Overview of manufacturer specifications
Low-profile fans are a special category, but sometimes they are unavoidable in more confined spaces. For technical reasons, it’s always about compromises compared to more respectable fans of normal thickness, but their weight can vary. If the Arctic P12 Slim and Alphacool SL-15 don’t fit your needs, the Scythe Kaze Flex II 120 Slim may be the closest thing to what you’re looking for.
Scythe Kaze Flex II 120 Slim |
+ Suitable for every use case |
+ Decent price/cooling performance ratio |
+ Extra compatibility due to the lowered profile |
+ Higher efficiency than weaker fans with a thicker profile |
+ Particularly attractive operation at lower speeds below 900 rpm... |
+ ... where the fan is more acoustically pleasing than selected competitive solutions |
+ Very quiet operation of bearings and motor |
+ Super low, negligible vibration |
+ Given the format, an extremely sturdy build |
+ Wide speed range |
+ Low speeds possible, stable via PWM down to approx. 309 rpm |
- At medium and higher speeds, tonal peaks at lower sound frequencies (around 190 Hz)... |
- ... and with obstacles also at higher sound frequencies between (380–500 Hz) |
- Eventual collision with nylon dust filters |
- No support for passive operation at low PWM duty cycle |
Approximate retail price: 17 EUR |
* When reading performance values, a certain amount of tolerance must always be taken into account. For maximum speeds, ±10 % is usually quoted, minimum speeds can vary considerably more from piece to piece, sometimes manufacturers will overlap by as much as ±50 %. This must then also be adequately taken into account for air flow, static pressure and noise levels. If only one value is given in a table entry, this means that it always refers to the situation at maximum speed, which is achieved at 12 V or 100 % PWM intensity. The manufacturer does not disclose the lower limit of the performance specifications in its materials in that case. The price in the last column is always approximate.
- Contents
- Scythe Kaze Flex II 120 Slim in detail
- Overview of manufacturer specifications
- 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 grill
- 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
On the evaluation page, the link to frequency analysis on plastic filters was wrong (39 instead of 29). Also, the summary was wrongly replaced by the spec table.
On your evaluation of frequency, you say thay the weakness of the fan only shows when it runs above 1100 RPM (that is 45 dBA). But from reading the charts, there seems to be strong peaks that appear in 39 dBA mode (959 RPM) as well. Did I interpret the data incorrectly?
Thank you for the heads up. Corrected. Including the charts that were really messed up. I was already in advanced stages of exhaustion when I released it yesterday…
… you read the spectrographs well. Yes, you are right, even the 39 dBA (~959 rpm) mode is characterized by more pronounced tonal peaks, so I’ve modified that statement a bit. Below 850 rpm it’s fine in that respect. Approximately such speeds at 39 dBA correspond to tests with a plastic filter and on a grille, which increase the noise level, so when tuned to the same level the fan speeds will always be a bit slower than in a use case without an obstacle.
So thanks for this observation and apologies for the inaccurate interpretation of the results. I wrote the article a bit under pressure and at the same time on the verge of complete exhaustion. I hope that similar mistakes will be avoided in the future.
You don’t have to apologize, it does not take away from the fact that the overall analysis is great work.
Health is very important. I hope you’ll find time to take a good rest and don’t push yourself too hard 🙂. Take care.
Guys, please test 120 and 140x25mm Kaze Flex – they were highly praised by other (but not as advanced as you) reviewiers, especially as case fans. I generally really like them from my own experience for being solid performers; sounding well; having quiet motor and bearing and representing nice quality additionally proven by few years of using them in my own pc.
Sure, the 120 and 140 mm Kaze Flex II will be next in line as far as Scythe fans are concerned. I mean, maybe the Grand Tornado model, which is close to release, will fit in between them.