SPACE HEATING AND HOT WATER SUPPLY SYSTEM WITH A TRANSCRITICAL CO2-HEAT PUMP
A transcritical CO2 heat pump prototype for a combined space and hot water heating system for residential European-style low-energy-houses has been designed, built and tested. The goal of the project was to verify the potential of the CO2-heat pump process in such an application and to gain experience with the CO2-heat pump for later commercial realisation. In this report the heat pump performance data are presented. The heat pump was implemented in a typical heating system of a European-style low-energy house which consists of a hot water supply, a heating system for floor and/or radiator heating system and a room ventilation facility. The heating system was modified to account for the characteristic performance losses of the transcritical heat pump at heat sink inlet temperatures above approximately 25-30°C. Design aspects of the heating system and overall system performance data are presented. The CO2 heat pump was found to be capable to significantly improve the overall performance of the heating system compared to similar systems with subcritical HFC or propane heat pumps. Based on the experimental results a preproduction prototype of a house heating system is built and tested. Field tests with the prototypes are going to be carried out to gain more experience on the system characteristics.