This International Standard establishes a classification of fan efficiency for all fan types driven by motors with an electrical input power range from 0,125 kW to 500 kW. This International Standard is applicable to bare shaft and driven fans, as well as fans integrated into products. Fans integrated into products are measured as stand-alone fans. This International Standard is not applicable to: a) fans for smoke and emergency smoke extraction; b) fans for industrial processes; c) fans for automotive application, trains and planes; d) fans for potentially explosive atmospheres; e) box fans, powered roof ventilators and air curtains; f) jet fans for use in car parks and tunnel ventilation.