Big test of 120 mm fans. We known everything about eight of them

Static pressure measurement…

To write that we have something mapped out to the last detail is perhaps too bold, but after proper preparation, few pieces of hardware are as easy to evaluate as fans. Of course, this had to be preceded by long preparations, developing a methodology, but you already know the story. What you don’t know yet is the first fruit, or rather the results of Akasa, SilentiumPC, SilverStone, Xigmatek or more exotic Reeven fans.

Static pressure measurement…

Finally, it is time to move further down the tunnel a bit. Just behind the fan is a static pressure sensing probe. Its position has been chosen with maximum measurement efficiency in mind. In other words, the sensors are placed at the points of highest pressure (although this is virtually the same everywhere in the unconstrained part of the tunnel).

The Fieldpiece ASP2, which is connected to the Fieldpiece SDMN5 manometer, is used to measure the static pressure in the tunnel. The latter also allows measurements in millimetres of water column, but we measure in millibars. This is a more finely resolved base unit for this meter. And only from there we convert the measured values into mm H2O to allow easy comparison with what the manufacturers state.

Internal part of the probe to measure the static pressure inside the tunnel…

The difference in cross-section at the intake and exhaust (where the exhaust in this case is considered to be the anemometer) is related to the fact that the pressure increases in the narrowed part and with it the airflow. In order to avoid distortion at this level and to prevent the airflow from being stated as higher than it actually is, the Bernoulli equation must be applied to the measured values to compensate for the difference between the intake and exhaust cross-section (it also takes into account the motor housings). After this, it is again possible to confront our results with the paper parameters.

… and the external part leading to the manometer

The greater the difference between the manufacturer’s claimed values and ours, the less the specifications correspond to reality. If the claimed values are significantly higher, it is certainly an intention to artificially give an advantage to the fans on the market. However, if the manufacturer quotes a lower pressure value than we do, it points to something else. Namely, a weaker tightness of the measuring environment. The less tight the tunnel is, the lower the pressure you naturally measure. This is one of the things we tuned for an extremely long time, but in the end we ironed out all the weak spots. Whether it’s the passage for the probe itself, the flanges around the anemometer, even the anemometer frame itself, which is made up of two parts, needed to be sealed in the middle. Finally, the flap at the tunnel outlet must also be perfectly tight. That’s because static pressure has to be measured in zero airflow.

The furthest part from the fan – cap for static pressure measurements

But there is one thing that often lowers the pressure of the fans a bit. And that’s protruding anti-vibration pads in the corners or otherwise protruding corners. In other words, when the fan doesn’t fit perfectly to the mounting frame at the inlet, and there are small gaps around the perimeter, that also affects what you measure. But we have not gone into this because it is already a quality feature of the fan. In the same way, it will “stand out” and perform a bit weaker than it has the potential to do with better workmanship, even after application by the end user.


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Retrotest: 8× PC case. From small to “large”

In the archives we found some remarkable tests that have never been published in English. Although they are heavily out of date ( cases included have not been sold for a long time), it illustrates well the possible impact of cooling across a wide variety of designs. And by those we also mean completely passive solutions that use their own shell to dissipate heat, as well as rather larger midi-towers and also something in between. Read more “Retrotest: 8× PC case. From small to “large”” »

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In vivo fan tests: 14 models in system positions

Here and there we come across the opinion that it is advisable to test fans in real life conditions, which we can easily refute. At the same time, we understand that a layman can best identify with the differences in component temperatures that arise precisely due to different fan airflows. To help you see the correlations of such tests with results from “unnatural” environments, here’s something we remembered. Read more “In vivo fan tests: 14 models in system positions” »

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Akasa Gecko Pro: An SSD cooler with a “different” orientation

The successor to the SSD cooler, which didn’t have much competition in its price range. That’s one way to introduce the Gecko Pro, which is a bit more expensive, but also more refined (in terms of mounting as well). And it also has a distinctive feature that clearly distinguishes it from other coolers – the fins are not longitudinal (as is common), but in width. The price to cooling performance ratio is again excellent. Read more “Akasa Gecko Pro: An SSD cooler with a “different” orientation” »

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Comments (2) Add comment

  1. Although the test a super, non of the recommended Fans can be bought today making it intentesting but overal not that usefull. For next test, please include some fans that are expeded to be solf for at least one year later.

    1. The selection of older, outdated fans for this test was purposeful. The goal was to get some results/ some basic idea to have something to go off of when evaluating current fans. When you look at the current database, it overwhelmingly contains fan models that are widely available in stores: https://www.hwcooling.net/en/bequiet-light-wings-bl072-sturdy-rotor-with-argb-leds/13/

      The first eight have been selected so that later on none of these models will lack (since they are no longer sold) an in-depth evaluation of all aspects, as we do at the end of the “solo” tests, of which there are 26 after this article.

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