Quote Originally Posted by PharmaCan
It's not so much the size of the vent as it is the cfm of the fan hooked to that vent.

Venting requirements also depend on the specifics of your particular setup - so a lot more information is necessary if you want an educated answer to your question.

Ceiling height in room (need cu.ft. of room) - lights - are lights cooled - ambient temps (vent reqs will be different in Siberia vs. Sudan ). Anyway, you get the idea.

PC :smokin:
Two six inch @ 250cfm each. Room size is ( 10' L x 8' W x 8.5' H ).
The lights are air cooled with blower. I am thinking that I will be installing one fan at the intake of the blower line to bring in air from outside. Then install the other on the exhaust side to push air out. I am trying not to have to cut more holes in the walls and use the existing line I have in place for the lights. Do you think this will be enough?