Ideas for reducing radiator+fan noise

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nsx241
Posts: 9
Joined: Tue Sep 09, 2008 12:40 am
Location: Here

Ideas for reducing radiator+fan noise

Post by nsx241 » Sat Jun 12, 2010 2:18 am

My current setup has a 360 rad mounted on top of a corsair obsidian 800D, and a three Gentle Typhoons (1450 rpm) in push config.

Even undervolting the fans to 800 rpm, I still get some annoying noise coming from the top grill. I think the cause is twofold:

The air being pushed through the radiator and through the top grill seems to generate a tone. And, with the fans mounted on the radiator, the motor noise and vibrations get amplified.

My first thought is to use some fan dampening sleeves. Looking for other suggestions.

ascl
Posts: 279
Joined: Tue May 05, 2009 1:15 am
Location: Sydney, Australia

Post by ascl » Sat Jun 12, 2010 6:54 pm

Can you please clarify exactly how you have the rads and fans? ie do you have:

case
-----
fan
-----
rad

(I hope that makes sense).

If its like the above, its possible the case grill is generating some noise, and removing the grill can help both the noise and the air flow. If the fan is on the other side of the rad than the case, I wouldn't have thought it would make much noise, but it still wouldn't hurt to remove the grill.

De-coupling the fans from the radiator/case is also a good move, I used some rubber grommets/washers to achieve that.

Using shrouds can both increase performance and reduce fan noise, so, if you have room, thats a cheap option which should help a little. Old fans with the guts cut out of them make very good shrouds.

Aside from those things, the only other thing I could suggest is running your fans slower, which will obviously impact performance. You may be able to run fans in push/pull to achieve similar performance with less noise (ie running the fans slower), although I am not convinced this is the case -- some tests indicate it should pan out that, including a heat sink test on this site.


Hope that helps. Please let us know what you try and what works out.

nsx241
Posts: 9
Joined: Tue Sep 09, 2008 12:40 am
Location: Here

Post by nsx241 » Sun Jun 13, 2010 8:54 pm

Yes, my setup is as you described.

Unfortunately, I'd rather not "remove" the grill as as it would require cutting up the top mesh of the case.

I think I'm just going with some fan dampeners for now.

The real issue I think is with cases that have radiators mounted at the top. I've gone through 3 cases with space at the top for 360 rads (coolermaster, corsair), and all three have the issue of tonal air noise (going through the rad and then through the honeycomb mesh of the case at the top).

For my next build, I think I'll go for cases with bottom/side mounted radiator space like the TJ07.

ascl
Posts: 279
Joined: Tue May 05, 2009 1:15 am
Location: Sydney, Australia

Post by ascl » Sun Jun 13, 2010 9:12 pm

If you have the room you should try shrouds, they can definitely help reduce that noise, although if its the grill rather than the rad (its probably both tho), it might not help so much.

There is a replacement to the TJ07 coming out, called a (I think) TJ11, which has the space at the bottom but with the rotated motherboard mounting (like the raven). Could be interesting... I agree the bottom is a much better spot for radiators!

nsx241
Posts: 9
Joined: Tue Sep 09, 2008 12:40 am
Location: Here

Post by nsx241 » Wed Jun 16, 2010 3:59 pm

I think I found something:

http://www.thewatercoolingshop.co.uk/Ph ... kness.html

These seem perfect as 7mm is not so thick that it would block the motherboard tray with an internal top rad, but sufficient as a semi shroud and decoupler.

Now I just need to find a place to buy them that will ship to the US.

ascl
Posts: 279
Joined: Tue May 05, 2009 1:15 am
Location: Sydney, Australia

Post by ascl » Wed Jun 16, 2010 4:08 pm

What about this?
http://www.sidewindercomputers.com/nois120mifan.html


Sidewinders have great customer service too.... so local and good :)

EDIT: Fixed link..... yes I'm an idiot and posted the wrong link...

echn111
Posts: 161
Joined: Thu Nov 02, 2006 2:15 pm
Location: UK

Post by echn111 » Sun Jun 20, 2010 2:41 am

Consider pulling the air through and see if it makes any difference. It will change the characteristics of the airflow through the radiator and fans, although whether that will replace the current tonal noise with something more or less annoying I don't know - but it will be different. At the very minimum, it puts something else between you and the noise making fans.

As for the fan dampeners, I prefer silicone to hard rubber, but anything is better than the metal of the radiator.

Case
-----
Rad
-----
Fan

p.s. might be a while before the TJ11 is available.

BlackWhizz
Posts: 266
Joined: Wed Mar 31, 2010 8:19 am
Location: OV, The Netherlands

Post by BlackWhizz » Sun Jun 20, 2010 5:11 am

What do you hear? The sound of air flowing through the grills?

You might use a shroud/fan housing on the rad like this:

Case
Shroud
Rad
Fans

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