mine is in the basement as well however that is also where my furnace is .... for intake make a square hole i dont know what size is best but here is my setup specs.... 4x4x6 diy room created of 2x4 boards and drywall (FLAT WHITE PAINT), 1-1000w apollo hps like yours , 240w of cfl lighting to kill shadows and hit the top of the plants in back of my room. 1-8inch 500cfm duct fan for exhaust 1 -6inch 90 cfm duct fan also for exhuast next to that (both at the top of my sidewall , 1-6inch 90 cfm duct fan for intake at the bottom of my back wall ,on the other side of that back wall i cut a 12inx12in sqaure hole and put a window screen over it (to keep out pests )that is my passive intake .... i also have a 12inch desk fan that blows between my plants and hps towards the exhaust fans... now ur problem unless ur room is in a seperate qaurters from ur living area is gonna be light proofing as the cannot have any light leaks during flowering ... so start prepping for that