An analysis of domestic heat pumps performance
The performance of heat pumps is influenced by several factors related to sizing, installation, and actual operating conditions. For instance, oversizing can lead to low partial load factors throughout the year; the type of heat emission systems and the presence of thermal storage systems affect the frequency of start-ups and its performance. Moreover, weather conditions and the manufacturer's control criteria influence the number of defrosting cycles. Due to the interplay of all these factors, the actual performance of heat pumps often deviates from values calculated based on COP figures declared by manufacturers. This paper analyzes the monitored performance of 182 air-to-water and 4 ground-source heat pumps, predominantly installed in residential settings, using data made available by the HeatpumpMonitor project. The results reveal general trends that can be used in preliminary analysis for both retrofit and new installations, providing an overall picture on the expected performance of heat pumps for residential applications. Besides the temperature lift, oversizing seems to have an influence on the variability in the actual seasonal performance, which can deviate significantly from average values.