Energy performance assessment of lifts and escalators

Energy issues have been a worldwide concern since the oil crisis in 1973. In the past, people were not interested in the energy consumption of elevators because it represented only up to 3% of the total consumption of an office building(1) in 1984. However, in 1998 the figure had already risen to 7%(2) in Hong Kong. Since 1996, a series of building energy codes had been prepared by the Hong Kong government. The last code, the Lift Code, was on the energy efficiency of lifts and escalators, and was very different from existing statutory regulations in Hong Kong. In this paper, a brief introduction to the new code and clarification of the meanings of the various electrical parameters— total power factor, total harmonic distortion, etc.-are given. A new measurement system has been developed for assessing the compliance of an installation with these electrical requirements. The hardware structure of this measurement system and the background mathematical formulae for producing graphic outputs are described. Graphs for one common type of lift drive-active power of a particular calculation cycle-are attached and analysed in detail. It is believed that the comprehensive-ness of this new measurement system with respect to the Lift Code is unique in the world.