# Ventilation Strategies to Ensure Thermal Comfort for Users in School Buildings: A Critical Review
## 3 Results
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Ref** & **Year** & **Location (Köppen** & **Type of** & **Season of** & & **Ventilation Strategy** \\  & **Climatic Classification** & **Building** & **the Year** & & & **Ventilation Strategy** \\ \hline  & & & & & \(\bullet\) & Natural ventilation with constant \\  & & & & & & window opening \\
[46] & 2023 & Basque Country, Spain (Cfb) & University & Summer & \(\bullet\) & Natural ventilation with window opening based on sensors \\  & & & & Spring & \(\bullet\) & Mechanical ventilation with \\  & & & & & variable flow according to sensors \\  & & & & & \(\bullet\) & Hybrid ventilation \\ \hline  & & & & & \(\bullet\) & Natural ventilation with constant \\
[47] & 2022 & Extremadura, Spain (Csa) & University & Winter & \(\bullet\) & window opening \\  & & & & & \(\bullet\) & Natural ventilation with window opening based on sensors \\ \hline  & & & & & \(\bullet\) & Natural ventilation with constant \\
[48] & 2024 & Graz, Austria (Cfb) & University & Winter & \(\bullet\) & Natural ventilation with window opening \\  & & & & Spring & \(\bullet\) & scheduled window opening \\  & & & & & \(\bullet\) & Mechanical ventilation with \\  & & & & & constant flow \\ \hline  & & & & & \(\bullet\) & Natural ventilation with random \\  & & & & & & window opening \\
[49] & 2011 & Ancona, Italy (Cfa) & Technical & Winter & \(\bullet\) & Natural ventilation with window opening based on sensors \\  & & & & & \(\bullet\) & Natural ventilation using \\  & & & & & & windcatcher \\  & & & & & \(\bullet\) & Mechanical ventilation with \\  & & & & & constant flow \\ \hline  & & & & & \(\bullet\) & Natural ventilation with \\
[50] & 2019 & Cassino, Italy (Csa) & Primary & School & Winter & \(\bullet\) & scheduled window opening \\  & & & & & \(\bullet\) & Mechanical ventilation with \\  & & & & & variable flow according to sensors \\ \hline  & & & & & & \\
[51] & 2020 & Jordan (Bsk) & University & Summer & \(\bullet\) & Natural ventilation using stack \\  & & & & Winter & \(\bullet\) & ventilation \\ \hline  & & & & & \(\bullet\) & Mechanical ventilation with \\
[52] & 2023 & Southern Sweden (Cfb) & Primary & School & Summer & \(\bullet\) & constant flow \\  & & & & & \(\bullet\) & Hybrid ventilation \\ \hline  & & & & & & \\
[53] & 2023 & United Kingdom (Cfb) & Educational & Winter + & \(\bullet\) & Natural ventilation with random \\  & & & & & window opening \\  & & & & & \(\bullet\) & Mechanical ventilation with \\  & & & & & constant flow \\  & & & & & \(\bullet\) & Hybrid ventilation \\ \hline  & & & & & \\
[54] & 2023 & Spain (Csa) & Primary/secondary & Summer & \(\bullet\) & Natural ventilation with random \\  & & & schools & Spring & window opening \\ \hline  & & & & & \\
[55] & 2021 & Sydney (Cfa) & Secondary & Winter & \(\bullet\) & Mechanical ventilation with \\  & & & & & variable flow according to sensors \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._Below are the articles published by year in Figure 4 and by country in Figure 5. As can be seen, the publication trend does not increase as a result of COVID-19, which is consistent with the initial assessment made, stating that, after COVID-19, most of the articles focused on air quality, leaving aside thermal comfort. In terms of the countries where these studies have been carried out, most (84%) have been conducted in Europe, and within this group there is a notable presence of the countries of Spain and Italy. Based on the articles selected and analyzed, a series of ventilation strategies is presented in Table 4, covering natural, mechanical, and hybrid ventilation. It should be noted that natural ventilation is defined as ventilation in which both intake and extraction are carried out naturally, while mechanical ventilation is ventilation in which both intake and extraction are carried out mechanically, or in which intake is natural and extraction is mechanical. Finally, hybrid ventilation is ventilation in which natural and mechanical ventilation are in simultaneous operation.