This document establishes a classification of fan efficiency for all jet fan types driven by motors with an electrical input power range from 5,5kW to 155kW (and this is likely to be in the size range 500mm to 1600mm diameter with motors rated between 5,5kW and 150kW from IEC60034-30-1).This document is not applicable to jet fans for use in enclosed car parks.This document can be used by legislators or regulatory bodies for defining future energy saving targets.