Greenstuff
Well-Known Member
I was wondering what size of an passive intake i should use and what size should my exhaust fan be? I'll be using a 400w HPS in a 3x3x7 box
Thanks for help!
Thanks for help!
I would think 1.5 is minimum.. 3 is optimal. just my opinion. Its jsut what ive heard from other places.
With HID lighting you want to cycle the air in the room at least once a minute, more ideally, can't have too much ventilation!
You want the passive intake slightly smaller than the exhaust, to create negative pressure in the room and prevent air/odour leaks. I don't know where all this talk of 3x the size has come from...
If you're getting a carbon filter for the exhaust, now or at any point in the future, make sure you uprate the fan so it can cope with the static pressure from that. Inline fans should be roughly doubled, as they really don't like to be held back! If you were getting a squirrel cage or centrifugal fan then an extra 20-30cfm would do, but I don't think one of those would be necessary unless the dimensions you gave were in metres!
Sorry pal! I do have a tendency to ramble on a bit when I'm stoned. I'll use 50 words where 5 will do...FUCK... i knew i shouldve read this post but it was the longest one so i was like fuck that. Now i sound like a tool.
no you want the passive intake slightly larger than the exhaust. a 6" exhaust should have a 7" passive intake.Thanks for the reply's guys.
Would a 4" passive intake and a 6" Exhaust fan work?
Why?no you want the passive intake slightly larger than the exhaust. a 6" exhaust should have a 7" passive intake.
its not the size its how you use it. ooops wrong forum.I think i get it now, passive intake slightly larger than the exhaust. I'm going to go with a 6" passive intake and a 4" exhaust in 3x3x7, how does that sound?
and is the size of a oscillating fan important?