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Noctua NF-A8 pwm. Is it too noisy?

Posted: Thu Jun 01, 2017 2:20 pm
by gingel
Hello,

I recently purchased the Noctua NF-A8 pwm 80mm fan,
and when i installed it, i noticed it's making a noise (buzzing noise?) when it's at high rpm speed.
I attached it to the case door using the screws, because i had some problem to use the rubber mounts, as i have a filter that is installed from the outside.
When at full speed, the buzzing/humming noise was actually louder when the fan was attached to the case door.

When i tested the fan at lower speeds, like around 1000-1200 rpm, it's much quieter.
When at 1000 rpm and lower, you can barely hear it (only if your ear is very close to the fan you might hear the air).

I made a video of the fan at full speed, when it's not attached to the computer case.
Is this a normal noise of Noctua 80mm fan at full speed?

https://www.youtube.com/watch?v=e3Qk8NDkXHo

(Sorry, i don't know how to embed the video here).

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Thu Jun 01, 2017 3:27 pm
by CA_Steve
Welcome to SPCR.

I don't know what a Noctua NF A8 PWM is supposed to sound like at 2200 rpm (full speed without the LNA adapter), I just know all fans are loud at 2200 rpm. Hopefully, you have no reason to run it anywhere near this speed - and 1000rpm and less will work for your thermal load.

The fan can be louder when screwed to the door because there is nothing to isolate the fan vibration from the door. The door in turn may resonate with this transmitted vibration.

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Thu Jun 01, 2017 8:36 pm
by quest_for_silence
gingel wrote:Is this a normal noise of Noctua 80mm fan at full speed?

TTBOMK, yes; and, as already said, virtually no fan at 2200rpm will be quieter.

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Fri Jun 02, 2017 3:08 am
by gingel
Hi,

Thank you for the quick answers.
I just wanted to make sure with the experts here, that this is normal, as i don't have much experience in these fans.

I'm going to connect the fan to the CPU pwm header (using the Y splitter that comes with the fan), so hopefully
it will run at around 1000 rpm or lower, so it will be almost silent.

I also have another Noctua fan, 120mm, and this one is actually dead silent even at full speed (1200 RPM).
I guess those little fans (80mm and lower) will make some noise when they are running twice the speed of the 120mm fan.

Thank you.

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Fri Jun 02, 2017 7:35 am
by gingel
Ok, so i'm bit confused now. :?
I also received an answer from Noctua support, and they are saying that from what they saw in the video,
they can tell that the fan is indeed defective.
I did tell them that it's much quieter at 1000-1200 rpm, and that at 1000 rpm and lower, you can barely hear it.
They are offering to replace it.

So maybe it is too noisy at high rpm? which can maybe cause it to not work properly after a while even if running at lower rpm's ?
:?

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Fri Jun 02, 2017 7:47 am
by Notwist
Noctua support is amazing so they may take the approach of "who cares just swap it". I agree with Steve: I would NEVER expect a fan to be quiet at anything over 1300RPM, much less 2200 Rpm, and especially an 80mm sized fan, as smaller fans tend to be whinier. Perhaps a better alternative is ditch the door fan entirely? Traditionally speaking good airflow doesn't require a door fan, just good pressure and flow from front to back.

I would expect the replacement from Noctua to sound similar, but doesn't hurt to try.

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Fri Jun 02, 2017 9:27 am
by Abula
As others have said, cant expect a fan to be quiet just by brand, for me a fan will be quiet around

80mm = 1300 rpms or lower
120mm = 1000 rpms or lower
140mm = 800 rpms or lower
180mm = 600 rpms or lower
200mm = 500 rpms or lower

But the above also depends on other things, from blade design, motor design, operation type, bearing, even location and what its cooling (heatsinks/radiators/mesh/grills/filters usually create turbulance as the air passes through, thus creating noise), etc, but i don't expect any fan above those rpms to be quiet regardless of the brand.

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Fri Jun 02, 2017 3:44 pm
by gingel
I'll update when the replacement fan will arrive.

Thank you all for the help.

Re: Noctua NF-A8 pwm. Is it too noisy?

Posted: Wed Jun 28, 2017 4:06 am
by gingel
Hi,

So the replacement fan that Noctua sent to me arrived.
For my opinion it is much quieter at high/full RPM.
You really need to put your ear on the fan to hear a slight noise.
It's also doesn't transfers vibrations to the case door like the first fan did.

For my opinion the first fan either had a bad bearing or maybe the blades were out of balance.

Thank you all for the help, and thank you Noctua for sending a replacment.