Quote:
Originally posted by Seyeklopz
I found a 172x50mm fan on www.nmbtech.com. Browse their site for Distributors, Fans to buy. I have the pdf file on my http here.
Can get it with a black aluminum housing, snazzy.
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You will not get the deep 172mm fans, nor the NMB x38mm deep
172mm fans to be particularly quiet. They are also very very hard
to get hold off in the lower-noise versions, and not cheap.
PWM can easily make them group, and undervolting whilst
working is /non-linear/. Specs for the temp-variable versions
often show the caveat - which for them is bearing noise.
o 50% 35dB(A) -- not the ~21dB(A) conservatively hoped for
o 100% 51dB(A)
Also, to feed them, they require very very open enclosures in
terms of "ease of intake". A 55mm fan of that type can create
very high suction forces, if allowed to develop into turbulence,
stall or thrust on the bearings due to inadequate intake then
the noise will be simply obnoxious. Also, the intakes must be
kept free of any major object for at least 8cfm in front of them,
otherwise again you get very considerable intake noise.
120mm is a reasonable biggest-size-to-use unless you come
up with a way of fitting 45dB(A) 254x89mm Caravels in there.
They are much quieter for the airflow, but ... A Bit Big.
Bearing rumble on a steel case without huge reinforcement
is likely to result in some interesting industrial sound effects.
You could borrow that rather high Nasa windtunnel building.
"Intel in 2050 released their new processor today, it powers
the planet's CPU needs, and its heatsink just fits in the building.
When asked about how windows 2050 performed, they were
quite confident office applications would be smartly responsive".
A 30W fan is ~1/25th of a horse-power, watch fingers :-)