I was wondering which way does an atx power supply push air? it feels like its coming out of the back of the case but i can't tell. I was told that they actually suck air into the case but I can't feel any wind coming from the openings in my supply. im asking this because I want to add a case fan to my system.
right now, Intel's specification of ATX cases/mobos/power supplies makes the direction of Power fan optional -- in other words, there really isn't a way for us to tell you for sure
Long time ago, all (or at least majority of) cases pushed air out... then, ATX pushed air in, in an attempt to cool the processor without active fan on CPU itself. Obviously today that's almost silly, since you MUST have active cooling on CPU anyway, so manufacturers are free to put the fan whichever way they please
It probably blows out. But it is hard to tell because most powersupplies are designed to be quiet and so the fans run slower. Also, some fans in powersupplies are temp controlled and your case would have to reach something like 60C for the fan to work at its peak.
This is why case fans are important. So put a couple in.