This study explored the impact of ambient heat on occupants of church buildings in Port Harcourt, Nigeria. The tropical climate of Port Harcourt, characterised by consistently high temperatures and elevated humidity year-round, poses significant thermal comfort challenges for religious buildings that typically accommodate large congregations for extended periods. Six purposively selected churches across the metropolis were investigated using a qualitative-dominant mixed-methods approach that combined non-intrusive observation, in-depth semi-structured interviews, and focus group discussions with occupants and administrators. Through thematic analysis of the collected data, the study identified that occupants experience substantial radiant heat discomfort arising primarily from building envelope surfaces, particularly roofs, walls, and windows. The findings revealed that roof surfaces contribute most significantly to occupants' sensation of overheating, followed by walls and glazing elements. Occupants consistently reported symptoms including excessive sweating, fatigue, reduced concentration, and general unease during worship services. The study identified inadequate natural ventilation, the use of heat-absorbing building materials, suboptimal building orientation, and insufficient shading as primary architectural factors amplifying radiant heat effects. The study recommends incorporating reflective roofing materials, improved cross-ventilation, strategic shading devices, and appropriate building orientation to mitigate radiant heat effects in church buildings.
Kaborlobari et al. (Mon,) studied this question.