Back in the late '70's , In High School , We built 8' x 4' solar water heaters . Started by making the 4' x 8' frame out of 2 x 6's . On Back of frame We added 2 sheets of Galvanized metal roofing , that was flattened on ends and 1 side , thus it would nail flat on the edges of the frame . In the middle , we drilled and riveted the 2 sheets together down the entire length .
Next step was to paint entire inside of frame and roofing with Flat Black paint . Not quite sure what size copper tubing We used , 1/4" , maybe 3/8" ??? But it started by coming through 1 corner , running all the way to other end of frame in the first valley . Then it was gently bent over the peak to the next valley and ran all the way back down to the other end of frame . This continued all the way across , were is was fed back out of frame to were ever the project was . After the tubing was finished , We experimented with covering the frame with every thing from a Heavy Thickness Clear Plastic film , to a thin plexiglass sheet to donated single pane glass from old windows . The glass was not a continuous sheet , think We ended up with like 4 pieces of glass to cover 1 frame .
Depending on flow , angle of panel in relation to sun , daylight hours , etc.. Most of the people , Who used them in pools were actually using their pools any were from 2 months early up to 3.5 months early , ( normally , around here , mid June is about time a pool will get warm enough to use with out any
aid ) .
Can't remember any kind of temp's or as I said earlier , the copper tube size , But do remember they were very effective , But also can't remember which was the most effective . Best Value was the donated glass or the plastic film . Plexi was $$$ back then and all though glass was donated , it was a pain to deal with , as We had to set a strip of wood all the way around inside frame to lay glass on , then another on top the glass to hold it in .
Fred H.
There is no hesitation... you just walk in. Not cold, not hot. Just right. I couldn't be happier with it.