TO MANY cfm'S?

ok, i got a 10" 250cfm roof vent fan and getting a secret jardin DS II 90 36x36x67". question is it is too much exshaut for the space dont wanna implode my teny.

The roof vents you get from the store typically are way over cfm rated from stores like menards lowes and home depot. If you got that fan from a hydroponics store then you will be all right. Also the amount of "implosion" will depend on the exhaust cfm and the intake hole size.

there is no such thing as too much exhaust as long as you have air to compensate for it

If your intake ports are too small, it doesnt matter if you have a jet engine exhausting your room. It will only be able to move as much air as its taking in. If your tent implodes, you didnt have adequate intake.

With a 10" fan, I would be looking for double that in intakes. Either a couple 10" round intakes or larger rectangle intake (at least 8"x10")

Also need to calculate for CFM loss due to restrictions/static pressure from ducting, filters, bends, etc.

thnx, thought about the intake beening the important think but didn't think of the math side