Radiant wall heaters would be a good option for someone with a completed garage. I'm at a building now with the old wall radiators. Boiler tripped and shut off 3 days ago, now that it's fixed it's bringing everything back up to temperature pretty quick...I'll go lay on the floor and see how it feels.
Dan
So after 4hrs it went from 41 to 56 degrees. Not bad for an old set up that once burned coal than oil and now gas...