Is it vented via a windows or have you done some kind of alteration to vent via (outside) wall?
I have often thought about getting one as the room where my computers are does get rather hot, especially in summer, but the venting issue has always stopped me proceeding with the idea...
Had it vented to window (was akward because of window style), but worked well. Now it is to the outside with a hole made to the outside. No real difference really.