Impact assessment of climate change on naturally ventilated residential buildings in Lebanon — Overheating risk under future climate scenarios

Abstract

In light of current climate change and global warming, indoor overheating poses a significant risk. Buildings in the Mediterranean climate heavily rely on natural ventilation to maintain acceptable indoor thermal conditions. This reliance poses an increased risk to built environments in this region, particularly those occupied by low-income populations who cannot afford conditioning systems. This study assesses the thermal performance of typical residential buildings in Lebanon in response to future climate change, considering various emission scenarios and climate zones. The study uses morphed future weather data and dynamic building simulations to assess indoor overheating and the potential for natural ventilation to establish comfortable indoor conditions. Findings indicate that indoor overheating occurrences in naturally ventilated apartments are expected to increase in both frequency and intensity in the future, across different emission scenarios, varying by climate. The risk of overheating was highest in inland region, followed by coastal then mountain regions. Regarding natural ventilation comfort hours, coastal climates saw a significant decrease (40% to 26% in the worst case), inland climates witnessed a slight reduction (27% to 23% in the worst case), and mountain climates observed a marginal increase (1% to 3%), accompanied by an increased risk of overheating during peak periods.