Noctua NF-A9 PWM computer cooling system

The NF-A9 is a highly optimised, premium quality quiet 92mm fan. Featuring Noctua’s AAO (Advanced Acoustic Optimisation) frame as well as sophisticated aerodynamic design measures such as Flow Acceleration Channels, the NF-A9 further improves the renowned quiet cooling performance of the award-winning NF-B9. 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 to reduce the maximum speed during PWM control from 2000 to 1550rpm. Its superb running smoothness, reference-class SSO2 bearing and Noctua’s trusted premium quality make it an elite choice for the highest demands.

Succeeding the award-winning NF-B9
Noctua’s NF-B9 fan has become a default-choice among PC enthusiasts looking for a premium quality quiet 92mm fan. Thanks to its thoroughgoing aerodynamic optimisations, the NF-A9 provides higher static pressure and an even better airflow/noise ratio than its much acclaimed predecessor.

Flow Acceleration Channels
The NF-A9 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
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
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
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 made from extra-soft silicone minimise the transmission of minute vibrations while maintaining full compatibility with all standard screws and other mounting systems.

SSO2 Bearing
The NF-A9 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
Supporting fully automatic PWM speed control, the NF-A9 PWM uses Noctua’s novel, 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
The NF-A9 PWM is supplied with a Low-Noise Adaptor (L.N.A.) that reduces the maximum fan speed from 2000 to 1550rpm. The L.N.A can be used either to run the fan at a fixed speed of 1550rpm or to cap the maximum speed when using automatic PWM control.

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 to connect a second NF-A9 PWM fan to the same PWM fan header for automatic control.