Anatomy of the Silent Fan

If you've ever tried building a media center in your living room, (or anywhere else if you have a significant other who always seems to have super-sensitive hearing), then I'm sure you've tried all you could to make sure your HTPC is as silent as possible. SilentPCReview is a great source for info, and they go in-depth as to what makes for a great silent fan & how it works.

 The advantages of ball bearings for general application in
computer equipment are clearly spelled out in the NMB comparison. For
silent computing, the advantages of ball bearing fans are only relevant
if the acoustics at low and very low speed are very good. The
advantages of sleeve bearings are certainly relevant for silent
computing. The Comair-Rotron article shows why PC silencers might
prefer sleeve bearing fans. They are…

Read the rest here.