Just built a base cabinet for our study to house two PC's, with two large vents either side to help circulate air through to keep the PC's cool. I'm going to remove the sides from the PC's to help the cooling, so basically the cabinet will become an oversized case. I have a couple of questions though. The vent opening either side are 140mm square, and I have a couple of options for what size fans to use. I could go with a matching 140mm size fan and simply place a couple of angled pieces of wood across the corners to screw the fan into. Or I could go with a larger fan, such as a 150 - 160mm, so I don't have to worry about the angled pieces, screw the fan directly into the sides of the cabinet,and simply have the blades overlapping the size of the hole. My only concern with the latter is that the air flow from the fan blowing on to the wood, rather than venting out, might make additional noise. The other point is speed and noise. I figured I'd just connect the fan directly to my PC's power supply and leave it at that (my PC is the one that runs most of the time) but my understanding from what I've read here and there is that this will mean that it automatically runs at full speed every time I run my PC, and that this could be quite noisy with certain models. Should I buy one that I can also connect to my motherboard so that the PC can control the speed? The Motherboard's an ASUS M2N-SLI Deluxe. Or is there one I could count on to run at full speed and still stay relatively quiet?