I've got one of those in my shop, but it's a different brand name...same heater. An electrician friend had it in a part of his shop for a couple of months till his big heater came in. It was just sitting on a shelf so I got a real good deal on it. Las fall I had my shop spray foamed! Now I work in an Igloo cooler...lol. A guy in KS was doing a motel remodel and had some extra spray foam liquid...use it or throw it away. So I git that job done at a real good price also. That combo does a decent job...when I need more heat I fire up a big patio heater for a few min...then shut it off.
When we replaced the cheap crappy gas fireplace, that was in the house when we bought it, I had the guys put in a T and cap it for future use. Next summer I'll run a pipe from there out the corner of the house into the shop (about 10-15 ft.) and I'll be looking for a gas furnace. With any luck a friend with a plumb./ht./ac company can find a good deal on something.