The basis of the methodology, the wind tunnel
With the addition of the Shadow Wings 2 tests, you now have a full overview of the features of all unlit BeQuiet! fans in 120 mm format. Shadow Wings 2 is between Silent Wings 3 and Pure Wings 2 in terms of both price and design. In terms of efficiency, they are closer to the more expensive Silent Wings 3 and in certain situations they give top-notch results. Given the lower price, this can be a very attractive option, but there are some things to look out for.
Základ metodiky, veterný tunel
The basis of the methodology, the wind tunnel
Before you start reading the methodology with all the details, take a look at the test tunnel as a whole. This is the heart of the whole system, to which other arteries are connected (manometer, vibrometer, powermeter, …). The only solid part of the tunnel from the measuring instruments is the anemometer.
The shape of the wind tunnel is inspired by the Venturi tube, which has long been used to measure the flow of liquids and gasses. The Venturi effect for wind speed measuring is also known from the aerospace industry. However, the design for measuring computer fans has its own specificities, which this proposal of ours reflects.
The individual parameters of the HWC wind tunnel for fan tests are the result of physical simulations and practical debugging. All the details (folds, material or finish used) have a rationale behind them and are designed this way for a specific reason. We will discuss the individual design details in turn in the description of the sub-variable measurements.
Now we will briefly elaborate on some things that do not fit thematically into the text of the following chapters. Namely, for example, that the skeleton of the wind tunnel is the work of a 3D printer (PLA). The rough print was, of course, then thoroughly machined by grinding, fusing, polishing and varnishing. Especially important is the smooth finish of the interior walls.
When joining the individual parts, the emphasis was on making sure that they fit together flawlessly, that they were sealed flawlessly (we will come back to this when we describe the test procedures for pressure measurement), but also that the joints were not loosened by use. Everything is disassemblable for servicing purposes, but it is ensured that the properties are maintained during use and, for example, even under the stress of vibration. The threads are secured with either lock nuts or thread-locking fluid. It depends on which is more suitable in which place.
When the wind tunnel is not in use, it is enclosed in a dust-tight chamber. In addition to the technical equipment and its correct storage, it is also important for objective outputs that all measuring instruments are calibrated according to the standard. Without this, it would be impossible to stand behind your results and rely on the manufacturers’ specifications. Calibration protocols are therefore an important part of the methodology. Testing is carried out at an ambient air temperature of 21–21.3 °C, humidity is approximately 45 % (± 2 %).
Fans come to us for testing in at least two pieces of the same model. If the deviations of any of the measured values are greater than 5 %, we also work with a third or fourth sample and the average value is formed by the results of the fans that came out the most similar and the differences between them fit under 5 %.
- Contents
- BeQuiet! Shadow Wings 2 (BL085) in detail
- The basis of the methodology, the wind tunnel
- Mounting and vibration measurement
- Initial warm-up and speed recording
- Base 6 equal noise levels…
- ... and sound color (frequency characteristic)
- Static pressure measurement…
- … and airflow
- Everything changes with obstacles
- How we measure power draw and motor power
- Measuring the intensity (and power draw) of lighting
- Results: Speed
- Results: Airlow w/o obstacles
- Results: Airflow through a nylon filter
- Results: Airflow through a plastic filter
- Results: Airflow through a hexagonal grille
- Results: Airflow through a thinner radiator
- Results: Airflow through a thicker radiator
- Results: Static pressure w/o obstacles
- Results: Static pressure through a nylon filter
- Results: Static pressure through a plastic filter
- Results: Static pressure through a hexagonal grille
- Results: Static pressure through a thinner radiator
- Results: Static pressure through a thicker radiator
- Results: Static pressure, efficiency by orientation
- Reality vs. specifications
- Results: Frequency response of sound w/o obstacles
- Results: Frequency response of sound with a dust filter
- Results: Frequency response of sound with a hexagonal grille
- Results: Frequency response of sound with a radiator
- Results: Vibration, in total (3D vector length)
- Results: Vibration, X-axis
- Results: Vibration, Y-axis
- Results: Vibration, Z-axis
- Results: Power draw (and motor power)
- Results: Cooling performance per watt, airflow
- Results: Cooling performance per watt, static pressure
- Airflow per euro
- Static pressure per euro
- Results: Lighting – LED luminance and power draw
- Results: LED to motor power draw ratio
- Evaluation
Which Fan would you recommend to use as 3x Intake and Rear Exhaust on the Corsair 4000D between the Shadow Wings 2(BL085), Pure Wings 2(BL039) and Light Wings(BL072)? I’m having a Hard time deciding.
Have you seen our Light Wings (BL072) tests? We published them later than the tests of Shadow Wings 2 (BL085) and Pure Wings 2 (BL039), so their results are missing in the graphs of this article. But you can find them in this one.
The behaviour of all three fans will be very similar in your case, both performance-wise and acoustically. Nevertheless, the Pure Wings 2 is the model that achieves the lowest airflow at equal noise level, but it is also the cheapest… If you are also considering the Light Wings (BL072), I assume you have a higher budget and at the same time we might not care so much about the ARGB LEDs (since you are also deciding between unlighted fans)? In that case I find Shadow Wings 2 (BL085), with which you will not get worse results, the most attractive option. The argument for Light Wings (BL072) could be a wider speed range with lower minimum speeds. Shadow Wings 2 (BL085) start from almost 500 rpm. If you were to run the fans above that anyway, it really doesn’t matter.
I also checked the vibrations, which can, especially in your type of use (on a case), increase the noise, but they are practically zero with the BL085 as well as with the BL072. Personally, I would reach for the Shadow Wings 2 (if you don’t crave the extra low speed of the Light Wings) and enjoy the 40 euros saved. 🙂