Climate-adaptive cooling strategies for thermal resilience in Mediterranean dwellings

Abstract

Rising temperatures and more frequent heatwaves pose a critical challenge for Mediterranean dwellings, where overheating in hot periods threatens indoor thermal comfort and energy efficiency. Most retrofitting strategies have focused on thermal insulation, but this approach can intensify overheating, highlighting the need for adaptive cooling strategies. This study evaluates the impact of cooling strategies on non-insulated and insulated dwellings in Barcelona during summer, under current and projected 2050 climate scenarios. Using DesignBuilder software, three cooling strategies were assessed: natural ventilation, mechanical cooling, and mixed cooling combining both. Results indicate that while insulation reduces active cooling energy demand, it increases overheating risks in passively cooled dwellings. Under current climate conditions, natural ventilation effectively mitigates overheating. However, by 2050, overheating risks will increase, with 18% and 25% of summer hours exceeding 29°C in non-insulated and insulated dwellings, respectively. Mechanical cooling demand is projected to double to 39.35 kWh/m2 and 37.7 kWh/m2, respectively. A mixed cooling strategy, integrating natural ventilation with mechanical cooling during heat peaks, proved to be an effective approach, reducing energy demand by up to 33%. These results highlight the need to rethink retrofit policies and integrate mixed cooling strategies to mitigate overheating and reduce energy demand in the face of the challenges posed by climate change.

Peer Reviewed

Postprint (published version)