Box, Contents & Bundle
The box features a photo of the product and the model’s description. The rich bundle is contained in a smaller package.
The fan’s bundle is rich, including the following:
- NA-RC16 Low-Noise Adaptor (L.N.A.)
- NA-YC1 4-pin PWM splitter cable
- NA-EC1 30cm extension cable
- 4x NA-AV2 anti-vibration mounts
- NA-AVG2-LR anti-vibration gasket
- 4x NA-AVP1-LR load-relief anti-vibration pads
- Fan screws
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The fan, which has nine blades, is made by Sterrox LCP. In this section, I want to stay on some of the fan’s most important features:
Progressive-Bend impeller
The NF-A14x25 G2 features a Progressive Bend Impeller with flow acceleration channels and winglets. Its nine blades are swept backward close to the hub and progressively bent forward further out. Working in tandem with the Centrifugal Turbulator hub, this design not only helps to push more air toward the outer blade areas where efficiency is higher but also ensures maximum lift and near-uniform loading across the entire blade span.
Centrifugal Turbulator Hub
The new Centrifugal Turbulator hub design improves flow attachment in the hub region. At the same time, its centrifugal driving motion pushes air outwards from the hub area where efficiency is low due to the slow rotational speed towards the outer, high-efficiency zones of the blades, thereby increasing overall efficiency by optimizing fluid distribution across the impeller area.
Flow Acceleration Channels
The NF-A14x25 G2 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, leading to better efficiency and lower vortex noise.
Winglets
Winglets can help reduce tip vortices caused by the pressure differential between the suction and the pressure side of fan blades but bear the risk of reducing efficiency due to extra fluid displacement in high-velocity regions. The NF-A14x25 G2’s small winglets have been fine-tuned to provide consistent efficiency gains working in tandem with its Progressive-Bend blade geometry, Flow Acceleration Channels, and AAO frame.
Ultra-tight tip clearance
The NF-A14x25 G2 has a tight tip clearance (distance between the blade tips and the inside of the frame) of only 0.7mm. This design helps the NF-A14x25 G2 work more efficiently against back pressure, such as on heatsinks or radiators, by reducing leak flows through the gap between the impeller and frame.
Stepped Inlet Design
Noctua’s Stepped Inlet design adds turbulence to the influx to facilitate the transition from laminar to turbulent flow. This 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 plowing 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.
Some more close-up photos of the fan.
