thank you i appriciate the response, and i have admired your post as you see to know your stuff....ok.....i am in a 300 cu' room with a 465 cfm exzaust, and 2 passive intakes, one is ac........also i just placed a piece if glass in my hood to air cool, what should i do to vent the air cooled hood? it has 3" vents on both sides, . i have a 400 hps.... 2 circular fans too.....i am in fl in the states so it gets hot here in summer, right now in april its cool....and its 73 in house and 83 in grow room, what do you suggest?....its bagseed 16 in 3 weeks of vegIt sometimes depend on the time you post..... Maybe i can help you, whats going on with you heat?