FmSwayze
Well-Known Member
OK. I'll do some measuring, and go big as possible. Appreciate it.Filters are rated for single pass. So if you put a 400 cfm fan with a 400 cfm filter the air will basically shoot right on thru the carbon and hardly filter it. Getting a filter that is rated double the amount your fan pulls will clean the air better at a slower rate. The air has more time to get a nice cleaning as it passes thru the carbon.
With a 2 x 4 you need about 200 cfm of air moved 24/7. I would use a 200 cfm fan and a filter rated between 350 to 450 cfm. Phat has 4 x 20 350 cfm, a 6 x 16 375 cfm and a 6 x 20 450 cfm.