## 5 Results and Discussion  
Table 4 shows the calculated EAHE COP (The highest values of Open/Closed loop are in bold text style). It shows that the open loop in heating mode has a better COP. While the closed-loop in cooling mode has a better COP. However, the average temperature of the exhaust air of the EAHE system is 13 \({}^{\circ}\)C.  
Figure 4 shows the variations in temperature and humidity inside and outside the greenhouses. The figure shows that as the air temperature decreases, the humidity increases, and at less than 15 \({}^{\circ}\)C drives to the humidity exceeds the levels already mentioned as harmful to plants (\(>\)80-90%) [20]. The differences between the GH and GH + EAHE microclimates range from 2.5 C to 5 C in air temperatures, and the differences in relative humidity vary from 8% to 12%. GH + EAHE microclimates' relative humidity is lower compared to GH. The increase in humidity at night is due to the decrease in temperature, which leads to increased condensation. However, in A3 and A4, the air temperature at night was warmer than in GH + EAHE. In addition, the air temperature was cooler during the day. It must be emphasized that the GHs with microclimates at reduced scale are only used to study the differences that occur when the EAHE system is used, and the design isn't the same as industrial GH. Figure 5 shows the heaters with different set temperatures, where \(T_{\text{set}}\) = 18 \({}^{\circ}\)C in B1 and B2, \(T_{\text{set}}\) = 20 \({}^{\circ}\)C in B3, and \(T_{\text{set}}\) = 15 \({}^{\circ}\)C in B4, B5, and B6. However, GH and GH + EAHE are quite similar, the differences in air temperatures in the microclimates are between 3.5 \({}^{\circ}\)C and 7.5 \({}^{\circ}\)C.  
Figure 6 shows the differences in relative humidity variations in the microclimates of the GHs. The highest values are measured at night in the GH + EAHE and range from 8.5% to 37.5%. We suspect that these values are due to condensation, and these measurements are consistent with the work of [PERSON] et al. [18]. In Figure 7 it can be observed that the energy consumption becomes lower when the difference between the set temperature of the heater and the outlet air temperature of the EAHE system is smaller (outlet temperature \(\approx\) soil temperature). However, if the difference is large enough, the EAHE system works as a pre-cooler and makes the heater consume more energy (B3: \(T_{\text{set}}\) = 20 \({}^{\circ}\)C and \(T_{\text{out}}\) = 13 \({}^{\circ}\)C). More energy consumption equals more CO\({}_{2}\) emissions. For the average CO\({}_{2}\) content abroad in the combustion of fuels, the Portuguese value of the base carbon was taken from a publication of the International Energy Agency [35]. It follows:  
\[\frac{m_{CO_{2}}}{E}=0.255(\text{kgCO}_{2}/\text{kWh})=255(\text{gCO}_{2}/ \text{kWh})\to m_{CO_{2}}=255\cdot E \tag{4}\] \begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{3}{*}{COP\({}_{\text{heating}}\)} & \multirow{3}{*}{Closed loop} & A1 & A2 & B1 & B3 & B4 \\ \cline{3-8}  & & **1.6** & 1.3 & **1.3** & 0 & 0.9 \\ \cline{2-8}  & & A3 & A4 & B2 & B5 & B6 \\ \cline{2-8}  & & 0.5 & **3.4** & 0.4 & **0.2** & **1.1** \\ \hline \multirow{3}{*}{COP\({}_{\text{cooling}}\)} & \multirow{3}{*}{Closed loop} & A1 & A2 & B1 & B3 & B4 \\ \cline{3-8}  & & **3.2** & 2.7 & **3.2** & **2.8** & **3.2** \\ \cline{2-8}  & & A3 & A4 & B2 & B5 & B6 \\ \cline{1-1} \cline{2-8}  & & 0.5 & **7.3** & 0.5 & 0.6 & 3 \\ \hline \end{tabular}
\end{table} 
Table 4: Relation between Open/Closed loops and maximum COP\({}_{\text{heating}}\)/\({}_{\text{cooling}}\). The measurements show that the highest CO\({}_{2}\) emissions belong to the B1 experience, where the value in the GH reached 359.55 g at 07:00 am.