I have a 100-cubic-foot grow closet. I'll be running a 600-watt HPS bulb inside an air-cooled hood with 6" flanges. I have 2 inline fans. One is an Elicent 8" 636 CFM, and the other is an Elicent 6" 300 CFM. I have PLENTY of passive air intake at the bottom of the closet. I will need to filter the air. So, how should I set up my ventilation? Which fan, or both? I have a nice motor controller to reduce the 636 CFM fan if needed.
Fan with higher CFM for reflector cooling (one duct as intake /reflector/second duct/inline fan/exhaust duct) and one with lower CFMs for ventilation(carbon filter as an intake/short duct/inline fan/ exhaust duct).... People said that with out carbon filter your grow area will produce detectable odor . Also they said that cheap carbon filters (and most home made carbon filters-(info based on posts)) will not work properly... So just get yourself Phresh filter or CAN filter, or something else...
so you have a giant gap at the bottom of the door? growing in a tent or box? you have to light trap the passive intake.. when your in flower you can have no light leaks...
No gaps. I installed three 8" circular vents at the bottom of the closet, and spray-painted them black inside. Outside the closet, these are covered with air-conditioner type vent covers. Looks perfectly normal. Inside the closet, I use black panty hose and a simple fliter to cover the intake holes. No light leaks.