## 3 Results and Discussion
### Simulation Results and Comparison with Conventional Glazing Solutions
The energy demand for artificial lighting is quite similar for all the windows (Tables 6 and 7); the daylight illuminance on the working plane is higher than the recommended value (500 lux \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Glazing** & **Description** & **Thickness** & \(\tau_{\
u}\) & \(g\) & \(U\) \\  & **[mm]** & **[-]** & **[-]** & **[W/m\({}^{2}\)K]** \\ \hline \multirow{3}{*}{AER- DGU} & Float clear glass (4.7 mm), & & & & \\  & monolithic aerogel (15 mm), & 24.4 & 0.69 & 0.70 & 1.0 \\  & float clear glass (4.7 mm) & & & & \\ \hline \multirow{3}{*}{LOW-E DGU} & Float clear glass (6 mm), & & & & \\  & Air (10\%) and Argon (90\%) (16 mm), & 26 & 0.76 & 0.55 & 1.1 \\  & Low-e float clear glass (4 mm) & & & & \\ \hline \multirow{3}{*}{LOW-E TGU} & Low-e float clear glass (4 mm), Air & & & & \\  & (10\%) and Argon (90\%) (12 mm), & & & & \\ \cline{1-1}  & float clear glass (4 mm) & 36 & 0.66 & 0.44 & 0.7 \\ \cline{1-1}  & and Argon (90\%) (12 mm), Low-e & & & & \\ \cline{1-1}  & float clear glass (4 mm) & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Constructive, thermal, and optical features of the investigated glazing systems. [30]) for most of the daylight hours for the three glazing systems during the year, also due to the high window-to-wall ratios of the investigated building. The energy demand for lighting is hence driven by energy uses in non-daylight hours during working time, making the impact of different lighting transmittance of the selected samples close to negligible. Based on these results, the glazing systems with monolithic aerogel could be considered a good solution for space heating demand, especially in moderate climates (namely, Turin). The energy savings could increase when considering higher aerogel pane thicknesses, which can allow a lower U-value and a higher reduction in heating loads. However, due to the energy demand increasing for cooling, the annual energy consumptions with monolithic aerogel solutions could be quite lower when compared to conventional double glazing systems, depending on the HVAC systems and their efficiency. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Glazing** & \begin{tabular}{c} **Heating Energy Demand** \\ **[kWh/m\({}^{2}\)]** \\ \end{tabular} & \
\begin{tabular}{c} **Cooling Energy Demand** \\ **[kWh/m\({}^{2}\)]** \\ \end{tabular} &
\begin{tabular}{c} **Lighting Energy Use** \\ **[kWh/m\({}^{2}\)]** \\ \end{tabular} \\ \hline \multirow{3}{*}{HELSINKI} & LOW-E DGU & 52.6 & 0.4 & 8.6 \\  & LOW-E TGU & 50.3 & 0.4 & 9.1 \\  & AER-DGU & 49.9 & 0.5 & 8.9 \\ \hline \multirow{3}{*}{TURIN} & LOW-E DGU & 14.8 & 9.4 & 7.5 \\  & LOW-E TGU & 14.4 & 9.2 & 8 \\  & AER-DGU & 13.4 & 9.8 & 7.7 \\ \hline \multirow{3}{*}{PARIS} & LOW-E DGU & 18.5 & 2.8 & 7.8 \\  & LOW-E TGU & 17.9 & 2.8 & 8.3 \\  & AER-DGU & 17 & 3.1 & 8.1 \\ \hline \multirow{3}{*}{ROME} & LOW-E DGU & 2.9 & 14.9 & 7.2 \\  & LOW-E TGU & 3.1 & 14.6 & 7.6 \\ \cline{1-1}  & AER-DGU & 2.2 & 15.5 & 7.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Heating, cooling, and lighting energy demand for the investigated glazing systems when considering WWR1 (50%).