Solar Water Heater

Abstract

A low-cost absorber panel for a solar hot water heating system is provided. An aluminum absorber plate, under exposure to solar radiation, makes an efficient transfer of heat to water circulating within the collector panel by direct contact with the medium in an optimized area-to-volume configuration. An innovative use of fasteners makes it possible to accommodate expansion for freezing and to allow for disassembly and maintenance.

1 . A low-cost absorber panel for solar hot water systems, comprising:
 an essentially rectangular aluminum absorber plate;   an essentially matching aluminum companion plate in spaced relationship to the absorber plate to which it is joined below by a means for fastening and shaping;   a means for spacing to create an internal space between the absorber and companion plates for a flow of water there through, the means for spacing providing a water-tight seal;   a means for channeling to create a serpentine flow path for the water; and   at least one port through one of the absorber and companion plates for water to enter the internal space and at least another port through one of the absorber and companion plates for water to exit, the at least two ports located so as to maximize the serpentine flow path, wherein the water flowing in contact with the absorber plate receiving solar radiation is heated by it and forms a medium for transferring heat.   
     
     
         2 . The low-cost absorber panel of  claim 1 , wherein the means for fastening and shaping is machine screws and nuts, optionally provided with o-ring seals for positioning in the internal space, the machine screws and nuts individually adjustable to shape the plate surfaces and the space there between. 
     
     
         3 . The low-cost absorber panel of  claim 2 , wherein the means for spacing is an elastic gasket of substantially circular cross-section which is arrayed peripherally and adjustably tensioned to provide a compression seal by the machine screws and nuts straddling the gasket along the extent thereof. 
     
     
         4 . The low-cost absorber panel of  claim 3 , wherein the spacing of the machine screws is at sufficient interval as to prevent bulging of the plates under pressure. 
     
     
         5 . The low-cost absorber panel of  claim 2 , wherein the means for channeling is lengths of elastic gasket of substantially circular cross-section extending in alternating fashion from one end or the other of the periphery gasket, beginning with the end closest to the entry port and ending with the end closest to the exit port, to a point short of the opposite end, whereby the parallel channels thereby formed are connected to adjacent channels by alternating passages. 
     
     
         6 . The low-cost absorber panel of  claim 1 , further comprising a pressure differential of not more than 2 psi to urge the flow of water through the internal space. 
     
     
         7 . The low-cost absorber panel of  claim 1 , further comprising a pressure differential of not more than 1 psi to urge the flow of water through the internal space 
     
     
         8 . The low-cost absorber panel of  claim 2 , further comprising a means for volume expansion of not less than 9% to accommodate freezing water. 
     
     
         9 . The low-cost absorber panel of  claim 8 , wherein the means for volume expansion is the loosening of screws and nuts interim the internal space to permit bulging therein. 
     
     
         10 . The low-cost absorber panel of  claim 1 , wherein the cost of materials is less than $4.00 per square foot. 
     
     
         11 . The low cost absorber panel of  claim 1 , wherein the rectangular aluminum absorber and companion plates each substantially measure 32 square feet. 
     
     
         12 . A low-cost absorber panel for solar hot water systems, comprising:
 an essentially rectangular aluminum absorber plate;   an essentially matching aluminum companion plate in spaced relationship to the absorber plate to which it is joined below by a means for adjustable fastening and shaping;   a means for resiliently creating an internal space between the absorber and companion plates, and further creating channels therein, for a flow of water there through, the means providing a water-tight seal; and   at least one port through one of the absorber and companion plates for water to enter the internal space and at least another port through one of the absorber and companion plates for water to exit, the at least two ports located so as to maximize the serpentine flow path, wherein the water flowing in contact with the absorber plate receiving solar radiation is heated by it and forms a medium for transferring heat.   
     
     
         13 . The low-cost absorber panel of  claim 12 , wherein the means for adjustable fastening and shaping is machine screws and nuts, optionally provided with o-ring seals for positioning in the internal space, the machine screws and nuts individually adjustable to shape the plate surfaces and the space there between. 
     
     
         14 . The low-cost absorber panel of  claim 13 , wherein the means for resiliently creating an internal space and channels therein is an elastic gasket of substantially circular cross-section which is arrayed peripherally and adjustably tensioned to provide a compression seal by the machine screws and nuts straddling the gasket along the extent thereof, the elastic gasket additionally extending in lengths positioned in alternating fashion from one end or the other of the periphery gasket, beginning with the end closest to the entry port and ending with the end closest to the exit port, to a point short of the opposite end, whereby the parallel channels thereby formed are connected to adjacent channels by alternating passages.