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Noctua Straight-Blade-Design
Current silent fans frequently employ conventional blade geometries, which were developed for higher speed ranges and significantly lose efficiency at lower rotation speeds. The Noctua Straight-Blade-Design of the NF-S12 series was developed by the Austrian Institute for Heat-Transmission and Fan Technology (Österreichisches Institut für Wärmeübertragung und Ventilatorentechnik, ÖIWV) and specifically tailored to 120mm fans with extremely low rotation speeds. The result is a performance improvement of up to 10% and more compared to conventional blade geometries.

    The Straight-Blade-Design of the NF-S12 series provides the maximum efficiency of a straight fan blade without the drawback of higher noise emission, which arises when straight blades are used at higher rotation speeds. At the low rotation speeds of the NF-S series, the Noctua Straight-Blade-Design achieves a significantly higher flow rate than forward or backward swept blade designs. Furthermore, among other measures to prevent vortices like the rounded rotor hub, the distance between rotor and stator (tip clearance) was increased in order to reduce the problem of tip vortices which plays an important part in the noise emission of axial fans. With its fan blade exactly tailored to ultra low noise application, the NF-S12 series is significantly more quiet than other high end silent fans.

    Mag. Manfred Stadler MBA of the Austrian Institute for Heat-Transmission and Fan Technology (Österreichisches Institut für Wärmeübertragung und Ventilatorentechnik, ÖIWV) about the development of the Noctua Straight-Blade and Raised-Blade-Designs:

    "In the area of PC cooling, the last years saw a growing demand for axial fans with the lowest possible noise emission, which manufacturers mostly met by simply reducing the RPM of existing models without sufficiently adapting the blade geometry and profile to the modified fluid dynamic parameters. The comparison of measured data and simulation outputs showed that the result was an average deficit of efficiency of 10-15%. The complete redevelopment of the blade geometry and profile was carried out with exact fluid mechanical adjustment to minimal noise emission in a speed range of 400-1800RPM at a height of 25mm and a radius of 40 and 60mm. Both fan blades possess 8-12% more flow rate than comparable products at the same total noise emission and static pressure." (Mag. Manfred Stadler MBA, Austrian Institute for Heat-Transmission and Fan Technology (Österreichisches Institut für Wärmeübertragung und Ventilatorentechnik, ÖIWV))

22.11.2014 - NF-A4x10 5V
Test verdict: "In the end, the NF-A4x10, NF-A8 and NF-A9 fans comply with Noctua’s Premium Fan statement. Backed by an outstanding six year warranty, these fans should last a computer’s life time without you needing to replace them. With pricing starting at $18.95 for the NF-A8, $19.99 for the NF-A9, and $23.99 for the NF-A4x10, you can’t go wrong buying these fans." (Justin Vendette,

21.11.2014 - NH-D15
Test verdict: "There’s no doubting that the Noctua NH-D15 is a very decent air cooler. Noctua improved the shortcomings of the old flagship cooler NH-D14 by expanding the dual tower design and offer a much better memory compatibility, which allows for more memory kits with high-profile heatspreader to sit under the heatsink. The build quality is excellent with the heatsink’s aluminium fins soldered nicely onto the heatpipes. The SecuFirm2 mounting kit makes cooler installation easier and more secured." (Kevin Owi Kheng Him,

21.11.2014 - NH-U14S
Test verdict: "Il est tout d’abord apparu que le NH-U14S est un ventirad très bien conçu et qui doit être produit selon des canons très stricts, c’est tout du moins l’impression qu’on a en considérant sa qualité de fabrication générale. Puis, la phase de montage s’est montrée aussi facile que dans le cas des autres ventirads Noctua (et pour cause) et relativement rapide. Quant aux performances en refroidissement, elles sont, comme toujours pour l’instant chez Noctua (après trois tests plus que concluants), elles sont au-dessus de la mêlée et le tout dans un silence plus que relatif, à la hauteur de la réputation que le constructeur s’est patiemment forgée au fil des années." (Laurent Dessinguez,