Evaluation of Eight Thermal Comfort Indices Based on Perception Survey for a Hot-Humid Climate through a Naturally Ventilated Apartment

Several thermal comfort indices have been proposed over the years and studies have shown that these models do not work universally. This study compares eight thermal comfort indices with results of occupant-perception survey during May and December of a hot-humid climate of the southeast coast of the Indian Peninsula. A 14-story naturally ventilated apartment building with cruciform planform provided living rooms located at different orientation and height for the study. A week-long occupant's comfort survey along with measurement of temperature, relative humidity, and indoor air velocity in the living rooms (located at different heights and orientations) during both in May and December were used for evaluating the thermal performance using predicted mean vote (PMV), e-PMV, a-PMV, TSI, SET, PTS ASHRAE-adaptive, and IMAC comfort scales. These indices were brought into a common seven-point scale, and the comparison was done in two stages: building level and then an in-depth comparison of shortlisted comfort indices by considering the microclimatic variation between living rooms located at different heights and directions. The indices that can predict the perception survey-based actual mean vote (AMV) closely under these variations are highlighted.