# Evaluating the Energy-Saving Potential of Solar Dedicated Ventilation Systems Based on ADRC
## 5 Results and Discussion
### Accurate Control  
According to Section 4, the experimental system has some outdoor conditions, which are temperature (25 \({}^{\circ}\)C, 30 \({}^{\circ}\)C, 35 \({}^{\circ}\)C), relative humidity (50%, 60%, 70%, 80%), and airflow rate (0.1 m\({}^{3}\)/s, 0.15 m\({}^{3}\)/s, 0.2 m\({}^{3}\)/s, 0.25 m\({}^{3}\)/s, 0.3 m\({}^{3}\)/s), and one indoor condition (22 \({}^{\circ}\)C and 50%). Therefore, there are 60 outdoor conditions (temperature \(\times\) relative humidity \(\times\) airflow rate = 3 \(\times\) 4 \(\times\) 5) in this experiment. Three representative outdoor conditions (25 \({}^{\circ}\)C, 50%, 0.1 m\({}^{3}\)/s; 35 \({}^{\circ}\)C, 80%, 0.3 m\({}^{3}\)/s; and 30 \({}^{\circ}\)C, 60%, 0.2 m\({}^{3}\)/s) were chosen from the 60 outdoor conditions for the analysis. The temperature of four test points has a smaller fluctuation range at different outdoor conditions, which are shown in Tables 1-3 and Figures 7-9. The maximum and minimum temperature standard deviations are 0.15 and 0.09 \({}^{\circ}\)C, respectively, at different outdoor conditions. The temperature difference \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Acquisition Time (min)** & **Test Point 1 (\({}^{\circ}\)C)** & **Test Point 2 (\({}^{\circ}\)C)** & **Test Point 3 (\({}^{\circ}\)C)** & **Test Point 5 (\({}^{\circ}\)C)** \\ \hline
18 & 35.28 & 13.51 & 16.26 & 22.27 \\
19 & 35.29 & 13.31 & 16.02 & 22.26 \\
20 & 35.33 & 13.15 & 16.06 & 22.24 \\
21 & 35.39 & 13.12 & 16.05 & 22.45 \\
22 & 35.38 & 13.33 & 16.09 & 22.27 \\
23 & 35.05 & 13.50 & 16.24 & 22.25 \\
24 & 35.05 & 13.31 & 16.35 & 22.34 \\
25 & 35.14 & 13.28 & 16.33 & 22.34 \\
26 & 35.48 & 13.14 & 16.30 & 22.45 \\
27 & 35.39 & 13.43 & 16.45 & 22.58 \\
28 & 35.31 & 13.32 & 16.45 & 22.42 \\
29 & 35.16 & 13.26 & 16.37 & 22.42 \\
30 & 35.16 & 13.04 & 16.37 & 22.41 \\ Average & 35.20 & 13.33 & 16.20 & 22.31 \\ Maximum & 35.48 & 13.51 & 16.45 & 22.58 \\ Minimum & 34.99 & 13.02 & 16.01 & 22.11 \\ Standard deviation & 0.14 & 0.15 & 0.13 & 0.11 \\ Temperature difference between & 0.50 & 0.49 & 0.44 & 0.47 \\ maximum and minimum & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Acquisition Time (min)** & **Test Point 1 (\({}^{\circ}\)C)** & **Test Point 2 (\({}^{\circ}\)C)** & **Test Point 3 (\({}^{\circ}\)C)** & **Test Point 5 (\({}^{\circ}\)C)** \\ \hline
1 & 30.36 & 12.70 & 15.48 & 22.12 \\
2 & 30.41 & 12.70 & 15.40 & 22.18 \\
3 & 30.40 & 12.66 & 15.62 & 22.11 \\
4 & 30.39 & 12.67 & 15.56 & 22.18 \\
5 & 30.38 & 12.75 & 15.47 Figure 8: Temperature data collection of four test points at 35 \({}^{\circ}\)C, 80%, 0.3 m\({}^{3}\)/s. Figure 7: Temperature data collection of four test points at 25 \({}^{\circ}\)C, 50%, 0.1 m\({}^{3}\)/s. The standard deviation and temperature difference between maximum and minimum are the lowest at 25 \({}^{\circ}\)C, 50%, 0.1 m\({}^{3}\)/s, as shown in Table 1. The highest value of standard deviation and temperature difference between maximum and minimum are 35 \({}^{\circ}\)C, 80%, 0.3 m\({}^{3}\)/s, as shown in Table 2. The results show that various outdoor conditions (temperature (T), relative humidity (RH), and airflow rate) influence the control accuracy of the proposed solar dedicated ventilation system. For different outdoor conditions (T, RH, and airflow rate), standard deviation and temperature difference between maximum and minimum have the same trend, increasing with an increase of outdoor conditions. These results also indicate that higher outdoor conditions (T, RH, and airflow rate) lead to lower control accuracy. The outdoor conditions of this experiment cover most subtropical climates and summer environments.