Subject's thermal adaptation in different built environments: An analysis of updated metadata-base of thermal comfort data in India

Abstract

Thermal comfort is considered one of the most essential aspects of user satisfaction and energy consumption in buildings. With substantive shreds of evidence of thermal adaptation, it is well established that occupants in hot climates like India are more flexible, tolerant, and act as active agents to control their immediate thermal environments. Therefore, the primary objective of the work is to evaluate the status of the thermal adaptation of Indian subjects in air-conditioned (AC), naturally ventilated (NV) and mixed-mode (MM) buildings across its wide and culturally diverse climatic zones. The study methods include the statistical analysis of an updated meta-database comprised of Indian field data published in recently ASHRAE Global Thermal Comfort Database-II and other field studies conducted in India for different built environments. A total of 17569 samples were sorted out, out of which 2912, 5230, and 9427 samples were collected from AC, NV, and MM buildings, respectively. Indian subjects were found tolerant over wide indoor thermal conditions prevailing during different seasons and ventilation strategies. Thermal acceptability ranges estimated for Indian subjects differed significantly with the International comfort standards like ISO 7730 and EN 15251 in different types of buildings. The database is further analysed to quantify the effects of contextual factors like building types, ventilation modes, and seasons on subject's comfort temperature and compared with existing comfort standards. The study suggests future research directions to meet the sustainable goals of energy efficiency and comfortable buildings in India.