Ben,
I loved the scale model you built where you showed how insulation can heat a room better.
Since heating the shop is expensive, and we do get the occasional sunny day even in the winter in the midwest, thought it might be neat if you built some solar boxes (you know, those 2x4 boxes, usually with matte black painted beer cans inside). Videos I've been seeing on youtube show that a box can easily get 120 degrees inside on a cold day (over 200F in the summer). You could use a small solar panel to run a small DC fan to blow the warm air from inside the box into the shop, maybe use some simple logic circuit to only blow air in when the box reaches a certain temperature. Have no idea the efficiency, perhaps it would only be useful to heat the small gameroom or office. But the good thing is that it's completely scaleable (IE build more boxes). Maybe it could be a challenge between the three of you to build the most efficient furnace by tweaking it with better insulators, or using some sort of liquid that doesn't freeze to help absorb heat? Maybe adding parabolic mirrors in front of the box to focus sunlight at the box like an archimedes death ray?
Joe
