SOLAR ENERGY FOR WATER HEATING BROOKS 177 



CONSTRUCTION OF SOLAR ENERGY ABSORBERS 



Essential features of solar absorbers are the absorber pipes or 

 tanks, the insulated box, and the glass cover. The angle of slope 

 toward the south is not very important except that for winter oper- 

 ation the slope should favor the winter sun, which at noon is only 

 about 30° above the horizon in California. Most solar absorbers are 

 placed on sloping roofs and it is much simpler to keep the same slope 

 than to provide a special slope for the absorber. In case of new 

 construction, seasonal solar heaters should be placed on roofs of 

 14 to y^ pitch, and all-year absorbers on %- or i/^-pitch roofs. 



The construction details for the insulated box should conform to 

 regular structural practice, and many different designs will give ex- 

 cellent results if simple requirements are met. Separate boxes 

 mounted in the yard where there is no shade or on a pergola do not 

 differ much in structure from the common roof box. 





/'/r?///ee/ fro/n ^'a£'). Of^e/! £/sed 

 /br ^/?/>i/^^/ec/ ar/a^//?^ o/" orree/r 



pos/d/o/? i6^ /eacf c///>s. 



Figure 8. — Construction plan of pipe absorber roof box. 



Construction "procedure for a 'built-in ahsorher hox on a new roof. — 

 When absorbers are built right into the roof structure the simplest 

 procedure (fig. 8) is to (1) sheathe solid the underside of the rafters; 

 (2) fill the rafter space with bulk insulating material such as glass 

 wool, or the equivalent; (3) solid-sheathe on top of the rafters the 

 same as for regular roofing; (4) frame in the sides of absorber 

 box; (5) lay galvanized iron pan with edges turned up and bottom 

 soldered and provided with screened drain pipe to carry off pos- 

 sible leaks from pipe joints or broken glass; (6) nail on furring 

 strips to support pipe coils or tanks; (7) install pipe coils, being 

 sure of a continuous rise from bottom to top; (8) flash around the 



