||Here is a simple project that you can
build out of easily available parts. Take two drums and paint them black.
Build a wooden box and insulate it with sheet styrofoam about one inch
thick. You can get this foam at most large "Home Do-It Centers" in 4ft.
x 8ft. sheets. Paint the inside of the box black. Make a lid by building
a wooden frame and insert a sheet of glass, double pane would be even better.
Place the heater at an elevated site or on tower (for water pressure) and
orient the glass towards the south.