## 3 Full-Scale Experiments  
### Experimental Site and Test Instruments  
The experiment was conducted in an office building in a university in Tianjin. The university is located in the suburbs, with flat and open surrounding terrain, and there are no other buildings around the experimental building. The experimental building has five floors, and the maximum number of building floors in the school is five, which reduces the influence of the complex building layout on the natural wind field. The experimental room is on the fourth floor of the office building, and the internal size of the room is \(8.1\) m \(\times\) 4.8 m \(\times\) 2.7 m (L \(\times\) W \(\times\) H). The orientation of the north wall is 13\({}^{\circ}\) north by east. The north wall of the office is an exterior wall having a window with two sheets, which is the casement window opening outwards. There are offices in both the east and west sides and in the floors above and below the experimental room. The south side, which has an inner door, is adjacent to the inner corridor, and the elevator hall is connected to the corridor. There is a glass window on the south side of the waiting hall, which is open and is equal to the window in the room. There are four sets of desks and chairs, and two sets of lockers in the experimental room. The dimensions of the experimental room and exterior window are shown in Figure 1, and the area and volume parameters are listed in Tables 1 and 2, respectively. Figure 1: Dimensions of (**a**) experimental room and (**b**) exterior window. The indoor ventilation rate was measured using a tracer gas concentration attenuation method. CO2 was selected as the tracer gas in this experiment, and a dry ice fire extinguisher was selected to release CO2 gas. The instruments used in the test included a small weather station, temperature and humidity recorder, miniature wind pressure gauge, infrared thermometer, warm air blower, CO2 detection recorder, and carbon dioxide fire extinguisher. The instruments used are shown in Figure 2. The measuring range, resolution, accuracy, model, and supplier of the instruments are listed in Table 3.  
Prior to the experiment, each instrument was calibrated to ensure test accuracy. For the small weather station installed on the experimental building roof, the installation height of the wind speed and direction sensor from the roof was at least 1.2 m according to the instructions. The wind vane of the wind speed and direction sensor was pointed north. The CO2 concentration sensors were placed in a well-ventilated outdoor environment without crowd interference, and the data acquisition host was connected. The sensors operated stably for more than 20 min at an outdoor concentration of 400 ppm, and a manual \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Exterior Wall Area** & **Exterior Window** & **Sheet Area of the** & **Interior Wall Area** & **Door Area (m2)** & **Room Area (m2)** \\
**(m2)** & **Area (m2)** & **Exterior Window (m2)** & **(m2)** & **Door Area (m2)** & **Room Area (m2)** \\ \hline
5.67 & 2.43 & 1.08 & 52.48 & 2.11 & 38.88 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Building area parameters of experimental room. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Total Volume (m3)** & **Furniture Volume (m3)** & **Net Volume (m3)** \\ \hline
104.98 & 16.64 & 88.34 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Building volume parameters of experimental room. Figure 2: Experimental instruments: (**a**) small weather station; (**b**) temperature and humidity recorder; (**c**) miniature wind pressure gauge; (**d**) dry ice fire extinguisher; (**e**) CO2 detection recorder; (**f**) warm air blower; and (**g**) infrared thermometer. calibration operation was performed. The indoor temperature and humidity recorder was calibrated before leaving the factory. The miniature wind pressure gauge was placed in a windless room, and it was ensured that no person directly breathed to the instrument.