Investigation of thermal comfort and air quality in typical student residences

Whereas thermal comfort and air quality have direct bearing on the health and productivity of occupants, rarely do naturally ventilated buildings meet requirements defined in international standards. Student residences are even more so important as the health of students can impact their productivity while in school. The monitoring and evaluating these two conditions (thermal comfort and air quality) have gained more prominence since the Covid-19 pandemic.

This study assessed thermal and air quality conditions in student residences at the University of Nigeria, Nsukka. First, indoor thermal comfort parameters such as temperature, humidity, clothing level and metabolic rate of occupants in naturally ventilated sample rooms owned by the school and private individuals were either measured or observed, and recorded. Temperatures and humidity in the dwellings were measured and recorded in 15 minute intervals for 10 hours using a combined data logger with external sensor probe. The average values were then evaluated using the CBE thermal comfort tool for comfort range plots. The results which were evaluated using the adaptive model revealed a wider range of comfort band than the PMV model owing to adaptive behavior of occupants. The results showed that most school hostels fall outside the 90% acceptability limit for adaptive comfort while private hostels are within 80-90% of the adaptive comfort chart. One major reason is the difference in population of students within each room.

Next, levels of indoor PM₁.₀, PM_2.5, PM₁₀ and HCHO were measured using on-the-spot detectors. Twenty rooms in each of 6 different buildings were surveyed and their results were graphically compared with standards specified by the World Health Organization. Residences outside the university showed levels higher than stipulated as activities such as tobacco intake and cooking with combustible fuels were allowed.