cfm needed for air exchange

[baddog]

Going to start another grow in my new seedling tent (2ft x 4 ft x 50" high ) , thought it may be more efficient to draw the air out than blow air in. thoughts on how many cfm for air exchange? Thinking variable speed so can be adjusted as plants get bigger. will be moved to a bigger tent at some point .

 

[Potted]

Adjustable 440 better to have more than wishing u did later. Lol

 

[Campesino]

Yes, it is better to suck than push. Exhaust should always be higher CFM than intake.
200 CFM exhaust should suffice.

 

[baddog]

Looking around online it looks like 120 cfm should work , but i agree ... more is always better . Just thought it would be more efficient to draw air out than try and aim a fan blowing air around the tent .

 

[Campesino]

It is best to have both an exhaust and a circulating fan