I've messed with similar systems in the past, as well as with a good variety of solar cookers (some of which we just might mess with in our 2011 Relaxshacks.com Hands-On Tiny Shelter/House Building Workshop), but here's a concept (especially the FREE part) that I always thought was great- and THEGOODHUMAN.com explains this solar heater build quite nicely with a photo gallery. I've long planned to film a micro-solar heating video, so who knows, I might finally get up off my butt and do so (when I finish about five other episodes and projects I'm involved with).
CLICK HERE: http://www.thegoodhuman.com/2009/06/09/solar-space-heater-made-from-soda-cans-an-old-window/
-Derek "Deek" Diedricksen
