A Study on the Evaluation of Domestic Water and Gas Consumption through the Application of Hot Water Recirculation System in Residential Buildings

In this study, recirculation system to individual hot water supply system is composed by scaled 1:1 model and the performance evaluation is executed in accordance with the standards of faucet usage schedule for 1 unit daily. Also, the application possibilities for recirculation system of individual hot water supply system in high-rise residential building is examined through the analysis of waiting time for hot water, quantity of wasted water and energy consumption quantity. The results of this study are as follows. The application plan of recirculation system shows that waiting time for hot water has not changed regardless of season and it can be reduced from about 72 to 85% compared to the prior plan. Also, the whole quantity of water wasted in a month is likely to be decreased approximately 74%. Gas consumption increasing rate is about 42% lower than that of the prior plan in comparison with spring/autumn and winter.