Help installing power supply

Im finally able to upgrade from the poo poo psu the came with my case. This is the first time im ever installing one myself. It has a 120mm fan and the power supply is gonna be at the top of my case. I wanted to know should the fan my facing the top of my case (its pure metal there no vent holes) or should i flip it upside down so the fan is facing down toward everything else in my case?

THANK YOU FOR YOUR TIME

Your fan should be facing down, if it's facing upwards then the fan will only blow right back into the PSU :P that'd be a problem heheh