Comparative study on small-scale HPs for decentral DHW preparation in multi-family buildings
Abstract
In renovated multi-family buildings, domestic hot water preparation is still predominantly supplied by gas-fired or electric boilers. Where centralized solutions cannot be adopted, flat-wise compact heat pump solutions can contribute substantially to the decarbonization of the building stock and reduce the invasiveness of the installation, but an experiments-based comparative study of different decentral hydronic concepts is missing in the literature. Within this work, three heat pumps based solutions for decentral domestic hot water preparation were tested and their dynamic behavior with a predefined tapping pattern was observed. The results highlighted that the use of a mantle heat exchanger in common boiler heat pumps results in longer charging intervals and increased electricity consumption. Through simulations, the monthly performance of the air-source systems was evaluated and indicated a mini-split solution as the most efficient, with a yearly performance factor of 2.5.