The COMFA model for assessing courtyard thermal comfort in hot and humid regions: A comparative study with existing models

Abstract

The present study introduces the development of the COMFAcourtyard model, which combines the strengths of COMFA, PET and SET* to create a reliable, practical and scientifically validated outdoor thermal comfort index for courtyards in hot and humid regions. To validate the model, four elements were implemented: validation in a real scenario (two classical courtyards in central Guangdong, China), comparison with relevant models (PET, SET*, UTCI, WBGT and COMFA), sensitivity analysis and statistical quantification of performance. Results show that COMFAcourtyard outperforms other models in terms of accuracy, interpretability and computational speed, with an R2 of 0.78 for linear regression and the ability to output intuitive and physically meaningful heat flow values. In terms of computational efficiency, COMFAcourtyard is approximately 1.5 times faster than COMFA and is two orders of magnitude faster than PET and SET*. In this study, a deeper understanding of the mechanisms of human thermal comfort is attained and the accuracy, interpretability and computational speed of the newly developed COMFAcourtyard model and previous models are systematically evaluated. The study also establishes a theoretical foundation for the thermal sensation scale and comfort thresholds in humid and hot courtyard environments. These efforts advance the design of climate-resilient outdoor environments and contribute to providing thermal security for individuals in the context of climate change.