… and airflow
It is made in the same injection mould as the FC120, but still has noticeably better properties. Stronger material, higher weight, different bearings and a more powerful motor make the FK120 one of the most attractive options among inexpensive fans. But that’s only assuming the “right” adjustment. Outside of that, this fan can be quite uncomfortable and ironically for the same reason it is sometimes unbeatable.
… and airflow
With airflow measurements, we can well explain why the test tunnel is shaped the way it is. It doesn’t consist of two parts just so that the “exhaust” can be conveniently clogged for pressure measurements. The anemometer (i.e. the wind speed measuring instrument) is held together by two parts, two formations, through the flanges.
The front part, at the beginning of which the fan is mounted, becomes steadily narrower and from about two thirds of the way through the cross-section is smaller than that of a 120 mm fan. The reason for this is that the cross-section of the anemometer is always smaller than that of the fans tested. The taper towards the anemometer fan is as smooth as could be chosen and the tunnel walls are smooth. This has minimized the occurrence of unnatural turbulence.
The difference between the cross section at the intake (fan under test) and at the constriction point (anemometer) also means a difference in dynamic pressure, the principles of the Venturi effect apply here. In order to avoid distortion at this level and to ensure that the fan airflow is not different from what it actually is, the Bernoulli equation must be applied to the measured values (for maximum accuracy, the calculation also takes into account the internal cross-sectional area of the anemometer, i.e. its inactive part ). After all this, it is again possible to confront our results with the paper parameters.
We use an Extech AN300 anemometer with a large 100 mm fan for the measurements. Its big advantage over other anemometers is that it is made for bidirectional sensing. This allows tests at different fan orientations. However, the “pull” position is more suitable or accurate for measurements, even though it may not seem so at first glance, but we’ll explain.
Here, we get to the second part of the tunnel, the part behind the anemometer. It is part of the whole device, mainly to allow a laminar flow of air to arrive at the rotor of the anemometer. Otherwise, uncontrolled side whirls would be reflected in the results, which are inconsistent with accurate measurements. Therefore, we will test the flow in the pull position. If anyone would like us to elaborate more on this topic, we can elaborate further at any time in the discussion below the article. Ask away. 🙂
In regard to the anemometer, we shall return for a bit to noise measurements and to setting modes according to fixed noise levels. It may have occurred to you as you were reading that the anemometer fan is also a source of sound that needs to be filtered out when measuring fans. For this reason, we insert a securing pad between the frame and the anemometer fan before each measurement and mode setting according to the fixed noise level. This, by the way, also holds the anemometer fan during static pressure measurements.
- Contents
- DeepCool FK120 in detail
- 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
Thank you so much for your hard work bringing us these reviews!
Greetings from Brazil!
Hello
Your expert explanation helped me make my final choice between the two DeepCool FK120 fans and the ASUS ROG Strix fan XF120.
The price difference of these two fans in Iran is insignificant and is around 5 dollars.
Overall, according to your tests, I would choose the Deep Cool fan.
I hope it is the right choice.
Your friend from Iran
Choosing the most suitable fan for a specific scenario is highly complex. In addition to the fact that all situations in practice are more or less different, each has a different set of priorities of individual characteristics. Someone may prefer lower vibrations to a slightly higher airflow, so that the fan does not end up being a source of excessive secondary noise in interaction with, for example, the case.
But when you have looked through our tests, taken a look at the context, evaluated the pros and cons, you must have made the right decision. 🙂
it would be more complex if we had more high quality fans on the market, but nowadays it’s mostly limited to whether you want maximum performance without noise or maximum performance disregarding the noise
in the first case you get A12x25 (or T30 if you have space for that), in the other probably some monster from Delta
if we had high quality fans optimized for specific usecases (like Noctua had in older generations, before releasing the overwhelmingly good A12x25) we could extend that choice to low vs high impedance, but nowadays S12A is entirely irrelevant and their static pressure fans are only used to save money