NF-F12 hummmm and vibration..

[Copyright]

Well after going through so many fans I finally ended up getting a fan I thought would be it.. The Noctua NF-F12 LInus edition (will do white corners later). For now I removed the soft corners and mounted to hte radiator. Anything over 300rpm I get a humm and a surprising vibration in the top of the case. I have never mounted an NF-F12 horizontal so maybe that is the nature of the fan. I know putting the soft corners back on may help some but only if I can isolate the mounting screw from the frame. The cheap Fractal case fans I was using had no vibration at all but the did have an annoying tick sound. Any ideas? How do you decouple the fan from the rad to eliminate vibration? If I could use the rubber pieces instead of screws that would probably resolve the whole issue... and it's how I do all the fans in my system other than those two.

[Abula]

I had issues with Noctua NF-A14 PWM and horizontal placement, but was only when the fan was facing down (pushing air down), very similar to what you describe a very noticible hum and vibration appeared at almost any rpms, that got worst at higher, but the fan doesnt have this behavior facing up (pushing air up). Nothing i did fixed it, so i didn't use them facing down, i think its something related to the bearing of the fan.

[doyll]

Have you tried them with the soft corners on?

My experience is fans usually run smoother and quieter when spaced away from restrictions 10-15mm.

There are several possible reasons, but the biggest is keeping smooth airflow. A spinning fan blade creates a "pulse" of airflow from each blade. Kinda like looking through a slow spinning fan at a light, or listening to a speaker through a slow moving fan. Have a space between fan and cooler or radiator allows this airflow "pulse" to equalize it's flow lowering the fan's vibration and noise.

But like everything involving airflow, it is often very hard to isolate the source of problems. Add the ever increasing number of "airflow gremlins" (their only purpose in life is to make airflow as complicated and miserable as they can) and it can drive use to drink and other vices.

[Copyright]

So the 140mm version I have blowing out the back is silent.. no issues.. Honestly I think the Redux fans have a better sound. Being an an all tile office I can hear EVERYTHING. So the NF-F12 are blowing upward exhausting air out. I may flip them to see if there is a difference. I will try soft corners in january when the whtie corners come out. Another thought.. since they are under my radiator I will probably big a screw that is 1/4" longer which I will need anwyasy to make up for the soft corner thickness.. I will use a washer to ensure hte head of the screw rests on the soft corner and maybe suspend them a little bit. I really expected better out of this fan but I am learning horizontal mounting seems to be hard on all fans I have tired up there. One way or another I have to make these work.. right now at 300rpm they are dead silent and no vibration.. soon as they hit 400 I hear a hum. I think If I can decouple the fans somewhat it will help.

[baii]

Is it pushing our pulling on the rad?