Hey all. I'm in the process of constructing a new tent. Before I head off to the shop to pick up the new hood and fans ect, I just wanted to double check and make sure my plan is efficient. My area is 5x7x7ft. 245cubic feet. I run a 1000w HPS in flowering. 1. will 6 inch flanges be adequate for a 1000w, or will i need to go to 8? I plan on going with a centrifugal fan vortex style, 450ish cfm. I have one source telling me that it might be over kill to some but he says keep it at 1cfm per 2watts. However that would leave the tent getting an air exchange almost 2 times a minute. I just dont think any axial or inline fan could cool the lamp enough, even though i dont have to duct very far. 2. my plan was to go with the 450ish cfm fan and get a variable speed controller with it, instead of working with a smaller fan? yes/no? my main concern is keeping a temp range of 75ish in the tent, and the rh around 40. general rh in my area is 20. also, how loud are centri fans, what can i expect? security is no issue in case of wondering... thanks guys. sorry for my poor punctuation, im workin on an old laptop with half the keys missing.