This is the most efficient way when you're burning a fuel, any fuel, always. Otherwise the machine wouldn't capture the waste heat.Gasoline engines capture only 25-40% of the the chemical energy in their fuel.
So 120V and 240V stuff. Be careful :) if you don't have it I'd recommend running some cat6e cabling while you're there.
This is the most efficient way when you're burning a fuel, any fuel, always. Otherwise the machine wouldn't capture the waste heat.
Gasoline engines capture only 25-40% of the the chemical energy in their fuel.