Bachelor's thesis Christian Tjorben Wenzel


Creation of a technology overview, a market report and a component supplier overview for hybrid heat pump systems

Heat Pumps use natural heat sources, for example the outside air, soil, or groundwater, to produce thermal heat and domestic hot water for buildings. To transfer the energy from the heat source to the heat sink and provide thermal energy with a higher temperature, the heat pump uses a small amount of external power. The efficiency of heat pumps decreases when the difference between the source temperature and the flow temperature of the heating circuit increases. To make sure that the heat pump stays within its ideal operating conditions, it can be combined with a second heat generator to cover the peak loads. Especially for energy-related renovations of existing buildings, hybrid heat pump systems can be integrated into existing heating systems, operated economically and cover some of the required thermal energy from renewable sources. The range of products in the market for hybrid heat pump systems is still small. Only a few companies offer products that combine a heat pump with a condensing boiler. Most of them have originally been boiler manufacturers. This thesis provides an overview of the companies and available systems on the market as well as operating modes and control strategies. Furthermore, it analyzes the communication systems between the system components and the integration into building automation. The bus systems used in heating technology are mainly proprietary. Nevertheless, in the context of smart grids and system optimization, companies are starting to work together on open standards, for example in the EEBUS initiative. Finally, the current market situation and future developments are analyzed. Various surveys conducted by the German heat pump association BWP or the research and consulting company Delta-ee predict a growing market. However, the consumer acceptance still depends on future developments. Increasing electricity prices and low prices for fossil energies reduce the appeal of heat pumps. According to the estimation of Delta-ee the additional costs of hybrid heat pump systems compared to condensing boilers must be below 1500 € to stay competitive.