Some enthusiasts will say some things in common – larger fans means that they could spin at lower RPM and is near-silent while moving the same volume of air. I’ve personally been a big fan (pun intended) of big fans since I first encountered them back when I got the Cooler Master HAF 932. Fans larger than 140mm never really caught on the mainstream market, but that doesn’t stop Noctua from releasing the NF-A20 fans.

Noctua NF-A20

Speaking of which, mega thanks to Noctua for providing us with both of the NF-A20 FLX and NF-A20 PWM for this review!


Size200x200x30 mm
Mounting hole spacing154×154, 110×180, 170x170mm
Connector3-pin4-pin PWM
Blade GeometryA-Series with Flow Acceleration Channels
Frame TechnologyAAO (Advanced Acoustic Optimization)
Rotational Speed (+/- 10%)800 RPM
Rotational Speed with L.N.A. (+/- 10%)550 RPM
Min. Rotational Speed (PWM, +/- 20%)N/A350 RPM
Airflow146.9 m³/h
Airflow with L.N.A.100.8 m³/h
Acoustical Noise18.1 dB(A)
Acoustical Noise with L.N.A.10.7 dB(A)
Static Pressure1.08 mm H₂O
Static Pressure with L.N.A0.51 mm H₂O
Max. Input Power0.96 W
Max. Input Current0.08 A
Voltage12 V
MTTF> 150,000 h
Scope of delivery
  • Low-Noise Adaptor (L.N.A.)
  • 3:4-pin adaptor cable
  • 30cm extension cable
  • NA-AV3 anti-vibration mounts
  • NA-AV4 anti-vibration mounts
  • Fan screws
  • 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
Warranty6 years

Comparing both FLX and PWM variants of the NF-A20, we can see that they’re both more or less the same with a difference with the flexibility for voltage- or PWM-controlled.


Noctua NF-A20

Once again the iconic Noctua packaging design returns in white and black/brown colour accent with its features highlighted right at the front.

Behind the box is a more detailed list of specs and features.

Opening up the box reveals a clean packaging design from Noctua. The fan rests on a plastic pedestal with its sleeved cable tucked behind.

Removing the pedestal reveals the accessory box that’s tucked underneath, clever packaging design from Noctua to keep everything tidy yet accessible.

Noctua NF-A20 PWM & NF-A20 FLX Review 5

Opening up the accessories box reveals all of the contents as listed in the table above. Do note that there is a slight variance when it comes to accessories of both the Noctua NF-A20 FLX and PWM versions.

Closer Look

Both the NF-A20 FLX and PWM variants fall under Noctua’s NF-A series of fans, which are optimized for airflow, and hence produced with Noctua’s Flow Acceleration Channels blade design. To keep the noise level low, the NF-A20 FLX and PWM come with Advanced Acoustic Optimization which further pushes the performance/noise ratio.


Of course, since it’s Noctua, the fans are in its usual brown and beige colour scheme. Noctua has recently made an announcement and unveiling of their Chromax lineup of fans, but the NF-A20 Chromax editions are yet to be seen at the moment of writing this article.

Noctua NF-A20

Both the NF-A20 FLX and NF-A20 PWM look identical too – and the only difference is signified by the fan’s sticker.

Performance Test


For those of you who own a chassis that comes with a 200mm fan, we’re pretty sure that you’re well aware that these big-sized fans don’t really make much noise even when it’s running on full speed. When the system is on idle, the internal temperature hits 38°C with the stock 200mm fan install. While with both the Noctua NF-A20 FLX and NF-A20 PWM, the internal temperature hovers only at 34~35°C without any need of increasing the fan speed. With 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 performs even better with 3°C lower than the stock fan.


Of course, we did some extra tests using the included Low Noise Adapter just to see what kind of performance we can expect from both the NF-A20 FLX and NF-A20 PWM. With the Low Noise Adapter installed, the maximum fan speed is lowered to around 540~560RPM (original maximum fan speed is around 800~810RPM). With the Low Noise Adapter installed, both the NF-A20 FLX and NF-A20 PWM now performs almost on par with the CM Storm Trooper stock fan. It’s not really recommended to do so as you’re losing that extra performance from a good piece of fan that is already silent to begin with, just for the sake of acoustic performance.

Our Verdict

200mm fan is definitely not something for the mass, mainly because of the limited amount of chassis that actually supports fan at this size. While most of the stock 200mm fan we have seen runs at around 900-1000RPM, not many of them are as well build and as capable of moving as much air as both the Noctua NF-A20 PWM and NF-A20 FLX does 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 is a choice that is definitely worth to consider for – especially for the 6-year warranty period which not many brands would offer. Just make sure that your chassis is able to support its additional 5mm thickness (30mm) compared to the mainstream 200mm fans (25mm). Pros

  • Solid build quality
  • Good acoustic performance, barely audible even when it runs at full speed
  • Good performance, still as capable as the stock fan even with the Low Noise Adapter installed


  • Not all chassis supports 200mm fans
  • Not all chassis that supports 200mm fans caters for its 30mm thickness

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