This manuscript examines installation of sewerage heat exchangers within sewerage systems in order to recover presently wasted heat energy. We focused on decreasing the costs associated with hot water supply or heating by utilization of the heating potential of greywater, the leftover water from baths, showers, hand basins and washing machines, i.e. water free of feces and urine. Different types of heat exchanger were modeled based on thermal performance and these data were compared with actual data from the greywater system in the building. A prototype heat exchanger was developed and constructed based on computational fluid dynamics models developed with STAR-CCM plus software. The thermal performance of the system was simulated and compared with a pilot-plant installation at a wastewater treatment plant. The combination of a sewerage heat exchanger and a heat pump allows utilization of wastewater with low temperature potential. While testing of heat exchanger fouling is still in progress, a number of recommendations as regards to design and operation are provided.