Hi, I'm a newbie and am building my first PC. I am getting conflicting advice. Does the fan on my Cooler Master power supply suck air into the power supply and exhaust it through the back of the unit (PS) or does the PS fan exhaust the heat. In other words, does the fan blow or suck air in. I have installed it in a rack mount case and have flipped it so the fan faces out the side of the case by cutting a square hole.