Energy Efficient Shower System with Waste Heat Recovery

This study proposes a high-efficiency energy-saving shower system consisting of a direct-heating heat pump water heater (HPWH) and a self-developed waste heat recovery heat exchanger. The system recovers the waste heat from both shower wastewater and hot steam. It is shown that the coefficient of performance of the heat pump (COP_HP) is equal to 5.6. Moreover, an energy consumption analysis of shower water was researched by the study, which finds the waste heat recovery is 12.51 kW and the heat recovery ratio is 72%. Finally, the overall coefficient of performance of the shower system (COP_sys) is equal to 9.4. Due to its high efficiency and waste heat recovery, the physical size of the shower system can be reduced, thereby enabling its integration into the building structure.