Chairman Ray said:
Fan should face outside the case. If you cannot orient the fan so that it's blowing through an air vent, then face it inside the case, but usually cases have an air vent for the PSU.
ok, not to sound noobish but just to be clear, the large fan on the top has to face outside of the case on an opening at the top of the tower? Il be honest iv never seen a case with a giant fan sticking out of the top or anything like that :P