Heater placement

Hemi, The efficiency isn't even something I thought about until I just happened to read that the mr. heater I was reading about was 81%.
75 sport, I may just do that. But my guess is that it's going to be more expensive than I'm going to want to spend.

We have two Modine 93% units in our 5000 sf. shop with 14' ceilings that work very well in our heavily insulated building. They were initially almost double in cost of the other brands but in the 5 years we had them they more than paid for themselves. Dan