Air conditioning is a predominant technique widely used to condition the indoor environment. Thermal comfort of occupants in an air conditioned microenvironment depends on several factors. In the present study, we have investigated the influence of indoor operative temperature, air velocity and thermal sensation of tropically acclimatized subjects in air conditioned microenvironment. A classroom size of 31 students (subjects) was considered in the present investigation. Several experiments were conducted in a microenvironment by varying indoor operative temperature between 25.5 and 29.7 °C and air velocity from 0.1 to 0.25 m/s. The results indicate that the thermal sensation vote of subjects was always above 80%. The neutral comfort temperature from the present study (28 °C) is comparable with the Griffiths comfort temperature (27.7 °C). The present study reveals that cooling asymmetry is a cause of concern for subjects in the air conditioned room since the air was directed toward the head and back of subjects. © 2020, The Institution of Engineers (India).