Performance variability of air-water heat pumps in cold and warm years across European climate zones

This study examines the performance and economic feasibility of air-water heat pumps across diverse European climate zones under varying energy price scenarios. Focusing on four regions (Poland, Lithuania, Croatia, and Spain), the analysis evaluates the seasonal coefficient of performance and net present value during cold and warm years. Results indicate that seasonal coefficient of performance is highly sensitive to climatic variability, with efficiency decreasing in colder regions up to 67 % noted in Poland and Lithuania. while remaining stable in warmer climates, with a variation of approximately 4 % observed in Spain. Economic analysis reveals that in the high electricity price scenario, only Spain achieved positive net present values in both periods, with smaller heat pumps (8 kW) being the most cost-effective. Conversely, in the high gas price scenario, all regions demonstrated positive net present values, particularly for larger units (13 kW) in cold years. This indicates the differing impacts of energy price variations on the operational efficiency and cost-effectiveness of heat pump systems in diverse climatic contexts. These findings emphasize the importance of adapting heat pump sizing to local climatic conditions and implementing energy policies that balance electricity and gas prices. Future studies should aim to develop more comprehensive approaches to capture the interplay between climatic variability and economic feasibility.