I was looking at 120mm fans (115vac) on Newark and noticed most of the lower noise figure fans were sleeve rather than ball bearing -- is this typical? or am I just seeing things? I would have thought ball bearing possibly would be.
"Lowest noise" seems to be 37dba -- the one I have now is 50dba. 37 should be about half as noisy as the 50? (That 10db = twice the volume thing?)
Anyone know of a manufacturer or fan model that is super quiet? (115v)
Thanks.
Until the sleeve bearings wear out anyway.
I have some that are super-quiet (probably because they fail to turn).
You might do better with a 12V fan. eg.
thanks Spehro, "fail to turn" -- you're killing me. I just bought an Orion at Digi key -- says 25 dba and ball bearing !
I always use Digikey to find parts as their search engine works great, then buy somewhere else if I can find it cheaper.
These two are a bit quieter, and use ball bearings.
Nice. More than half the air flow of the noisiest one at 17dB less noise.
We had some (not sure of the dB claim) but the noise was a particularly irritating whine. Moved air nicely, but not suitable for use anywhere near humans.
Yes, sleeve bearings will run quieter. Balls and races have some minimal roughness, and make noise, and get a lot worse over time. I used to rebuild the fans on my Dell desktop every couple years with new bearings from Boca Bearings. Probably should have gotten better quality bearings, as these didn't last as long as the original ones.
3 dB is twice the "volume", but that is a REALLY subjective measurement.Jon
The problem could be the grille, not the fan; one gets a siren effect if the grille is near the blades, and has evenly-spaced spokes. Curved spokes, random spoke spacing, even logarithm-distributed holes, can help. So can using a spacer to put the fan a few extra millimeters away from the grille.
No, 3 dB is twice the *power*, but the volume is roughly linear in dB. That is why we use dB for sound, because our ears are not linear.
Think about it a little. We can hear sounds at 10ish dB level (leaves rustling) and also tolerate sounds at 110 dB (chain saw). If our hearing was linear with sound pressure that would be a volume difference of 10^10 or 10 billion.
-- Rick
** No connection really, fan noise does not come from the bearings.
For the same diameter, quiet fans blow less air volume per second, noisy ones blow a lot more.
.... Phil
Stick a capacitor in series
-- umop apisdn
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