The impact of occupants' window opening behaviour during summertime overheating in high-rise social housing

People living in social housing spend 17 % more time indoors compared to the general population. However, these dwellings often experience high indoor temperatures, significantly affecting households, particularly older people, who are more vulnerable to heat-related health issues. Economic limitations restrict these residents' access to cooling systems, increasing their vulnerability during hot weather. The urban heat island (UHI) effect can increase urban overheating by 2.33 degrees C to 4.39 degrees C, impacting mortality rates. This study introduces a novel approach to investigate window opening behaviour, and its impact on thermal performance, and residents' thermal perceptions in high-rise social housing apartment units during summer. Thermal conditions within each apartment were monitored over four weeks from December 2022 to March 2023. Residents' perceptions were assessed using survey questionnaires that captured their thermal sensation, thermal satisfaction, and window operability behaviour. On average, the apartment units show risks of overheating (>26 degrees C) for approximately 25.74 % of the time. Notably, during these overheating periods, indoor temperatures were higher than the outdoor temperatures for 70.7 % of the time, primarily due to closed windows, suggesting that adequate ventilation can minimize overheating, maximize thermal comfort, improve residents' resilience to the UHI effect, and help dissipate stored heat, thereby mitigating the UHI effect.