I'm rebuilding my son's PC in a HAF XM and have an extra 200mm fan I can use. The case comes with a 200mm intake fan in front, a 200mm exhaust fan on top, and a 140mm exhaust fan in the rear.
Am I better off adding my extra 200mm fan on top and creating more negative pressure, or placing it on the side for positive pressure? Dust isn't a large concern, as we have a whole-house air purifier that runs continually.
That's one awesome case, too bad I am moding mine. The cooling on it is very awesome. I say place the 200 on the side to create a positive pressure and you should be golden. I think that case would have been the best if they didn't slap it with plastics. It's time Cooler Master goes the other way and give people more classy looking cases with the usual great cooling capabilites.