ventilation concerns

[weedmann]

my concern is my intake and exhaust set up.do i have to have the intake alittle bigger then the exhaust.can i have two passive intake to one exhaust.how does that work and whats the best way.right now i have two 4'' hole one for exhaust one for intake but my question is can i have two 4'' inch intake to one 4''exhaust with a intake fan

weedmann Reviewed by weedmann on 04-25-2008. ventilation concerns my concern is my intake and exhaust set up.do i have to have the intake alittle bigger then the exhaust.can i have two passive intake to one exhaust.how does that work and whats the best way.right now i have two 4'' hole one for exhaust one for intake but my question is can i have two 4'' inch intake to one 4''exhaust with a intake fan Rating: 5

[fresheadies]

I don't see a problem, but perhaps someone else will. But things really depend on the fans and size of the setup. You want air to linger a little in the container, but you want fresh air to be abundant as well and it works by simple math. Fans are measured, among other things, in Cfm (cubic feet per minute). Now in order to measure the cubic feet of your container, multiply the length, by the width, by the height and that will give you how many cubic feet you're dealing with. Then just find out how many Cfm your fans are pumping out. Also, do you have a thermostat checking the temp. of the intake air? Once you know these things people can really help you out.

[TheMetal1]

I'm not 100%. I was reading something the other day on here. Very thorough. If I can find it I will edit and post a link. With passive intakes though, you should be fine. The amount of air coming in naturally through 1-2 small passive intakes would probably not match the power of an active exhaust. Like Fresh said, you want air to linger for a bit, while also constantly re-circulating fresh air. The real problem lies in an active intake and active exhaust. If the force of the exhaust is matched or exceeded by the intake, the air will be pushed out before the plants have time to utilize it. Again, I am no expert... and I'll try to hook it up with some sweeet factoids. Keep :jointsmile: