AccessoryCoolingReviews

Noctua New A Series Fans and Accessories

NF-A4x20 PWM, NF-A4x20 FLX, NF-A4x20 5V and PWM NF-A4x20 5V fans

For those who need small fans, Noctua designed 40mm A series fans in four versions. We can divide them to 12V and 5V.

PRODUCT
mm
RPM
dB/A
mm H2O
connector
40x40x20
5000
14,9
9,4
2,26
4-Pin PWM
40x40x20
5000
14,9
9,4
2,26
3-Pin
40x40x20
5000
14,9
9,4
2,26
4-Pin PWM
40x40x20
5000
14,9
9,4
2,26
3-Pin

 

NF-A4x20 PWM and NF-A4x20 FLX

40x20mm size

40x20mm size

Compared to Noctua’s award-winning NF-A4x10, the NF-A4x20 is twice as thick, which allows for increased static pressure performance and makes the NF-A4x20 ideal for demanding applications with high flow resistance.
 
Flow Acceleration Channels

Flow Acceleration Channels

The NF-A4x20 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 mounting systems and fan clips used on heatsinks.
 
SSO2 bearing

SSO2 bearing

The NF-A4x20 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.
 
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-A4x20 PWM is supplied with a (L.N.A.) that reduces the maximum fan speed from 5000 to 4400rpm. The L.N.A. can be used either to run the fan at a fixed speed of 4400rpm or to cap the maximum speed when using automatic PWM control.
 
OmniJoin™ adaptor set

OmniJoin™ adaptor set

Many devices featuring 40mm fans use proprietary fan headers, so the NF-A4x20 comes with Noctua’s OmniJoin™ adaptor set. Just cut the original fan’s cable, fix it to the adaptor using the supplied 3M Scotchlok™ connectors and you can plug the NF-A4x20 to proprietary fan headers!
 
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.
 
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-A4x20 features an MTTF of more than 150.000 hours rating and comes with a full 6-year manufacturer’s warranty.

 

Featuring advanced aerodynamic design measures such as Flow Acceleration Channels and Noctua’s AAO frame, the NF-A4x20 is a highly optimised, premium-quality quiet fan in size 40x20mm.

The PWM version sports Noctua’s custom-designed NE-FD1 IC for fully automatic speed control via 4-pin fan headers and comes with a Low-Noise Adaptor as well as an OmniJoin™ Adaptor Set for easy connection to proprietary fan headers. Its superb running smoothness, reference-class SSO2 bearing and Noctua’s trusted premium quality make it an elite choice for the highest demands.

The FLX version provides 5000/4400/3700rpm speed settings via the supplied Low-Noise Adaptors and includes the OmniJoin™ Adaptor Set for easy connection to proprietary fan headers. Its superb running smoothness, reference-class SSO2 bearing and Noctua’s trusted premium quality make it an elite choice for the highest demands.

The same as in previous fans, also here are PWM and FLX versions so option to connect fan directly to the motherboard or use additional cable in three speed options.

Above and below are photos of the NF-A4x20 fans in PWM and FLX versions and 12V DC voltage. These 40mm fans have 0.6W and 0.05A what we can read on the label on the back of the fans.

Package includes all necessary components which let you install the fans. Something that I’m repeating all the time but it’s actually really important as you don’t have to worry about anything while buying Noctua products. Noctua simply thinks for you.

NF-A4x20 5V and PWM NF-A4x20 5V

5V version of NF-A4x20 fans is not much different except lower voltage. We have to remember to use 5V cables for these fans as standard 12V voltage will probably damage the fan. All required cables are delivered by Noctua together with screws and anti-vibration mounts which we can find in all presented fans.

Even though these small fans have high speed then generated noise is low. Knowing older fans this size, I was surprised to hear so low noise out of NF-A4x20 series.

Above are couple of additional photos of the NF-A4x20 5V which looks similar to its 12V version and it would be hard to recognize them if not the label on the back of the fan.

On the next page we will take a closer look at the additional accessories from A series product line.

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