## 4 Influence of Space-Arrangement and Exterior Wall Thermal Resistance on Indoor Air Temperature
### Influence of the Space-Arrangement Mode on the Indoor Temperature  
Space-arrangement modes affect the thermal process of passive solar buildings, and consequently affect the indoor air temperature. According to the parameters in Table 3, the Design Builder software was used to analyze the indoor air temperature in the coldest month (January) of the main room in a multi-space passive solar building. In three space-arrangement modes, the thermal resistances of exterior walls in different orientations were all set to 0.53 m\({}^{2}\)-K/W, and the average calculated indoor air temperature values of the main rooms in January are illustrated in Figure 10.  
Figure 10 indicates that the indoor air temperature of the bedroom and living room in mode \(c\) is the highest, followed by that of mode \(b\), while that of mode \(a\) is the lowest. Apparently, the indoor  
Figure 10: Indoor air temperature of the main rooms in three space-arrangement modes.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Envelope** & **Material** & **Thickness** & **Thermal Conductivity** & **Density/(kg m\({}^{-3}\))** & **Thermal Resistance** \\  & & **(mm)** & **(Wm\({}^{-1}\)K-\({}^{-1}\))** & **(m\({}^{2}\)K-W\({}^{-1}\))** \\ \hline \multirow{3}{*}{The exterior wall} & Cement mortar & 20 & 0.93 & 1800 & \multirow{3}{*}{0.53} \\  & Dimas brick & 370 & 1.10 & 1900 & & \\  & Cement mortar & 20 & 0.93 & 1800 & \\ \hline \multirow{3}{*}{The partition} & Cement mortar & 20 & 0.93 & 1800 & \multirow{3}{*}{0.48} \\  & Dimas brick & 240 & 1.10 & 1900 & & \\  & Cement mortar & 20 & 0.93 & 1800 & \\ \hline \multirow{3}{*}{The roof} & Cement mortar & 30 & 0.93 & 1800 & \multirow{3}{*}{1.43} \\  & Extruded polystyrene & & & & \\  & plate insulating layer & & & & \\  & Waterproofing layer & & & & \\  & (two modified asphalids) & & & & \\  & Cement mortar & & & & \\  & leveling layer & & & & \\  & Cement expanded & & & & \\  & perlite slope & & & & \\  & making layer & & & & \\  & Reinforced concrete slab & & & & \\  & Cement mortar & & & & \\  & Plastering & & & & \\ \hline \hline \end{tabular} Note: The thermal resistance of the inner surface of the exterior wall is set to 0.11 m\({}^{2}\)-K-W\({}^{-1}\), and that of the outer surface is 0.04 m\({}^{2}\)-K-W\({}^{-1}\)[17].  
\end{table}
Table 3: Component and thermal parameters of the building envelope.  
space-arrangement modes have a significant impact on the thermal environment under the same thermal parameters of the building envelope. Compared to 8.8 \({}^{\circ}\)C of the indoor air temperature of the living room in the mode \(a\), that of living room in the model \(b\) is 10.6\({}^{\circ}\)C, increased by 20.5%, and the indoor air temperature growth rate of the living room is higher than that of the bedroom. When the space-arrangement mode is changed from mode \(b\) to mode \(c\), the increase rate of the air temperature of the bedroom is higher than that in the living room. The air temperature rise from 8.3 \({}^{\circ}\)C to 10.8 \({}^{\circ}\)C in bedroom 1, and from 8.5 \({}^{\circ}\)C to 11.1 \({}^{\circ}\)C in bedroom 2, and from 10.6 \({}^{\circ}\)C to 11.6 \({}^{\circ}\)C in the living room. It is worth noting that the indoor air temperature of bedroom 1, bedroom 2, and living room has increased by 30.1%, 30.6%, and 9.4%, respectively.  
Comparing three space-arrangement modes and corresponding indoor air temperatures of the main rooms, it can be found that the north-facing auxiliary rooms in the model \(c\) not only enrich the function of the building interior space, but also act as a \"temperature buffer\" which is beneficial to improve the temperature of the main rooms.