Thermal comfort in undergraduate laboratories — A field study in Kharagpur, India

A thermal comfort field survey is carried out inside a naturally ventilated laboratory in the tropical climatic region of India. The building chosen is used for courses in an undergraduate engineering curriculum. We aimed at assessing how the occupants perceive their thermal environment in a free running building while carrying out their normally scheduled tasks. A total of 121 acclimatized subjects were interviewed and 338 responses were collected during the months of spring semester. Survey results show a strong correlation between indoor comfort conditions and outdoor temperature. Occupants show adaptability across a comfort zone that is well beyond recommendations of rational models. Overall, 78% of the responses found their thermal environment to be acceptable. Based on indoor temperature observations, we calculate comfort temperatures for the subjects using Griffithsʹ method. The comfort temperature values are then related with prevailing mean outdoor air temperature to give an adaptive comfort equation. Predictions from our equation show satisfactory to good agreement with the predictions from similar equations in comfort standards.