of the metal studs- The foam panels are then secured to each other by the metal studs through adhesive or screws and similarly affixed to the internal and external faces of the sheets through adhesive or screws. However, one problem that arises is when the external wall heats up due to 20 excessive outdoor temperatures, which heat is then transferred to the internal foam insulation. As there is no escape path for the heat in order to dissipate the heat away from the foam insulation, the excessive heat leads to cracking in the outer sheet and the surface finish on the sheet. Furthermore cracking can also appear at the joints between the various panels. Such weakening in the panels also weakens the structure of the wall.
The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art in Australia. Summary of the Invention 5 According to a first aspect of the invention, there is provided a panel of insulating material for use in the construction of walls, said panel including: first and second substantially parallel sides and first and second end faces, a top face and a bottom face; a plurality of channels extending along the panel in order to dissipate heat 10 absorbed within the panel such that air in the plurality of channels transfers the absorbed heat externally of the panel of insulating material. The plurality of channels may be formed in either the first side or the second side. The panel may further including a cavity formed in the side opposite the side having the plurality of channels, the cavity being used to house conduits for utility services for a 15 building structure formed from the walls. The panel may be substantially elongate and each of the plurality of channels and the cavity may extend substantially along the entire length of the first side or second side. The panel may have a ledge formed in the top face adjacent to the first end face, the ledge provided so as to enable the fitting of a spacer member to the first end face so that 20 the spacer member and the first and second sides present a flush surface. The panel may have a second ledge formed in the top face adjacent to the second end face, the second ledge provided so as to enable the fitting of a further spacer member to the second end face so that the further spacer member and the first and second sides present the flush surface. 2 The channels may have a rectangular shape in profile and be each separated by corresponding ridges having substantially the same width as each of the channels. According to a second aspect of the invention, there is provided a composite building panel for use in the construction of walls including: 5 first and second facing sheets spaced apart from one another; at least one elongate spacer member having one end secured to the first facing member and another end secured to the second facing sheet; at least one panel of insulating material between the first and second facing sheets, the at least one panel of insulating material having a first side abutting the first 10 facing sheet, a second side abutting the second facing sheet, first and second end faces, a top face and a bottom face; the at least one panel of insulating material having a plurality of channels extending therein along either the first side or the second side; said plurality of channels adapted to dissipate heat absorbed within the composite is building panel externally of the composite building panel. 'rief Description of the Drawings A preferred embodiment of the invention will hereinafter be described, by way of example only, with reference to the drawings in which: 20 Figure 1 is a perspective view from above of a panel of insulating material for use in the construction of walls according to an embodiment of the invention; Figure 2 is a plan view of a pair of panels of insulating material joined together, side by side, through spacing members and having first and second facing sheets abutting against the first and second sides of each panel of insulating material; 3 Figure 3 is a plan view of a panel of insulating material in accordance with an embodiment of the invention; and Figure 4 is a plan view showing the abutment of one panel of insulating material against another panel of insulating material through spacing members and sandwiched 5 between facing sheets. Detailed Description of the Preferred Embodiment With reference to Figures 1 and 3, there is shown a panel of insulating material 2 which is adapted to fit between a first facing sheet and a second facing sheet for use in the construction of walls of a building. The panel 2 is preferably made of polystyrene 10 foam and has first side 4, second side 6 substantially parallel to the first side 4, a first end face 8, a second end face 10, a top face 12 and a bottom face (not shown in the figures). Formed in the first side 4 are a series of channels 14 that extend substantially along the whole length of the front first side 4. The channels 14 are rectangular in profile and are separated by corresponding elongate ridges 16. Preferably the ridges 16 have 15 substantially the same width as the channels 14 and also are rectangular in profile. It is to be understood that any other suitable shape, profile, pattern and dimensions may be used for the channels 14 or ridges 16. Furthermore, other suitable materials may be used to form the panel 2. Formed in the second side 6 is a cavity 18 which extends substantially along the 20 whole length of the second side 6. The cavity 18 is used to house conduits for utility services of a building structure that is formed from the walls of which the panel is a part Such conduits may include electrical wiring and plumbing pipes or hoses. The purpose of the channels 14 is to dissipate the build up of heat in the panels of insulating material that arises from high temperatures experienced in the environment in which the building 25 structure, having such panels, is situated. 4 Adjacent each of the first end face 8 and second end face 10 are ledges 20 and 22 that extend from the respective end faces to a small step 24 and 26 respectively a short distance along each of the first and second sides 4 and 6. Thus the width of end face 8 and end face 10 is less than the width of the top and bottom faces between each of steps 5 24 and 26. The purpose of the ledges 20 and 22 is to enable the fitting of a spacer member, in the form of a stud, preferably made from steel, that extends substantially along the whole length of the panel 2. Each of the spacer members are made of a web portion 28 and a pair of legs 30 and 32 as shown in Figure 1 where one of the spacer members 27 is connected or affixed to end face 8. The thickness of each of the legs 30 10 and 32 are substantially the same as the difference between the width of the respective ledge and the width of the top face 12 between the first and second sides 4 and 6. Typically this spacing is about 1.5 um. Thus when a spacer member 27 is attached to each of the end faces 8 and 10, the respective legs 30 and 32 present a substantially smooth and flat surface against the respective sides 4 and 6. This is required in order to 15 have a smooth attachment of facing sheets to each of the spacing members and the panel of insulating material so as to form a complete wall in the building structure. With reference to Figure 2 there is shown a pair of panels 2 joined side by side with spacing members 27 located at each end face of the panels 2. The panels 2 can be secured to the spacing members 27 by adhesive or fasteners, such as screws. Facing 20 sheet 34 is affixed as an external face to side 4 of each of the panels 2. A second facing sheet 36 is affixed to an internal face, which is second side 6 of each of the panels 2 The arrangement shown in Figure 2 shows two panels 2 formed as a block and secured side by side between the facing sheets 34 and 36. Typically adhesive is used to attach the facing sheets 34 and 36 to the panels 2. In this manner any heat that is received and 25 absorbed by the external face, in this case facing sheet 34, of which the heat is transferred 5 to the panels 2, is quickly able to be dissipated through the longitudinally extending channels 14 out of the top or the bottom of each panel into another environment. Thus the air that exists in the channels 14 is able to absorb the heat built up within each of the panels 2 and transfer that heat outwardly from the panels 2. 5 The arrangement shown in Figure 2 shows the left most panel 2 extending at the left side beyond the edges of each of the facing sheets 34 and 36 while the right side panel 2 is shown as being contained within the facing sheets 34 and 36 such that the right hand ends of the facing sheets 34 and 36 extend beyond the right side edge of end face 10. The reason for this is to enable a smooth interlocking fit to be established between 10 various sets of blocks as shown in Figure 2 when formed side by side. In other words, the end face 8 that protrudes from the facing sheets 34 and 36 on another block would fit directly into or abut against the end face 10 which is recessed from the end edges of the facing sheets 34 and 36- Such an arrangement is shown in Figure 4 where a spacing member 27 is fitted to the end face 8 of the right most panel 2 abuts against the spacing 15 member 27 fitted to the end face 10 of the left most panel 2. 6 The Claims Defining the Invention are as follows: I. A panel of insulating material for use in the construction of walls, said panel including: 5 first and second substantially parallel sides and first and second end faces, a top face and a bottom face; a plurality of channels extending along the panel in order to dissipate heat absorbed within the panel such that air in the plurality of channels transfers the absorbed heat externally of the panel of insulating material. 10 2. A panel of insulating material according to claim 1 wherein the plurality of channels is formed in either the first side or the second side. 3. A panel of insulating material according to claim 1 or claim 2 further including a cavity formed in the side opposite the side having the plurality of channels, said cavity being used to house conduits for utility services for a building structure formed from said 15 walls. 4. A panel of insulating material according to claim 3 wherein said panel is substantially elongate and each of said plurality of channels and said cavity extend substantially along the entire length of the first side or second side. 5. A panel of insulating material according to claim 4 having a ledge formed in the 20 top face adjacent to the first end face, the ledge provided so as to enable the fitting of a spacer member to the first end face so that the spacer member and the first and second sides present a flush surface. 6. A panel of insulating material according to claim 5 having a second ledge formed in the top face adjacent to the second end face, the second ledge provided so as to enable 7 the fitting of a further spacer member to the second end face so that the further spacer member and the first and second sides present the flush surface. 7. A panel of insulating material according to any one of the preceding claims wherein the channels have a rectangular shape in profile and are each separated by 5 corresponding ridges having substantially the same width as each of the channels. 8. A composite building panel for use in the construction of walls including: first and second facing sheets spaced apart from one another; at least one elongate spacer member having one end secured to the first facing member and another end secured to the second facing sheet; 10 at least one panel of insulating material between the first and second facing sheets, the at least one panel of insulating material having a first side abutting the first facing sheet, a second side abutting the second facing sheet, first and second end faces, a top face and a bottom face; the at least one panel of insulating material having a plurality of channels [5 extending therein along either the first side or the second side; said plurality of channels adapted to dissipate heat absorbed within the composite building panel externally of the composite building panel. 9. A composite building panel according to claim 8 wherein the plurality of channels is formed in either the first side or the second side. 20 10. A composite building panel according to claim 9 wherein the at least one panel of insulating material further includes a cavity formed in the side opposite the side having the plurality of channels, said cavity being used to house conduits for utility services for a building structure formed from said walls.
11. A composite building panel according to claim 10 wherein said at least one panel of insulating material is substantially elongate and each of said plurality of channels and said cavity extend substantially along the entire length of the first side or second side. 12, A composite building panel according to claim 11 wherein a ledge is formed in 5 the top face of the at least one panel of insulating adjacent to the respective first end face, the ledge enabling the fitting of a spacer member to the respective first end face so that the spacer member and the first and second sides present a flush surface. 13. A composite building panel according to claim 12 wherein the at least one panel of insulating material includes a second ledge formed in the top face of the at least one 10 panel of insulating material adjacent to the respective second end face, the second ledge enabling the fitting of a further spacer member to the respective second end face so that the further spacer member and the first and second sides present a flush surface. 14. A building panel according to any one of claims 8 to 13 wherein the channels have a rectangular shape in profile and are each separated by corresponding ridges is having substantially the same width as each of the channels. 9