Detailed Analysis on Operation Characteristics and Cooling Energy Saving Effect of Chiller Staging in an Office Building

Abstract Commercial buildings account for a significant proportion of the total building energy use in Korea, and coolingenergy, in turn, accounts for the largest proportion of total energy consumption in commercial buildings. Under this circumstance,chiller staging is considered to be a reasonable and practical solution for cooling energy saving. In this study, the part-loadratio and the operating characteristics of a vapor compression chiller were analysed within an office building. In addition,energy consumption among different chiller staging schemes was comparatively analysed. As a result, significant proportionsof total operating hours, cooling load and energy consumption turned out to be in the part load ratio range from 0% through50%, and thus energy consumption was significantly affected by the chiller COP at low part-load conditions, indicatingthat the chiller operation at the part-load is an important factor in commercial buildings. In addition, utilizing a sequentialchiller staging scheme can reduce the annual cooling energy usage by more than 10.3% compared to operating a singlechiller.