Air turbulence noise?

[alm4rr]

Hi,
I have fans that run at near silence outside the case. The case is a Cooler Master CM 690. Fans are Prolimatech Blue Vortex 14 & cooler master A12025-12cb-33bn-f1

However, when I mount the case fans inside the side panel on my Cooler Master case *to blow air in*, the air noise is like a small airplane. Holding or bending the fan or metal panel doesn't seem to make a difference, so I don't think it's vibration. If I mount it inside and blow out OR mount it outside and blow in, it's still quiet.

Any suggestions? Is this a common problem?

I was thinking of just finding longer fan screws and offset the fan by .33" off the inside of the panel, which makes it quiet. I assume it is the air being pulled by the grill-like holes on the side panel.

TIA

 

[ethebubbeth]

If there is a grill of any sort over where the fan mounts, you can remove it with a dremel or a nibbler to remove any obscructions to the fan airflow.

Then, you can either use a rubber fan gasket to isolate vibration from the fan to where it's mounted. You could also over drill the hole with a 1/4" drill bit and install a rubber washer.

 

[masterkaj]

I was having some turbulent noise issues yesterday after moving my build to a Define R5 case. My my CPU cooler was pushing too much air into the rear fan, which caused an unpleasant sound to say the least. I had to lower the RPM's on my CPU cooler to fix the issue.