Field investigation on occupant's thermal comfort and preferences in naturally ventilated multi-storey hostel buildings over two seasons in India

Abstract

In India, there is a scarcity of field data reported on occupant's comfort preferences and expectations in multi-storey naturally ventilated (NV) hostel buildings over the last three decades. To fill the research gap, a field study of adaptive thermal comfort was carried out in twelve NV hostel buildings in a composite climate of India, six from each of the two case cities, Jalandhar and Jaipur, respectively. The study is spread over rainy (July–September) and autumn season (October). 1516 valid responses from hostel occupants were collected and were further analyzed statistically to determine comfort temperature and thermal comfort zone for hostel buildings operated under NV mode. Mean Griffiths comfort temperature (Tc) of 29.7 °C and 30.4 °C was observed for Jalandhar and Jaipur city, respectively. Preferred temperature of hostel occupants was about 3 °C lower than mean Tc obtained for both cities. The comfort temperature found in present study were well within the thermal acceptability limits defined in adaptive models EN 16798 (formerly 15251) and NBC-2016 except ASHRAE standard 55–2017. Analysis of the data showed that at elevated air speed (using ceiling fans) the comfort boundary extends by 1.8 °C.