Noctua NF-A9x14 PWM review

Like every Noctua cooling fan all A-series fans are packed in full size cardboard boxes full of accessories.

All three fans feature the further optimised second generation SSO2 bearing as well as Noctua’s AAO (Advanced Acoustic Optimisation) frames that feature integrated anti-vibration pads as well as Noctua’s proprietary Stepped Inlet Design and Inner Surface Microstructures, both of which further refine the fans’ performance/noise efficiency. Like all Noctua fans, the NF-A9x14, NF-A6x25 and NF-A4x10 have an MTBF rating of more than 150.000 hours and come with a full 6-year manufacturer’s warranty.

NF-A4x10’s and  NF-A6x25’s motor hub is smaller than with conventional 40mm and 60mm fans. This allows for more blade surface area and thus contributes to their superior airflow and pressure performance. Also NF-A4x10 comes with Noctua’s OmniJoin Adaptor Set and you can plug the NF-A4x10 to proprietary fan headers. Before I continue with this review I want to share some pictures of NF-A4x10 and NF-A6x25 fans.

Noctua NF-A4x10 FLX

Technical details:

Size 40x40x10 mm
Connector 3-pin
Bearing SSO2
Blade Geometry A-Series with Flow Acceleration Channels
Frame Technology AAO (Advanced Acoustic Optimisation)
Rotational Speed (+/- 10%) 4500 RPM
Rotational Speed with L.N.A. (+/- 10%) 3700 RPM
Airflow 8,2 m³/h
Airflow with L.N.A. 6,6 m³/h
Acoustical Noise 17,9 dB(A)
Acoustical Noise with L.N.A. 12,9 dB(A)
Static Pressure 1,78 mm H2O
Static Pressure with L.N.A. 1,21 mm H2O
Max. Input Power 0,6 W
Max. Input Current 0,05 A
Voltage 12 V
MTBF > 150.000 h

Noctua NF-A6x25 FLX

Technical details:

Size 60x60x25 mm
Connector 3-pin
Bearing SSO2
Blade Geometry A-Series with Flow Acceleration Channels
Frame Technology AAO (Advanced Acoustic Optimisation)
Rotational Speed (+/- 10%) 3000 RPM
Rotational Speed with L.N.A. (+/- 10%) 2400 RPM
Rotational Speed with U.L.N.A. (+/- 10%) 1600 RPM
Airflow 29,2 m³/h
Airflow with L.N.A. 23,5 m³/h
Airflow with U.L.N.A. 16,7 m³/h
Acoustical Noise 19,3 dB(A)
Acoustical Noise with L.N.A. 14,5 dB(A)
Acoustical Noise with U.L.N.A. 8,2 dB(A)
Static Pressure 2,18 mm H2O
Static Pressure with L.N.A. 1,41 mm H2O
Static Pressure with U.L.N.A. 0,61 mm H2O
Max. Input Power 1,44 W
Max. Input Current 0,12 A
Voltage 12 V
MTBF > 150.000 h

Noctua NF-A9x14 PWM

Noctua NF-A9x14 is much slimmer than standard 92x92x25mm fans, it’s only 14mm in thickness.  This makes it ideal for all applications where standard fans would take up too much space, such as low profile CPU coolers in HTPC builds or server environments. On the box we can find all the information about the fan, like used technologies, technical details, the contents of the box and a view of the fan itself.

Noctua NF-A9x14 PWM uses completely new propeller design with nine blades and features suction side Flow Acceleration Channels. These channels alter and speed up the airflow at the outer blade regions. With rotation speed increased these channels reduce the flow separation, which permits lower vortex noise and higher airflow efficiency. The fan uses Noctua’s custom designed NE-FD1 PWM controller that integrates Smooth Commutation Drive (SCD) technology for quieter operation and allows for ultra-low power consumption. The NF-A9x14 features the further optimised second generation SSO2 bearing. The rear magnet is placed closer to the axis compared to SSO bearing, to provide even better stabilisation, precision and durability. Once again we see the Stepped Iinlet Design and Inner Surface Microstructures, which reduce the intake and blade passing noise, and improve airflow, and pressure efficiency. Also, the fan has Anti-Vibration Pads around the mounting holes for reducing the vibrations in working mode.

Technical details:

Size 92x92x14 mm
Connector 4-pin PWM
Bearing SSO2
Blade Geometry A-Series with Flow Acceleration Channels
Frame Technology AAO (Advanced Acoustic Optimisation)
Rotational Speed (+/- 10%) 2200 RPM
Rotational Speed with L.N.A. (+/- 10%) 1700 RPM
Min. Rotational Speed (PWM) 300 RPM
Airflow 50,5 m³/h
Airflow with L.N.A. 38,1 m³/h
Acoustical Noise 19,9 dB(A)
Acoustical Noise with L.N.A. 13,5 dB(A)
Static Pressure 1,64 mm H2O
Static Pressure with L.N.A. 0,92 mm H2O
Max. Input Power 1,32 W
Max. Input Current 0,11 A
Voltage 12 V
MTBF > 150.000 h

Inside the cardboard box there is a plastic package with the cooling fan and its accessories. Noctua NF-A9x14 PWM is powered by 20cm long cable ending with 4-pin connector. Apart from the fan itself, the set includes Low-Noise Adapter (L.N.A.), 4-Pin Y-Cable, 30cm Extension Cable, 4 Vibration compensators and 4 fan screws.

All the cables are in black sleeves with white and beige connectors, maybe due to the white fan headers of most of the motherboards.

NF-A9x14 is in typical for the brand colors. I found this color combination unobtrusive but when you see it you know that’s  Noctua.

It’s time to see how Noctua NF-A9x14 PWM performs. The test is a measuring of the velocity of airflow passing through the fan at 5V, 7V, 9V, 12V and calculating the volumes of the flow per unit time. Also the fan is tested for minimum voltage at which starts to spin. For this I use an anemometer, a digital voltmeter with an accuracy of a tenth, a simple voltage controller and a 4-pin Y-Cable. The fan is connected through the Y-Cable and the voltage controller to 12V 3- pin connector on my PC bench. The other Y-Cable connector is connected to a digital voltmeter, which receives power through a 4-pin connector (Molex) from my PSU. The results achieved during the test can in no way be the same if the fans are mounted on a cooler or on the case fan hole of any modern computer case.

Before testing the NF-A9x14 PWM I leave it to run at 12V for reaching the full rotation speed. After that I reduce the voltage, turn off the fan and turn it on again to measure the starting voltage. The fan began to spin at 6,8V and the voltage drop to 6V. The rotation speed was 1271 revolutions per minute at which it was completely silent. The results of the measuring of airflow speed and monitoring the rotation speed at the different voltages are in the tables below:

The starting voltage of the model is higher than the voltage for the first test, so I had to decrease it to 5V. At this voltage the fan reached 1115 rpm with airflow speed of 1,5 m/s and was completly silent. At 7V the rotation speed was 2,1 m/s at 1464 rpm and the fan was still very silent. At 9v the airflow speed increased to 2,6 m/s at 1760 rpm. This time there was some noise at 10 cm from the air passing through the propeller. After increasing the voltage to 12V the NF-A9x14 reached its maximum rotation speed of 2160 rpm and the airflow speed was 3,3 m/s. At this voltage there was noise which could be heard at a distance of about 100 cm in silent environment.

In the following table the values for the airflow level at different voltages are calculated:

According to the rotation speed, propeller design and the low profile Noctua NF-A9x14 PWM is with very similar performance/noise ratio to bigger 92x92x25mm fans rotating at around 1700 rpm.  It can be used everywhere where the space is precious.

I think Noctua NF-A9x14 PWM deserves the following reward:

I thank Noctua for the test samples.

We will be happy to see your thoughts

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