# Growing Kratky Basil in Trombe Wall Cavity: Energy Performance
## 3 Results  
### General Thermal Effects of Plants on TW Cavity Air  
The addition of plants to the Trombe wall (TW) cavity primarily reduced high-temperature spikes at noon. This cooling effect was most pronounced during autumn and winter, with reductions of 35-40 \({}^{\circ}\)C and 25-28 \({}^{\circ}\)C, respectively. During spring and summer, the effect was less significant, with temperature reductions of 18-20 \({}^{\circ}\)C and 10-12 \({}^{\circ}\)C, respectively (Figure 3).  
Figure 3: Air temperatures of the Trombe wall’s air cavity during average days of each of the stages of the experiment, roughly corresponding to seasons of the year: (**A**) 1 July to 10 October, (**B**) 11 October to 21 January, (**C**) 22 January to 29 March, (**D**) 30 March to 30 June. The solid and dashed lines depict the measured and modeled temperatures during the baseline and experimental year (separated by color).The dotted lines depict the outside temperatures recorded during the same season. The areas in yellow and cyan show the solar radiation during both years for reference. Scatterplots in the corner depict the correlations between the model and the measurements with their 95% confidence ellipses.  
During the sunny days (Figure 4), the cooling and balancing effects of the plants and additional thermal mass on the Trombe wall were more extreme and pronounced, bringing the temperatures to acceptable for cultivation levels throughout the year. The night temperatures were almost unaffected by the additional thermal mass and shade, differing just slightly, with 0.52 \({}^{\circ}\)C temperature dips at dawn when compared to the baseline year (BY) readings (Table 4).  
Figure 4: Air temperatures of the Trombe wall’s air cavity during the studied sunny days. The solid and dashed lines depict the measured and modeled temperatures during the baseline and experimental year readings (separated by color) during: (**A**) 20 July 2021 and 28 July 2022, (**B**) 31 October 2021 and 31 October 2022, (**C**) 9 February 2022 and 5 February 2023, (**D**) 4 May 2022 and 2 May 2023. The dotted lines depict the outside temperatures recorded during the same day. The areas in yellow and cyan show the solar radiation during both years for reference. Scatterplots in the corner depict the correlations between the model and the measurements with their 95% confidence ellipses.  
Due to constant ventilation in TW (with air speeds ranging between 0.3 and 1.5 m/s), the Trombe wall cavity air became less static and stratified during the experimental year (EY), causing the density, humidity, and air temperatures to be more even. Additionally, the air movement negatively impacted its heat-transfer-related properties as its insulating capabilities significantly decreased, especially when combined with the slight increase in humidity levels (by 2.68% or 0.88g/m3).  
The additional thermal mass also delayed the peak temperatures by approximately 30 min to 1 h, allowing for more gradual cooling. The TW cavity generally returned to baseline-year temperature levels 3.5-6 h after sunset. On cloudy days (Figure 5), the cooling effect was negligible or absent due to limited available solar radiation.