## 3 Results and Discussion  
### Thermal and Solar Properties  
Thermal properties, measured following the thermal flux meter methodology, are reported in Table 3. Several tests were carried out on the sample, considering two set-point air temperatures in the hot chamber: 45 \({}^{\circ}\)C and 50 \({}^{\circ}\)C; only the most significant parameters measured in each test are shown in the table. During measurements, lasted for about 2 hours, the surface temperatures recorded by the probes differ at most for 0.6 \({}^{\circ}\)C on the cold side and 0.5 \({}^{\circ}\)C on the hot one. Furthermore, the air-temperature trends in the hot chamber and in the laboratory (cold side) are constant, ensuring stationary test conditions; the air temperature difference between the two sides is in \begin{table}
\begin{tabular}{c c c} \hline
**Building Elements** & **Thickness [m]** & **Thermal Transmittance [W/m\({}^{2}\)K]** \\ \hline External wall & 0.24 & 0.57 \\ Internal wall & 0.11 & 3.41 \\ Ground floor (including gravel layer) & 0.99 & 0.48 \\ Roof & 0.52 & 0.32 \\ Floor between storeys & 0.50 & 0.52 \\ \hline \end{tabular} \
\begin{tabular}{c}
\begin{tabular}{c} \hline **N/m\({}^{2}\)K]** \\ \end{tabular} \\ \hline External wall & 0.24 & 0.57 \\ Internal wall & 0.11 & 3.41 \\ Ground floor (including gravel layer) & 0.99 & 0.48 \\ Roof & 0.52 & 0.32 \\ Floor between storeys & 0.50 & 0.52 \\ \hline \end{tabular}
\end{table} 
Table 1: The investigated building: features of the opaque envelope components. \begin{table}
\begin{tabular}{c c c} \hline
\begin{tabular}{c} \hline \end{tabular}
\end{table} 
Table 2: Simulation hypothesis: internal loads, operating periods of heating and cooling system, infiltration rate. \begin{table}
\begin{tabular}{c c c} \hline
**Building Elements** & **Thickness [m]** & **Thermal Transmittance [W/m\({}^{2}\)K]** \\ \hline External wall & 0.24 & 0.57 \\ Internal wall & 0.11 & 3.41 \\ Ground floor (including gravel layer) & 0.99 & 0.48 \\ Roof & 0.52 & 0.32 \\ Floor between storeys & 0.50 & 0.52 \\ \hline \end{tabular} \begin{tabular}{c} \hline **Nighting peak power (500 lux [30], fully dimmable lamps)** & **7 W/m\({}^{2}\)** \\ \hline \begin{tabular}{c} **People** \\ \end{tabular} & \begin{tabular}{c} 0.05 people/m\({}^{2}\) \\ \end{tabular} & \begin{tabular}{c} 8:00 a.m. to 6:00 p.m. \\ weekdays \\ \end{tabular} \\ \hline \end{tabular} \begin{tabular}{c} **Operating periods of heating and cooling system** \\ \hline \begin{tabular}{c} **Location** \\ \end{tabular} & **Heating (20 \({}^{\circ}\)C)** & **Cooling (26 \({}^{\circ}\)C)** & \\ \hline Helsinki & 01/01–12/31 & 05/01–09/04 & \\ Paris & 10/15–04/30 & 05/01–10/14 & 8:00 a.m. to 6:00 p.m. \\ Turin & 10/15–04/15 & 04/16–10/14 & weekdays \\ Rome & 11/01–04/15 & 04/16–10/14 & \\ \hline \end{tabular} \begin{tabular}{c} **Infiltration rate** \\ \hline \begin{tabular}{c} \hline **Whole building** \\ \end{tabular} & \begin{tabular}{c} 0.3 vol/h \\ \end{tabular} & \
\begin{tabular}{c} 12:00 p.m. to 08:00 a.m. \\ 6:00 p.m. to 12:00 p.m. \\ \end{tabular} & All days \\ \hline
\begin{tabular}{c} 0.6 vol/h \\ \end{tabular} & 08:00 a.m. to 6:00 p.m. \\ \end{tabular} & \end{table} 
Table 1: The investigated building: features of the opaque envelope components. the 18.3-22.9 \({}^{\circ}\)C range (average value about 20 \({}^{\circ}\)C). The thermal resistance of the sample varies in the 0.72-0.74 m\({}^{2}\)K/W range, with a corresponding thermal transmittance of about 1.1 W/(m\({}^{2}\)K). A reference test, able to provide a direct comparison of the monolithic aerogel sample with a standard solution, was carried out on a double glazing system with the same two float glass panes, but with air in the gap (15 mm of air) instead of aerogel; it was tested in the Small Hot Box apparatus. A thermal resistance of 0.155 m\({}^{2}\)K/W, corresponding to a thermal transmittance of 3.12 W/m\({}^{2}\)K, was found: the presence of the monolithic aerogel pane allows a reduction of the total thermal transmittance of about 65%.