in terms of Db how quiet can a fan get

[SHUJeff]

I'm looking to get a very quiet fan for my box and the quietest one i've found that looks like it has a good CFM number is an 80mm panaflow. It's 32Db. How much quieter can a fan get than that?

 

[AT]

Papst 8412NGL: 12dB

I have 3 in my case.

 

[beamrider]

I've got fans that put out 0 db. Of course, at that noise level, they also put out 0 cfm.

My nef for the day.........

Actually, I've got a 120V 120mm fan here that is the quietest thing I've ever seen. Puts out about the same airflow as my 120mm Panaflo M series, and you can't hear a thing. Only has 3 blades tho, so that might have something to do with it.

 

[PCHPlayer]

0 dBA... Turn it off

 

[Shaorinor]

<< same Panaflo but different variations get low as 23dBA @ 28CFM >>



I think the lowest one is rated at 21 dB(A) @ 24 CFM.

 

[erikiksaz]

<< Papst 8412NGL: 12dB

I have 3 in my case. >>



That's a waste. A whisper is around 20 db. At 12dB, potential airflow is lost. This case would be "underkill."

 

[KenAF]

erik,

Yes, but the noise adds up....just two of those Papst fans add up to 15dB. And it's not clear whether or not he also has a processor fan (I assume the Papst are for intake, exhaust, and power supply)...which you would need to figure in as well.

From experience, I can tell you that three 21dB Panaflo fans is nowhere near silent.

 

[erikiksaz]

Well, i s'ppose that's as close to a quiet comp as anyone may come, but with his cpu fan and hard drive factored in, i don't think those 12db fans would do the computer justice.

 

[mechBgon]

My suggestion would be to pick up some Panaflo L1A's and try them. They move enough air to be practical, but are fairly quiet, to the point where most hard drives would be the noisiest thing in the system (or possibly a motherboard-chipset fan or video-card fan).

If the L1A's are the loudest thing and you would like them even quieter, then switch 'em to 7 volts and that should take care of it. At 7 volts, I think even my Seagate Barracuda ATA IV, an extra-quiet hard drive, would be louder than the fans. And when you're trying to quiet things down, you should target the loudest thing first.

 

[fatbaby]

My aol fans produce -94 cfm and are 120 dba

 

[Becks2k]

wow 120dba eh... ya know, a jet taking off is ~120dba

 

[AT]

To clarify those wondering. My Papst setup:

- CPU fan with Alpha 8045 heat sink
- PSU fan
- video card fan

And fourth one is coming for exhaust fan. Four 12dB fans equal 18dB so it is below whisper level. Using 21dB fans for this would equal 28dB and I dont think anyone can deny the difference between 28dB and 18dB.

It is also true that HDs are the ones making noise in my case. Using hdsleep to manually shut down them the computer is barely noticeble by listening. The case is also filled with noise dampening material. I'm looking into different solutions about the HDs but haven't decided on anything yet.

 

[mechBgon]

AT, I'm curious why you bother leave the computer running, if you're taking the step of manually shutting the hard drives down. Are you using applications that don't need HDD access?

I leave my system running 24/7 because I'm running SETI@home for the AnandTech team, and it does access the HDD every minute or so. The loudest thing in my rig is the Enermax "whisper" power supply, but it's just a pleasant "whoooosh" noise, thankfully.

 

[AT]

Mainly I use hdsleep for testing purposes. I just want to know how far I am in silencing when removing hd noise. Although I do have two hds so sometimes I shut down my secondary drive (storage drive) just to decrease noise.

Basically I just want to find out how quiet I make my PC. Gives me bragging rights at LAN parties

 

[FACTION95Si]

<< Four 12dB fans equal 18dB so it is below whisper level. Using 21dB fans for this would equal 28dB and I dont think anyone can deny the difference between 28dB and 18dB.

>>



How do you figure out the sound level of your fans like that?

 

[AT]

A rule of thumb: when you take two noise sources of the same noise level, the sum of their noise level is 3dB more than their individual noise level. That's pretty much the only thing I remember from my acoustic studies

So two 12dB sources equals 15dB, then two of these 15dB sources (2 fans + 2 fans) we get 18dB.

Edit: this thread has the comprehensive answer to calculating noise levels
How to calculate noise level

 

[Skawttey]

The pc power and cooling silencer fans are rated at 20 db and 27 CFM.

 

[KenAF]

> The pc power and cooling silencer fans are rated at 20 db and 27 CFM.

Yes, and these claimed specs are widely recognized as pure BS.

 

[Skawttey]

ok then