In addition to the size and speed of a fan, airflow and static pressure are two important indicators for evaluating the performance of a fan.
For airflow, the amount of air transported is specified either in cubic meters per hour (m³ / h) or alternatively in CFM (cubic feet per minute). In contrast, static pressure is measured in mm H²O with the so-called (milli-) meter water column and corresponds to the pressure in the specified water depth.
Information on the airflow therefore indicates the maximum amount of air that can be moved by the fan, whereas figures on the static pressure provide information about the pressure at which the air is transported.