The heat output isn't huge, 6800 btus(about 10' of radiant HW baseboard). But if you mount it toward the ceiling, it would only come on if that area got below 45 degrees(not the cold floor below). Is it pipes hanging from the floor you'd be most concerned about or will you blow the pipes out of all water?

It is a cheap installation, 150 for the heater, 12/2WG wire for supply and a 20 amp double pole breaker.

It will cost about .30 cents an hour to (CMP rate) when it runs, which would add up if for some reason it needed to run constantly. But if the space only rarely gets below 45 degrees, it should take little heat to keep it above. I'm pleased with results of the one I installed so far and it's running less than I expected it would.