The Noctua NF-A4x20 5V PWM is a premium 40 mm cooling fan designed for compact electronics that require strong airflow, high static pressure, and very low noise. Its 5V PWM design makes it particularly well suited as a cooling upgrade or replacement fan for Bitaxe and NerdAxe miners.
Premium Cooling for Bitaxe and NerdAxe Miners
With a 40 × 40 × 20 mm form factor, the NF-A4x20 is thicker than a standard 40 × 10 mm fan, allowing it to generate higher static pressure while remaining extremely quiet.
This makes it an excellent choice for pushing air through dense heatsinks found on compact Bitcoin miners, where maintaining consistent airflow is important for stable ASIC temperatures and long term operation.
Quiet and Powerful
Despite its compact size, the NF-A4x20 5V PWM can reach up to 5000 RPM while producing a maximum noise level of only 14.9 dB(A).
Its maximum airflow is 9.4 m³/h (5.53 CFM), with up to 2.26 mm H₂O static pressure, providing strong cooling performance without the high pitched noise commonly associated with small high speed fans.
PWM Fan Control
The integrated 4-pin PWM connector allows the miner to control fan speed automatically based on cooling demand.
Fan speed ranges from approximately 1100 RPM at 20% PWM up to 5000 RPM at full speed, with support for complete fan stop at 0% PWM.
Compatibility
The NF-A4x20 5V PWM uses a standard 40 mm mounting format and is compatible with Bitaxe and NerdAxe miners using a 5V PWM fan connection, including:
- Bitaxe Supra
- Bitaxe Ultra
- Bitaxe Hex
- Bitaxe Gamma
- NerdAxe Gamma
- NerdAxe Gaia BM1373
- Other compatible Bitaxe and NerdAxe models using a 40 mm 5V PWM fan
It can be used as a replacement for the stock fan or as part of an upgraded cooling setup.
Noctua SSO2 Bearing
The fan uses Noctua's SSO2 bearing system, designed for smooth operation, low mechanical noise, and long service life.
Noctua rates the NF-A4x20 5V PWM for an MTTF of more than 150,000 hours, making it well suited for miners operating continuously.
Technical Specifications
- Dimensions: 40 × 40 × 20 mm
- Rated voltage: 5V
- Connector: 4-pin PWM
- Maximum speed: 5000 RPM
- Speed at 20% PWM: approximately 1100 RPM
- Maximum airflow: 9.4 m³/h / 5.53 CFM
- Maximum static pressure: 2.26 mm H₂O
- Maximum noise level: 14.9 dB(A)
- Typical power consumption: 0.42 W
- Maximum power consumption: 0.5 W
- Maximum current: 0.1 A
- Bearing: SSO2
- Cable length: 20 cm
- Mounting hole spacing: 32 × 32 mm
- MTTF: >150,000 hours
Important Voltage Notice
This is the 5V version of the NF-A4x20 and must only be connected to a 5V fan output.
Do not connect the fan directly to a 12V power source, as this can damage the fan.
What’s Included
- 1× Noctua NF-A4x20 5V PWM fan
Not Included
This product is supplied as the fan only. Retail accessories normally included with a boxed Noctua fan are not included.
- No splitter cable
- No extension cable
- No OmniJoin adaptor
- No anti-vibration mounts
- No mounting screws
