I have had 3 homes with shops, and I made sure all had heat. My first was a basement attached garage under the bedrooms of our split level home (22×30). I cut an opening in the back wall, framed it according to code, and permanently installed a 220v heat/AC window unit. It kept me warm and cool. The only problem with this unit is it either ran or it didn’t, so I would have to turn on the heat about a half hour at least before I wanted to work.
My second home had an outbuilding, 24×36. It was a simple pole barn without power. I trenched in power and called in the assistance of a HVAC company for their suggestions since we had an all electric home. Electric heaters are not that efficient, so I was looking for the best bang for the buck. The contractor suggested a heat pump as the most efficient way to maintain a constant temp (my minimum was 50 degrees), and then I got AC as a bonus. It was great, I kept the temp at 50, would kick it up to 55 when I got in there and work in a sweatshirt, no problems. The only thing is it required a 60 amp breaker, which some outbuildings only have 100 or less, I had 125 and it was fine. The thing that really sucked, is we moved into that home in November of 2005, I spent Nov-Dec-Jan and about $10k making it into a cabinet shop, then in May of 06, my wife’s company shuts down and we have to take a job 4 hours east.
My current home has a 24×24 shop, and our home is on propane. I tried the wood stove, but can’t keep a constant temp all the time. So I again called my HVAC connection in KC and he supplied me with a 70k BTU furnace that could be ceiling mounted. He told me this is the ones they use in 1-2 bedroom apts. I just had to install a propane conversion kit, $20. I use the furnace to maintain 50 deg, then use the wood stove to warm it up.
Just be sure to insulate well. Oh, the heat pump system costs me $2750 (in 2005) installed, and the 70k furnace cost me $750, I installed myself and had a local contractor come check it out for $75 service call. Was worth that since I used the wrong type of shutoff and had a small leak which would have been a big problem otherwise.
