DIY

Fan mod | Unifi Switch Enterprise 24 PoE

Jukka

• 4 min read
Fan mod | Unifi Switch Enterprise 24 PoE

This Ubiquiti USW 24 Enterprise 24 PoE switch is truly great for my needs, but the fans .. so annoying, the high pitch noise they produce at a certain speed, just keep killing whatever brain cells I have left.

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I do not recommend that you do this MOD. If you go forward anyway, please note that your warranty for the device will be void. I do not take any responsibility for any damages that this might cause to you or to your device(s).

Background

I have been monitoring the fan levels now for months and seems they float somewhere between 41% and 54%. The annoying part hits somewhere around 47% and actually goes away above 50%

So I thought, I'd replace them with two silent Noctua NF-A4x20 PWM (40x20mm) fans, I know the airflow is not the same .. not even close, but monitoring the temperatures and fan levels for some months now, I am quite sure these are enough.

Opening the case

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First, let's take a quick look out of the window, and see the warranty flying away.

Remove the rack ears to uncover all the screws that hold the top cover in place. There are 7 screws in total. (You don't need to remove the front panel screws.)

7 Screws approximately where the arrows are that needs to be removed.
Remove the rack ears from both side, to uncover the front screw
Rack ears removed, 

Slide the cover back, there are "lips" that go under and over the front part

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Notice that on the back you need to clear the power cable locking mechanism.
The front lip needs to be cleared.

Lift the cover off

Removing the fans

First detach the POE cable, that gives better access to the screws and fan cables under it.

Detach the POE cable next to the fans

Detach the two fan cables

Unscrew the 6 fan cover screws

six fan cover screws

After that, you should be able to carefully pull up the cover.

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Be careful not to touch any of the components under the cover.

Unscrew the fan screws and pull off the old fans. The cables are taped in two places so you need to remove that temporarily.

Old Fans

Fan specifications

Delta Electronics EFB0412VHD
Noctua NF-A4x20 PWM
AIRFLOW CONVERSIONS:
1 m³/h = ~0.589 CFM | 1 CFM = ~1.699 m³/h
1 m3/h = ~0.0166 m³/min | 1 m³/min = 60 m3/h

According to the specifications, the Noctua NF-A4x20 PWM is capable of 9.4 m3/h, which translates to roughly ~0.157 m³/min, or 5.5 CFNM. So on the paper, the Noctua fans do not match even close to the airflow produced by the original fans.

Installing new fans

Slide in the new Noctua fans, the fan grills facing inward towards the PSU (the fans are blowing air in that direction). Check that the cables are not stuck too badly or do not obstruct the airflow.

The old fan screws do not fit, so use the ones that came with the Noctua fans. Also the fan headers are a little bit different.

From the black Noctua header, I cut off the "middle" plastic tab. 

Reassemble

  1. Reattach the fan cover, and check that cables are not pinched from any side.
  2. Screw-in the six fan cover screws
  3. Attach the fan cables: I had to use the Noctua extension cables to get the cables reattached, the fan headers are not exactly the same, so you will need to slice off one of the plastic tabs (of the extension cable heads that attach to the board). Otherwise, it fits in place fine.
  4. Attach the POE cable!
  5. Slide the top cover back
  6. Screw the 7 top cover screws back-in
  7. Attach the rack ears

Restarting and monitoring

So far the temperatures seem to hold at 44-45 degree Celsius, and the fan level is around 45 - 50%, but noticeably silent.