MODELING OF URBAN BUS DRIVERS' THERMAL SENSATION VOTE AS A FUNCTION OF THE THERMAL COMFORT PARAMETERS

Abstract

Research into thermal comfort in vehicle environments has been gaining prominence among researchers due to the impacts generated, which range from maintaining the thermal sensation of the occupants, to ensuring the satisfactory performance of drivers in terms of safety in traffic and in energy sustainability. With this background, this study aimed to evaluate the thermal comfort parameters that influence the thermal sensation of urban bus drivers. To this mean, the four environmental parameters in the cabins of urban buses were measured and the two personal parameters of three drivers of the same bus line were estimated, and the influences of these six parameters on the subjective thermal sensation were analyzed using the Ordinal Logistic Regression Models of the Generalized Linear Models methodology. The field survey was performed from September to December 2021 and over three daily trips, totaling 180 measurements of thermal conditions. As a result, both the Predicted Mean Vote index and the thermal sensation votes indicate that the environments of the bus drivers' cabins analyzed are, in general, within the scale of thermal discomfort by heat, with a predominance of the "Warm" class. Furthermore, the model adjustments converged on only three distinct models and they demonstrated that the thermal sensation was influenced by the environmental parameters, and not by the personal parameters. Finally, we concluded that the model that best fit to the sensation was that as a function of the air temperature, with a moderate explanatory ability due to the value of Pseudo R2 = 0.669. In addition, the proportional chance curves of this model indicated the following air temperature ranges for the respective heat thermal discomfort classes: when ta < 28°C, the greater chances are in the choice of thermal neutrality and the other classes of thermal discomfort by cold that were not reached by this research, which were not achieved by this research; for 28°C ≤ ta ≤ 30°C the tendency is higher for a slightly warm sensation; for values in the range 30.5°C ≤ ta ≤ 32.5°C it is more natural that they opine on the heat scale; and for values of ta > 33°C the tendency is for conductors to feel extremely hot.