Inclusive analysis and performance evaluation of solar domestic hot water system (a case study)

In recent years Solar Domestic Hot Water systems have increased significantly their market share. In order to better understand the real-life performance of SDHW systems, a single detached house was selected for extensive monitoring. Two solar panels were installed on the house roof to provide thermal energy to the Domestic Hot Water (DHW) system. The house was equipped with data logging system and remotely monitored with performance data collected and analyzed over one year. The paper presents the inclusive analysis and performance evaluation of SDHW system, including DHW recirculation loop, under Canadian weather conditions for average family occupancy (two adults and two kids) with daily average DHW, draws of 246 L. Moreover, the study is carried out a significant recommendation to improve the SDHW performance, decrease the gas energy consumption and reduce greenhouse gas (GHG) emissions. The SDHW performance depends mainly on DHW flow rate, draw time and duration, city water temperature, DHW recirculation loop control strategy and system layout. The performance analysis results show that 91.5% of the collected solar energy is transferred to the DHW heating load through the solar tank. The contribution to DHW heating load is about 69.4% from natural gas and 30.6% from solar. The recirculation loop is responsible for close to 34.9%, of DHW total energy.