Abstract
To reach the goal of decarbonization, the thermal loads of buildings are being electrified with the use of heat pumps in replacement of traditional fossil fuel boilers. In the European project HAPPENING, a cascade heat pump system has been designed for the renovation of a building originally heated by a gas boiler. Air-to-water heat pumps provide heat to a water-loop which is the source for a water-to-water heat pump used to produce domestic hot water and for different water-to-air heat pumps, located in the apartments, that cover the heating and cooling loads. The system is controlled with a model predictive control which aim is the optimization of renewable energy consumption. The performance characterization of the heat pumps and the system is crucial for the definition of such advanced control. In the “Heat Pumps Lab” of Eurac research, the system has been characterized in two phases. In this paper we present the first step which includes the investigation of the operational limits, the definition of a performance map and the calculation of the system performance. The second step is the dynamic whole system test where the system is installed in three climatic chambers: one for the external unit, one for the water-loop and one for the internal units