EffPlusWW – Efficiency boost for hygienic perfect domestic hot water with heat pumps

Due to the necessary decarbonization of the heat supply, heat pumps are becoming increasingly important for domestic hot water preparation. However, the relatively high requirements for hot water preparation and distribution temperatures for hygiene reasons often cannot be met with current heat pump concepts without the additional use of electric immersion heaters, and the system efficiency of the heat pump and storage tank combination often falls well short of the technical possibilities in the field. This project compares different concepts for hot water preparation with heat pumps in multi-family houses. The focus is on hygiene requirements and efficiency. The aim is to develop and investigate new approaches to achieve significantly higher efficiency in apartment buildings with hot water circulation. Only natural refrigerants are to be used. The project is co-financed by the Swiss Federal Office of Energy (SFOE) and involves the Institute of Energy Systems (IES) at the OST, Lucerne University of Applied Sciences and Arts (HSLU) and various industrial partners.