Eximo said:
Power supply fans mounted in that fashion are always intake. Your supply should be installed with the fan facing down so that it intakes and exhausts without interfering with the internal components.
Only caveat to that is if your computer will sit on carpet. Then you should flip it over. Not ideal, but better then carpet fuzz.
Ok. That makes sense. I don't intend to place it on a carpet, but the small bottom hole does worry me a bit.