Fan airflow performance
On this page, we will place a focus on airflow of a single fan, and while a totally precise measurement, I'll classify this page as somewhat subjective. But we can get a good indication of airflow per fan at each setting.
Anemometer measuring airflow
With the help of a simple to use Anemometer, we can see how airflow behaves. An anemometer is a device used for measuring the speed of the wind, and actually also is a common weather station instrument. The term is derived from the Greek word anemos, which means wind, and is used to describe any wind speed instrument used in meteorology. It's a relatively cheap device to get and does seem to provide pretty steady results. Each fan is measured with the Anemometer positioned precisely as shown above. Now we can measure how much air the fan is sucking inwards, the value is measured in meters per second, higher is in this metric better, of course.
At a voltage of 5V, you're looking at massive airflow for the included ML140 fans. In this chart, higher is better of course. As you can see the airflow at that voltage surpasses even a 200mm fan.
Once we fully load up the fan with 12V we can measure 3.6 meters of air being moved (wind speed) each second. The fans rate extremely well for high airflow. As mentioned the fans are very loud at high voltage, but this test proofs that airflow-wise, the ML fans deliver proper airflow at a lower (more silent) RPM.