We have a customer in Guatemala who has our biggest amps. He has no air conditioning, and does not need it (Minnesota is hotter in the summer than Guatemala...). This despite the amps often being on all day long; the room stays very comfortable. He does this by having vents in the ceiling above the amps. The hot air is then moved out of the house. It works very well indeed (I was there)!
Its probably not a good idea to choose an amp based on heat (or lack of heat) output. But it is a fact that if you choose an amp for its low heat output, it will represent a compromise in the sound of the system overall. So far no-one has been able to change the laws of physics...
