Investigating the Effect of Hot Water Consumption Profile on the Performance of Solar Water Heating Systems

In this paper, a forced-circulation solar water heater system is simulated for different hot water consumption profiles using flat plate collectors as well as evacuated tube collectors. The profiles studied are the actual samples of hot water consumption profiles for different commercial centers and institutions. Dynamic simulation outputs of system thermal performance are used as economic analysis inputs of solar water heater to evaluate the effect of hot water consumption profiles on the economic performance of system. The results show that profiles allocating large amounts of hot water consumption from 6 to 10 a.m. increase the cost of providing required energy for the auxiliary system. As a result, the system payback time increases. According to the simulation findings, changing profiles in the system can moderately increase the annual life cycle saving by 61% and 31% for the flat plate and evacuated tube collectors respectively.