Vantec sells a series of fans titled "Stealth" which run at 20 decibles or less, which, in the world of PC fans, is extremely quiet. TigerDirect.com has a great selection of Vantec's Stealth fans. The Stealth fans are the only case fans I use. If I have a new case or PS that comes with fans already, I chuck them and buy Stealths. They're great.