Well I couldn't find the number, but everywhere I looked they kept refering to it as quiet. Also, if your not happy with the fans you can swap them out, my post was mainly made because the fortrons are pretty much the highest quality you can get for a reasonable price (pc power & cooling units go for about $230). The fortron is a great snag, and I have a 6 year old fortron sitting next to me, and its still running, no problems.