which size fan

alright I'm just getting ready to convert my closet into a grow room..the dimensions are: 30in.w x 22in.d x 98in. h. I was planning on using a couple axial fans for ventilation just wondering if I should use 6 inch fans or if I could get by with 4 inch fans? thanks.

More is better

what KIND of lights are you using?

400 watt high pressure sodium

you will have to air cool the light seperate from the room. The six" will have more than twice the capacity of the four". VV

Go with the six,and at least two of them...good luck