I've been looking in my pile of "left overs" from past upgrades, and found an 80 cm fan. Now my current set up has a rear case fan pumping air out, and a side panel fan pumping air in. There is also space for 2 additional fans in front of the HD mounting space. I'd like to put the extra fan I found in the case to provide extra air flow, so I though I'd look on this forum to find out the best configuration for case fans, and it looks like the general rule of thumb is: Rear case fans should pump air out of the case, Side, and front fans should pump air into the case. So I was thinking of moving my side fan to the front, and putting my extra fan in the front as well. Or would I be better off leaving the side fan on the side, and puting the extra fan in the front? I currently only have 1 HD, but I am looking at getting 2 additional 7200rpm SATA drives. Will the fan vent on the side cause any "issues" if it doesn't have any fan mounted? (eg. the positive presure created by the two front mounted fans escaping out the hole in the side...) Also, I have noticed a large build up of dust on all components that are near the air flow from the current side mounted fan. Is there any way to filter the air being sucked in so that not so much dust builds up internaly? How do you filter the air without restricting the airflow too much? I had a mental image of my PC with my Landcruiser's air filter sitting on top Intel Active Monitor has only ever reported an over temp alert when there was too much dust on the CPU heat sink for the CPU fan to keep the CPU cool. Where I work, all our servers are in a nice dust free data centre, but I don't have that luxurary at home, so if any tips on dust filtering would be helpful.