Hybrid Infrared Thermography and Thermocouple Approach for Thermal Comfort Evaluation of Chair Seats

The thermal comfort of chair seats, crucial for user well-being, particularly in urban transportation and service sectors, necessitates effective evaluation methods. This paper introduces a hybrid procedure integrating infrared thermography (IRT) and thermocouple thermometry to analyze upholstered chair seats’ thermal behavior over extended periods. A series of experiments were conducted on a polyester fabric and polyurethane-foam chair, with temperature monitoring during warm-up (60 min) and cooldown (55 min) phases using embedded thermocouples and IRT imaging. The results revealed significant temperature variations, with maximum seat surface temperatures reaching 33.9 ± 2°C (IRT) and 33.0 ± 0.6°C (thermocouples). A mathematical model based on regression analysis was developed to describe the exponential temperature evolution, predicting a steady-state maximum of 34.05°C after 305 min of continuous sitting. The study also identified thermal inertia effects, with delays of 4 to 7 min in temperature stabilization due to foam heat retention. These findings emphasize the influence of user posture, material composition, and measurement methodology on seat thermal comfort. The proposed approach enables continuous monitoring, two-dimensional temperature mapping, and nondestructive assessment, making it applicable to product development and in-use seat evaluations.