[EN 13141-7:2021, 3.10]pressure increase induced by the ventilation unit given as difference between the total pressures at the unit outlet and the unit inlet.Note 1 to entry: In case of equal cross-section areas of the inlet and outlet, the total pressure difference is equal to the external static pressure difference.Note 2 to entry: The parameter pu for a ventilation unit is defined as the parameter pf described in EN ISO 5801 for a stand alone fan.