What i did with my HAF X was, i installed the 2 top fans, both for exhaust. underneath them, i mounted the radiator which cools the CPU. the 2 fans pull air through the rad, so i didn't have to use the crummy 120mm fans that were meant for it. The rad i have is a 2x120mm. You CAN put a 3x120mm rad in there, but just have to leave the top drive bay empty, which is no big deal. One of my future upgrades will have me doing just that.