I think this is getting way off the subject of what the opening poster wants to know. He says he wants to know what is the best and the cheapest way of heating a garage in Michigan. In other words, he wants to know if he should go with natural gas, a wood stove, LP gas, solar heat, a heat pump, etc. He wasn't asking what size heating unit he should get or how much it would cost to heat the garage. I realize everyone is just trying to be helpful and that's great, but as near as I can tell from reading his opening post, that it isn't really what the guy wants to know.