Assessment of thermal comfort in a hot and humid indoor built environment of a kitchen at a university canteen

BACKGROUND: The hot and humid environment inside the kitchen is a cumulative sign of health impact that deteriorates the well-being and productivity of cooking workers, which could be a barrier to thermal comfort. As the cooking task progresses throughout the day, uncomfortable thermal conditions inside a kitchen work environment may diminish the work quality of the kitchen workers. OBJECTIVE: The objectives of the study were to evaluate the measured environmental factors of thermal comfort during various cooking periods [morning, day, evening, night] and examine the occupant's perception votes followed by further investigating the worker's thermal comfort conditions using PMV, PPD, SET, WBGT, and TSI indices. METHODS: The study was carried out inside the kitchen of the university canteen at IIT Guwahati, India. The objective and subjective measurements were accomplished during the summer season, while CBE thermal comfort software was employed for calculating the thermal comfort indices like PMV, PPD, and SET. RESULTS: The results of this study revealed that during entire cooking time, the recorded environmental factors of thermal comfort were found outside the recommended limits as per ASHRAE-55 standard, which indicates very hot prevalent conditions. Also, cook's perception vote (TSV, TCV) for the existing environment did not follow the central three categories of votes (+1, 0, -1), even the cooking workers were also not satisfied with the prevailing environmental conditions, as 88% subjects responded dissatisfaction with the thermal environment. While, estimated values of thermal comfort indices (PMV, PPD, and SET) designated morning time cooking period slightly comfortable than the other cooking periods, but still not accordance with the ASHRAE-2017 standard. The WBGT index designated day cooking period as hazardous, with rest of cooking periods under severe risk level. In contrast, the TSI index indicated entire cooking periods under "slightly warm" thermal sensation. CONCLUSION: The assessment of this study showed that the existing kitchen environment of the university canteen is not conducive for workers. Improper ventilation design may cause the overheating inside the kitchen, which may increase the dissatisfaction rate of the employed workers and also affects the energy savings in the kitchen environment, which helps maintain thermal comfort. Further studies are required to improve the thermal comfort of the kitchen occupants by providing proper design interventions based on heating and cooling air ventilation systems.