Impact of natural ventilation on the subjective thermal comfort in low-income tropical housing

Abstract

Low-income households in Uganda and similar tropical regions predominantly depend on natural ventilation for indoor thermal regulation due to limited access to and affordability of mechanical cooling systems. Various factors, such as building orientation, window design, roofing materials, and occupant behavior, shape the effectiveness of natural ventilation in providing thermal comfort. Despite its significance, research on the impact of these factors on the thermal comfort of low-income residents in tropical climates remains inadequate. Therefore, this study aimed to investigate the subjective thermal comfort of low-income, naturally ventilated building occupants in Kampala, Uganda. Employing cross-sectional surveys involving 413 participants, IBM® SPSS® V24 was used to conduct statistical tests to examine relationships between variables. ANOVA revealed that building orientation and window type significantly influenced subjective thermal comfort, with North- and East-facing homes providing greater comfort than those oriented South and West. Clay tile roofs offer better thermal comfort than iron sheet roofs. Despite relying on several adaptive measures like opening windows and adjusting clothing, most respondents expressed dissatisfaction with the thermal environment, with a preference for cooler conditions, redesigning or improving ventilation systems, and planting vegetation to improve their subjective thermal comfort. This underscores the need to optimize building design and orientation, integrate passive cooling strategies, and promote green spaces in urban residential planning to enhance thermal comfort in tropical climates. These findings contribute to achieving SDGs 3, 7, and 11, promoting health, energy efficiency, and resilient urban environments.