How much desibel does your fans make?FWIW, I've always tried to replace all the air in the room every five minutes. Pretty easy to
calculate the total cubic footage of the grow space (length x width x height), and once
you have that number you can select an appropriate exhaust fan.
My flower room is roughly 450 sq. ft, and I use a Vortex fan that moves roughly 500 cubic
ft. per minute. I have it on a speed controller and run it at about 25% power. A quality fan
is important as you don't want your plants sitting in stagnate air, plus cheap fans are noisy
and it'll drive ya nuts.