That is an EXCELLENT suggestion EK....should be standard on the list....something nobody thinks about.

HID lights put out some STRONG heat.....I have 1 1kw in a 16x16 room (approx) and even with cental A/C the room cooked. I stuck an ADDITIONAL room ac in there....couldn't touch it. The only thing that I can think of is a good air-cooled reflector for your light. Cool tubes are also something to think about...they hold the heat in very well. That of course is seperate from a system that brings fresh air into the room and removes the old air.