Thermal condition and heat exposure within buildings: Case study of a tropical city

Abstract

This study aims at examining the thermal relationship between indoor-outdoor temperature and relative humidity using houses with two different window types in Ile-Ife, Nigeria. Indoor and outdoor temperatures and humidity were measured simultaneously using digital mobile weather stations placed in different residential houses with sliding and louvre window type. Measurements were taken within the houses for the periods of three years, both day and night at 30 min interval. Box plots, scatter plot, correlation and inferential statistics were used for the analysis of the data collected and conclusions were drawn. The results showed significant variations in mean temperature between the indoor and outdoor temperature in the two house types. The house with the sliding window had a higher temperature, with a mean temperature of 28 ≤ °C ≥ 31, compared to the house with the louvres window, with a mean temperature of 21 ≤ °C ≥ 28. Though indoor temperature appears higher than the outdoor throughout the seasons but much more during the months of the dry season (November to April), with 26≤ °C ≥ 33 for indoor temperature and 25≤ °C ≥ 29 for outdoor temperature. The mean temperature within the houses with sliding windows type was found to have nearly 2 °C more than the louvres window. The correlation results show the high negative relationship between temperature and humidity with 0.60 ≤ R2 ≥ 0.88 but a very low relationship was observed between outdoor temperature and humidity with R2 ≤ 0.48 in all the houses for the entire period. The study concluded that materials used to provide ventilation in houses especially the window type have a significant influence on the indoor temperature and comfortability of its occupants.