## 3 Results and Discussion  
Figure 7a,b shows the summer and winter validation results. The computed results were obtained with the same physical and operating conditions as those of the experimental greenhouse, and are detailed in Table 5. Specifically, the internal greenhouse temperatures were compared. The statistical analysis of both validation results (given in Figure 7a,b) indicate R\({}^{2}\) values of 0.84 and 0.63; RMSE values of 1.8 \({}^{\circ}\)C and 1.3 \({}^{\circ}\)C; and rRMSE values of 6.7% and 7.4%, respectively. The R\({}^{2}\) value of 7a indicates that the model is accurate enough to calculate the inside temperature. In the case of the 7b, the value is a little less at 0.63, which is because the temperature fluctuations are much less. The RMSE \begin{table}
\begin{tabular}{l l c c c c c} \hline \multicolumn{2}{c}{**Parameter**} & \multicolumn{5}{c}{**Test Condition**} \\ \hline Orientation & & 0 (E-W) & 30 & 45 & 60 & 75 & 90 (N-S) \\ \hline Covering material & & PE & PVC & HG & PMMA & PC \\ \hline \multirow{2}{*}{Double glazing} & PC (mm) & 4 & 6 & 8 & 10 & 16 \\ \cline{2-6}  & PMMA (mm) & & 8 & & 16 & \\ \hline \multirow{2}{*}{No. of Screens} & Thermal & 1 & & 2 & 3 & \\ \cline{2-6}  & Shading & & & 1 & & \\ \hline Screen Materials & Ph-77 & Ph-Super & Luxous & Tempa & Polyester \\ \hline Natural ventilation & & Fully closed & & Naturally ventilated & \\ \hline North-wall insulation & & With & & Without & \\ \hline Roof shape & & Venlo & & Wide-span & \\ \hline \end{tabular}
\end{table} 
Table 6: Details of studied parameters. \begin{table}
\begin{tabular}{c c c} \hline \multicolumn{2}{c}{**Parameter**} & **Condition (a)** & **Condition (b)** \\ \hline Greenhouse type & Multi-span & Multi-span \\ \hline No. of span & 15 & 15 \\ \hline Roof type & Venlo & Venlo \\ \hline Roof Glazing & HG-4 mm & HG-4 mm \\ \hline Side Glazing & PC-16 mm & PC-16 mm \\ \hline Dimension & 120.2 m x 63 m x 7.5 m & 120.2 m x 63 m x 7.5 m \\ \hline Floor area & 7572.6 m\({}^{2}\) & 7572.6 m\({}^{2}\) \\ \hline Orientation & North–South & North–South \\ \hline Period & 20–29 August 2019 & 1–10 December 2019 \\ \hline Screen & Shading (Ph-77) & Ph-77, Ph-Super \\ \hline \multirow{4}{*}{Screen control} & & Ph-77 retract (After sunrise, or Temp 10, or S.R 100 W) \\ \cline{2-6}  & & Ph-77 deploy (After sunset, or Temp 12, and S.R 100 W) \\ \cline{1-1} \cline{2-6}  & & Ph-Super\_1 retract (After sunrise, or Temp 5, or S.R 50 W) \\ \cline{1-1} \cline{2-6}  & & Ph-Super\_1 deploy (After sunset, or Temp 12, and S.R 50 W) \\ \cline{1-1} \cline{2-6}  & & Ph-Super\_2 retract (After sunrise, or Temp 12, or S.R 150 W) \\ \cline{1-1} \cline{2-6}  & & Ph-Super\_2 deploy (After sunset, or Temp 14, and S.R 150 W) \\ \hline Natural ventilation & \multicolumn{2}{c}{Rof vents} & \multicolumn{2}{c}{Rof vents} \\ \hline Natural vents control & 18 \({}^{\circ}\)C (0:00–04:00) & 18 \({}^{\circ}\)C (00:00–05:30) \\ \cline{1-1} \cline{2-6} set point temperature & 20 \({}^{\circ}\)C (0:00–18:00) & 15 \({}^{\circ}\)C (16:15–21:30) \\ \cline{1-1} \cline{2-6}  & & 18 \({}^{\circ}\)C (18:00–24:00) & 18 \({}^{\circ}\)C (21:30–24:00) \\ \hline \multirow{2}{*}{Heating} & & & 17 \({}^{\circ}\)C (00:00–16:15) \\ \cline{1-1} \cline{2-6}  & & No & 15 \({}^{\circ}\)C (16:15–21:30) \\ \cline{1-1} \cline{2-6}  & & & 17 \({}^{\circ}\)C (21:30–24:00) \\ \hline \end{tabular}
\end{table} 
Table 5: Summary of reference greenhouse conditions. value for the prediction of the greenhouse's internal temperature is less than those of the studies conducted by [PERSON] et al. and [PERSON] et al. (2016); [PERSON] et al. (2017). Their studies indicated that an rRMSE value less than 10% is reasonable. According to that, our model prediction is sufficiently accurate. The good agreement between the computed and experimental internal temperatures encourages the adoption of the proposed multi-span greenhouse BES model.