Exploring the mutual relationship between heat pumps and Urban Heat Islands via building simulation
Rising temperatures, a key consequence of climate change, are driving increased cooling demands, which in turn lead to higher greenhouse gas emissions, particularly when relying on fossil fuel-based power supply. While direct emissions from heat pumps are projected to decrease with the adoption of low global warming potential refrigerants, and increased energy consumption might be balanced by renewable energy sources, the widespread use of these systems has also a significant, and often neglected, local environmental impact. In dense cities, the thermal energy discharged by condensers exacerbates urban heat islands (UHI) phenomena, which can have substantial negative effects on human health. This study investigates the mutual relationship between heat pump technology and UHI through an empirical analysis grounded in building energy simulation. A real building located in Southern Italy is analyzed to assess the impact of UHI-induced temperature variations on heat pump performance in both heating and cooling modes. This includes quantifying changes in energy consumption, performance, and evolving users’ behavior in different scenarios. The environmental impact is evaluated through the Expanded Total Equivalent Warming Impact, an index specifically developed to improve traditional assessments by accounting for UHI phenomena. The results demonstrate how even a slight increase in external temperature can significantly alter the building's energy requirements: while UHI phenomena decrease energy consumption in winter, cooling demand is projected to increase rapidly. The findings of this analysis highlight the growing influence of UHI phenomena on the heating, ventilation, air conditioning, and refrigeration sector, providing valuable insights into its complex interactions with the adoption of heat pumps. This research offers crucial information for urban planners, building designers, and policymakers seeking to optimize building energy efficiency and mitigate the adverse health effects of rising temperatures.