Abstract
The production of hot water for bathing in Poland accounts for around 15% of the total energy consumption of a typical household. According to EU data, final energy consumption for lighting and appliances is similar to final energy consumption for hot water preparation. This makes it a significant contributor to housing and utility costs, exceeded only by heating expenses. Research has indicated that only about 10% of the water utilized during a shower is necessary for hygiene purposes. Consequently, around 90% of the hot water supplied to the shower is ultimately discharged into the sewage system. By harnessing the primary energy from wastewater, we can effectively conserve heat energy and reduce the overall expenditure associated with hot water. The objective of this article is to explore the utilization of heat recovery from domestic wastewater as a means to enhance the energy efficiency of residential buildings.