A Multimodal Physics-Informed Neural Network Approach for Mean Radiant Temperature Modeling
Pouya Shaeri, Saud AlKhaled, Ariane Middel
TL;DR
This work tackles outdoor thermal comfort assessment by estimating Mean Radiant Temperature $T_{mrt}$ in urban environments using a multimodal Physics-Informed Neural Network (PINN). The approach fuses meteorological data, built-environment descriptors, and fisheye-image shading to enforce the six-directional radiative transfer physics within a deep learning model. Key results show the PINN achieving RMSE of $3.50$ and $R^2$ of $0.88$, with shade prediction accuracy of $94\%$, and the ability to deliver competitive performance even with reduced input metadata by leveraging image-derived shading. The framework advances scalable, physically consistent urban microclimate assessment, offering a practical pathway for heat-health planning in hot desert cities and beyond.
Abstract
Outdoor thermal comfort is a critical determinant of urban livability, particularly in hot desert climates where extreme heat poses challenges to public health, energy consumption, and urban planning. Mean Radiant Temperature ($T_{mrt}$) is a key parameter for evaluating outdoor thermal comfort, especially in urban environments where radiation dynamics significantly impact human thermal exposure. Traditional methods of estimating $T_{mrt}$ rely on field measurements and computational simulations, both of which are resource intensive. This study introduces a Physics-Informed Neural Network (PINN) approach that integrates shortwave and longwave radiation modeling with deep learning techniques. By leveraging a multimodal dataset that includes meteorological data, built environment characteristics, and fisheye image-derived shading information, our model enhances predictive accuracy while maintaining physical consistency. Our experimental results demonstrate that the proposed PINN framework outperforms conventional deep learning models, with the best-performing configurations achieving an RMSE of 3.50 and an $R^2$ of 0.88. This approach highlights the potential of physics-informed machine learning in bridging the gap between computational modeling and real-world applications, offering a scalable and interpretable solution for urban thermal comfort assessments.
