Thermal comfort in Indian naturally ventilated buildings: A comprehensive review

A significant amount of global energy is expended to meet the cooling requirements in buildings. There has been a huge shift from naturally ventilated buildings to air-conditioning with an annual shift of 15.75% considering an overall increase in extreme heat incidences in cities during summer. Studies show that reducing cooling energy consumption significantly is possible by applying passive approaches in buildings. In this study, thermal comfort in naturally ventilated buildings on a global scale, with a specific emphasis on India, has been examined through a review of existing studies. Bibliometric analysis, followed by comparative analysis, is used to identify and evaluate research on methods for assessing thermal comfort and developing adaptive models for occupants in diverse buildings and climates. It is observed that Griffith's method is popularly used along with PMV-PPD to obtain thermal comfort interpretations in Indian naturally ventilated buildings. Moreover, the major contributors to thermal comfort studies are Europe and Southeast Asia. Further, Indian subcontinent has a wider comfort range than what international field studies have suggested. While the residents of naturally ventilated buildings in cold climates have a comfort range of 12.5-32 degrees C, for composite climates, the range is 15.3-33.8 degrees C, and for hot and humid climates, the range is 18.4-33.5 degrees C. Additionally, the variation in the thermal comfort range is also significantly influenced by local cultural factors. Therefore, a customized thermal comfort model that should not only reflect the unique climatic conditions but also include cultural factors of the Indian subcontinent can ensure that building occupants are provided with a comfortable and healthy indoor environment.