Last spring I purchased an old fuel oil furnace to put in the shop at my parent's place. My plan was to build a centrifuge and make fuel from used oil. I have about 400gal of used oil on hand. But, since I baught the house, the garage is already set up with NG in the garage. I'm trying to buy my old reznor hanging furnace back and then I'll be set up. I've used torpedo heaters for years and I know the smell you speak of. If you ever use brake clean in the shop, you best be shutting off your heat source.