Quantification of the interactions between indoor environmental conditions and human thermal comfort and susceptibility in tropical coastal environments

The indoor environment in most of the tropical coastal regions is associated with the residents’ health and well-being. However, limited studies reported on quantifying the interrelation between indoor environmental quality, thermal comfort and residents’ health risks in such climatic regions. Here, we evaluate indoor thermal comfort in coastal eastern India that falls under the ‘Tropical Savanna’ climatic region. The perception survey was conducted to collect primary data in summer, monsoon, post-monsoon and winter across the year and the perception of warmth appeared to have a similar trend to direct and rational human thermal indices derived from a composite body heat exchange. Results indicate that indoor thermal stress significantly differed (p < .05) between seasons and across study locations. The maximum summer and monsoon days lay in a warm to very hot zone. Additionally, most of the heat-related stress or disorders significantly differed (p < .01) amongst different age groups of people. Finally, a principal component analysis using the human thermal indices yielded three groups of heat-related symptoms (a) physical fatigue and responses, (b) neural stressors and (c) hyperhidrosis disorder. Overall, results suggested that physical fatigue and responses arose predominantly from climate-induced thermal stress. The study recommends an effective bioclimatic design strategy following human-environment friendliness that can improve indoor thermal comfort in coastal eastern India.