Investigation of summertime thermal comfort at the residences of elderly people in the warm and humid climate of India

Abstract

According to WHO (World Health Organization) data, people spend at least 80% of their lives indoors, with the percentage rising to 95% for older people with mobility impairments. Creating a thermally comfortable indoor environment is essential for improving users’ productivity and well-being, particularly for those who spend maximum time indoors, such as elderly people. India’s ageing population is increasing significantly; however, there is lack of studies in the field of thermal comfort for the elderly. The main aim of this paper is to determine the thermal comfort range of elderly people in residences of warm and humid climates during summers in India and to find out the adaptive actions opted by the elderly population to achieve thermal comfort. 740 responses were collected from elderly people through questionnaire surveys along with simultaneous field measurements during the summer. The linear regression analysis found the occupant’s comfort temperature of 30 °C and the comfort range was found to be 28.5 °C- 31.5 °C, which was narrower than the younger people’s thermal comfort studies at residences. The neutral temperature was higher for the male elderlies than the female elderlies, which was highly correlated with their clothing adjustments. The probit analysis revealed that 90% of the elderly felt comfortable when the operative temperature varied between 26.9 °C and 30.9 °C. Clothing adjustments and taking cold showers are the most preferred behavioural actions by the elderlies in summer, whereas changing the cooking time and tying up hair are the most preferred behavioural adaptations to overcome thermal discomfort for female elderlies.