I replaced all the fans in my Koolance PC2-C with PC Power & Cooling fans. Three 80mm in the top unit, an 80 & 92mm in my Enermax 350w PS and one 80mm in the rear. My hard drive noise now ties all five fans for noisiest components. VERY quiet and still runs 33c with an AthlonMP 1600+, chipset cooler, video card cooler (GF3) and hard drive cooler (pair of 7200rpm Maxtors).