Ok so I was reading rhizomes (i think) beginnerguide pertaining to ventilation just now and read that a rule of thumb for intake area was CFM of fan*.05 sq inches. Right now for a 450 CFM only 2 6 inch openings are present which is roughly 60 sq inches which is WAY less than 225 and there is negative pressure/suction inside the box.. so obviously adding more intake area is required but how can I do this and make it light proof at the same time? I mean for the current situation there are just 4 6 in 90 degree ducts making it light proof. I need at least 2 10 inx10in square cut holes or something similar equalling total of 200-225 sq in. how can i do this without having to buy 12 in circular duct and keeping it light proof? any help would be grrrrrreat
bloodbrother Reviewed by bloodbrother on . Ventilation question Ok so I was reading rhizomes (i think) beginnerguide pertaining to ventilation just now and read that a rule of thumb for intake area was CFM of fan*.05 sq inches. Right now for a 450 CFM only 2 6 inch openings are present which is roughly 60 sq inches which is WAY less than 225 and there is negative pressure/suction inside the box.. so obviously adding more intake area is required but how can I do this and make it light proof at the same time? I mean for the current situation there are just Rating: 5