Thanks again rollone your expertise is appreciated. You are correct I dont have any experience with HPS and the heat does concern me, I had the cab customized a bit, have 2 200 watt HPS on either side of the cab. The intake fan is on the back of the unit in the center. The intake fan looks like its 60cfm. I had an additional exhause fan put in the cab too. There are 2 exhaust fans on the top of the unit, Im not sure how much air they push when I briefly had it on it seemed to move a lot of air. I guess I should at least let it run and see what the temp gets up to... i dont wanna set my house on fire!