Part-load efficiency is rapidly becoming the most important measure of energy efficiency in chiller units. Around the world, new environmental standards are increasingly based on a combined part-load figure, reflecting the fact that chillers are rarely run at their full cooling capacity. Instead, measures such as Integrated Part Load Value (IPLV) and Seasonal Energy Efficiency Ratio (SEER) combine weighted averages at 100%, 75%, 50%, and 25% load for a more realistic view of energy consumption as it varies throughout the year.
With China and the U.S. both setting minimum acceptable standards for IPLV, and the European Union building SEER into its Ecodesign directive, equipment manufacturers are challenged to consider efficiency in a new way and prioritize part-load energy use — even ahead of nominal efficiency figures.