Well.. where i'm at here in Ohio winters can be cold, and if your going to be out in the shop all winter you got to have some kind of heat source right? I like to stay warm when i'm out here and I don't like to have five layers of clothing on. It makes it harder to move around and besides it tends to get caught up in things it shouldn't be. Flywheels?? This is the heating section. 2 furnaces here, one is a 100,000 btu 90+ propane furnace, and the other is a 90,000 btu waste oil furnace. But why waste oil and propane? Well natural gas insn't available where i'm at so that leaves me with the alternatives. I only use the propane furnace when it gets really cold, or as a backup to the waste oil furnace since they are a higher maintenance furnace. It has to be cleaned about once a month to keep it running smoothly. I keep the shop at 70 deg. F 24/7 and all it costs me is a little electricity to run the furnace. I'll typically burn about 1,000 gallons of waste oil in a heating season.