</font><font color="blue" class="small">( I see a ceiling mount heater in you 28X36. Is it gas? Details and satisfaction? Dave in VA )</font>
Yes, it is natural gas. (Most common heat source in this area.) I didn't spend as much time in there as I would have liked this winter, but I am very satisfied with its performance and fuel consumption.
I generally keep the thermostat set at 45° in there and it keeps every thing happy. When I go out to do a project or something, I'll raise it up to 60°. It will get there in less than 30 min. I figure average is $15 per month to run.
Stats: It is a 45,000 BTU unit (sorry I don't remember the brand, but I don't think it is a Modine, Junk) with a horizontal flue out the back wall. Garage has 2x4 walls insulated with regular fiberglass, and 16" of cellulose in the attic. If I had it to do again, I would have sprung for the in floor heat.