Noctuas fan blades are using another angle then on most other fans, it wasn’t possible to get a good shot to compare this with another fan, but Noctua have explained it pretty well on their webpage.

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 quieter than other high end silent fans.

In these pictures you can see the Power draw of both fans.

Noctua has not only come up with an different angle on the fan blades, they also use different kind of bearings called self-stabilising oil-pressure bearing (SSO bearing) which surpasses current types of ball, sleeve or liquid bearings in terms of long-term stability and quietness.

Here is an explanation on how it works:

The rotary motion of the axis generates pressure upon the special oil enclosed within the bearing. This causes the build-up of a dynamic pressure field that centres and stabilises the axis within the bearing shell. While conventional liquid bearings employ the principle of hydrodynamic pressure too, the SSO bearing is equipped with an additional magnet that supports the self-stabilisation of the rotor axis. This allows for a faster, more precise and more reliable centring of the rotor axis and thus increases the long-term stability and quietness of the bearing: When the fan starts, the dynamic pressure field of the liquid bearing needs to build up first, which results in an initial precession of the axis, the so called gyro effect. This amounts to an increased abrasion until the axis is stabilised through the build-up of the dynamic pressure field, which may by and by lead to increased noise emission and bearing defects. Because of this, the SSO bearing possesses a built in magnet, whose field ensures the immediate self-stabilisation of the rotor and hence reduces the gyro effect. In addition to the stabilisation during the start-up phase of the fan, the supporting magnet allows for a more exact centring of the axis within the bearing shell and thus further reduces bearing resistance, abrasion and noise emission.

 

The straight blade design coupled with the SSO bearings makes the Noctua fans a very ingenious product indeed.

Noctua was nice enough to send me a great selection of fans. I used the 1200 version on my Noctua NH-U12 CPU cooler and compared it to both a Coolink Swif-1202 fan that Noctua has recommended in the past for this particular cooler, and a YS-Tech 120mm fan that spins at about 2100 RPM.

The Noctua fan was able to keep the CPU at the same temperature as the faster spinning YS-Tech fan but at a much lower sound level. To be completely honest the Noctua fan running at full blast was nearly inaudible, and when using the U.L.N.A resistor I almost couldn’t distinguish it from the HDD’s spinning.

Then it was time to test the 800 version of the fans, I used three of them in my CM Stacker 830 and I was even more impressed by these. At its default 12v setting I couldn’t hear anything but a faint sound of air flowing, the motor was not audible even if I put my ear only a few inches from it. I also tried to connect the U.L.N.A connector to the 800 fans which brought the RPM down to about 500 RPM; it still was able to push a fair amount of air through the case, but the difference in sound was negligible so I recommend running the 800 at its 12v setting for achieving the best performance.

Final words and conclusion

Noctua impressed us at Driver Heaven greatly a few months back when we reviewed the CPU coolers NH-U12 and U9, and now they have done it again! Not only did the NF-S12-1200 keep up with the YS-Tech 120mm fan performance wise, it did so without any noise. This is honestly something we thought impossible.

The NF-S12-800 was able to maintain our case temperatures at more than acceptable levels, it actually didn’t let the temperatures get any higher than when using the cooler master stock fans. To think a short while ago I considered the cooler master fans quiet!

Is there anything we did not like about these fans? I am pleased to say that this is a rare occasion when I can not find fault with the product in our labs. It has it all, it pushes a substantial amount of air (81 m³/h for the 1200, and 59 m³/h for the 800), and it does so at the lowest level of sound I’ve experienced with fans at this performance. The only thing I could imagine people complaining about would be the choice of colouring. Personally I like the brownish colour; I think it makes them stand out from the crowd of all black, acrylic and LED fans currently saturating the market.

The only real downside with these fans are the price, they cost about €22 which is rather expensive for a fan. That said, you get what you pay for.

Objectively, the price is the only factor that stops us from giving it our highest award; the “Driver Heaven Heavenly Hardware Gold Award” until then, it receives our Editors Choice Award for its superb performance to noise ratio.

What do these awards mean?

The Noctua fans can be found at QuietPC for approximately €22.