Approach on enhancing the air conditioning system to improve the winter thermal environment in Eastern China Region's airport terminals

• Investigating thermal environment in terminal's commercial zone. • Creating an CFD model with experimental validation. • Improvements in air conditioning system enhance localized thermal comfort. • All-air jet ventilation affects indoor thermal comfort. • The results can provide reference for airport terminal design and operation. Passengers typically spend much time in commercial zones of terminals for retail, meals, and other services. Enhancing the study of thermal comfort in this local space is necessary. The climate in the Eastern China Region is variable and complex, making it more challenging to maintain the indoor thermal environment. This study conducted field measurements in winter in a commercial zone of one terminal to assess the thermal environment. Numerical simulations and PMV-PPD analyses were performed using the Computational Fluid Dynamics (CFD) program The results showed that the overall humidity in the commercial zone was low. There were notable differences in the temperatures and velocities of supply air among different air vents on the commercial island. Based on these initial conditions obtained by measurements, the simulations showed that localized areas under the breathing plane are either too hot (24°C and above) or too cold (18°C and below). The dissatisfaction percentage of the population exceeds 27%. This paper proposed that through enhancements in the air vent dimensions, layout, and air supply conditions, the temperature can be maintained in the range of 20-24°C. Furthermore, the PMV could be controlled within the range of -0.5 to 0.5. PPD was below 10%, reflecting compliance with Class I heating standards. Overall, findings from this study provide a less costly modification for thermal comfort improvement in commercial zones, and serve as a reference for the design and operation of air-conditioning systems to ensure thermal comfort in airport terminals’ commercial zones.