Improved energy efficiency standards for vapour compression chillers serving buildings

This study discusses how to improve energy performance standards for vapour compression chillers. A review on the national standards adopted in the USA, Canada, Australia, the European Union, China, Chinese Taipei and Hong Kong showed that minimum allowable levels are simply stated for the coefficient of performance (COP) of chillers at full load conditions. These requirements are insufficient to promote high efficient products. To facilitate the labelling and certification of high efficient chillers, it is more preferable to have a classification scheme for the full load COP. Such a scheme has been adopted in the European and Chinese standards. Yet the minimum COP for each class needs to be fine-tuned based on a comprehensive range of chiller products. While the American-based ASHRAE standard sets out the minimum integrated part load value (IPLV) to specify the minimum COP of chillers at part load operation, it is inadequate to use the IPLV to present the actual chiller performance under diverse building cooling load and climate conditions. The significance of this paper is to highlight a pragmatic rating method which specifies precisely the part load performance of chillers and to address the ways of properly developing minimum COP levels for chillers at part load operation.