Thermal comfort field study in undergraduate laboratories – An analysis of occupant perceptions

• A total of 338 responses are collected from 121 acclimatized subjects in tropics.
• Preferred temperature of 24 °C is found from responses on McIntyre scale.
• Occupants are well adjusted to high air velocities and high humidity levels.
• Flexibility available in a laboratory class is utilized by occupants to adapt.
• Occupants are empathetic to environmentally friendly buildings.

A thermal comfort field study was conducted in an undergraduate laboratory classroom involving 121 subjects giving 338 responses. The building is located in a tropical climatic region of India. In addition to objective measurements of indoor climate, subjective responses on perceptions regarding thermal sensation, thermal preference, air velocity, and humidity were also collected. We present here an analysis of the subjective preferences and disposition of the occupants. While acceptability of higher air velocities seems ubiquitous amongst our subjects, a high level of tolerance for humid environments is also observed. Most of the responses (78%) are accepting of their thermal conditions. The occupants do have a predilection towards cooler thermal sensations and higher air velocities. Since the location is in a warm and humid region where fans are used in almost every building, this observation fits expectations. Students effectively adapt their clothing according to prevailing weather and even subject their clothing to some atypical adjustments. They also make use of the fact that laboratories have lesser constraints on posture and movement than lecture classes. Overall, the students are affable to indoors of naturally ventilated buildings and at the same time are empathetic to a naturally ventilated building's environmentally friendly nature.