http://www.silverstonetek.com/techtalk_cont.php?tid=wh_positive&area=usa I have no top exhaust, just 1 back exhaust fan, and 1 intake (case is a 650d) i was planning on changing out the fans on it, cause even though it is a silent case, the noise coming from it bothers me i'm willing to downclock my cpu/etc.. but it doesn't seem that bad oc'd if i setup my fans like that, where the top is an intake, would it be considered a positive pressure case?
If you have more intake cfm that exhaust cfm your will have a postive pressure case, doesn't matter how many fans, just how much cfm they move. Seems like a waste of time and resources to me.
I would think you would want to make the top fan the exhaust fan because heat rises so, wouldn't that make air flow more efficient?