## 3 Results and Discussions
### Variability in Temperature and Humidity
During the daytime, the humidity of the bottom layer was lower than that of the top layer because the crop respiration rate was higher; however, the humidity of the bottom layer was higher than the other two layers at night. The humidity inside both CSGs was approximately 15.6% lower than the outside humidity. Snowfall was observed during the experiment at night; however, it had little effect on the environmental conditions inside the greenhouses due to  
Figure 5: Temporal variation in the temperature inside both greenhouses in different layers and the temperature outside the greenhouses. the cotton blanket. Thus, temperature and humidity varied at different times and heights within the CSGs. The experimental data from both solar greenhouses (with and without crops) with three different layers (bottom, medium, and top) were analyzed using the Kriging method in Surfer 8.0 (Golden Software, LLC, Golden, CO, USA). Figures 7 and 8 show the spatial and vertical variability of the temperature using the 1 h average from 11:00 to 12:00, 16:00 to 17:00, and 22:00 to 23:00 h for the winter experiment in both greenhouses. The temperature levels on the three distinct sides were comparable, as were the temperatures inside each layer, which were also homogeneous. In the CSG with crops, the highest temperature of 28.22 \({}^{\circ}\)C was found in the top layer of the rear side between 11:00 and 12:00 h, and the lowest temperature of 5.42 \({}^{\circ}\)C was found in the lower layer of the rear side between 22:00 and 23:00 h. For the CSG without crops, the maximum temperature reached 27.81 \({}^{\circ}\)C in the middle layer of the center side from 11:00 to 12:00 h, while the minimum temperature was 5.18 \({}^{\circ}\)C in the lower layer of the rear side between 22:00 and 23:00 h. During the observed time period, it was found that the front and center sides of the CSG were relatively warmer, potentially indicating a heat loss induced by the structural flaws. To address this, implementing additional heating or repairing the defective parts could be effective remedies. Temperature variations were found to be consistent across all locations within the CSG. The presence of crops restricted air mobility within the greenhouse, leading to a warmer bottom layer compared to the bottom layer without crops. As sunset approached, the air temperature in both greenhouses decreased. However, the brick wall surrounding the greenhouse radiated stored energy during the night, thus helping to maintain a warm environment, albeit with slightly cooler temperatures in the bottom layer compared to the middle and top layers. Snowfall and rain had minimal effects on the overall temperature distribution within both greenhouses. Figures 9 and 10 show the spatial and vertical variability of the average inside humidity of the CSGs with and without crops for the front, middle, and rear sides at different heights. The humidity level at the center was lower than that at the front and rear. In the case of the CSG with crops, the maximum humidity was 88.32% in the bottom layer of the front side from 11:00 to 12:00 h, whereas the minimum humidity was 25.62% in the middle layer of the center side from 16:00 to 17:00 h. For the CSG without crops, the maximum humidity was 89.41% in the top layer of the rear side from 22:00 to 23:00 h, whereas the minimum humidity was 23.33% in the middle layer of the front side from 11:00 to 12:00 h. The humidity distribution was more stable in the greenhouse with crops than in the greenhouse without crops. During the winter, the temperature and humidity increased and decreased significantly. Monitoring the temperature and humidity with sensors is critically important for determining how the environment inside greenhouses could be best controlled to enhance crop growth and productivity. Figure 6: Temporal variation in the humidity inside both greenhouses in different layers and the temperature outside the greenhouses. Figure 8: Temperature distribution inside the CSG without crops.