Study and Analysis of Adaptive Thermal Comfort Model in Darjeeling Hills

Abstract

The definition of a good indoor climate is vital for the success of any building. This will make newlinethe occupants comfortable and also will decide the energy use pattern in the building thereby influencing both it s econom y and sust ainabili t y. Fan ge r s predict ed mean vote (PMV) model is often used to estimate the comfort requirements for a building. However, recent studies suggest that the PMV model frequently either overestimates or underestimates the thermal sensation in warmer or cooler climate, respectively. This leads to a prediction of a lower set point temperature in warmer condition and higher set point temperature in cooler condition, than required, which is energy consumptive. In the field survey based comfort studies the adaptive opportunities undertaken by the subjects are accommodated, which gives a true picture of the indoor conditions. In this research, a year round survey was conducted following ASHRAE class II protocol in 10 naturally ventilated buildings of different types in the Darjeeling Himalayan Region. The buildings are situated at 5 (five) different locations having different elevation from the sea level. An overall of 2608 responses of thermal comfort were gathered from 436 subjects in the 12 months of survey, all of whom participated voluntarily.It was seen that the clothing insulation showed a significant increase with the elevation of the locations, whereas the comfort temperature showed a significant decrease with the elevation of the location. Two models are proposed, first the variation of indoor comfort temperature with the outdoor environmental condition and secondly, the variation of indoor comfort temperature with the elevation of the location. The research being first of its kind in the region is expected to be of help to building designers, architects and engineers for determining comfort conditions of indoor environment in the region or region elsewhere having a similar bioclimatic set up. newline