Unclebudman i think the better term would be "new" air not necessarily fresh outdoor air. Just need to replace the air that is exhausted. Curious about your power draw with 4 1000 watt bulbs. Have you already ran new circuits to the room. How much do you think it will cost to run them per month? I want to use 2 1000's in a 7x5x8 room. I think it will cost about 260 just for the lights.