I vent into my attic, have the fan and filter up there, actually just checked the filter still blowing nice kitty litter smell after 3 grows! anyway its pretty simple setup, i let it suck air in from under the door ( has a big gap so it had plenty of area) and made a shelf in there a foot up from the ground so i could put in 4 abs 90 degree elbows so the light would not leak.