Thermal Comfort Assessment in Mixed-Use High-Rise Buildings in Ibadan, Nigeria: Implications for Passive Design in Hot-Humid Climates

Abstract

This study examines the climatic characteristics of Ibadan, Oyo State, Nigeria, and evaluates their implications for thermal comfort and the design of mixed-use high-rise buildings in a hot-humid tropical environment. Both secondary and primary data were utilised. Secondary data were obtained from the WeatherSpark Climate Database, Nigerian Meteorological Agency (NiMet), and NASA MERRA-2 reanalysis records, while primary data included field observations, environmental measurements, and user perception surveys within selected case study buildings. Data were analysed using descriptive statistics, including mean values, seasonal variations, and comparative assessments. Findings indicate that Ibadan experiences persistently high temperatures ranging from 26°C to 29°C annually, with peak values exceeding 32°C during the dry season (December–April). Relative humidity remains high (typically between 70% and 90%), particularly during the wet season (May–October), contributing to elevated discomfort levels. Solar radiation intensity and prolonged sunshine hours further increase heat gain in building envelopes, while wind speeds remain relatively low to moderate, limiting effective natural cooling. Field measurements revealed indoor temperatures frequently exceeding outdoor values in poorly ventilated spaces, while user surveys indicated that over 65% of occupants reported thermal discomfort, particularly in upper floors of high-rise buildings. The study establishes that temperature, humidity, solar exposure, and ventilation are critical determinants of indoor environmental quality and occupant satisfaction. It concludes that integrating passive design strategies such as optimized building orientation, effective shading devices, cross ventilation, and high-performance building envelopes is essential for reducing heat gain, improving thermal comfort, and minimizing reliance on mechanical cooling systems in mixed-use high-rise developments in Ibadan.