## 3 Results and Discussion
### Application of the Composite Hygroscopic Material in Different Climate Regions  
The computational modeling of hygroscopic material is validated by combining the benchmark test with the benchmarks of the CHMFE model which was initiated to develop a platform to assess the heat, moisture and air transport mechanism in building physics. The basic properties of the composite hygroscopic mortar are based on the above experiments. The properties of composite hygroscopic material are obtained from experiments. The properties of the wall components are shown in Table 13.  
Taking typical cities as examples, the indoor relative humidity distribution and thermal performance of residential buildings with CHM-WSE and CM as the surface material are analyzed. In order to compare the impact on indoor thermal environment of hygroscopic material and common mortar, the building size and envelop structure of different climatic region keep the same, which may be different from practical situation. The room schedule of residential building air conditioning is shown in Table 14. The sealing performance and orientation of on-site doors and windows are taken into account, and the air exchange rate of 0.5 times/h. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Material**} & **Thermal Conductivity** & **Thermal Storage** & **Density (kg/m3)** & **Specific Heat (kj/(kg-k))** & **Thermal Inertia Index** & **Water Vapor Permeability** \\  & **(W/(m-k))** & **(W/(m2-k))** & **(kg/m3)** & **(k/(kg-k))** & **(D)** & **(kg/(m-Pa-s))** \\ \hline CM & 0.930 & 11.30 & 1800 & 1.05 & 0.24 & 5.467 \(\times\) 10\({}^{-11}\) \\ Porous brick & 0.580 & 7.87 & 1400 & 1.05 & 3.28 & 2.6 \(\times\) 10\({}^{-11}\) \\ CHM-WSE & 0.115 & 2.45 & 654 & 1.05 & 0.80 & 5.08 \(\times\) 10\({}^{-11}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 13: Properties of the wall components. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Season**} & **Typical City** & **Operating Date** & **Time (Weekend)** & **Time (Weekday)** \\ \hline Winter & Guangzhou & 1.1–2.28 & 0:00–24:00 & 18:00–8:00 \\  & Changsha, Wuhan, Nanjing & 12.1–2.28 & 0:00–24:00 & 18:00–8:00 \\  & Xi’an & 11.15–3.15 & 0:00–24:00 & 00:00–24:00 \\ \hline \multirow{2}{*}{Summer} & Guangzhou & 6.1–9.30 & 0:00–24:00 & 18:00–8:00 \\  & Changsha, Wuhan, Nanjing & 7.1–9.30 & 0:00–24:00 & 18:00–8:00 \\  & Xi’an & 7.1–8.31 & 0:00–24:00 & 18:00–8:00 \\ \hline \hline \end{tabular}
\end{table} 
Table 14: Schedule of residential building air conditioning in summer and winter. (1) Hot summer and cold winter region  
This paper mainly focuses on the hot summer and cold winter region with high humidity in both summer and winter. Therefore, three typical cities in this region, including Changsha, Wuhan, and Nanjing are selected to study the performance of CHM-WSE. In the hot summer and cold winter region where the relative humidity fluctuates greatly during day and night, the indoor relative humidity in the room with CHM-WSE is controlled at 35-65% in winter (Figure 23) and 50-70% in summer (Figure 24). The results show that the indoor relative humidity fluctuation of the room with CHM-WSE is about 10% lower than that of the room with CM. The results of building heating load show that the heating load of the room with CHM-WSE is obviously lower than that of the room with CM (Figure 25). The results of building cooling load show that the sensible cooling and latent cooling load of the room with CHM-WSE are lower than that of the room with CM (Figure 26). (2) Cold region  
This study chooses Xi'an as a typical city in the cold region. This region has dry and cold winters and humid and hot summers. In the cold region where the relative humidity of day and night do not change obviously, the CHM-WSE has small effect on the indoor humidity environment in winter (Figure 27), but the indoor relative humidity is about 55% in summer (Figure 28), which is 10% higher than that of CM.