Also, should point out that cfm does'nt translate into room temperature unless you know the intake temperature - there's that whole differential temperature thing, which gets into a fair bit o' math.
(Also, I don't know how to make the little triangle delta symbol on this keyboard, which makes the equations pretty unreadable.)

But obviously, you'll need fewer cfm if your intake air is 50F than if your intake air is 74F, to remove the same # of calories from the room.
rhizome Reviewed by rhizome on . How do i find how many cfm's i will need? i am going to be using a 400w GPMH and HPS for my second grow. i have a closet that is approx. 2' deep x 4' wide x 8' tall. How many cfm's do i need to keep this area at a good 75F??? Rating: 5