EN 16573-2017, 3.1.2]:total pressure difference between the outlet and the inlet of the unit, without any recirculation, declared by the manufacturer, and corresponding to 100 Pa or to a lower total pressure if the intended use declared by the manufacturer is less than 100 Pa[SOURCE: EN 13141-7:2010, 3.1.6, modified — The original term was “Ptud/2” and it was defined with the beginning of the present definition.]