i have an extra 90mm fan. any ideas about the best place to put it? i have a Enlight 7237 case, with 3 80mm fans, 2 in back, 1 in front. i have no idea where to put the 90mm to make the most efficient airflow. my only idea is to place it at a 45 degree angle in front of the intake. good idea? any help will be greatly appreciated. thank you