## 4 Discussion
Table 9 summarizes and compares the main values detected during the indoor monitoring campaign with the main characteristics of the HVAC systems present in the respective analyzed rooms. From the data, it is clear that the high concentrations of CO2 could have been partly due to the modalities of introduction and extraction of the air in the environment that can negatively influence the air exchange. For example, Room 10 was served by a system with air inlet and outlet from the ceiling with possible short circuit. For Room 71, the air inlet and outlet were from the floor with possible similar problems, aggravated by the poor cleaning of the floor grilles. In the case of Room 2, even in the presence of air intake from above and return of air from below, the air flow rates may not have been adequate. In particular, the higher CO2 concentrations corresponded to lower air changes. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**VOCs Classes** & **Entrance** & **Room 2** & **Room 10** & **Verone** & **Room 35** & **Room 41** & **Room 71** & **Room 160** & **Verone** & **Total** \\  & **II Floor** & **Room 2** & **Room 10** & **II Floor** & **Room 35** & **Room 41** & **Room 71** & **Room 160** & **Sum** \\ \hline Cut off & 0.006 & 0.004 & 0.002 & 0.002 & 0.002 & 0.002 & 0.002 & 0.002 & 0.002 & \\ Alicyclic & 0.007 & 0 & 0 & 0 & 0.002 & 0 & 0.002 & 0 & 0.011 \\ hydrocarbons & 0.012 & 0.009 & 0 & 0.013 & 0.014 & 0.018 & 0.004 & 0.003 & 0.021 & 0.094 \\ Define & 0.014 & 0.009 & 0.008 & 0 & 0 & 0 & 0 & 0 & 0.031 \\ hydrocarbons & 0.109 & 0.007 & 0.016 & 0.009 & 0.004 & 0.015 & 0.006 & 0.019 & 0 & 0.185 \\ Terpens & 0 & 0.005 & 0 & 0.007 & 0.003 & 0.002 & 0.002 & 0.004 & 0.002 & 0.025 \\ hydrocarbons & Oxygenated— & 0.026 & 0.018 & 0.025 & 0.016 & 0.007 & 0.009 & 0.009 & 0.007 & 0.016 & 0.133 \\ acids & 0.099 & 0.111 & 0.034 & 0.091 & 0.058 & 0.083 & 0.065 & 0.064 & 0.066 & 0.671 \\ Oxygenated— & 0.124 & 0.099 & 0.092 & 0.063 & 0.071 & 0.064 & 0.061 & 0.064 & 0.088 & 0.726 \\ Oxygenated— & 0.060 & 0.033 & 0.045 & 0.011 & 0.017 & 0.008 & 0.005 & 0.012 & 0.009 & 0.200 \\ Oxygenated— & 0.008 & 0 & 0.005 & 0.003 & 0.005 & 0.005 & 0.008 & 0.008 & 0.004 & 0.046 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: VOCs classes and relative concentrations (mg/m3) in the analyzed rooms of the Uffizi Gallery. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Room** & **HVAC System** & **V \({}^{*}\)** & **A\({}_{\text{fr}}\) \({}^{**}\)** & **A\({}_{\text{cr}}\) \({}^{**}\)** & **A\({}_{\text{cr}}\) \({}^{**}\)** & **Ave t** & **Ave CO\({}_{\text{2}}\)** & **VOCs** & **TBL** & **Mold** \\  & **[m3]** & **[m3/n]** & **[vol/n]** & **[\({}^{*}\)C]** & **[\%]** & **[ppm]** & **[mg/m3]** & **[CFU/m3]** & **[CFU/m3]** \\ \hline Verone I & Primary ventilation air & & & & & & & & & \\ floor & fluorectors; no & 1642.5 & 1400 & 1.70 & 22 & 51 & 650 & 0.222 & 262 & 27 \\  & recirculated air. & & & & & & & & \\ Room 71 & Air inlet and & & & & & & & & \\  & outlet floor grids & 2598.5 & 9000 & 3.46 & 24 & 51 & 1156 & 0.188 & 242 & 56 \\  & Air inflets graaf the & & & & & & & & \\ Room 160 & skylight and air outlet & 1260.7 & 8000 & 6.35 & 23.9 & 52 & 859 & 0.254 & 305 & 30 \\  & grids at the bottom of the wall & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Comparison among the main values detected during the indoor monitoring campaign and the main characteristics of the HVAC systems present in the analyzed rooms.