i have 3 bath fans at 50 cfm ea. for 2 rooms 5'x3'x7' w. One room for vegg, one for flowwer, and the other is 4'x4'x4' guess for drying or what ever i need it for. one 400w MH for flower. and cfl for veg. i think my fans r under sized ( i was planning on using led till i got such bad reviews so i wasn't planning on the heat being so high witch is why my fans r small but oh well it can b fixeed easy). i can put bigger in or add a booster but i'm running all 3 fan vents into a duct board/fiber board like for furnaces. That i made into a 1'x 1'x 2' box. Running 3 vents in to hold mostly the smell(kinda like a holding chamber just to run all my vents into) thats my biggest concern and then venting out of that with a 6" fan booster into and Air Box Stealth(ne ever use one ne good ????).then to the outside. and thought about also adding a carbon filter in the flowering room to help kill the smell .Is that over kill not enought i'm try to have the smallest amout of smell possible. Also going to put a ozium time mist some where in the basement just in case any leeks out of the room there pretty tight but not air tight there r some cracks and holes couldn't get everything to fit just right thanks i also have a radon fan i ripped out of a job that i have it drawls a a good cfm not sure exact cfm but i have that i need to add some where and thoughts or comments are welcome thanks