Noctua NF-A4x20 FLX, Premium Quiet Fan, 3-Pin (40x20mm, Brown)
The NF-A4x20 is a highly optimised quiet 40×20 mm fan in premium quality, which uses future-oriented construction measures such as Flow Acceleration Channels as well as Noctua’s AAO frame system. The FLX version offers three speed settings via the included low-noise adapter (5000/4400/3700rpm) and thus ensures full flexibility between maximum flow rate and almost silent operation. Its excellent smoothness, the SSO2 reference class bearing and Noctua’s proven premium quality make the NF-A4x20 a sophisticated choice for the highest demands.
40 x 20 mm format.
Compared to Noctua’s award-winning NF-A4x10, the NF-A4x20 has double the depth. This allows for higher printing performance and makes the NF-A4x20 the perfect choice for higher air resistance applications.
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Flow acceleration channels.The impeller of the NF-A4x20 is equipped with so-called flow acceleration channel. By accelerating airflow in critical external regions of the fan blades, suction side vortex detachment, resulting in higher efficiency and lower turbulence-related noise emission. | SSO2 bearing system.The NF-A4x20 is equipped with the further optimised second generation of Noctua’s proven SSO bearing system. With SSO2, the rear magnet sits closer to the fan axis, resulting in even better stabilisation, resulting in further improved precision and durability. | Integrated anti-vibration pads.Made from extra-soft silicone, the anti-vibration pads reduce the transmission of minimal vibrations and are also compatible with all standard screws as well as standard mounting systems or fan clips used in CPU coolers. | Box contents:Low-noise adapter (L.N.A. Ultra-low noise adapter (U.L.N.A. OmniJoin 4-pin Y-cable, 30 cm cable extension, adapter set, NA-AV3, anti-vibration attachments, fan screws. |
AAO frame system.
Noctua’s AAO (Advanced Acoustic Optimisation) frames have integrated vibration buffer as well as a stepped inlet area and an internal micro-structure (inner surface microstructures) that allow even better performance/noise efficiency.
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| Connection & Pin Configuration | 4-pin PWM. | 3-pin. | 4-pin PWM. | 3-pin. |
| Operating voltage: | 12 V. | 12 V. | 5 V. | 5 V. |
| RPM. | Max. 5000 / min: 1000. | 5000. | Max. 5000 / min: 1000. | 5000. |
| RPM with L.N.A. | 4400. | 4400. | – | – |
| RPM with U.L.N.A. | – | 3700. | – | – |
| Noise: | 14.9 dB(A). | 14.9 dB(A). | 14.9 dB(A). | 14.9 dB(A). |
| Noise with L.N.A. | 12.2 dB(A). | 12.2 dB(A). | – | – |
| Noise with U.L.N.A. | – | 8.5 dB(A). | – | – |
| Format: | 40 x 40 x 20 mm. | 40 x 40 x 20 mm. | 40 x 40 x 20 mm. | 40 x 40 x 20 mm. |
| Weight: | 180 g |
| Dimensions: | 4 x 2 x 4 cm; 180 Grams |
| Brand: | Noctua |
| Model: | NF-A4x20 FLX |
| Colour: | Beige / brown |
| Batteries Included: | No |
| Manufacture: | NOCTUA |
| Colour: | Beige / brown |
very quiet.
easy to work out what connectionsto use even though a good selection of connectors are supplied with fan. only gave 4 stars for noise even though it is very quiet no fan can be totally silent. much better than fan originally fitted.
Ubiquiti USG Pro 4 fan noise
These fans are brilliant so easy to install and now my USG is silent 5 STARS
Can’t believe how quite it is !!!
Good little fan , my 3d printers e3d hermera stock fan was loud whilst cooling so was looking for a replacement and took gamble on this , wow what a difference , extremely quite no noise at all i can’t here it working . Also cools the heartbreak really well running hotend around 260c .
Is pricey but it’s premium quality !!
Worth the price - superior to most if not all alternatives
Inaudible when inside the case along with other fans. Extremely well built. Perfect fit for an LSI SAS card if you are using it in a tower with no airflow over the sas heatsink (you can mount it with 2x3mm bolts).
Very happy with this purchace and will buy again if i need any more of this size.
Pricey but good
These were used specifically for my ender 3 V2, they work like a charm and arm super quiet but they are quiet for a reason, the don’t push that much air but I know they will be reliable and that’s a plus in my book! The only thing I find silly is the price, I feel they shouldn’t be as much as they are, it’s more of a brand name your payih for there which is why I only give them 4 stars
Very pleased with this
I bought this to replace the noisy and failing hotend fan on my Creality Ender 3 Max 3D printer. The original started making noise after only a couple of months, I tweaked it a bit and it went away, but came back a month or so later, so after enduring the noise and rattling for a few more months I decided to replace it.
Finding a decent, quiet and reliable fan is hard; I originally thought about just getting the Creality replacemment, but thought that would probably just last as long as the original. All the other 40x40x10 fans other than the Noctua’s seemed to have a lot of bad reviews, so given that Noctuas larger PC fans have a good reputation, I decided to go for this one.
I had read that people were concerned that being a low noise fan it wouldn’t push enough air, but I haven’t found this to be the case, and feeling the air flow it was at least putting out more air than my noisy fan that was still managing to keep things cool. After fitting this fan I have tested the temperature of the heatsink on the hot end and it hovers around 30 degrees C which is more than acceptable. I have made several long prints and there are no signs of cooling problems, and I hope that the extra cost yields good reliability that will pay off in the long run.
Of course, this is a 12v fan and the old one was a 24v fan, but the heatsink fan on the E3Max is on continuously so I was able to use a small 24v-12v buck converter to reduce the voltage to 12v so as not to overload the fan.
Good stuff but atrociously expensive
Atrociously expensive for a tiny 5v fan. The luxurious gift box easily costs 1/3 of the price we end up paying, something that goes straight to the bin after the fan is installed.
Be wary that in order to achieve the lowest noise levels you have to use the included rubber screws/pins as any touch of the fan with a metal surface using the metal screws easily doubles or triples the emitted noise levels!
Quick and easy for a quiet life
Bought this fan kit as a replacement for my Reolink NVR which records images 24/7 from the CCTV cameras. The NVR fan was noisy within the home and I couldn’t relocate it anywhere else easily. So replacement fan kit was the answer. Before ordering I checked the fan size was correct with current fan. When fan kit arrived, power off my NVR, unplug all leads, open case and then remove the old fan (two machine screws and nuts), and fit new fan as direct replacement so same screws into same holes. For the electrical connections the fan is three contacts in the block, and the connector on the circuit board was two, so used the 3 to 2 adapter included. I also used the quiet fan adapter too, which i assume reduces voltage to reduce fan speed. Then tested to check working electrically and refit all camera cables etc. Probably the only ‘5 minute job’ I have done in a while, didn’t bother reading instructions. For me this was a straight replacement item, so really easy. Immediate difference in reduced fan noise.
Quite, does the job, useful accessories
I recently acquired a Netgear switch that had seen some use, and the fans that were in the unit when I got it were loud and screamy. The person who I’d bought it from suggested these fans as a replacement, and I am not disappointed with my purchase.
It’s been a few months since I installed the fans, and they’re still running as quiet as day one.
I really like the quick-join accessories that were included. I forget the exact name, but you simple place two wires you would like to join and then snap it closed with pliers – it has a secure connection and seals itself – very convenient.
Works really good with my 3D printer cools down the extrude
I replaced the fan on my 3d printer with this. It works fine… bit quiter than the OEM on the printer.
I liked the dampping screws, well… they aren’t really screws, but, they seem to work so fine! much better than screws, easier to install, damp the vibrations! really cool. I liked it allot!
Noctua is so cool giving all of these things in the box, just a great company.
Quality fa
Used it to cool my battery while charging, very quiet, very low power usage, easily cools my battery area down to 13c. Removing the fan it warms up to 22c, removing the heat pump it goes up to 47.
Quiet and easy to install
Well pleased with the product, its ease of installation and value for money. This has totally transformed my moaning PC.
I wonder whether you can get one for the ….. (better not go there).
Great for my reolink nvr model RLN16-410 so quite
I got this because the fan in my Reolink NVR RLN16-410 is very noisy and have the NVR is a bedroom as it was easier for me to wire cameras too. The new fan is remarkable quite can hardly hear it, the old fan which is only been in use 3 weeks was too noisy it was louder than my Dyson fan on number 4 setting out of 10. I have to sleep with a fan on, but not when reading in bed. It was easy to install, came with all the extra cables and screws. I just removed the old fan had to remove some glue as it was stuck on the motherboard of the plug. Enlarged the two old holes in the NVR case for old fan only a tiny amount, and use the screws supplied. Easy fix. The fan seemed good quality too.
Excelle
Purchased Noctua fans before as they just work.
Exactly what I needed for replacement of an NVR fan.
Awesome Noctua quality!
Fantastic little fans. These come with a variety of little extras, such as the low noise adapter and anti-vibration attachment stems. Have now attached a total of 6 (with buck converters to run them at 12V) on two of my Ender 3 3D printers, they’re incredibly versatile and feel premium – worlds beyond the standard fans that typically ship with a 3D printer.
Top quality, but probably not the best for the budge
Price is the main con of this product, but in terms of quality, cooling power and noise level still the best option.