I became interested in solar air heaters several weeks ago and have decided to build a few. I plan to make one for my garage at first to see how affective they are. From what I’ve read on the net they do work very well given a solid design and of course sunlight.
My first attempt will be to recreate a commercial unit built from pop cans. This will be my garage unit and a testbed. I’ve seen several other people have mimicked this unit with success. Here is one of the do it your self units http://www.fieldlines.com/story/2007/8/20/124818/249.
If this is successful I plan to make a unit for my house. The house unit will have to be very presentable as the front of my house faces South. I have some interesting ideas that do not involve pop cans. More to come in a few weeks on this unit. In the mean time I’m still collecting pop cans. I may just go to the local recyclers and buy 240 pop cans from them at 5 or 10 cents each. It’s really only $12 or $24 dollars. Pretty cheap if you ask me.
Any unit I build will have automatic controls for the fan based on temperature of the space being heated and temperature of the air from the unit. Like the Cansolair commercial units I’ll have mine use a snap disk controller that turns the fan on if the output air is 110 degrees F (43.3C) and off at temperatures less than 90 degrees F (32C).
A basic wiring diagram.
possible temperature control