I've got a cab about 28"x43"x68"tall. Will 1 8"x8" dark room louvre do me, or do I need another? I've will have a 6" vortex pulling thru a scrubber and a cooltube.
Thanks all

Highly doubtful ,
Plants need lotsa oxygen , living in a vacuums not cool . Look up midget louvers 4in. round / darkroom on the net . a place in Ct . If my memory serves me right you need 3 to 4 times the exhausts area = 6in. dia. for passive intake to be effictive . Latewood , Zandor , or Free Wheeling Frank may have the actual mathmatics to figure it out scientificaly .
Peace
Crispi

Thanks for the reply So can I take like 2 aluminum dryer vents and put them in the cab, with the vent trap in the cab and the tube going out? will the little flapper be able to open? So ive already have an 8x8 hole, and with 2 more 4" holes, will this suffice?
Thanks for the help!

anyone?

Math 101
First u need to find the area of the 6in dia. hole the blowers in .
The formula to find area of a circle = diameter / 2 sqared x pi.
6 in dia. / 2 = 3 x 3 = 9 x 3.14 = 28.26 square inches of exhaust .
your passive intake is 8 x 8 sq. = 64 square in .

To be at all effective you need 3 to 4 times the passive area .
28.26sq. in. x 3 = 84.76
28.26sq. in. x 4 = 113.04

You have 64 sq.in. now w/ the 8 x 8 sq. darkroom vent . I suggest another 1 just like it . = 128 sq. in. of passive area total .

Peace man
Crispi