I did a quick ball-park CFM test on my extraction setup today. I used a duct anemometer to measure ft/min at the intake of the fan (6" AC Infinity 6S) with filter disconnected. The fan output goes into 16" of straight 6" flex to a 6"x4" adaptor, then into the 4" dryer vent. I expect the net cfm will be lower when I install it later during stink production. CFM = FPM * 0.2 sqf (approx using 6" dia round duct)
Speed -- FPM -- CFM
1 -------- 290 ---58
2 -------- 463 --- 93
3 -------- 624 --- 125
4 -------- 773 --- 155
5 -------- 933 --- 187
6 ------ 1066 --- 213
7 ------ 1249 --- 250
8 ------ 1449 --- 290
Grow space is about 12 sqf, 96 cuf. I will run on 2-3, 5 and above is noisy, 7-8 are ridiculously loud.
