Personally, I don't see it being any more beneficial this way. It's a, if it isn't broke, don't fix it, kinda thing. Plus, all the "dirty" air would be making its way out of the grow room, allll the way to where you have the carbon filter hooked to the ducting, leaving a lot more room for air leakage. And then your house will reek of skunk, and/or other beautiful smells. My homemade one's already losing its spunk. Soooo, I'm driving out of town to pick up a 700 cfm can fan, and a BIG ole carbon filter. Plus a lot of other crap.
KickYoAss Reviewed by KickYoAss on . carbon filter -making of Assembly of a homemade carbon filter. I used two 8"-6" reducers, a 6" and 8" plug, 12 screws, chicken wire, door screen, some aluminum foil tape, and a crapload of zip ties. Only thing left now is to fill it with carbon that I ordered, and hook it up to my 250 watt attic fan, wooooeeee. Materials cost around $25, 27 pounds of carbon for $49. Rating: 5