Influence of different roof design parameters on classrooms' thermal performance in tropical savannah climate of Nigeria

Abstract

Hot weather conditions, seasonal rainfall, intense solar radiation and low relative humidity are the characteristics of tropical savannah climate. Building interiors become overheated in this climatic region due to the effect of heat transfer through the roofs, walls and the openings (doors and windows). The roof is one of the critical components that constitutes about 70% of the overall heat gain in buildings. In classroom buildings, uncomfortable indoor conditions affect staff and students’ teaching and learning, performance and healthy well-being. The purpose of this study is to evaluate and compare the influence of different roof design parameters on the thermal performance of classrooms within the tropical savannah climate of Bauchi city. The study will provide vital information on how to improve the indoor comfort conditions of the secondary school classrooms for better teaching and learning. The studied classrooms have the same dimensions but varied roof design parameters roof (material, colour, angle and room height). Field experiments and observation were used as tools for data collection. Measurements of indoor air temperature and relative humidity were conducted in 3 different case studied classrooms using onset HOBO data loggers (UX100-011) during the lesson periods. Physical characteristics of the classroom buildings such as; types and sizes of doors and windows, walling materials and floor finishes were observed and mapped out to better understand the role of other contributing factors. The data collected were analyzed using MS Excel software. The result indicated that the indoor temperature of the studied classrooms range from 26.89⁰C to 29.56⁰C. This shows that the studied classrooms were thermally uncomfortable and therefore require improvement.