Initial warm-up and speed recording
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.
Initial warm-up…
Before we even start measuring anything, we let the fans run “idle” for a few minutes after plugging them in. This is because immediately after a cold start the fans reach different parameters than after a certain amount of short-term operation.
Until the operating temperature of the lubricant is stabilized, a typically lower maximum performance is achieved. This is because at lower temperatures the lubricant is denser, which is associated with higher friction. Therefore, the fans do not reach maximum speed immediately, but only after the first few seconds. Before the first measurements, we therefore leave the fans running for at least 300 seconds at 12 V, or 100 % PWM intensity.
…and speed recording
The speed of the fans is monitored using a laser tachometer, which reads the number of revolutions from a reflective sticker on the rotor. For this purpose, we use the UNI-T UT372 device, which also allows real-time averaging of samples. Thus, we do not record the peak value in the graphs, but the average speed value from a 30-second time period.
However, the speed itself is a relatively unimportant parameter that is often given more attention than is appropriate. This is the case even in many fan or cooler tests, where speed is used to normalize the different modes in which other variables are measured.
However, hyper-focusing on a specific speed is a rather unfortunate decision if only because the fans don’t gain any commonality. At the same speed all other variables are different, there is no intersection. It can be noted that a better normalization would have been by any other variable, whether it be static pressure, flow or noise level, which wins in our case. But more on that in the next chapter.
We only measure the speed so that you can associate a particular parameter (such as the amount of static pressure or some noise level) with something according to which you can adjust the fan yourself. Perhaps for that alone, the information about the achieved speed is useful. As part of the fan analysis, we will also indicate what the fans’ starting and minimum speeds are. Start-up speeds tend to be higher than minimum speeds because more force is required to get the rotor moving than once the fan rotor is spinning, and a minimum power intensity is sought at which the fan does not stall.
- 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. 🙂