Ballast goes outside of the grow room to avoid added heat and humidity getting inside the ballast.

I have about 120CF with a 4x5x6 area.. and i use a 8" Vortex. I would go with at least the 6" for an area of your size.

Have Fun!
Bob.
BobBong Reviewed by BobBong on . Big enough fan? I'm going to purchase a vortex. I have 208 cubic feet (total room that is in shape of L). I'm going to make a scrubber (bodom's) and I am venting into the attic which will be only a couple feet away from the light. I will be running 800w in one reflector. Will the 172CFM 4 inch vortex be enough, or should I go to the 6 inch 440? The light has a 4inch hole, but if I am correct, I will have to use a reducer in any case since I believe the proper set up is light, scrubber (which uses reducer, Rating: 5