Features:

  • Premium quiet fan, 40x40x20 mm, 12V, 4-pin PWM, max. 5000 RPM, max. 14.9 dB(A), >150,000 h MTTF
  • Award-winning A-series design with Flow Acceleration Channels and Advanced Acoustic Optimisation frame for superior quiet cooling performance
  • 40x20mm size ideal for 1U servers or replacing fans in network and storage equipment (routers, switches, NAS etc.) or other devices such as DVRs
  • 4-pin PWM version for automatic speed control via 4-pin PWM fan headers, 5000rpm maximum speed (4400rpm with supplied Low-Noise Adaptor)
  • Includes anti-vibration mounts, fan screws, extension cable and OmniJoin adaptor set for connecting the fan to proprietary fan headers
AWESOME

This little fan kicks butt! I was worried it wasn’t going to push enough air to keep my switch cool (Cisco c3750g) but so far it’s been doing a good job. I'm monitoring the temps but may add a second one just to be safe. Plus it’s so quiet I can’t even tell it’s on. For those of you attaching to a Cisco switch, I had to rearrange the pins to line up with the mobo but it was easy and total install took less than an hour.

What a difference in the NVR..

I used this fan to replace the one in my Lorex LNK71082TC4B NVR security system. I had the NVR in my Movie Room and the stock fan was annoyingly loud. I had to modify the mounting a little but I was able to get it mounted inside the NVR using the Rubber mounts they provide. What a difference this fan makes it's so much quieter than the stock Lorex fan and now it's more of just a minor background noise instead of the whining sound the Lorex made. It has been keeping the NVR adequately cooled at least in a temperature controlled room since I purchased it on 6/18. Hopefully it will last a while running 24/7. If it lasts at least a year it's still a 5 star fan for me as I would order another replacement so I can enjoy the Movie Room again.

Great quality and nice accessories. Price seems high, but the quality appears excellent. Quiet and effective.

I thought the price was high for such a tiny fan. It's being used with a bracket to blow air on my m.2 heat sink (asus z370-a mobo). It doesn't feel super impressive with airflow, but it makes a HUGE difference with my m.2 temperature. The heat sink was picking up heat off of a hot graphics card and conducting it to my m.2 SSD. Now with the fan my temps have dropped from 55c down to more like 35c. The fan comes with high quality goodies, like fan cable extender, noise reducer (not necessary for this fan), and fan cable splitter. Just in case you need any of that stuff.

Very silent fan with unique design.

With over a dozen NF-A4x10's in use here on various systems, I was shocked to find the NF-A4x20 is MUCH much quieter than the NF-A4x10, in fact it is nearly inaudible. (A4x10 is still a great product, but there is not much they can do about such a thin fan). Initially I was a bit concerned at the fan blade design of 7 instead of the usual 5 blade in this form factor, however it appears to be doing quite well. In fact, I believe this design is better suited to lower RPM fans for generating more static pressure. The intake side of the fan is also somewhat recessed, which increases it's ability to generate a stable vortex when installed in environments with moderate intake restriction (though all fans are generally designed for static pressure on the output side and not the intake side, so they often are louder in these situations.) While it probably can't replace most beefy 40x38mm server fans, it CAN if your cooling requirements are much lower than your chassis was designed for (but keep in mind that small ICs and other components often rely on very high airflow in small servers, although this can be remedied by applying small heatsinks to any hot spots). I'm currently using this NF-A4x20 in a 900w Flex-ATX server power supply which originally had an obnoxiously loud 13k RPM 40mmx38mm fan. I definitely would not recommend that others try this too (unless you REALLY know what you're doing), but I knew I could get away with it since I have never loaded the PSU past 40% and the chassis has high airflow already with additional (Noctua) fans added to quiet it down. In conclusion, these surprised me with their silent performance - Noctua has done it again. It should be noted, however, that these are probably intended for and better suited for adding extra cooling to network switches and other small devices (maybe 3d printers, but I don't have any expertise there). If the device in question had a similar fan, then it's probably fine to replace with these - otherwise I'd say your mileage may vary if intending to replace very high RPM 40mm fans. [Disclaimer: Review written by item recipient, not by above account holder name]

Super quiet!

Playing with 1U server equipment? Have it too close to your head? These will save your ears and your sanity. I installed two into my Supermicro SYS-E300-9A unit and the fans are not audible on startup or at runtime, and only become audible when you force them into a high throughput mode. In exchange, your system temperatures will creep up a bit. Leaving the system in "optimal mode" will let the system cycle the fans appropriately. All sensors respond appropriately, and at idle they spin around 2700 RPM with the CPU at 51C and the 10G chip at 59C. Notes: The screws in the kit do not fit in the metal fan bracket. The screws in the existing fans are too small for the Noctua fans. I kitbashed the rubber mounting posts to bind them to the bracket and cut off the excess, works great.

Purchased two of these to quiet down my Ubiquiti 24 ...

Purchased two of these to quiet down my Ubiquiti 24 AT-250 (a beta version of the US-24-250w). They work perfectly, the switch is now totally silent, and the two fans keep the temperature at around 40-45*C (according to the UniFi Controller, anyway). I'll be picking up two more for my USG-PRO-4, which is now the loudest thing in my installation. :)

Thank you Noctua for helping me regain my sanity. 17.5dB is exponentially better than my stock fan 45dB noise.

I purchased these fans after a bit of googling to replace the stock fans in 1U Rackmount Lenovo RS140 boxes. Each system has 3 of their stock fans, and they operate at nearly 45dB. I'm running my stuff in a homelab in my office, not in a datacenter. I swapped out the stock fans with these and BAM! The systems have become effectively silent! I will say however that the 4-pin PWM version seems to not be recognized correctly by the system, but that's a board problem not the fan itself. It's operational and near silent. Temperatures are great, the fans work great, and I'm overjoyed by how well these work! I highly recommend these!

Works great on Supermicro E200-8d. Very quiet.

I used three of these fans on Supermicro E200-8d server. The server comes with 40mm x 40mm x 28mm fan but this fan is 40mm x 40mm x 20mm. The screw that comes with this fan is too big for the server fan screw hole. But, you can use rubber mounts that come with the fan and little dabs of glue gun. The CPU can go as little as 55C with three fans spinning at 5000RPM. Extremely quiet and it is perfect for my office. At normal mode 3000RPM, CPU is at 65C, which is within normal range. I highly recommend it.

Noctua NF-A4x20 returned my sanity, installed on NVR.

I had a LaView NVR, which fan sounded like a jet and was driving me insane. I have used Noctua 120mm fans in computers, and I aware of the quality and capabilities of their fans so I decided to give this 20mm fan a try. The hard drives on the NVR are louder than this Noctua quiet fan. They could move a ton of air while been silent. I had to cut the two-wire mini connector from the fan on the NVR PSU and soldered to the Noctua fan. Also, the Noctua fan takes up to 20 seconds to start spinning after powering on NVR.

the best

For just a few dollars more you move from junk to the best. This is the best in my opinion... excellent in every way. I am cooling electronics placed in a small electronics box used for my LED taillight upgrade. This little fan keeps everything cool. I tested without the fan and I got component temperatures that were nearly too hot to handle. BUT, with this fan, the temps are maintained just a bit above ambient. literally no draw on the car electrical system.....literally!!! ...its just 0.05amps.......it is a great fan

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