This is a solar air convection heater for my garage that is powered by the low angle winter sun. It's easy to build and it works very well. With enough building insulation, this can be a primary heat source with a secondary needed for cloudy days. The idea and design is from Mother Earth News December/January 2007
glass, plexiglass, or some kind of clear material.
black aluminum window screen
caulking, paint, screws, lag screws, staple gun + other tools
I have some results on temperature differences from the first weeks of operation. Just like when you put up your first wind generator, the wind won't blow for days/weeks, I had overcast and mostly cloudy weather the first few days operating this thing. The heater puts out 87 to 104 degrees F at the vents on partly cloudy days to sunny days. The uninsulated garage hits about 17 to 30 degrees F above outside temps, very comfortable for me. It seems the colder it is outside, the bigger the temperature difference between the garage and outside. If you want more heat in an uninsulated area I would recommend possibly 1/3 more collector area than the ratio I give in the instructions. Seal up any drafts, it will do a lot
to hold the heat. This thing works great.