MY insulated,attached garage is 22 wide X 32 deep with 10 foot ceilings. It is partially heated by solar panels so it is easy to raise the temp from 41 degrees to the 60's with this heating unit. One impressive thing was the electric fan motor. I expected the fan motor to be a typical cheap bathroom fan. The motor appears to be similar in construction to the cooling fan I just replaced in a 32 year old Whirlpool refridgerator. Very heavy duty!