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The NF-A20 is a highly optimised, premium quality quiet 200mm fan. Featuring an AAO (Advanced Acoustic Optimisation) standard frame as well as sophisticated aerodynamic design measures such as Flow Acceleration Channels, the NF-A20 brings the renowned quiet cooling performance of Noctua’s award-winning A-series to the increasingly popular 20cm form factor. The PWM version uses Noctua’s custom designed NE-FD1 IC for fully automatic speed control via 4-pin fan headers, which allows it to strike a perfect balance between quietness and ventilation performance in each given situation. Its superb running smoothness, reference-class SSO2 bearing and Noctua’s trusted premium quality make the NF-A20 an elite choice for the highest demands.
Please refer to our case compatibility list for detailed compatibility information.

Details
Award-winning Noctua quality in 20cm size

Award-winning Noctua quality in 20cm size

While more and more PC cases support 20cm intake, side-panel or exhaust fans, many of the bundled stock units and available aftermarket options are of questionable quality. By contrast, the NF-A20 is a true premium grade solution worthy of Noctua’s award-winning A-series.
154mm, 110x180mm and 170mm hole spacing

154mm, 110x180mm and 170mm hole spacing

In order to ensure broad compatibility with today’s PC cases, the NF-A20 features three sets of mounting holes: While the 154x154mm and 110x180mm spacing allow it to replace most 200mm fans, the 170x170mm spacing is used by many 230 and 250mm fans, which can thus also be replaced by the NF-A20.*
Flow Acceleration Channels

Flow Acceleration Channels

The NF-A20 impeller features suction side Flow Acceleration Channels. By speeding up the airflow at the crucial outer blade regions, this measure reduces suction side flow separation and thus leads to better efficiency and lower vortex noise.
AAO frame

AAO frame

Noctua's AAO (Advanced Acoustic Optimisation) frames feature integrated anti-vibration pads as well as Noctua's proprietary Stepped Inlet Design and Inner Surface Microstructures, both of which further refine the fan's performance/noise efficiency.
Stepped Inlet Design

Stepped Inlet Design

Noctua's Stepped Inlet Design adds turbulence to the influx in order to facilitate the transition from laminar flow to turbulent flow, which reduces tonal intake noise, improves flow attachment and increases suction capacity, especially in space-restricted environments.
Inner Surface Microstructures

Inner Surface Microstructures

With the tips of the fan blades ploughing through the boundary layer created by the Inner Surface Microstructures, flow separation from the suction side of the blades is significantly suppressed, which results in reduced blade passing noise and improved airflow and pressure efficiency.
Integrated anti-vibration pads

Integrated anti-vibration pads

Integrated anti-vibration pads made from extra-soft silicone minimise the transmission of minute vibrations while maintaining full compatibility with all standard screws and other mounting systems.
Custom-designed PWM IC with SCD

Custom-designed PWM IC with SCD

Supporting fully automatic PWM speed control, the fan uses Noctua's custom-designed NE-FD1 PWM IC that integrates Smooth Commutation Drive (SCD) technology. By providing smoother torque impulses, SCD suppresses PWM switching noises and thus makes the fan quieter at low speeds.
Low-Noise Adaptor

Low-Noise Adaptor

The NF-A20 PWM is supplied with a (L.N.A.) that reduces the maximum fan speed from 800 to 550rpm. The L.N.A. can be used either to run the fan at a fixed speed of 550rpm or to cap the maximum speed when using automatic PWM control.
Extensive cabling options

Extensive cabling options

The fan's short 20cm primary cable minimises cable clutter in typical applications while the supplied 30cm extension provides extended reach when necessary. Both cables are fully sleeved and a 4-pin y-cable allows the connection of a second fan to the same PWM fan header for automatic control.
SSO2 bearing

SSO2 bearing

The NF-A20 features the further optimised second generation of Noctua's renowned, time-tested SSO bearing. With SSO2, the rear magnet is placed closer to the axis to provide even better stabilisation, precision and durability.
6-year manufacturer’s warranty

6-year manufacturer’s warranty

Noctua fans are renowned for their impeccable quality and outstanding longevity. Like all Noctua fans, the NF-A20 features an MTTF of more than 150.000 hours rating and comes with a full 6-year manufacturer’s warranty.
*As there is no fixed industry standard for the size or hole spacing of 200mm, 220mm, 230mm or 250mm fans, please see our case compatibility list and carefully check both the hole setup of your chassis and the available space (the NF-A20 is 30mm thick whereas some other 200mm fans are only 20mm!) in order to verify that the NF-A20 is compatible with your chassis. In case of doubt, please contact your chassis manufacturer.
NF-A20 PWM
General
Notes and warnings
Please refer to our case compatibility list for detailed compatibility information.

FAN Specification
Size
200x200x30 mm
Mounting hole spacing
154x154, 110x180, 170x170 mm
Connector
4-pin PWM
Bearing
Blade Geometry
Rotational Speed (+/- 10%)
800 RPM
Rotational Speed with L.N.A. (+/- 10%)
550 RPM
Min. Rotational Speed (PWM, +/-20%)
350 RPM
Acoustical Noise
18,1 dB(A)
Acoustical Noise with L.N.A.
10,7 dB(A)
Static Pressure
1,08 mm H₂O
Static Pressure with L.N.A.
0,51 mm H₂O
Max. Input Power
0,96 W
Max. Input Current
0,08 A
Voltage
12 V
MTTF
> 150.000 h
Scope of delivery
  • Low-Noise Adaptor (L.N.A.)
  • 4-pin y-cable
  • 30cm extension cable
  • NA-AV3 anti-vibration mounts
  • NA-AV4 anti-vibration mounts
  • Fan screws
Warranty
6 years
NF-A20 PWM
A-Series fans
Video Reviews
The following video reviews have not been created by Noctua. Responsibility for the information and views expressed in the videos lies entirely with the authors.
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04.12.2017 // GamersNexus.net
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NF-A20 PWM Review

At roughly 34.5dBA, +/- 0.5dBA, the Noctua fan pushes 424LPM, where Cooler Master does 334LPM. At 33dBA, we’re running 386LPM on Noctua, and 302LPM on Cooler Master. 31dBA has us at 316LPM and 275LPM, respectively. [...] The Noctua fan remains generally ahead, but has a wider acoustic performance lead at the low-end. If you recall, Cooler Master had a bit of an LPM lead at the same low-end, which would mesh with these noise findings.
Test verdict: "[T]he Noctua fan pushes a higher LPM than Cooler Master at the higher RPMs, and manages to do so while retaining competitive noise levels. The Noctua NF-A20 could be run at 90% and achieve similar airflow and acoustic performance to the Cooler Master fan at 100%, which is potentially beneficial to some noise-sensitive users;" (Stephen Burke, GamersNexus.net)
30.11.2017 // islaBit.com
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NF-A20 PWM Review

Hemos podido probar de forma exhaustiva a los ventiladores Noctua. Estos no nos han defraudado de ninguna manera y han cumplido con cada una de nuestras expectativas en todo momento. Los hemos puesto a prueba en condiciones bastantes exigentes y han dado la talla. No han flaquedo nunca.
Test verdict: "Así pues, si estás en busca de un ventilador que cumpla con tus exigencias podemos recomendarte ampliamente a ventiladores Noctua. Realmente cumplen con el trabajo y siempre rinden al máximo." (Juan José, islaBit.com)
28.11.2017 // TodoHTPC.com
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NF-A20 PWM Review

Noctua sigue siendo el mejor fabricante del mundo en lo relativo a ventiladores y disipadores. No hay ningún otro fabricante que se le acerque. Es impresionante la amplia gama disponible, pero sobre todo la calidad y el detalle con los que se fabrica y distribuyen sus productos. Sus ventiladores son robustos y utilizan gran cantidad de patentes y desarrollos nacidos dentro de Noctua. Incorporan gran cantidad de accesorios y extras para cualquier tipo de montaje. Basta con ver el sistema OmniJoin que incorporan los modelos de 40mm, pensado para facilitar la instalación de ventiladores en equipos que no siempre llevan el conector estándar. El precio va desde las 15 Euros de los modelos de 40 mm hasta los 30 Euros del modelo de 200 mm. Personalmente no son caros, viendo lo que incorporan y la calidad que ofrecen.
Test verdict: "A modo de conclusión final, indicar que nos volvemos a encontrar con los mejores ventiladores que podemos adquirir. Antes de comprar hay que asegurarse del modelo que necesitamos y estoy seguro que Noctua lo tendrá dentro de su amplio catálogo. Toda la gama A obtiene 5 estrellas y nuestro llevo de producto recomendado." (Abel Hernandez Valero, TodoHTPC.com)
27.11.2017 // Tech-Critter.com
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NF-A20 PWM Review

With the Intel stock cooler installed, we let our Intel i7 4790K system run on full load using Prime95 for extended hours. The highest temperature recorded while using the stock 200mm fan is 46°C, but both the Noctua NF-A20 FLX and NF-A20 PWM perform even better with 3°C lower than the stock fan.
Test verdict: "While most of the stock 200mm fan we’ve seen run at around 900-1000RPM, not many of them are as well built and as capable of moving as much air as both the Noctua NF-A20 PWM and NF-A20 FLX are without compromising the acoustic performance. If you happen to have one and planning to upgrade its 200mm fan, the Noctua NF-A20 FLX or NF-A20 PWM are a choice that is definitely worth considering – especially for the 6-year warranty period which not many brands would offer." (Clement Thien, Tech-Critter.com)
23.11.2017 // Overclockers.com.ua
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NF-A20 PWM Review

Долгожданная 200-мм модель от австрийского производителя, наконец-то позволит заменить обладателям больших корпусов свои старые стоковые вентиляторы. Но подойдет она далеко не всем, потому для начала стоит ознакомиться со списками совместимости с шасси на официальном сайте. NF-A20 PWM имеет высокое качество изготовления, богатую комплектацию и отличные показатели производительности при относительно невысоком уровне шума. Наличие ШИМ у данной модели позволяет снизить скорость пропеллера до минимального порога в 350 об/мин, при которой он будет полностью бесшумным. Однако, наиболее эффективная по соотношению производительности и шума скорость для него — это 550 об/мин, в которые легко можно попасть, используя комплектный понижающий резистор. Noctua NF-A20 FLX: Мало чем отличается от NF-A20 PWM по техническим параметрам и производительности. Тут нет ШИМ для гибкого и оперативного управления скоростью вентилятора, зато есть трехконтактный разъем, и переходник для подключения к блоку питания. Потому типичный сценарий использования данного пропеллера выглядит так: подключаем его к БП, используя переходник, удлинитель и комплектный резистор, снижаем скорость до 550 об/мин и забываем о его существовании.
Test verdict: "Как видно из результатов тестирования, и это вполне ожидаемо, 200-мм вентиляторы являются чемпионами по объему прокачиваемого воздуха. Что еще интереснее — благодаря технологиям Noctua им удается сохранять при этом относительную тишину." (Vasilenko Andrey, Overclockers.com.ua)
24.10.2017 // ThinkComputers.com
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NF-A20 PWM Review

Like we stated in the beginning, Noctua offers a great variety of fans and accessories, many of which we didn’t realized they produced. By taking a look at these not so common fan sizes, we have really opened up our eyes to the number of solutions Noctua is providing. Loud or dead fan in a Cisco switch? Swap it out for a compatible Noctua NF-A4x20 model. Need a slim 120mm fan for your low-profile CPU cooler? Check out the NF-A12x15 options. Looking for a compact solution to control the speed of a few fans? The NA-FC1 might do the trick. One thing that really impressed us was the 6-year warranty that each of the items we looked at comes with; not just the fans. We expect some type of warranty on a fan controller, but to have the same 6-year warranty on the tiny anti-vibration mounts, as well as the simple SATA to 4-pin fan adapter, is just fantastic.
Test verdict: "Color us impressed." (Ryan Kerschner, ThinkComputers.com)
04.10.2017 // NewEsc.com
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NF-A20 PWM Review

Das fans que recebemos o destaque vai provavelmente para a primeira fan mainstream de 200mm da Noctua que a introduz com dois modelos, PWM com 4-pin, para um melhor controlo da nossa parte, e o FLX com 3-pin apenas, para um controlo automático. As NF-A20 PWM e NF-A20 FLX seguem as linhas principais da companhia, integrando a melhor tecnologia Noctua. Desde a moldura AAO, para redução do ruído, ao controlador PWM NF-FD1 no caso da primeira, para garantir o melhor controlo das velocidades da ventoinha, e rolamentos SSO2 reconhecidos pela sua estabilização, precisão e durabilidade. Isto, com 6 anos de garantia do fabricante! A esta junta-se a nova ventoinha slim de 120mm, com apenas 15mm de espessura, perfeita para os radiadores no topo das caixas quando temos falta de espaço. E as ventoinhas de 40mm, com opção de 5v para menor velocidade e menor ruído. Vindo da Noctua só esperamos qualidade na hora de testar, em termos de fluxo de ar e ruído, a Noctua é das melhores companhias. A Noctua não se foca só nas ventoinhas, mas em tudo o que sirva estas no sistema. A companhia austríaca tem uma vasta oferta de adaptadores e acessórios de montagem. Alguns desses os seus extras acompanham mesmo as ventoinhas nas respectivas caixas, como os adaptadores LVA/LNA que ajudam a reduzir os níveis de ruído ao estrangular a voltagem. Mas o destaque desta vez vai mesmo para o Noctua NA-FC1, um pequeníssimo controlador de ventoinhas.
Test verdict: "A Noctua não desilude, demonstrando mais uma vez saber o que faz. A introdução de novas soluções na sua principal linha é muito bem vinda." (Filipe Teixeira, NewEsc.com)
02.10.2017 // PC Update
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NF-A20 PWM Review

Pour essayer de mettre en perspective l’intérêt d’un tel monstre, nous l’avons benché dans un PC assemblé dans le boîtier Prodigy avec une configuration de joueur, à savoir un i5-4670K et une GeForce GTX 780 Ti. Nous avons comparé ce Noctua A20 avec un ventilateur BitFenix Spectre Pro 200 mm ainsi qu’avec le 120 mm d’origine du boîtier et en limitant la rotation du 120 mm à 1000 tours pour rester silencieux (les 200 mm étant à fond, respectivement à 800 et 900 tpm). En mettant le PC en charge ludique (la démo du dernier 3Dmark en boucle), la température du CPU refroidi par un NH-U12S passe de 59° avec le 120 mm à 56° avec le 200 mm BitFenix et 55° avec le 200 mm Noctua et c’est surtout le GPU qui en profite réduisant de 85° à 76° et 72°. Sachant que le Noctua est en plus le plus inaudible des trois, on comprend que la qualité du célèbre fabricant autrichien est au rendez-vous.
Test verdict: "Noctua ne sort pas des produits aussi souvent qu’on aimerait, mais au moins, la qualité est toujours au rendez-vous. C’est encore valable cette fois avec trois séries de ventilateurs atypiques, mais les meilleures dans leurs domaines d’application. Le prix est certes premium, mais en adéquation avec les performances, le bundle et même la garantie de 6 ans incluse avec tous ces ventilateurs." (Thomas Olivaux, PC Update No. 90)
01.10.2017 // EnlaceHW.com
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NF-A20 PWM Review

Los ventiladores Noctua NF-A20 son el resultado de años de continua investigación y desarrollo de los ingenieros especializados de la marca. Indudablemente, la espera valió la pena, ya que no todos los días uno se encuentra con un ventilador de 200mm y mucho menos con el nivel de calidad que conocemos de Noctua. Los NF-A20 reúnen las dos características fundamentales de un excelente ventilador – una operación casi imperceptible y un rendimiento del flujo de aire digno de alabar. El único detalle que podría causar algunos problemas de compatibilidad debido a su grosor de 30mm. Algunos gabinetes que no cuentan con mucho espacio particularmente en la parte frontal podrían no ser compatibles con los ventiladores NF-A20. Actualmente, ambos modelos de la familia NF-A20 cuestan 540 pesos mexicanos antes de impuestos, lo que nos lleva a recomendar el modelo PWM sobre el modelo FLX, ya que el primero brinda un mayor control de la velocidad. Como ya es costumbre, Noctua respalda tu compra con una amplia y generosa garantía de seis años, donde los ventiladores seguramente vivirán más que cualquier otro componente de tu sistema. Si estás buscando un ventilador de 200mm, podemos decirte con seguridad que no hay ninguna opción en el mercado que se compare con los nuevos Noctua NF-A20.
Test verdict: "El ventilador Noctua NF-A20 es una excelente opción para el entusiasta que requiere de un ventilador de 200mm de alto rendimiento."
27.09.2017 // El Chapuzas Informático
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NF-A20 PWM Review

Noctua ha lanzado una nueva colección de productos de gama alta para el apartado de refrigeración que, como siempre, dejan a la marca en excelente lugar. Por un lado, tenemos los ventiladores Noctua NF-A12x15, una excelente alternativa para disipadores slim o chasis compactos donde no tengan cabida los tradicionales de 25 mm de grosor. Los NF-A20 son una opción para chasis que permitan los modelos de 200 mm, aunque no ofrecen una gran mejora frente a modelos de 120 mm. Mientras, los NF-A4x20 son un sustituto ideal para dispositivos ultracompactos, ya sea por reparación o para mejorar su sonoridad. Por si fuera poco, todos ellos ofrecen nada menos que 6 años de garantía, por lo que tenemos ventiladores para rato. Además, Noctua siempre busca suplir todas las necesidades de sus clientes y para ello lanza algunos accesorios como los que hemos visto, los se unen a un inmenso portafolio que podemos consultar aquí.
Test verdict: "Como no podía ser de otra forma, desde del El Chapuzas Informático le otorgamos el Galardón de Platino a los ventiladores Noctua NF-A12x15, NF-A4x20 y NF-A20 y los nuevos accesorios, productos todos ellos de la más alta calidad. En lo que respecta al precio, en el momento de la redacción no están listados en nuestro país." (Iván Martínez, El Chapuzas Informático)

Installation Manual (PDF)

Information Sheet (PDF)

Can I use Low-Noise Adaptors with y-cables / multiple fans?

Yes, Low-Noise Adaptors (L.N.A.s) can be used with y-cables, but please make sure to use one L.N.A. per fan and to place the L.N.A.s between the y-cable and the fans as shown below. Never use one L.N.A. for two (or more fans) by placing it between the mainboard and the y-cable!

D15S

Can Noctua fans be used to replace noisy stock fans in switches, routers or other network devices?

Noctua fans such as the 40, 60, 80 or 92mm NF-A series models are ideal for replacing noisy stock fans in switches, routers and other network devices in order to make them quieter and thousands of users have managed to significantly reduce the noise levels of their units this way. However, while it is easy and straightforward to replace the fans in some cases, it can be very difficult in others, so Noctua strongly recommends that users carefully research if it is possible to easily replace the fan(s) of their network device before purchasing a Noctua fan for this purpose. Some of the common issues that can occur when replacing pre-installed fans are:

  • Different pin assignment: Whereas Noctua fans use the standardised pin assignment for PC fans (see this FAQ for details), some network devices use different assignments. For example, some devices have the power and GND or rpm and PWM pins swapped. Therefore please carefully verify that your device uses the same pin assignment as standard fans. Experienced users may also change the pin assignment by cutting and resoldering the fan cables, but please note that this will void your Noctua manufacturer’s warranty.
  • Different pin functions: Noctua fans use the standardised pin functions for PC fans (see this FAQ for details); however, some network devices use fans where certain pins serve a different function. For example, some devices use the RPM pin for “power good” signals. Therefore please carefully verify that your device uses the same pin functions.
  • Firmware speed control: Some network devices demand a certain maximum or minimum fan speed. If the new fan doesn’t have the same or similar maximum or minimum speed, the device may display errors or even shut down.
  • Different starting voltage: Most network devices use voltage-based speed control. If the new fan has a higher starting voltage than the original fan, it may not start up right away. This may lead the device to display errors or even shut down because it suspects a fan failure.
  • Different power draw: Some network devices monitor the fan’s power draw. If the new fan has a lower power consumption than the stock fan, the device might display errors or even shut down.

Please note that most network device manufacturers don’t provide detailed documentation regarding fan compatibility and control, so users who want to replace the fans of their devices usually have to rely on “How to” guides, blog and forum posts or video tutorials. Please also note that fan compatibility and control can vary from model to model and even from revision to revision even if the devices stem from the same manufacturer. As a result, it is important to make sure that the information or guidelines you rely on when replacing your fans are applicable to your specific model as well as your specific hardware and firmware revision.

Due to the possible issues listed above, Noctua recommends that only experienced users attempt to replace their pre-installed fans in network devices. Please note that since there are so many different devices and most of them lack documentation for aspects such as fan compatibility and control, Noctua customer support cannot assist you with compatibility issues when replacing pre-installed fans. Please contact your network device manufacturer for any questions regarding aspects such as the device’s pin alignment or fan monitoring and control.

Can I use Noctua fans in my system from Acer, Apple, Dell, HP, Lenovo or other major brands?

Noctua 12V fans comply with the established specifications for standard PC systems issued by Intel and AMD. Systems from Acer, Apple, Dell, HP, Lenovo or other major brands often deviate from these specifications e.g. by using proprietary fan headers, custom pin-alignments or pin-configurations, different methods of fan speed control, etc. This can lead to compatibility issues when using Noctua fans in systems from said brands. Some of these problems can be avoided with some technical knowledge, but especially BIOS related issues (e.g. errors or shutdowns due to low fan speed) can often not be resolved. As a result, Noctua does not officially support systems from Acer, Apple, Dell, HP, Lenovo or other major brands.

Can Noctua fans be used to replace noisy stock fans in NAS devices?

Noctua fans such as the 40, 60, 80 or 92mm NF-A series models are ideal for replacing noisy stock fans in NAS devices in order to make them quieter and thousands of users have managed to significantly reduce the noise levels of their NAS units this way. However, while it is easy and straightforward to replace the fans in some cases, it can be very difficult in others, so Noctua strongly recommends that users carefully research if it is possible to easily replace the fan(s) of their NAS device before purchasing a Noctua fan for this purpose. Some of the common issues that can occur when replacing NAS fans are:

  • Different pin assignment: Whereas Noctua fans use the standardised pin assignment for PC fans (see this FAQ for details), some NAS units use different assignments. For example, some devices have the power and GND or rpm and PWM pins swapped. Therefore please carefully verify that your NAS device uses the same pin assignment as standard fans. Experienced users may also change the pin assignment by cutting and resoldering the fan cables, but please note that this will void your Noctua manufacturer’s warranty.
  • Different pin functions: Noctua fans use the standardised pin functions for PC fans (see this FAQ for details); however, some NAS units use fans where certain pins serve a different function. For example, some devices use the RPM pin for “power good” signals. Therefore please carefully verify that your NAS device uses the same pin functions.
  • Firmware speed control: Some NAS devices demand a certain maximum or minimum fan speed. If the new fan doesn’t have the same or similar maximum or minimum speed, the device may display errors or even shut down.
  • Different starting voltage: Most NAS devices use voltage-based speed control. If the new fan has a higher starting voltage than the original fan, it may not start up right away. This may lead the NAS device to display errors or even shut down because it suspects a fan failure.
  • Different power draw: Some NAS devices monitor the fan’s power draw. If the new fan has a lower power consumption than the stock fan, the device might display errors or even shut down.

Please note that most NAS manufacturers don’t provide detailed documentation regarding fan compatibility and control, so users who want to replace the fans of their devices usually have to rely on “How to” guides, blog and forum posts or video tutorials. For example, there are excellent video tutorials available for changing the fans in popular Synology NAS models (DS416j, DS1515+ and DS1812+ in English, DS416/DS415/DS916/DS216/DS214 and DS1515+ in German). Please also note that fan compatibility and control can vary from model to model and even from revision to revision even if the devices stem from the same manufacturer. As a result, it is important to make sure that the information or guidelines you rely on when replacing your NAS fan are applicable to your specific model as well as your specific hardware and firmware revision.

Due to the possible issues listed above, Noctua recommends that only experienced users attempt to replace their NAS fans. Please note that since there are so many different NAS models and most of them lack documentation for aspects such as fan compatibility and control, Noctua customer support cannot assist you with compatibility issues when replacing NAS fans. Please contact your NAS manufacturer for any questions regarding aspects such as the device’s pin alignment or fan monitoring and control.

Which Noctua fan or CPU cooler should I buy? How to choose the right model?

Not sure which Noctua product to buy? Our detailed buying guides for fans and CPU coolers help you to choose the model that works best for you.

How can I check if my 4-pin fan header supports PWM?

Some mainboards feature 4-pin fan headers that actually don‘t use a PWM signal on Pin 4 to control the fan speed but rather reduce the voltage on Pin 2 (like a standard 3-pin fan header). As the fan speed at minimum voltage is usually higher than the speed at 20% PWM duty cycle, the fan can not reach as low minimum speeds under voltage control as under PWM control. Please refer to your mainboard manual to check whether or not your mainboard has 4-pin fan headers that control the fan speed by reducing voltage on Pin 2 rather than by changing the PWM duty cycle on Pin 4:

4 pin fan header types

Note that mainboard manufacturers use different terms to indicate that Pin 4 is not being used for PWM control (e.g. “+5V”, “VCC” or “NC”), but if one of these terms is used, you can be sure that the fan header does not support PWM. If Pin 4 is described as “Speed Control” or “PWM” or the like, you can be sure that the fan header supports PWM.

Unfortunately, the description of Pin 2 is not always a clear indication as some manufacturers use terms such as “Fan PWR” or “Power” for both types of fan headers. However, if Pin 2 is described as “Speed Control”, you can also be sure that the fan header does not support PWM based speed control. If Pin 2 is described as “+12V”, this is a clear indication that the fan header supports PWM.

Please also note that in some cases, the descriptions of the pin layouts in the mainboard manuals may not be correct and some models actually allow you to switch the fan headers from voltage control mode to PWM control mode in the BIOS even though the pin descriptions do not indicate PWM support. We thus recommend to look for these options in the BIOS before taking other measures. In case of doubt, please contact your mainboard manufacturer.


If your mainboard features other 4-pin fan headers that use PWM for speed control, you can run multiple fans from these headers using Y-split cables. Make sure not to exceed the specified maximum power draw of the fan headers (usually 10-12W) though.

How should I clean my Noctua fan?

Fans inside computer cases tend to accumulate dust over longer periods of usage. In order to maintain maximum performance, please clean your fans regularly using a duster, slightly moist tissue or canned air. Please be careful not to use too much force in order to prevent any damage to the fan. Please do not use a vacuum cleaner as this may apply excessive force to the fan and do not put the fan under running water as water residues inside the motor may lead to short circuits.
In order to ensure flawless operation over many years of usage, Noctua’s premium grade SSO bearings are fully sealed to prevent the entering of fine dust particles. Please note that the fan is not designed to be taken apart by the user. Removing the impeller from the frame will break the sealing of the bearing and results in a loss of warranty.

What pin configuration do Noctua 12V fans use?

All Noctua fans feature the standard pin-configurations set out in the Intel and AMD specifications. These standard pin-configurations are used on most mainboards and fan controllers today:

pin configuration

Can I run 4-pin PWM fans on 3-pin fan headers?

PWM fans come with a 4-pin connectors for fully automatic speed control via your mainboard’s 4-pin PWM fan headers. Please note that 4-pin fans can also be connected to your mainboard’s 3-pin fan headers though. When connected to 3-pin fan headers, the fan will run at full speed (unless the mainboard supports voltage based speed control).

Can I disassemble my fan for cleaning (or other purposes, e.g. painting)?

In order to ensure flawless operation over many years of usage, all Noctua fans come with a premium grade SSO bearing, which is fully sealed to prevent the entering of fine dust particles. Please note that the fan is not designed to be taken apart by the user. Removing the impeller from the frame will break the sealing of the bearing and results in a loss of warranty.

It is thus recommended to clean your fans using a duster, slightly moist tissue or canned air. Please be careful not to use too much force in order to prevent any damage to the fan. Please don’t use a vacuum cleaner as this may apply excessive force to the fan.

Which cases does the NF-A20 fit?

Please refer to our case compatibility list for detailed compatibility information.

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