Passive Intake & Exhaust Fan Size

[Budz]

Hey Guys.

I've just put my grow box together, the size is 3x3x7 and i will be using 175w of CFL's for Veg and 400w HPS for flowering and the inside is covered with panda film. The problem I'm having is i dont know what size my passive intake should be and what size my exhaust fan should be, would one 4" hole be ok for passive intake?

Thanks.

 

[rayvon]

Hey Guys.

I've just put my grow box together, the size is 3x3x7 and i will be using 175w of CFL's for Veg and 400w HPS for flowering and the inside is covered with panda film. The problem I'm having is i dont know what size my passive intake should be and what size my exhaust fan should be, would one 4" hole be ok for passive intake?

Thanks.

your intake (if passive) should be at least twice the size of your extraction and your gonna need a 100mm extract minimum for a 400w in that space so two 4" holes and you be sweet.

 

[ukcheesehead]

myself i would go for a 125mm extrator and filter set up ... for the intake i would make x5 125mm holes around the bottom of your cab. and cover them with cooker hood filter to stop light leaks .

 

[Budz]

Thanks for the reply's guys.

I think i will go with the 125mm extractor fan with filter set up, would i get away with 2 4" holes with this size of fan? I would like to keep the holes down to a minimum, Im also guessing ill need PVC elbows for the passive intake holes, will 90 degree ones be ok?