After our review of Noctua’s new-generation NH-D15 G2, let’s take a closer look at its fans. The new heatsink features a pair of NF-A14x25r G2 fans, which we briefly described in our test. However, there’s a lot to say about them, which is why we’re dedicating an article to them.
Presentation:
Broadly speaking, Noctua’s new fans are a new generation of 140 mm windmills. These are the successors to the old NF-A14 PWMs, and come with a number of improvements, as we shall see.
In the meantime, these are particularly expensive fans. The single fan costs around €40, compared with around €80 for the Sx2-PP pack.
The NF-A14x25r G2 Sx2-PP :
Without further ado, let’s get down to the nitty-gritty of these fans. First of all, these fans come in two versions: the basic fan and the Sx2-PP pack. The two-pack is specially designed for upgrading the fans in your existing cooling system. We’ll come back on that later.
In any case, compared to the existing NF-A15 PWM, this fan retains a format similar to that of its predecessor. In fact, this new fan also benefits from a circular format. However, this doesn’t prevent the brand from using rubber silentblocks. What’s more, if you like colour, we’ve checked and the Chromax NA-SAVP3 accessories are compatible !
Nevertheless, in addition to its shape, the frame inside features asperities that improve airflow and pressure without compromising noise.
As for the blades, these fans have nine of them. They have a rather unusual profile, being relatively thin with a sort of ‘break’ in the curvature. Noctua calls this the Progressive Bend Impeller. The Flow Acceleration Channel and a fin are located at the ends of the impeller. The central part has a turbine-shaped pattern, which the brand calls the Centrifugal Turbulator hub.
All this combined allows the hub to send some of the air towards the tips of the blades, where they are most effective. This assembly also ensures a more uniform load on the blades, limiting ‘dead’ zones. Finally, like the NF-A12x25, the blades run very very close to the frame: 0.7 mm.
To ensure maximum rigidity, the blades of the NF-A14x25r G2 are made from liquid crystal polymer, the famous Sterrox. In addition, the SSO2 motor is reinforced to ensure precision running, stability and durability. And last but not least, it benefits from high torque to ensure it doesn’t slow down when the blower is mounted in pull mode, for example.
Without further ado, here are the specifications:
- Without L.N.A(Low Noise Adapter) :
- Rotation range: up to 1500 rpm
- Air flow: 155.6 m3/h – 91.58 CFM maximum
- Static pressure: 2.56 mmH2O
- With L.N.A. adapter
- Rotation range: up to 1250 rpm
- Air flow: 127.1 m3/h – 74.81 CFM maximum
- Static pressure: 1.3 mmH2O
The fan also features a semi-passive mode with 0% PWM signal. This makes it possible to create fan curves where the fan stops completely at low load. Still on the subject of speed, the NF-A14x25r G2, when offered in the Sx2-PP pack, are not exactly identical. At the rear, you can see that they are labelled PPA and PPB. The difference is in the rotation speed, which varies by ±25 rpm. The aim, without sacrificing performance, is to prevent the fans from periodically “resonating”.
The :
The accessories section is very comprehensive and features :
- A NA-YC1 PWM splitter
- Eight NA-AV2 siliconised nipples for screwless case mounting
- Eight screws for mounting in an enclosure
- Two NA-RC16 L.N.A adaptors
- Two 30 cm sheathed PWM extension leads NA-EC1
Clearly, the accessories section makes it easy to install these fans. The cable extensions are very welcome, as there’s always a shortage of length in some cases. Note that the original cable is 20 cm long, so you can extend it to a total of 50 cm.