This had been discussed a little in a separate post, but I'm looking for recommendations for heating an attached 3-car garage. Garage is about 900 sq. ft with 9 foot ceilings. I live in Wisconsin, so the winters get cold, but I'm only looking to keep things above freezing and warm it up enough (~60 deg) to work comfortably with a light jacket. I wouldn't bother going above 40 on the coldest days. The garage walls, ceiling, and doors are all insulated, and with 2 shared walls with the house, keep the garage above freezing for all but the few coldest days currently.
I'm leaning toward a natural gas unit heater becuase the ceiling mounting gets it off the floor for space and fume considerations. I also like the idea of sealed combustion, although it may not be required for my needs. Any other options, though, are appreciated.
Options I have heard of include:
Any opinions or experience on the best (or worst) options are appreciated.