Kingrow1
Well-Known Member
With your tent at 40 cubic feet anything above 200cfm seems over kill, thats five air changes every sixty seconds, one every twelve seconds.As far as I understand, you won't be able to push any more cfm than your filter can handle. I'd consider getting a 6" filter with close to the same cfm as the fan you're looking at.
You're rigging this to your HPS or LED? My hood has 6" connections, so I matched all my equipment to that.
Edit: I'm in a 2x4x5 tent and even with a 6", I've got very little wiggle room concerning negative pressure. I'd even look into 8" rather than 6" since you're worried about noise. At least with an 8" you can run it at a lower speed, which will be quieter than a 6" at full tilt.
Too much negative pressure takes you into the realms of wind tunnels and wont cool much past your ambients.