I'm hoping to turn my PC into a Home Theatre/Hi Fi type system but before I do this I'm hoping to make it's cooling capabilities a little Quieter. I've already decided on the Noctua NF-S12 1200 RPM 120mm Quiet Case Fan to replace the rear fan on my OEM case, what I'm a little uncertain about is whether I can replace the fan on my CPU heatsink without taking the whole contraption off of my CPU. I'm aware that some CPU Coolers possibly use what are basically just 80 or 92mm case fans attached to the top or even sides of the heatsink - is this true? My Heatsink is the Akasa AK-861CU AMD Cooler which is cooling an AMD X2 6000+ - the fan on top looks like something you could just screw off and replace. The Fan I hope to replace it with is the Noctua NF-B9-1600 Vortex-Control 92mm Quiet Case Fan. It has a lower RPM but slightly better airflow and operates at only 17.6 dB(A) as opposed to the near 25 dB(A) of the Fan that is already attached to the heatsink. I'm fairly confident I can replace it but am a bit of a noob so need some sort of confirmation from someone who might know better in case I'm about to make a bad mistake (better to be safe than sorry).
Looks like it'll work all you do is take out the screws and replace. But make sure you get around the same CFM with the Noctua fan. Monitor temperature levels in your BIOS Hardware Monitor or get a program like speedfan.