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Quiet fans with high static pressure for 2U servers

Arseni Mourzenko
Founder and lead developer, specializing in developer productivity and code quality
134
articles
January 27, 2019
Tags hardware 5

Recently, I purchased a bunch of 2U chassis for a SAN. Since the servers are in my home office, they should be quiet. This wasn't a problem when I used 4U servers, but with 2U size factor, and especially in the context where the front panel is all covered by hard disks, cooling options become quite limited.

Discussions on forums about quiet server fans abound. People buy server chassis, expecting, as I do, to keep them at home, but when they discover how noisy those machines are, they understand that they can't even keep them in an attic. But while there are lots of questions, I haven't found any concrete recommendation. I even asked for one myself, but had no valid answer yet. On forums, people do recommend other fans, but rated above 50 dBA, or even above 60 dBA, they are not an option for me.

So I spent hours searching for alternatives and converting american units to the metric system. The results were inconclusive, but I think they may be useful for other people as well, so you can find them below. I started by searching for the PWM fans for the server, but then continued with 3-pin fans for an UPS as well.

4-pin PWM fans for servers

I used the following ranges when assigning stars.

Static pressure (higher is better):

<3 mm/H₂O 3 and 10 mm/H₂O 10 and 20 mm/H₂O >20 mm/H₂O
☆☆☆ ★☆☆ ★★☆ ★★★

Noise (lower is better):

>40 dBA 30 and 40 dBA 20 and 30 dBA <20 dBA
☆☆☆ ★☆☆ ★★☆ ★★★

Here's the comparison of the fans:

Model Size (mm) Current (A) Speed (RPM) Air flow (m³/h) Static pressure (mm/H₂O) Noise (dBA)
FAN-0126L4 (original) 80×80×38 0.60 7,000 123.2 27.69 ★★★ 53.5 ☆☆☆
FAN-0094L4 80×80×38 1.10 6,300 153.4 21.59 ★★★ 51.0 ☆☆☆
Noctua NF-A8 PWM 80×80×25 0.08 2,200 55.5 2.37 ☆☆☆ 17.7 ★★★
Silent Wings 2 80mm BL028 80×80×25 0.15 2,000 44.2 2.25 ☆☆☆ 15.5 ★★★
Pure Wings 2 80mm BL037 80×80×25 0.08 1,900 44.4 1.85 ☆☆☆ 19.2 ★★★
Cooler Master Blade Master 80 80×80×25 0.26 3,000 69.3 4.23 ★☆☆ 28.0 ★★☆
Coolink SWiF2-80 P 80×80×25 0.09 2,000 52.3 Unknown¹ 19.0 ★★★
Evercool EC8025H12BP 80×80×25 0.20 3,000 62.0 3.56 ★☆☆ 33.0 ★☆☆

Noctua and be quiet! fans, have a nice air flow while being nearly silent, but unfortunately, a poor static pressure makes them unsuitable for 2U servers. Cooler Master's fan seems to be the only interesting alternative, but would work only for servers which stay idle most of the time. I would probably try ones for SAN machines, if I can't find any alternative.

3-pin fans for UPS devices

In the same way, I wanted to find replacement fans for an UPS device (same 2U format). Its original fans (two ME80251VX-000U-A99) are not particularly terrible, but still produce more noise than my 4U servers and the 1U network devices.

For static pressure, I'm using a different star rules here, since the UPS device needs much less powerful fans.

Static pressure (higher is better):

<3 mm/H₂O 3 and 5 mm/H₂O 5 and 10 mm/H₂O >10 mm/H₂O
☆☆☆ ★☆☆ ★★☆ ★★★

Noise (lower is better):

>40 dBA 30 and 40 dBA 20 and 30 dBA <20 dBA
☆☆☆ ★☆☆ ★★☆ ★★★

Here's the comparison of the fans:

Model Size (mm) Current (A) Speed (RPM) Air flow (m³/h) Static pressure (mm/H₂O) Noise (dBA)
ME80251VX-000U-A99 (original) 80×80×25 0.16 3,600 76.5 5.84 ★★☆ 37.0 ★☆☆
Evercool EC8038H12B 80×80×38 0.60 5,000 114.0 14.22 ★★★ 43.8 ☆☆☆
Evercool EC8025H12B 80×80×25 0.16 3,000 62.0 3.55 ★☆☆ 33.0 ★☆☆
Evercool EC8025HH12B 80×80×25 0.28 3,500 72.8 4.57 ★☆☆ 35.0 ★☆☆
Silent Wings 2 80mm BL060 80×80×25 0.08 2,000 44.2 2.25 ☆☆☆ 14.5 ★★★
Pure Wings 2 80mm BL044 80×80×25 0.14 1,900 44.4 1.85 ☆☆☆ 18.2 ★★★
Coolink SWiF2-801 80×80×25 0.07 1,500 39.7 Unknown¹ 11.0 ★★★
Coolink SWiF2-80L 80×80×20 0.16 2,600 65.0 Unknown¹ 26.0 ★★☆

Evercool fans have comparable static pressure, but they are nearly as noisy as the original one. This leaves me with be quiet! fans, and more precisely with Silent Wings 2. I ordered two of them, and will keep an eye on the temperature of the UPS.

Connectors unknown

For one fan, I couldn't find whether it it a PWM or a 3-pin fan.

Model Size (mm) Current (A) Speed (RPM) Air flow (m³/h) Static pressure (mm/H₂O) Noise (dBA)
Silverstone FM81 80×80×32 0.50 5,500 123.87 13.78 ★★★ 48.0 ☆☆☆

Seems quite promising regarding its high static pressure, although it's also noisier than Evercool EC8038H12B.

1 Data not provided by the manufacturer. Contacted Coolink to ask for static pressure data.