Introduction

From time to time people come up to me and ask what can they do to make their computer quieter but not loosing some of the features in it. Most computer users out there seek for ways to improve cooling for their systems but also minimizing the sound of the fans. What does it take to make a quietest computer? Well you could go with water cooling, but there is a big risk of block crack and leakage. You can also go with an old fashion air cooling which is much cheaper and way more dependable. Today we are going to take a look at some of the most promising fans on the market which are provided by Noctua, NF-S12B FLX. NFS12B FLX claims to have best performance at low speeds and minimum sound noise. With this in mind, lets see if we can build an ultra-quiet case:)

About the Product

Following information is taken from the Noctua website.

Succeeding the vastly successful NF-S12, the NF-S12B is a next generation quiet fan featuring Noctua's advanced SCD2 technology as well as a highly optimised blade geometry with Bevelled Blade Tips that improves its award-winning predecessor's airflow efficiency by up to 10%. Topped off with Noctua's time-tested SSO-Bearing, 6 years warranty and versatile 1200/900/600 rpm speed settings, the NF-S12B FLX is a premium quality fan that offers full flexibility in quiet to ultra-quiet case cooling. More information: NF-S12B Blade Design The NF-S12B sports a further refined version of the original NF-S12’s Straight-Blade-Design that broke new ground in the realm of quiet PC cooling in 2006 and quickly became renowned for its excellent airflow/noise ratio, making the NF-S12 one of the last years’ most successful fans in the PC cooling market. Building on the proven basis of the award-winning NF-S12’s impeller, the design goal for the NF-S12B was to further improve its predecessor’s much acclaimed airflow/noise ratio and to increase static pressure in order to allow for a broader range of application. These goals have been achieved by reducing the tip clearance at the leading edge and adding Bevelled Blade-Tips, a feature first introduced with the NF-B9 92mm fan. Reducing the tip clearance by increasing the length of the blades allows for a bigger blade surface area as well as improvements both in airflow and static pressure. This measure though tends to come at the expense of increased noise emission due to critical rotor-stator interaction. For the NF-S12B, this issue has been dealt with by only increasing the length of the blades at the leading edges and adding a bevelled structure (Bevelled Blade-Tips). By increasing the distance between the impeller and the frame at the outermost areas of the fan where the impeller achieves the highest velocities, Bevelled Blade-Tips help to reduce critical rotor-stator interaction. As a result, the NF-S12B’s modification of the original NF-S12 blade geometry combines the benefits of a reduced tip clearance with those of a bigger distance between the tip of the trailing edge and stator parts, achieving up to 10% improvement both in airflow to noise and pressure to noise ratio. At 1200rpm, the NF-S12B FLX produces 18% more airflow and 14% more static pressure than its predecessor at 1300rpm. Running at 100rpm slower, the NF-S12B is almost 1dB(A) quieter at the same time! At 700rpm, the NF-S12B ULN produced 13% more airflow and 16% more static pressure than its predecessor. Despite of this impressive boost in performance, the NF-S12B runs just as quiet as the NF-S12!   NF-S12B & NF-P12: Technical Backgrounds In the design and development of axial fans, the three aerodynamic key parameters of airflow, pressure and noise play a major role. Usually, the goal is to achieve the amount of airflow and static pressure required by a specific application at the lowest possible noise emission. The design should hence provide the optimal balance of airflow, pressure and noise for a given application. However, even in the field of PC cooling, each application has different requirements: Whereas CPU coolers with tighter fin-spacing require high static pressure, it's mostly the airflow to noise ratio that counts when it comes to case fans. Common fans are usually designed to be all-round solutions with compromises in certain areas in order to achieve solid results in all typical applications. Noctua, on the other hand, is following a two-fold approach with its S12 and P12 fan series in order to achieve optimal results at various applications: While the NF-S12B was optimized so as to provide a class-leading airflow to noise ratio and therefore makes for an excellent case fan, the NF-P12 was designed to produce high airflow and an outstanding amount of static pressure, which makes it perfect for use on CPU coolers and other high-impedance applications. The following illustration shows how this approach differs from common all-round solutions: While the NF-S12B delivers less static pressure, it provides a better airflow/noise ratio. Therefore, it's perfectly suited for case ventilation as well as all applications which don't demand high static pressure and where maximum quietness is the first priority. The NF-P12 on the other hand provides a better pressure/noise ratio and should therefore be the first choice for all applications which demand high static pressure such as CPU cooling.

Size 120x120x25 mm Bearing SSO-Bearing Blade Geometry NF-S12B Blade Design with BBT Rotational Speed (+/- 10%) 1200 RPM Rotational Speed with L.N.A. (+/- 10%) 900 RPM Rotational Speed with U.L.N.A. (+/- 10%) 600 RPM Airflow 100,6 m³/h Airflow with L.N.A. 75,8 m³/h Airflow with U.L.N.A. 49,2 m³/h Acoustical Noise 18,1 dB(A) Acoustical Noise with L.N.A. 10,6 dB(A) Acoustical Noise with U.L.N.A. 6,2* dB(A) Static Pressure 1,31 mm H2O Static Pressure with L.N.A. 0,76 mm H2O Static Pressure with U.L.N.A. 0,34 mm H2O Input Power 1,2 W Input Current 0,1 A Voltage Range 12 V MTBF > 150.000 h Scope of Delivery Ultra-Low-Noise Adaptor (U.L.N.A.) Low-Noise Adaptor (L.N.A.) 4 Vibration Compensators 3:4-Pin Adaptor 4 Fan Screws Warranty 6 years

Now that we got technical information out of the way, lets take a closer look at NF-S12B FLX.

Closer look

NF-S12B FLX		Box Front

Noctua has a very unique and stylish packaging for their fans. Every fan comes in its own box which is decorated with various logos and specifications of the product. NF-S12B FLX is presented to the user right a way trough a see-trough front cover. We can also see the vibration compensators in the front. These vibration compensators are designed to lower the vibration of the fan and the case, very impoerant when designing an ultra quiet case.

1200/900/600 RPM		Back of the box

NF-S12B FLX is able to perform on three different speed levels, 1200, 900 and 600 RPM. This is noted on the front of the package. On the back of the package we found more detailed specifications about the NF-S12B FLX. Noctua also explain what are the Bevelled Blade Tips and why they are needed.

Specifications		Side of the box

NF-S12B FLX is also equipped with SSO-Bearing. SSO-Bearing technology was designed by Noctua and is well respected on the markets. This particular technology is designed to provide a smooth and super quiet operation. If you are not sure what kind of fan you need, you can look at the sales pitch on one of the sides of the packaging box of NF-S12B FLX. Along with NF-S12B FLX Noctua also has NF-S12B ULN and NF-P12 fans for extreme cooling.

Side of the box		Detailed specifications

The back side of NF-S12B FLX package comes a part for more detailed specifications of the fan. Is you are a geek like me, you would appreciate this information. Noctua lists their models and blade types which you can see the difference of performance comparing to the standard fans. By the way, if you look closely you can find UMLan logo in the reviewers section:)

NF-S12 Awards		Out of the box

NF-S12B FLX comes in a clear plastic molding that allows users to see all of the components that come with the unit. By having a protective molding around the parts, Noctua protects your investment from scratches or dings. Pretty much all of their products come with some kind of protective plastic. Great design.

Contents		NF-S12B FLX Front

The NF-S12B FLX comes with a molex adapter (fan runs as 1200 rpm), 900 rpm adapter, and 600 rpm adapter. Inside of the 900 and 600 rpm adapters are small resistors which limit the current which is applied towards the fan itself, causing it to spin at slower rate. Later in our testing's we are doing to be running all 3 fans at 600 rpm to achieve silent case.

NF-S12B FLX Back		Unique Blade Design

Both front and back of the NF-S12B FLX are very similar to other fans by Noctua. The base of the fan is 'cream' color and the actual blades are brown. You know what they say, brown is a new red. I find it very stylish. NF-S12B FLX has a Bevelled Blade tips. If you would like to know more about Bevelled Blades, i advise you to check Noctua website for more info.

Air Flow Markings		Vibration Compensators

Just like every fan NF-S12B FLX has markings of which way the blades rotate and the way the air flow is being pushed. These markings do not stand out so you would need to pay attention to the fan while installation. NF-S12B FLX could be installed in two methods. Noctua has included fan screws and vibration compensators. For our project we will be using vibration compensators across three NF-S12B FLX fans.

Vibration Compensators		Vibration Compensators

These compensators are made of rubber material and very easy to install. You have to be careful with these because if you pull too much on the compensator, it could rip. This happened to be few times with other Noctua fans. I guess i ve learner my lesson heh.

Installed		Ready to rock!

There are no finger guards or anything that would protect your fingers from accidental damage so please be careful while working on open case. DO NOT WORK WITH FANS WHILE SYSTEM IS RUNNING. We have installed 3 fans, 1 in the back and 2 in the front in about 10 minutes. Easy!

Testing

With NF-S12B FLX we did couple of tests. We have used stock fans from Lian Li PC-K10, which run at 1200 rpm to perform testing and temperature reading. The way we overloaded the CPU was Folding at Home method. We have clocked our dual core CPU to 100% and let it run for 20 minutes. The details of the SpeedFan and Asus utility are below.

Stock Cooling

As you can see the stock fans ran at 1200 rpm and the system temperature was at 28C CPU at 31C and motherboard at 19C. Not too bad at all for stock cooling. For the second test we have replaced 3 stock fans with NF-S12B FLX fans running at only 600 rpm. The results are below.

Noctua Cooling

You can clearly see that the new fans were running at 600 + - rpm and that the system temperature did not change at all. This is a great news for us since we are looking to make a quiet case.

So wait, how quiet is it? Well as many of you know, sound is measured in Decibel. The level of Decibel range is described below.

Decibel Range Chart

With this chart in mind we went to the Digital Level Recorder.

Stock Fans		Noctua NF-S12B FLX Fans

We have measured the sonar level of stock fans and NF-S12B FLX fans and these are the numbers. For the Stock fans we have gotten 53.4 Decibel and for the NF-S12B FLX fans we got 47.4 Decibel. These tests were done in our lab with everything off except light. So going back to our chart, we are running as 'Quiet Conversation'.

Conclusion

We have been reviewing fans for a very long time now and every time we face a Noctua product we get excited more and more. Waiting on that new special fan that will make everything cooler and quieter. Air cooling is still very much used everywhere you can turn and it is very important. By proper cooling your systems you prolong the life of your components. Noctua NF-S12B FLX is a great example of a product which has been led to perfection to aid you with all your cooling. Noctua does a great job engineering their fans for maximum performance and i am very proud to say that NF-S12B FLX is one of the best fans i ve seen on the market. Running at 1200, 900 or 600 rpm NF-S12B FLX provide maximum cooling with minimum sonar levels. The actual sonar levels of 1 NF-S12B FLX running at 600 rpm is 10.6 Decibels. This could be compared to a mosquito flying in the room. The SSO-Bearing and Bevelled Blade designs are responsible for giving quietest operations possible and maximum air flow performance to a user. It gives me a great pleasure to award Noctua NF-S12B FLX a perfect score 10/10!!

Some pros we found:

Easy to install and use

Flexible speed settings

Very low sonar levels at maximum air flow

Some cons we found:

None that we could find