20decibel doesn't sound that loud. I'm going to buy some new fans, what noise level is considered 'unhearable'

I'm thinking of letting my rig run 24/7, but I sleep in the same room. I'm going to use a lot of noise isolating mats, but they don't do miracles. the slightest background noise is going to keep me awake I think :/

so what fans should I choose to make my rig unhearable (so silent you can sleep next to it)?

I'm gonna need 2 120mm fans (top, on radiator), 2 80 mm's (one PSU, one back) and a 92mmk; the PSU is an enermax 350W

@Bosw8er: move to new thread (with other replies) please!

Do note that the Specs say 20db.
Just like a HD is 120GB but actually isn't. (1000 <=> 1024)

I've got 5 of these, and I can vouch that these things definitly can keep you awake for some time on 12V.

1) manufacturers measure sound at a certain distance and with unrestricted airflow. And even then they tend to flex the measurements.
2) my case is a chieftech with the metal fan grills removed, this is pretty free airflow, but I estimate more of a 30-35dba. Definitly NOT unhearable.

Silent should be below 25, with unhearable below 20.
This is in EFFECTIVE db and not spec db.

what's the noise level at 5volt, a few metres away from it?

I always put foam inbetween case & fan.

The mentioned papst fan NGML is thus almost inaudible. :grin:

almost... at what voltage?

they're 11€ at funcomp, I think I'll order some there

mod: papst NGL
· Leistung: 33,0 m³/h (ca. 19,5 CFM)
· Geräusch: 12 dB(A)

even more quiet!

ARCTIC COOLING Fan TC-1; 6€ a piece

Fan Dimensions: 80 (l) x 80 (w) x 25 (h) mm
Fan Speed: 1400 RPM - 3000 RPM
Airflow: 14.7 - 31.0 CFM (je nach Drehzahl)
Noise Level: 10 - 32 dB (je nach Drehzahl)

less expensive, tempcontrolled (handy when it's hot, no rheo needed) and as silent. can still be put at lower voltage and tempsensor removed!

Zalman CNPS7000A-AlCu

Over all, if your requirements include quiet operation, and you don’t plan on any extreme overclocking endeavors, you can hardly go wrong by purchasing a Zalman CNPS7000A-AlCu. Zalman combines great looks, great performance, near silent operation, and superior workmanship into a package that’s hard to pass up.

don't forget that if u have 2 fans of 20 each the total DB will be something of 22-23 db

for every fan u should ad 2-3 db

so 5 fans would make around 30 db if they all are 20 db fans off course

true, 5 10decibel fans will give something like 15decibel. it'll be fine with some noise-isolation

5 10 db fans wil give 20 db, for each fan 2-3 db needs to be added