if your not to concerned about a lil noise, not much, i run the samecabinet almost just about 2x the size.home depot sells bathroom exhust fans already wired for about 20 bucks! they work great i run one in the bottom corner (inlet)and one in the opposite side top for the exhaust. there quiet for the 1st year, after that they get a lil noisey not much. u can see my box in just afewthreads down (sharing my love).