H440 Exhaust Fan Hums (Turbulence)

[Manolito Mystiq]

Dear all,

 

I just replaced the H440 stock fans with Noctua ones. The case is now about inaudible . . . until a bit later when I heard a soft humming. I believe it is because of the honeycomb grill of the exhaust fan. When I disable that fan, that humming sound is gone. I PWM lowered the fan as low as I could—even with the Noctua noise adapter included—but the hum can only be removed if the exhaust fan is turned off.

 

I could dremel the grill, which I read is actually a very efficient option, even increasing airflow, but I am not so good with such DIY-ing (and it is maybe overkill for the situation). I might try to use a filter (panty hose some mentioned?). Any other recommendations?

 

Right now, the exhaust fan is just off. Temperatures are around 30 degrees Celcius (using RealTemp 3.70), but I understand an exhaust fan is necessary. Or is my mostly passive, non-OC’d system okay without an exhaust fan?

 

NF-S12A PWM front (bottom)

NF-S12A PWM on CPU EVO 212 heatsink (replacing the stock one)

NF-A14 PWM exhaust

 

All HD holder thingies on the front of the case are removed.

 

Case: NZXT H440 Black/Blue

PSU: Seasonic Platinum 520 Fanless

CPU: Xeon E3-1231 v3

GPU: GTX 750 Zone Edition (Passive)

MOBO: Asus H97-Pro

Storage: OCZ-ARC 100 and OCZ-VERTEX 4 

 

Thank you.

 

[Majestic]

How low did you set that NF-A14 in rpm?

[Manolito Mystiq]

It is now set at 700 RPM. Now, I put it on the top of the case. No more noise. CPU temps are around 35 degrees Celsius idle and 50 degrees full load. I might put a second NF-A14 on top, just in case (no pun intended).