ISO 12759-4-2019 风扇--风扇的效率分类--第4部分:以最高运行速度驱动风扇 Fans — Efficiency classification for  fans — Part 4: Driven fans at maximum operating  speed

This document establishes a system for the classification of fan efficiency for all fan types driven by 
motors of nominal rating 0,125 kW and above. It applies to driven fans only, but not to the system 
(finished original equipment manufacturer’s product, for example box fans and roof fans or ventilation 
system) in which they might be installed. This document 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: 
— ISO 12759-3;
— this document (ISO 12759-4);
— ISO 12759-5;
— ISO 12759-6.
There is no method described to compare these classifications and MEL’s.st edition 2019-10 Fans？—？Efficiency？classification？for？ fans — Part 4: Driven？fans？at？maximum？operating？ speed Ventilateurs？—？Classification？du？rendement？des？ventilateurs？— Partie？4:？Ventilateurs？entra？nés？à？vitesse？maximale？de？fonctionnement Reference number ISO 12759-4:2019(E) ？ ISO 2019 ISO 12759-4:2019(E) COPYRIGHT PROTECTED DOCUMENT ？ ISO 2019 Al