I have an Aspire Chameleon 550W PSU which has a 120mm intake fan blowing down upon my CPU. I was thinking about opening up the PSU (I am fully aware of the safety issues) and simply flipping the fan, essentially making it an exhaust. From what I can gather most people recommend using fans at the back of the computer for exhaust anyway and the aspire has got to be a bad source of dust when used as an intake. Has anyone ever tried this? By the way, I use a Zalman 7700 120mm CPU heatsink and I am not having overheating issues at all.