## 2 Materials and Methods
### Outdoor Conditions  
The outdoor environmental conditions were monitored using the weather station, and the data were collected via the WeatherLink Cloud(r) online service. This program automatically compiles a data log file that records the average weather conditions measured every 15 min in GMT+1. As shown in Figure 2, the highest temperature recorded during the experimental campaign was 39 \({}^{\circ}\)C on 31 July 2020 at 15:45, while the lowest was 16.2 \({}^{\circ}\)C on 1 September 2020, at 06:45. The average temperature throughout the campaign was 27.7 \({}^{\circ}\)C. The temperature trends were fairly consistent, with only one notably colder day (1 September 2020). A rainy day occurred on 31 August 2020, with a total of 10 h of precipitation, amounting to 13.8 mm of rainfall. The humidity levels also remained relatively stable, reaching a maximum of 91% RH on the rainy day (31 August 2020) and a minimum of 25% RH on 25 July 2020, at 15:00, on 9 August 2020, at 13:30 and 14:45, and on 13 August 2020, at 15:00. The average humidity was 58.42% RH. The dew point, as calculated by the software, indicated a maximum of 24.4 \({}^{\circ}\)C (31 July 2020, at 23:00), a minimum of 10.7 \({}^{\circ}\)C (5 August 2020, at 14:45), and an average of 18.2 \({}^{\circ}\)C. Daily variations, due to the night-day cycles, showed an average range of 12.5 \({}^{\circ}\)C for outdoor temperature, 43.8% RH for humidity, and 4.1 \({}^{\circ}\)C for the dew point.  
The solar radiation measured during the campaign is shown in Figure 3. As can be seen, most of the measurements were taken on sunny days, except for one rainy day (31 August 2020) and one cloudy day (11 September 2020). The maximum solar radiation measured flux was 928 W/m\({}^{2}\) on 25 July 2020 at 13:15, and the average daily value (between 8:00 and 20:00) was 573.6 W/m\({}^{2}\).  
The Wind Rose chart of the reference period is shown in Figure 4a. As can be seen, the main wind directions were North-East and West-South-West, with the strongest wind from the North-East (>5 km/h). Wind depends on the surrounding environment, and the building is located below the level of the street in a cavity surrounded by buildings. This limits the wind direction as well as its intensity. As can be seen in Figure 4b, the average wind speed in km/h comes from the North-East, South-West and South-East with about the same intensity (4-4.3 km/h).  
\begin{table}
\begin{tabular}{c c} \hline
**Variable** & **Value** \\ \hline Pressure & \(\pm\)1.0 hPa \\ Dewpoint & \(\pm\)1 \({}^{\circ}\)C \\ Humidity & \(\pm\)2\% RH \\ Rainfall & The higher between 250 mm/h and \(\pm\)3\% \\ Solar Radiation & \(\pm\)5\% of full scale \\ Temperature & \(\pm\)0.3 \({}^{\circ}\)C \\ Wind Direction & \(\pm\)3\({}^{\circ}\) \\ Wind Speed & \(\pm\)0.9 m/s \\ \hline \end{tabular}
\end{table}
Table 1: DAVIS VANTAGE PRO2 measurement errors (source: Datasheet).  
\begin{table}
\begin{tabular}{c c} \hline
**Variable** & **Value** \\ \hline Humidity & \(\pm\)3\% RH \\ Temperature & \(\pm\)1 \({}^{\circ}\)C \\ \hline \end{tabular}
\end{table}
Table 2: VOLTCRAFT DL-121 TH measurement errors (source: Datasheet).  
Figure 4: (**a**) Wind Rose chart with principal wind components (in [km/h]) measured by the weather station during the period from 24 July 2020 to 15 September 2020; (**b**) Average wind speed components (in [km/h]) measured by the weather station during the period from 24 July 2020 to 15 September 2020.  
Figure 3: Solar radiation [W/m\({}^{2}\)] measured by the weather station during the period from 24 July 2020 to 15 September 2020.  
Figure 2: Environmental data (Temperature [°C], Relative Humidity [%RH] and Dew Point [°C]) collected by the weather station during the period from 24 July 2020 to 15 September 2020.