Transpired Solar Collector

Abstract

A transpired solar collector includes the follows. An absorber panel having a body formed of stainless steel; a surface layer of chromium oxide on an exterior face of the body through-holes formed through the body and surface layer, in which the surface layer has a thickness of at least 70 nanometres.

1 . A transpired solar collector comprising:
 an absorber panel having a body formed of stainless steel;   a surface layer of chromium oxide on an exterior face of the body; and   a plurality of through-holes formed through the body and surface layer, wherein the surface layer has a thickness of at least 70 nanometres.   
     
     
         2 . The transpired solar collector of  claim 1 , wherein the surface layer has a thickness of between 70 nanometres and 400 nanometres. 
     
     
         3 . The transpired solar collector of  claim 2 , wherein the surface layer has a thickness of between 100 nanometres and 280 nanometres. 
     
     
         4 . The transpired solar collector of  claim 1 , wherein the thickness of the surface layer is arranged to determine the colour of the transpired solar collector. 
     
     
         5 . (canceled) 
     
     
         6 . The transpired solar collector of  claim 1 , wherein the absorber panel has an emissivity of no more than 0.30. 
     
     
         7 . The transpired solar collector of  claim 6 , wherein the absorber panel has an emissivity of between 0.10 and 0.30. 
     
     
         8 . The transpired solar collector of  claim 1 , wherein the absorber panel has a solar absorptivity of at least 0.50. 
     
     
         9 . The transpired solar collector of  claim 7 , wherein the absorber panel has a solar absorptivity of between 0.50 and 0.90. 
     
     
         10 . The transpired solar collector of  claim 1 , wherein the surface layer forms an exterior surface of the transpired solar collector. 
     
     
         11 . The transpired solar collector of  claim 1 , further comprising:
 a rear panel, spaced from the absorber panel, defining a cavity between the absorber panel and the rear panel, the surface layer being outside of the cavity.   
     
     
         12 . The transpired solar collector of  claim 11 , wherein the rear panel is formed by the wall or roof of a building. 
     
     
         13 . The transpired solar collector of  claim 1 , wherein the surface layer is a chemically or electrochemically thickened layer of chromium oxide. 
     
     
         14 . (canceled) 
     
     
         15 . A method of manufacturing a transpired solar collector, the method comprising: providing a stainless steel plate, the stainless steel plate having an original chromium oxide layer on a first surface;
 chemically or electrochemically thickening the original chromium oxide layer on the first surface to form a thickened chromium oxide layer;   forming a plurality of through-holes through the stainless steel plate; and   forming the stainless steel plate as an absorber panel of a transpired solar collector, the thickened chromium oxide layer forming an exterior surface of the transpired solar collector,   wherein the step of chemically or electrochemically thickening the original chromium oxide can occur before or after the step of forming a plurality of through-holes.   
     
     
         16 . The method of  claim 15 , wherein the step of chemically or electrochemically thickening the original chromium oxide layer on the first surface to form a thickened chromium oxide layer comprises:
 chemically or electrochemically thickening the chromium oxide layer on the first surface, to form a thickened chromium oxide layer having a thickness of at least 70 nanometres.   
     
     
         17 . The method of  claim 15 , wherein the step of chemically or electrochemically thickening the original chromium oxide layer on the first surface to form a thickened chromium oxide layer comprises:
 chemically or electrochemically thickening the chromium oxide layer on the first surface, to form a thickened chromium oxide layer having a thickness of between 70 nanometres and 400 nanometres.   
     
     
         18 . The method of  claim 17 , wherein the step of chemically or electrochemically thickening the original chromium oxide layer on the first surface to form a thickened chromium oxide layer comprises:
 chemically or electrochemically thickening the chromium oxide layer on the first surface, to form a thickened chromium oxide layer having a thickness of between 100 nanometres and 280 nanometres.   
     
     
         19 . The method of  claim 15 , further comprising:
 forming a transpired solar collector by mounting the absorber panel on the roof or wall of a building,   wherein the absorber panel is spaced from the roof or wall, to define a cavity between the absorber panel and the roof or wall; and   wherein the surface layer forms an exterior surface of the building.   
     
     
         20 . The method of  claim 15 , further comprising:
 forming a transpired solar collector by providing a rear panel, spaced from the absorber panel to define a cavity, the surface layer being outside of the cavity.   
     
     
         21 . A stainless steel transpired solar collector having a chemically or electrochemically thickened chromium oxide surface layer.