When I lived in Maryland, I had a 28'x32' shop. I bought an old furnace from a mobile home for $75.00.I had a 55 gal barrel of keroscene sitting outside the back wall and just piped a line into the furnace.I didn't even use a thermostat, just wired it up thru a switch.
The thing would run a few minutes to heat-up, then the fan would kick on and it'd be nice in there after 10-15 minutes...Cost very little to run it, I think it burned about ½ gal and hour