Impact of solar radiation on human comfort in a vehicle cabin: An analysis of body segment mean radiant temperature

Abstract

Ensuring ideal thermal comfort inside vehicle cabins can be a challenging task, especially when accounting for the impact of solar radiation on human occupants. The mean radiant temperature (MRT) is crucial in determining thermal comfort levels in enclosed spaces. This study investigates the impact of solar radiation on the MRTs of local human body segments in a vehicle cabin. A modified solar-adjusted MRT model was proposed, and experiments were conducted to validate the accuracy of the model in predicting MRT values under varying solar radiation conditions inside a vehicle cabin. The model had a mean absolute error of 1.02 °C, a mean absolute percentage error of 2.83%, a root mean square error of 1.28 °C, and a mean bias error of −0.17 °C. The results demonstrate that the proposed model provides precise and reliable MRT predictions with low variability and unbiased outcomes. The proposed model was also used to analyze the effects of solar radiation on MRTs during different seasons, revealing the vulnerability of specific body parts to solar radiation exposure. This study emphasizes the importance of considering solar radiation when designing and assessing thermal comfort in vehicle cabins. The proposed model can be integrated into existing thermal comfort models to provide more accurate and reliable assessments of the impact of solar radiation on vehicle cabin occupants.