## 3 Results and Discussion
### EN 16798-1  
EN 16798-1 [10], which supersedes EN 15251 [11], has been prepared by Technical Committee CEN/TC 156 \"Ventilation for buildings\". Regarding IAQ, EN 16798 is based on the results described previously for non-adapted people, considering both the emissions generated by humans and buildings and their components.  
Looking at the different simulations through the requirements of EN 16798-1, some conclusions can be drawn. All simulations showed very satisfactory results, with at least 86% of the year in IAQ categories 1 and 2.  
The simulation with the lowest IAQ was Sim_1, which is the simulation where the closed period is extended throughout the year, and for this reason, a true comparison cannot be made due to the lack of occupants to experience the space. However, since some standards divide the ventilation rates into the number of people and the area of the compartment, this ventilation strategy was included in the comparison, as can be seen in Figure 21.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{3}{c}{\(\mathbf{\Delta CO_{2}}\) Concentration (ppm) Compared to Sim_02} \\ \hline
**Month** & **Sim\_1** & **Sim\_2** & **Sim\_3.1** & **Sim\_3.2** & **Sim\_4** \\ \hline January & - & 0\% & \(-15\%\) & \(-7\%\) & 80\% \\ February & - & 0\% & \(-14\%\) & \(-7\%\) & 80\% \\ March & - & \(-15\%\) & \(-16\%\) & \(-8\%\) & 80\% \\ April & - & \(-31\%\) & \(-17\%\) & \(-8\%\) & 80\% \\ May & - & \(-38\%\) & \(-26\%\) & \(-11\%\) & 80\% \\ June & - & \(-18\%\) & \(-20\%\) & \(-11\%\) & 80\% \\ July & - & 0\% & \(-20\%\) & \(-9\%\) & 80\% \\ August & - & 0\% & \(-22\%\) & \(-8\%\) & 80\% \\ September & - & \(-10\%\) & \(-20\%\) & \(-9\%\) & 80\% \\ October & - & \(-31\%\) & \(-18\%\) & \(-7\%\) & 80\% \\ November & - & \(-30\%\) & \(-13\%\) & \(-5\%\) & 80\% \\ December & - & \(-20\%\) & \(-13\%\) & \(-6\%\) & 80\% \\ Average & - & \(-17\%\) & \(-18\%\) & \(-8\%\The similarity in the results shown in Figure 22 can be explained by the fact that the church is closed for 77% of the week, which corresponds to 129 h. The remaining 29 h are divided asymmetrically into the visitation period and the mass period. This last period occurs for 6 h per week, resulting in a higher height factor for the attendance status, with the least amount of relevance in terms of IAQ. For this reason, a study of the presence status was carried out. Considering the visitation period, all simulations showed very high IAQ levels. Due to the higher number of visitors in Sim_4, 8 h of the year were identified outside the categories I and II.  
The largest differences in CO\({}_{2}\) concentrations (Figure 23) were found in the mass service status, as expected, due to the significantly larger number of occupants.  
Sim_02 showed 29 days of the year where the mass service was in category III and only 1 day where the mass service was in category IV.  
Sim_2, the first simulation with a ventilation strategy in mind, shows the 14 h where category I and II ventilation rates were not achieved.  
Between Sim_3.1 and 3.2, there is only a difference of 1 h in category III, which is a negligible difference. Sim_4, trying to estimate the increase in future occupants with the same ventilation strategy as at present, presented 19 mass services where IAQ levels were inserted in category IV and 75 services where IAQ levels were inserted in category III.  
Regarding the closed period (Figure 24), Sim_1 displays a difference from the other simulations due to the schedule change, that is, the church is closed the entire year.  
Figure 23: Comparison of the percentage of time respecting EN 16798-1-recommended ventilation rates for the mass attendance status.  
Figure 22: Comparison of the percentage of time respecting EN 16798-1-recommended ventilation rates for the visitation attendance status.