抄録
In recent years, energy efficient hot water supply system is installed in houses to save energy for hot water. However the system performance and its effect in actual condition depend on the hot water usage of each house. Therefore in our study, field survey on the hot water consumption and the performance of CO2 heat pump water heater was carried out in 14 residential houses of 7area in Japan. The survey consists of 2 parts, on-site measurement and questionnaires. Monthly and daily changes of hot water consumption in each house based on the annual measurements were shown in this paper. The characteristics of hot water usage in each house, the relation between a number of families and using hot water, the difference of lifestyle, were considered with the results of questionnaire.
