CHALLENGE - Highly efficient use of hot gas and waste heat in air/water heat pumps for plus-energy buildings and quarters

CHALLENGE is further developing the system concept from the H2020 HYBUILD project for air-to-water heat pumps for densely built-up urban areas. Using simulation calculations and laboratory-scale prototypes, it has been demonstrated that the CHALLENGE concept can save 38% of electrical energy, minimise noise from the outdoor unit in summer, and prevent the formation of local heat islands.