Performance of oil-free water-cooled chiller for a shopping center air conditioning system

Many researches have been conducted on cooling equipment to reduce its energy consumption, maintenance and operation cost. Oil-free chiller uses a magnetic bearing compressor to avoid friction loss from the bearing's contact surface. In comparison to a conventional compressor, the magnetic bearing of the motor, with the help of variable speed drive (VSD), runs more efficiently at partial loads. This paper presents the application of oil-free compressors in a chiller plant. The chiller plant also includes a chilled water system. In designing an energy-efficient air conditioning system it is important to choose proper chilled water and cooling water system. The evaporator is used to absorb the heat from the conditioned room while the condenser rejects the heat from the chiller to the environment through circulating cooling water. This research also aims to analyze the chiller plant for the air conditioning system operates in one of the shopping malls in Indonesia and how it affects the performance of the magnetic bearing chiller. The research also presents an analysis of the efficiency of the chiller plant, the coefficient of performance of each compressor, and their compliance with both national and international standards.