## 3 Methodology
### Simulation Parameters  
As mentioned above, five major categories of energy use during the building operation phase, namely lighting, space heating, space cooling, ventilation, and appliances, were simulated in this study. The life of the residential building was set at 50 years. The heat given off by the occupants in the main rooms (living room and bedroom) was also taken into account. The room occupancy parameters are presented in Table 11.  
Other simulation parameters were set as follows. (1) Space Cooling and Space Heating  
According to the local residential building regulations in China, the indoor temperature of the main rooms is to be controlled between 18 \({}^{\circ}\)C and 26 \({}^{\circ}\)C. In actual conditions, the heating system is operated for 24 h in the Cold and Severe Cold regions during the heating season. The minimum indoor temperature in auxiliary space is not to fall below 12 \({}^{\circ}\)C. The cooling system will run if the indoor temperature exceeds 26 \({}^{\circ}\)C during working hours. The simulation parameters for space cooling and space heating are displayed in Tables 12 and 13. \begin{table}
\begin{tabular}{c c c c c} \hline
**Room** & **Cooling Set Point** & \multicolumn{2}{c}{**Cooling Month**} & \multicolumn{2}{c}{**Working Time**} \\ \hline  & 26 \({}^{\circ}\)C & Hailar & 15 June–31 August & Workday & 7:00–9:00 \\ Bedroom & 26 \({}^{\circ}\)C & Harbin & 15 June–15 September & & 17:00–24:00 \\ Living Room & 26 \({}^{\circ}\)C & Urumchi & 15 June–15 September & & \\  & 26 \({}^{\circ}\)C & Lanzhou & 1 June–30 September & & 7:00–24:00 \\  & 26 \({}^{\circ}\)C & Beijing & 1 June–30 September & & \\ \hline \end{tabular}
\end{table} 
Table 12: Simulation parameters for cooling operation in the five cities. Figure 6: Flowchart of the study. (2) Ventilation  
Both natural ventilation and infiltration were considered in the simulation. The infiltration occurred over 24 h with a maximum flow rate of 0.300 ach/h, and the natural ventilation was defined separately according to the climate locations. Taking Hailar as an example, the simulation parameters for natural ventilation in Hailar are tabulated in Table 14.  
(3) Appliances  
The appliances that are operated in each household can vary significantly depending on the habits of the occupants. In this study, only the most commonly used appliances were considered. The parameters for this equipment are tabulated in Table 15. The lighting hours and power density are tabulated in Table 16. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Room** & **Heighting Set Point** & **Heating Month** & **Working Time** \\ \hline Bedroom & 20 \({}^{\circ}\)C & Hailar & 1 October–10 April \\ Living Room & 20 \({}^{\circ}\)C & Harbin & 10 October–10 April \\ Bathroom & 20 \({}^{\circ}\)C & Urumchi & 20 October–31 March \\ Kitchen & 20 \({}^{\circ}\)C & Lanzhou & 10 November–20 March \\ Corridor & 12 \({}^{\circ}\)C & & \\ Stairs & 12 \({}^{\circ}\)C & Beijing & 15 November–15 March \\ Elevator & 12 \({}^{\circ}\)C & & \\ \hline \hline \end{tabular}
\end{table} 
Table 13: Simulation parameters for heating operation in the five cities. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Room** & **Ventilation Month** & **Ventilation Time** & **Ventilation Condition** & **Max Flow** \\ \hline Bedroom & 1 May–14 June & Workday & 7:00–9:00 & \\  & Weeked & 17:00–24:00 & - & \\ Bedroom & 15 June–31 August & Workday & 7:00–24:00 & Outdoor Temp \(<\) 26 \({}^{\circ}\)C & 1.000 ach \\  & Weeked & 17:00–24:00 & and Room Temp \(>\) & \\  & Weeked & 7:00–24:00 & Outdoor Temp & \\ \hline Bedroom & 1 September–30 September & Workday & 7:00–9:00 & \\  & Weeked & 17:00–24:00 & - & \\  & Weeked & 7:00–24:00 & - & \\  & 1 October–30 April & & 7:00–7:10 & - & \\ \hline \hline \end{tabular}
\end{table} 
Table 14: Simulation parameters of natural ventilation in Hailar.