[Beowulf] Desktop fan reccommendation

[mathog]

This isn't that hard a problem.  Visit the major fan manufacturers 
sites, buy
the one that will fit, moves at least as much air as the original, and 
is much quieter.  The manufacturers
all list their products size (ie, the ones that will fit) and then 
check cfm and noise.  For instance, I have
bought fans from these guys a couple of times:

http://www.dynatron-corp.com/en/product_list.aspx?cv=20-72

Generally you have to go through a distributor and not buy direct, but 
that is no big deal.

Jim Lux wrote:
> -> acoustics of fans are a black art.

Especially when they fail.  We had a 20mm fan go bad in a sort of 
scanner recently.  This itty bitty fan
barely moves any air at the best of times (it cools a 486, which really 
doesn't need to be cooled) and under normal circumstances the fan is 
completely inaudible.  The users contacted me and told me that scanner 
was making horrible mechanical failure sounds, as if the scan stage was 
scraping on something.  I didn't measure it, but
the sound was really loud, I'm guessing at least 85 decibels, and it 
really did sound like the end of the world.  The sound came in bursts, 
with no noise in between.  I'm guessing a bearing moving around in the 
fan, between a noisy position and a quiet one, or maybe it had developed 
some sort of resonance.   All that racket was from one tiny fan.

Regards,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech