Abstract
A cup vending machine needs both hot water for hot drinks and chilled water and ice for cold drinks simultaneously. In a conventional cup vender, an electric heater is used for water heating and refrigeration circuit is used for water cooling and making ice. Using CO_2 heat pump system, hot water can be obtained from high pressure side and chilled water from low pressure side simultaneously. So it will be expected that the energy consumption and global warming potential is reduced by using CO_2 as working fluid. This report is described the performance evaluation of a cup vending machine applying CO_2 heat pump system.