That's a nice big fan that will still serve you well in a larger room.
You only need one, and it should be set up at the exhaust end to suck air throuhg the whole thing.
Now remember, unless you are running 2 fans (one light cooling system and one room cooling system, totally seperate ducts), you leave one end of the hood open to the room so that the exhaust goes out through the cooltube.
stinkyattic Reviewed by stinkyattic on . ** Will this work?? Come quick, order on the way! ** Im growing in a homebox xs (2x2x4) and im growing buddha white dwarfs (From ) they will be under a 250w hps with a cooltube (from htpsupply?).. Well what im asking is would 1x intake 6'' inline fan pushing 250 CFM (cubic feet per minute), and i have 1x of the same 6'' fans on the cooltube.. Will another 6'' fan of the same one work?? Or would i need more?? Here is the specs of the fan.. And will i need 2x fans for my cooltube (One sucking in and out) or what?? PLEASE HELP ME! Heres specs Rating: 5