Hi guys Im building my room right now and I have a easy simple question

my exhaust is 4". What should I cut my intake hole to be? I need negative pressure to ensure all air is sucked thru the carbon filter, correct? So I would need the intake hole to be the same size if not smaller,right?. Any suggestions? Thanks guys

4 inchs is quite small are you using cfls or something? just you dont really get much smaller fans, youd either use a small pc fan for intake or just have a hole for passive intake. the latter is probably best on a budget

yes Im using a passive intake and I am using a 4 " exhaust fan. I would like to know what size intake is required for a 4" exhuast, while having all the air being sucked out thru the carbon filter(neg pressure) thanks

thanks...i read it...but the only problem is im gonna be using a fan speed controller because im not gonna have it running full blast.....