Alphacool 120 mm Apex Stealth Metal Fan Reality Check – Exact error and root cause analysis and reworking including perspectives

1 - Introduction 2 - Measurements with different results 3 - Measurement protocols 4 - Variance comparison 5 - Summary and conclusion

Summary and fact check

In the end, the post-test did reveal some very interesting findings. These are essentially:

1. Measurement setup:
   The measurement technology used would generally be able to provide fairly accurate, stable and also reproducible measurement results for volume flow, as long as all parameters were set correctly and use was in accordance with the specified guidelines, which rules out major deviations. However, the test setup cannot determine a valid static pressure above 0.29 hPa in its current state and with the components supplied by the tester. The sound pressure level measurements still need to be validated separately. However, the general condition of the set-up and the components handed over is fundamentally deficient. This is simply not the way to handle sensitive technology.
2. Variance:
   The measurement setup as such also offers too many variables which, due to improper work (carelessness and errors during assembly, incorrect input, etc.), can ultimately lead to very different results, which can deviate more or less significantly from the expected result.
3. Comparability of the results:
   Due to these variables in the measurement setup, it is also no longer possible to compare the values with each other or with those of third parties in case of doubt. This means, for example, that comparability is no longer guaranteed if you test one fan on the left and the next on the right.
4. Flow straightener:
   The use of a flow rectifier is definitely helpful, but was obviously completely misunderstood by the tester in the application. Testing with the honeycomb in the given form must therefore be fundamentally questioned, because who would install such a flow straightener directly behind the fan in their housing? Furthermore, this is also just another variable that can be changed in the test setup. If you want/need to test with a flow straightener, then it must be installed in such a way that it cannot have a negative influence on the result.
5. It is shocking to see that I only had to intervene briefly (and deliberately) twice in the parameters of the measurement software in order to arrive at the fabulous values from the Apex article fairly accurately. However, this fact makes me doubt that it was an inadvertent incorrect entry of parameters by the former tester, because you only really have to set these values once, when you first start up the chamber, and then never again (apart from the current air pressure). Furthermore, they do not have to have been changed just once during the measurements in order to produce the results in this way.

Test Result of Alphacool 120 mm Apex Stealth Metal Fan

Despite its 3000 rpm, the Alphacool Apex Stealth Metal Fan does not deliver what we all read in the article about the fan revolution, and what Igor, in good faith, published based on the documents. The values for the airflow volume can, based on my extensive measurement series, only have been generated through a presumed manipulation of the device settings. Even accidental incorrect installation is out of the question, as such values cannot be provoked in that manner. There is no theoretical or practically usable possibility to measure the declared values of static pressure with the setup provided to me! It’s likely that the values were merely extrapolated by the tester, and they also correlate surprisingly accurately with the also false measurements of airflow volume.

How exactly the results published in the article were arrived at, I cannot say with ultimate certainty, as I was not present. Therefore, the truth will probably remain hidden from us forever, especially since the tester’s statements via YouTube allow no plausible conclusions in this regard. The fact is, however, that I was at least able to reproduce the incorrect results. But this was only possible with completely wrong measurement parameters and intent. And even then, it is not even clear whether the tester published the maximum or average values.

If the fan is mounted correctly and measured with professional settings of the anemometer, one can achieve results very close to the actual values produced by the fan, which has now also been validated and professionally documented by third parties. This can be thoroughly substantiated with the real measurement protocols that I have linked. The resulting damage, particularly to Alphacool (and to a lesser extent, surely also to Igor), should serve as a stark reminder of the importance of professional and honest testing, as well as comprehensive and clean documentation including follow-up checks.

This is about real financial losses, but also about reputational damage and the future of the affected companies. The Alphacool 120 mm Apex Stealth Metal Fan has a lot of potential, but needs to be repositioned in its current form, as it is indeed not a bad fan and would have likely performed differently without the outer ring. From this perspective, one must also ponder what the development of the fan could have been like if correct results had been the basis for all the iterations. Since we don’t have any valid measurement protocols of the anemometer from the course of its development since 2022, this remains speculative, but it still leaves many legitimate questions unanswered.

Conclusion

In the course of my investigation, Igor saw correct measurement protocols for the Apex for the first time ever. Alphacool did not know these either, but only some Excel tables manually filled with measurement data, which did not contain minimum, maximum and average values. I personally would have been skeptical at this point. Igor has already learned his lesson from the circumstances and published his mistakes, including the necessary consequences, in his statement. There’s no need to say any more, that was clear enough.

Personally, I can say the following about the measurement setup: Yes, the idea is by no means wrong. Unfortunately, every FMEA idea and the human factor were neglected during implementation. In the end, too many variables spoil the actually valid result and provide a breeding ground for such errors. Intentional or not, it doesn’t matter in the end. A wrong result remains wrong. Personally, I can only say that the whole situation has ultimately resulted in one thing – a lot of resentment, anger and wasted resources on all sides. For the readers and buyers, for Igor and especially for Alphacool.

Under no circumstances should the design remain as it is now. If only because the installation of a fan can cause a crisis, which already provokes errors. The handling is very simple and modest, to put it mildly. The assembly of the whole thing and, above all, its condition after a year of use is also very close to the limit of what is acceptable – according to the motto: they always tried to meet the requirements. Even the simplest tasks could only be carried out with the help of expert third parties. I could go on and on at this point. Unfortunately, I have to say it so bluntly because these are the facts, even if it may hurt the feelings of some outsiders. But business is business, only facts and figures count and you have to have seen (and smelled) it yourself to understand my displeasure.

Outlook

A water cooling system, where the fans have to show their real performance, is already in preparation. The plausibility will be tested on this system. Similar to what Roman did. As soon as the setup is ready, there will be something to read. Furthermore, I personally would like to retire the current box. We need a valid measurement setup, which Igor will finance himself. I have brought along an idea for discussion:

The topic of fan testing will not take place at my place in the future, that’s for sure. Igor and I have already found a really qualified person who will do this. The good thing about it is that this person lives just around the corner from me, I’ve known him since 2015 and can also exercise direct control, which is easy to do locally. I will of course continue to support the project until the measurement setup has been validated. Everything else will come at the appropriate time.

But it will take a while until then. In the meantime, I’m going to do a few more tests in order to finish off the pressure measurement and test the volume. Tim Kutzner is currently printing me optimized funnels from a special material, which I can use to ensure a better seal. I also need a new board, but that shouldn’t be a problem. In addition, the complete new construction is still on the agenda. With this in mind, see you later in the forum…

I would like to take this opportunity to thank Alphacool, who were of course just as interested in the refurbishment. The Noctua NF-F12 and other fans were provided to me by Alphacool free of charge, without any influence or conditions for this review.