how much venting in a greenhouse is need?

In a completly sealed greenhouse how many times doe the air have to be changed? is it the same rules as an idoor grow, or because there are no heat form the lights u dont need to as much.


just want to calculate how many intake fans ill need.

buuuuuuuuuump!!!!

come on someone has to no this

at least one time every minute is best but every 2 minutes could be ok depending upon outside temp