Progress in thermal comfort studies in classrooms over last 50 years and way forward

A classroom thermal environment quality has an important role in a student's life as it influences student's performance and well-being. It is well known that at each educational stage, curricula demands different activities, different learning approaches and systematic thinking, requiring increasing levels of concentration. With increasing awareness about energy efficiency in buildings and indoor environment quality, somehow more emphasis is being given to energy efficiency. The absence of any standard or reference document relating to the design appropriate classrooms based on educational stages is worsening the situation. In this context, present study is done to find out the progress in classrooms based thermal comfort studies over last fifty years. Total 93 research articles selected from Scopus database were considered for this study. It was found that at each educational stage in the studied schools, students were highly unsatisfied with the prevailing indoor thermal environment and preferred cooler temperature than the existing indoor thermal environment. Primary school students were least sensitive to outdoor temperature changes. There are relatively few published articles published on thermal comfort in classrooms. Based on reported findings, no consistent temperature change was found necessary to record a shift of one thermal sensation vote by students at different educational stages in classroom. Identical behaviour was observed for classrooms operated under different operation modes. Moreover this study provides robust evidence that there is a need for separate set of different guidelines or standards for students of different ages in different stages of their education. This study also proposed adaptive comfort equations to estimate the indoor comfort temperature in classrooms at different educational stages. (C) 2019 Elsevier B.V. All rights reserved.