## 2 Materials and Methods
### Research Methods and Experimental Parameter Design
#### 2.2.3 Verification of ENVI-Met Feasibility  
The Version 5.1.1 of the ENVI-met was used to carry out the simulations. Many scholars have proven that the research results regarding the microclimate at the block level, which use the PET simulated by ENVI-met software, are reliable. However, in order to better find the errors in the simulation experiment and prove that using ENVI-met is feasible as the simulation software for this research, the feasibility of ENVI-met software is to be verified in this paper. The numerical significance of the PET is its ability to reach the temperature corresponding to the same thermal state as the outdoor environment in a typical indoor environment with a temperature of 20 \({}^{\circ}\)C and a relative humidity of 50% [37; 38]. Therefore, determining whether the PET value simulated by ENVI-met is reasonable is approximately equivalent to determining whether the temperature and humidity calculated by ENVI-met are within the error range.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Initial Simulation** & **Simulation** & **Temperature (\({}^{\circ}\)C)** & **Relative Humidity** & **Average Wind** & **Average Wind** \\
**Time** & **Duration** & & **(\%)** & **Speed (m/s)** & **Direction (\({}^{\circ}\))** \\ \hline \multirow{8}{*}{11:00} & & 33.3 (11:00) & 59 (11:00) & & \\  & & 33.8 (12:00) & 58 (12:00) & & \\  & & 34.9 (13:00) & 56 (13:00) & & \\  & & 35.4 (14:00) & 58 (14:00) & & \\  & 10 h & 35.3 (15:00) & 57 (15:00) & & \\  & (From 11:00 to 20:00) & 35.0 (16:00) & 56 (16:00) & & \\  & & 34.6 (17:00) & 59 (17:00) & & \\  & & 34.0 (18:00) & 64 (18:00) & & \\  & & 33.1 (19:00) & 59 (19:00) & & \\  & & 32.2 (20:00) & 66 (20:00) & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Initial simulation conditions.  
Figure 2: Relationship between PET and human senses.  
The researchers conducted field data collection at a fixed location on Pozi Street in Changsha City from 11:00 a.m. to 8:00 p.m. on 12 July 2022. The selected instrument was a JT2020 multi-function tester (by China Shiji Jiantong Technology Co., Ltd., Beijing, China). The range and accuracy of the instrument are shown in Table 2 below. The error in the simulation was obtained by comparing the measured and simulated data for temperature and humidity at the observation points between 11:00 a.m. and 8:00 p.m.  
As shown in the table below, the temperatures of a fixed point within the study area were measured and simulated every hour, on the hour, from 11 o'clock to 20 o'clock on 12 July 2022. After analyzing the temperatures, it is clear that the coefficient of determination (R\({}^{2}\)) between the measured temperature and simulated temperature was 0.89, that the root mean square error (RMSE) was 1.41, and that the index of agreement (d) was 0.71. For the measured humidity and simulated humidity, the R2 was 0.81, the RMSE was 2.7%, and d was 0.76. Compared with other similar studies, this simulation study is in a reasonable error range [39]. The measured temperature and humidity and their corresponding simulated temperature and humidity are shown in Table 3 below.