This International Standard establishes a classification of fan efficiency for all jet fan types driven by motors with an electrical input power range from 5.5 kW to 155 kW (and this is likely to be in the size range 500 to 1600 mm diameter with motors rated between 5.5 kW to 150 kW from IEC 60034-34-1). This standard describes a number of different procedures to classify the efficiency of a fan or to apply a minimum efficiency limit (MEL). Those procedures are described in parts 3, 4, 5 and 6. There is no method described to compare these classifications and MEL s. Direct comparison shall not be made between the classifications and MEL s described in parts 3, 4, 5 and 6. This International Standard is not applicable to: a) Jet fans for use in enclosed car parks