An improved algorithm of thermal index models based on ENVI-met

ENVI-met is a microclimate simulation software that is used for urban planning. BIO-met is used to calculate the thermal index within the ENVI-met software and can simulate the universal thermal index, including the predicted mean vote, physiologically equivalent temperature, universal thermal climate index, and standard effective temperature. Given the accuracy of thermal index calculation, BIO-met can provide better urban planning guidance to ensure human thermal comfort. To verify the accuracy of the thermal index calculation, an on-site walking experiment was conducted in a transitional space, and an ENVI-met building model was established at the experimental site. The results indicated that the simulated air temperature overestimated the actual measured air temperature by up to 2 °C. Additionally, the output thermal indices (β-thermal index models) were calculated by combining the experimental data with the micro-environment calculation results obtained from ENVI-met using the BIO-met software. Despite the deviation between the BIO-met calculation results and the actual situation, there were cross-values when the improved thermal indices (α-thermal index models), based on the results of our previous studies, were compared to the β-thermal index models. Furthermore, an improved algorithm for calculating the thermal index models of the BIO-met program was developed.