hey subcool man i can really use ur help i have a room that i want to vent but i really want to do it the right way its about 200sq feet and eventually will be running 5 600watt HPS in there i dont really have an idea on how to vent it ..the room has a window that i plan on using for the exhaust and a hole that i was planning to use as the intake it comes in from the furnace room ill only be running 2 lights at 1st tho but i wana make sure everything is vented good im also using co2 pls help me out i can pay u if u'd like just tell me how much and ur paypal email address ...thanks again