Just built and tested my grow box, its about 40cm x 120cm and about 130 cm tall, 400 w HPS , 280 cmm bathroom fan installed in the top corner, passive intake in the opposite bottom corner (this intake is currently too small, only half the size of the outake) . after running for half an hour the temp was above 35 C (thats 95 F) . too hot i think.
The reason i've not cut the intake hole bigger is i was trying to use a centrifugal fan inside the box (CMM/cfm unknown, but pretty powerful), but that was way too hot, so i tried using it as an active intake with no fan on the out vent, also too hot! if i keep this fan as an intake and have the other fan sucking out, will it work or will i have some sort of negative air flow?
I'd rather not have both fans going as its bloody loud, will widening my passive intake help to decrease temp? or would it be better to build a cool tube or something.
Thanks in advance
Jimbob
The reason i've not cut the intake hole bigger is i was trying to use a centrifugal fan inside the box (CMM/cfm unknown, but pretty powerful), but that was way too hot, so i tried using it as an active intake with no fan on the out vent, also too hot! if i keep this fan as an intake and have the other fan sucking out, will it work or will i have some sort of negative air flow?
I'd rather not have both fans going as its bloody loud, will widening my passive intake help to decrease temp? or would it be better to build a cool tube or something.
Thanks in advance
Jimbob
