yes i have the fans running on the big one working on chopping a hole in the front for a nice 120 mm and setting up a few new os's on the drives, need to swap between udma 66 and 33 often, and might get a new processor for it soon, or ram, or slap in a second video and sound card, so it stays open with fans running, but the one with the printer on it is the only one that stays running 24/7