There are plenty of choices when it comes to case fans, and the vast majority of 120mm models will fit any modern PC. However, before you go screwdriver-ing in new fans to your rig, make sure that the ones you pick have both the correct orientation and that their screws line up with those on your case (to ensure proper placement). In addition, it’s worth checking that any fan connectors will match with the ports on your motherboard or fan hub – as this will save you from having to run extra cables between the two.
Case fans are generally installed in pairs to either pull air in for intake or push out hot air for exhaust. To do this, they have frames that include bars extending from their centre. These are oriented so that the side with the bars faces outwards, allowing them to direct airflow in one direction. The other side is flat, and therefore face towards the case – ideally so that the airflow from a front-mounted fan channels through the drive bays (then through the hottest component like the video card), and is escorted out of the rear exhaust fans.
Ideally, you should also have some fans pushing air upwards on the bottom of your case, as this will cool components near the GPU without drawing hot air from other places in your rig. This is especially effective in cases that have large vents on the bottom of the case and feet that lift it significantly off the ground. Case fans