The top does, the rest doesn't. I have the AC pumping into the top and then let gravity do the rest.
The AC is more for me than the computer, but a byproduct of cooling me is that the computer runs colder. Also, I'd assume that my AC unit uses between 250-300 watts per hour at full blast.
Plus i could just keep the pc open and in front of it and it would keep it real cool and then fan out and cool the room.