Tent bowing in from exhaust fan vacuum


I’m setting up a new tent and looking for advice on fan size. I have a 2x2 currently and have ordered a 2x4 to setup soon.

In the 2x2 I have a 4" 190 CFM fan with a variable speed controller functioning as my exhaust. The intake is a 4" inline with 100 cfm and this fan has no speed controller at this point.

With the exhaust fan at half speed and the intake at full speed, the tent is drawing in tightly due a vacuum being established. I will use these same fans in the 2x4, but should I consider a larger fan for the intake such as a larger 6" inline fan with higher cfm to more or less equalize the pressure differential?

I have a spare speed controller, so I can always adjust the two fans to equilibrium if the two fans are more similar in size.

How are others setting up the fans to achieve this balance?

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Best balance is to install only one fan, and slow it down. Just have a passive intake. You’ll be good.


OK! I’ll try that!!

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You actully want the walls to suck in that tell you the tent is in a negitive pressure and all smells will say inside tent except what’s being pulled out with exhaust
Your intake shrouds run 3/4 speed of exhaust to ensure this
Runnning a passive vent would be ok but may also cause more of a issue unless you open all the vents


I had to open 4 vents on my tent to just have a slightly negative pressure :+1: