The development and critical evaluation of learner thermal comfort protocol for applicability to two primary schools in Mamelodi, City of Tshwane

Abstract

The purpose of this study is to develop a Learner Thermal Comfort Protocol (LTCP) for the assessment of thermal comfort in naturally ventilated public school classrooms occupied by primary learners aged between 7 and 14 years and to establish whether there is a relationship between the thermal comfort standards (ASHRAE 55-2004 and ISO 7730-2005) and the learners’ perception thereof. The study tests the LTCP on two primary school case studies in Mamelodi Township, City of Tshwane (CoT), South Africa, by following the adaptive or field study method to collect quantitative data from the classroom and the learners. The classrooms’ actual temperature is measured and recorded by HOBO pendant data loggers while the learners’ thermal comfort perception is surveyed using questionnaires. The actual classroom indoor temperatures are compared to the ASHRAE 55 and ISO 7730 standard temperature range recommendations of ±22°C to ±27°C, based on the heat balance model, and ±20°C to ±27°C temperature range based on the context related adaptive model. To establish whether there is a relationship between standards and learners’ perception, the learners’ perception results are compared to the predicted percentage that occupants would find acceptable. This predicted percentage is based on the heat balance model (i.e. 80%) and adaptive model (i.e. 80% - 90%). The results indicate that the indoor temperature range did not meet the recommended temperature range of either of the thermal comfort models. However, the thermal perception scale shows that the indoor temperatures were accepted by most of the learners. A relationship between the learners’ perception, the thermal comfort standards’ recommended temperature range and predicted percentage of acceptance was established. However, a wider temperature range is suggested for the thermal comfort assessment of classrooms located in the South African climate.

This study will contribute to the body of knowledge on thermal comfort in schools and provide the Department of Basic Education (DBE) with an assessment tool for the evaluation of school classroom indoor environments.