# Improving School Transition Spaces Microclimate to Make Them Liveable in Warm Climates
## 2 Materials and Methods
### Experiments  
As part of the research, the materials of the courtyards' envelope, facades and pavement were changed during the field monitoring campaigns: in case study 1, a change in the albedo of the pavement, with a specific color modification (Experiment 1) and in case study 2, the incorporation of vegetation inside the courtyard consisting of the installation of a vegetal facade (Experiment 2).  
Experiment 1. Taking into account previous research [16], in which a study was conducted to see the effects on the microclimate of the albedo in a courtyard, the pavement was covered with two  
Figure 8: Case study 1: Cumulative insolation from 9 th September to 16 th September.  
Figure 9: Case study 2: Cumulative insolation from 24 th September to 1 st October.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Case Study** & **Maximum Cumulative Insolation** & **Minimum Cumulative Insolation** \\ \hline Case 1 & 28 kWh/m\({}^{2}\) & 4 kWh/m\({}^{2}\) \\ Case 2 & 33 kWh/m\({}^{2}\) & 4 kWh/m\({}^{2}\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Cumulative direct solar radiation in both courtyards.  
sheets, one white (albedo 0.91) and one black (albedo 0.37). This showed the influence of surface color on indoor and outdoor thermal comfort in public and urban spaces, such as courtyards. Based on this methodology, a similar experiment was carried out in case study 1. The main goal was to study the impact of the albedo on the courtyard microclimate in a warm climate area such as Seville. Due to the current condition of the courtyard pavement (a black waterproofing membrane), another sheet with a higher reflection coefficient was used to study its impact, and to analyze its possible use as a cooling strategy, thus improving the courtyard thermodynamic performance and the comfort of the surrounding classrooms.  
To carry out this experiment, air and surface temperature data loggers and a thermal imaging infrared camera were used. The sheet used in the experiment was a 2.00 m \(\times\) 7.50 m waterproof polymer roofing SIKA (r) (SIKA, Baar, Switzerland) membrane (Figure 10). Based on the solar study, this sheet was placed in the area that receives the highest direct solar radiation during the students' time at the school (from 9:00 a.m. to 5:00 p.m.). The sheet used is Sarnafil TS 77-18 (SIKA, Baar, Switzerland) (waterproof membrane for roofing purposes), it has a CIGS (Copper Indium Gallium Selenide) reflectance of 95%, a solar reflectance of 0.90, an initial emittance of 0.85 and a solar reflectance index of 112. A TESTO 885 thermal camera (TESTO, Lenzkirch, Germany) and a TESTO 435 surface temperature sensor (TESTO, Lenzkirch, Germany) were used to check the surface temperature of the courtyard.  
Experiment 2. Knowing the significance of vegetation as a key strategy in minimizing urban overheating, the second study consists of a modification of one of the facades' surface coating of the courtyard in case study 2. For this purpose, a plant layer with drip irrigation was installed on the facade with the highest direct radiation from the sun as shown below (Figure 11). The vegetal system used was an optimal passive facade solution consisting of an industrialized and sustainable system that puts together different plants in the same module to be part of the constructive elements in the building's facade. The vegetal facade was defined by several 100 cm \(\times\) 100 cm modules (39.4 inches \(\times\) 39.4 inches). Each module was constituted by several elements that are available in the market and do not require advanced technology: galvanized welded mesh and a plastic cell (replaceable by a metal box) with a substrate for the development of plants. The system includes a galvanized steel structure as a support frame.  
Figure 10: Case study 1: Waterproof polymer roofing SIKA (r) membrane placement.