The NF-A14x25 G2 PWM Sx2-PP is a set of two NF-A14x25 G2 PWM square-frame 140mm fans that are offset in speed, which can be beneficial in push-pull operation as well as in situations where two fans are operating side by side, such as in case cooling applications or on 280mm water cooling radiators. When two fans are running at almost the same, constant speed in a push-pull configuration or, albeit to a lesser extent, side by side, their acoustic interaction can lead to undesirable harmonic phenomena such as intermittent vibrations or periodic humming due to interference, which can be heard as beat frequencies. Therefore, the two NF-A14x25 G2 PWM fans contained in the Sx2-PP set are slightly offset in speed (+/- ~25rpm) in order to avoid such phenomena. With one fan running ~25rpm slower (PPA) and one ~25rpm faster (PPB), the overall cooling performance can be kept the same while efficiently preventing intermittent vibrations or periodic humming.
Bundling two NF-A14x25 G2 PWM fans that are speed-offset by +/- ~25rpm in order to avoid undesired acoustic interaction phenomena, the Sx2-PP set is the ideal choice for push-pull configurations as well as situations where two fans are operating side by side such as on 280mm radiators or in typical case cooling applications.
The NF-A14x25 G2 features a unique Progressive-Bend impeller with Flow Acceleration Channels and winglets. Its nine blades are swept backwards 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 towards the outer blade areas where efficiency is higher but also assures maximum lift and near uniform loading across the entire blade span.
The NF-A14x25 G2 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.
The NF-A14x25 G2 has a record tight tip clearance (distance between the blade tips and the inside of the frame) of only 0.7mm. This highly ambitious design sets a new benchmark for 140mm fans and helps the NF-A14x25 G2 to work more efficiently against back pressure, such as on heatsinks or radiators, by reducing leak flows through the gap between impeller and frame.
*In chassis with more than 165mm CPU cooler clearance, the front fan can be moved upwards to make room for memory modules taller than 32mm.
- NF-A14x25 G2 PWM PPA
- NF-A14x25 G2 PWM PPB
- 2x NA-RC16 Low-Noise Adaptor (L.N.A.)
- NA-YC1 4-pin PWM splitter cable
- 2x NA-EC1 30cm extension cable
- 8x NA-AV2 anti-vibration mounts
- 2x NA-AVG2-LR anti-vibration gasket for water cooling radiators
- Fan screws
| Products | |||||
|---|---|---|---|---|---|
| Connector | 4-pin PWM | 4-pin PWM | 4-pin PWM | 4-pin PWM | 4-pin PWM |
| Voltage | 12 V | 12 V | 12 V | 12 V | 12 V |
| RPM | 1500 RPM | 800 RPM | 1500 RPM | 1500 RPM | 1500 RPM |
| RPM with L.N.A. | 1250 RPM | 600 RPM | 1250 RPM | 1250 RPM | 1250 RPM |
| Acoustical Noise | 24.8 dB(A) | 11.4 dB(A) | 24.8 dB(A) | 24.8 dB(A) | 24.8 dB(A) |
| Acoustical Noise with L.N.A. | 19.7 dB(A) | 8.6 dB(A) | 19.7 dB(A) | 19.7 dB(A) | 19.7 dB(A) |
| Size | 140x140x25 mm | 140x140x25 mm | 140x140x25 mm | 140x140x25 mm | 140x140x25 mm |
| Colour | Brown & Beige | Brown & Beige | Brown & Beige | Brown & Beige | Brown & Beige |
| Quantity | x1 | x1 | x1 | x2 | x2 |
