120 mm case fan (side panel) noise

[Engr62]

I recently mounted an ARCTIC F12 PWM 120mm fan on my case's (Rosewill Redbone) side panel. It is oriented so that it pulls air into the case since my AIO radiator is mounted on the back of the case with the fan on the radiator blowing out. This helped to lower my CPU (i7-4770K) temperatures from 60C full load to 52C full load.

However, the fan makes a lot of noise since it's pulling air in through the perforated side panel. I intend to get a dust filter to put over this so I don't pull dust into the system. Will the dust filter also lower the noise of the fan or will it make it worse?

 

[Crono]

Are you sure it's not vibration noise?

What RPM is it running at?
I don't think dust filters change the noise by much, although I guess it could depending on how restrictive it is. I have the same fans and some Silverstone "ultra fine" filters going into a build soon, so I hope they don't make much noise if I turn down the RPM, at least.

 

[Engr62]

I tried turning the fan down to "quiet mode" in my BIOS (ASRock Z87 Pro 3), and that helps some but not a lot. My idle temperatures went up a little from 23/24C to 26/27C (room temperature is 20C). I'll make a Handbrake run tonight to fully load the CPU for a substantial period to see if the loaded temperature increases much. I ordered some dust screens today, so I'll update once I have those installed. I'd hate to end up back at the same temperatures after spending money on fans (I have a second fan that I haven't installed since I'll need to get a splitter to power another PWM fan) and dust filters.

The case I'm using doesn't have the room to mount my AIO cooler's radiator in the front of the case where I can pull fresh air from outside the case over it. It's only got room for the one 120mm intake fan in the front due to the HDD and DVD drive bays. I had to mount it in the back of the case, so its fan is pulling warmer air from within the case over the radiator.

The Rosewill Redbone case has been a good case, but I know it's time to get a new case. I'd really like to get the NZXT S340 Elite, but I can't really go without a Blu-ray drive. I know I could go the external drive route, but I really hate to add to the clutter.

 

[Engr62]

In "quiet mode," the fan noise was not as prevalent--even during full load, but it's still there to a certain extent. From what I've read elsewhere, the noise is probably caused by the air moving over the perforated side panel of the case. So, maybe the dust filters will be the trick when they arrive since--if they don't reduce the air flow so much that it negates the benefit of the fan.

As I stated in my previous post, the CPU idle temperatures went up a little (from 23/24C to 26/27C) by using the "quiet mode" setting. And my full load test had the same maximum temperature (52C) as it did when I ran the fan in "standard mode."

 

[bfun_x1]

The noise might go away if you could separate the fan from the case by a few mm. I can't think of anyway to do that that isn't cheaper than buying another fan. Some fans have bad harmonics when put against grills. Does the noise change if you flip the fan around and have it blow out?

 

[Engr62]

bfun_x1,

Thanks for the response (and in my thread on the two cases I'm considering). I put the dust screen on the case, and that seemed to help the noise a little but at the expense of raising the load temperatures by 3C. I'll try to find some rubber washers to use as a stand-off from the grill. And, I'll try flipping the fan to blow air out to see if that helps the sound (although that will probably pull dust into the case in other unfiltered openings).

 

[bfun_x1]

I was just curious if flipping the fan would make any difference. If it does then it's is most likely some kind of bad harmonics caused between the blades and grill. The fan blows air onto the grill and the grill bounces it back at the fan. I'd say try another fan with different blades and see if it makes any difference. Pull the one from your AIO if you have to. If the noise goes away you know a different fan will help.