# Growing Kratky Basil in Trombe Wall Cavity: Energy Performance
## 2 Methodology  
### Location and Functioning of the Preexisting Trombe Wall  
This study was conducted at an operational Trombe wall (TW) facility within a newly constructed building in Kitakyushu city, Japan, situated near the northeastern edge of Kyushu Island, Japan (33.89\({}^{\circ}\) N, 130.71\({}^{\circ}\) E). The region experiences a humid subtropical climate (Cfw classification by Koppen-Geiger) characterized by warm winters, hot and humid summers, and an annual average temperature of 17.5 \({}^{\circ}\)C. A distinct rainy season occurs between mid-June and mid-July, with only a few days annually experiencing subzero temperatures.  
The studied building is constructed with cross-laminated timber, making it lightweight and well-insulated. The Trombe wall occupies 16.53 m\({}^{2}\) (5.45 m\({}^{3}\)) of the south-facing facade (rotated 19\({}^{\circ}\) southeast), which constitutes 8% of the surface area. It serves a large interior space of 155.5 m\({}^{2}\) (1.157 m\({}^{3}\)) as an auxiliary heating mechanism, supplementing conventional air-conditioning (AC) systems that maintain indoor temperatures between 20 \({}^{\circ}\)C and 22 \({}^{\circ}\)C during the heating season. A summary of the TW's dimensions and thermal properties is presented in Figure 2 and Table 1.  
Figure 2: Building materials, geometry, and contents of the green Trombe wall (**A**), and an interior view of the facility (**B**) taken on 28 May 2023.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Building Element** & **Area, m\({}^{2}\)** & **Thermal Resistivity R\({}_{\rm Y}\)** & **Thermal Conductivity** & **Density.** & **Specific Heat** & **Volume,** & **Thermal Mass,** \\  & **m\({}^{2}\)** & **(excl. ref. Resist.), m\({}^{2}\)** & **Lypers of Materials** & **\(\lambda\), W/m\({}^{*}\)K** & **kg/m\({}^{3}\)** & **Capacity Cp, J/kg\({}^{*}\)K** & **m\({}^{3}\)** & **J\({}^{0}\)K** \\ \hline Humidity in air BV (year) avg of 9.3 g/m\({}^{3}\)) & & & & & & \\ \hline Humidity in air EV (year) avg of 10.3 g/m\({}^{3}\)) & & & & & & \\ \hline Ladder aluminum & & & & & & \\ \hline Ducts steel & & & 6500 & 4700 & 44.33 & 208.351 \\ \hline Middle beam wood & & & 600 & 2300 & 12.882 & 29,628.6 \\ \hline Shelves & & & 480 & 1200 & 144.67 & 173,606.4 \\ \hline Water in deposits & & & 1000 & 4188 & 21 & 87,280 \\ \hline Fans oscillating and static & & & 1600 & 1950 & 16 & 25,896 \\ \hline Glass bottles & & & 2700 & 840 & 98.355 & 26,618.2 \\ \hline Plant pool, PP & & & 900 & 1920 & 2.765 & 5308.8 \\ \hline Rockwood cube & & & 166 & 1030 & 0.925 & 610.28 \\ \hline Nutrient solution & & & 1000 & 4188 & 94.8 & 397,022.4 \\ \hline Living basal plants & & & & & & \\ \hline Total Baseline year & & & & & & \\ \hline Total Experiment year & & & & & & \\ \hline \end{tabular}
\end{table}
Table 1: _Cont._During the colder months (late November to early May), the TW operates through twin temperature-offset fans (85 m\({}^{3}\)/h each [74]), which extract hot air from the upper portion of the TW cavity and deliver it to the interior via vents at chair level, with passive inlets allowing cooler air inflow at floor level. The system is active whenever the TW air temperature exceeds the indoor air temperature. Excess heat is vented via a ceiling-mounted exhaust fan (85 m\({}^{3}\)/h [75]) into the attic. During summer, air exchange with the building is ceased, and only the exhaust fan mitigates overheating. Continuous monitoring of thermal and environmental conditions is performed using dataloggers (T and D TR-71 and TR-72 series [76] equipped with THA-3001 and TR-0106 sensors, with operating environment between \(-\)10 to 80 \({}^{\circ}\)C, \(<\)90% Rh, accuracy \(\pm\) 0.5 \({}^{\circ}\)C, \(\pm\) 5% Rh) placed inside and around the TW, recording data at 10 min intervals.