## 3 Results
Temperatures of the water leaving the pad were closer and even lower than the inlet air wet-bulb temperature, as was expected from the adiabatic cooling process existing through the wetted pads. The statistics analysis of the inlet air velocities, which were used in the wind tunnel to test the pads, are summarized in Table 7. The cellulose pad allowed us to evaluate its behaviour for a wider range of velocities (0.5 to 3.5 m s\({}^{-1}\)). However, the alternative materials, except the \(CS_{1}\) and \(BC\) pads, were tested for three inlet air velocities; 0.5, 1.0 and 1.5 m s\({}^{-1}\). The \(CS_{1}\) and \(BC\) pads were tested for two velocities, 0.5 and 1.0 m s\({}^{-1}\), due to the higher pressure drop across the pads that caused water to come out of them. Small variations of the inlet air velocity through all the tests were presented. The average inlet air velocities for all the tests were similar. \begin{table}
\begin{tabular}{l c c c c c c c c} \hline \hline
**Pad** & & & \(\eta\) & & & & **THI** & \\  & \(\bar{\eta}\)**[\%]** & \(\bar{\eta}\)**[\%]** & \(\sigma\)**[\%]** & \(\sigma^{2}\)**[\%\({}^{2}\)]** & \(\overline{\mathbf{THI}}\) & \(\overline{\mathbf{THI}}\) & \(\sigma\) & \(\sigma^{2}\) \\ \hline \(CL\) & 68.6 & 68.8 & 6.0 & 35.6 & 68.8 & 68.8 & 0.4 & 0.2 \\ \(CS_{1}\) & 45.9 & 45.9 & 6.7 & 45.1 & 70.6 & 70.4 & 1.6 & 2.6 \\ \(CS_{2}\) & 65.1 & 65.0 & 1.8 & 3.3 & 67.6 & 67.60 & 0.2 & 0.1 \\ \(BC\) & 56.4 & 56.6 & 1.7 & 2.9 & 67.9 & 68.0 & 0.2 & 0.1 \\ \(PS_{1}\) & 45.2 & 45.4 & 1.9 & 3.6 & 70.4 & 70.1 & 0.8 & 0.6 \\ \(PS_{2}\) & 42.4 & 41.0 & 4.0 & 15.8 & 72.3 & 72.4 & 0.5 & 0.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Statistical descriptions of the cooling efficiency (\(\eta\)) and the Temperature–Humidity Index (THI) for the wind tunnel tests. \(\bar{\eta}\) and \(\overline{\mathbf{THI}}\) are the means, \(\bar{\eta}\) and \(\overline{\mathbf{THI}}\) are the medians, \(\sigma\) is the standard deviation and \(\sigma^{2}\) is the variance. \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline  & & \(\Delta T\) & & & & \(\Delta\phi\) & \\
**Pad** & \(\overline{\Delta T}\) & \(\widetilde{\Delta T}\) & \(\sigma\) & \(\sigma^{2}\) & \(\overline{\Delta\phi}\) & \(\widetilde{\Delta\phi}\) & \(\sigma\) & \(\sigma^{2}\) \\  & [\({}^{\circ}\)C] & [\({}^{\circ}\)C] & [\({}^{\circ}\)C] & [\({}^{\circ}\)C] & [\({}^{\circ}\)C2] & [\%] & [\%] & [\%] & [\%] & [\%] \\ \hline \(CL\) & \(-3.6\) & \(-3.6\) & 0.7 & 0.4 & 21.2 & 21.1 & 3.7 & 13.7 \\ \(CS_{1}\) & \(-3.6\) & \(-3.3\) & 1.0 & 1.1 & 27.9 & 27.0 & 3.6 & 13.3 \\ \(CS_{2}\) & \(-5.0\) & \(-5.0\) & 0.2 & 0.1 & 35.2 & 35.3 & 1.4 & 1.9 \\ \(BC\) & \(-4.8\) & \(-4.7\) & 0.2 & 0.1 & 32.2 & 32.0 & 1.1 & 1.2 \\ \(PS_{1}\) & \(-4.0\) & \(-4.0\) & 0.5 & 0.2 & 25.5 & 25.5 & 2.3 & 5.1 \\ \(PS_{2}\) & \(-3.2\) & \(-3.1\) & 0.4 & 0.1 & 22.9 & 22.8 & 1.3 & 1.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Statistical descriptions of the change in the dry-bulb temperature (\(\Delta T\)) and relative humidity (\(\Delta\phi\)) across the pads in the wind tunnel tests. \(\overline{\Delta T}\) and \(\overline{\Delta\phi}\) are the means, \(\widetilde{\Delta T}\) and \(\widetilde{\Delta\phi}\) are the medians, \(\sigma\) is the standard deviation and \(\sigma^{2}\) is the variance. The porosity (\(\epsilon\)) of the alternative pads varied between 0.44 and 0.59, which is considerably below that of the cellulose pad, which has an estimated value of 0.94. The lowest value was found for the \(BC\) pad (0.44), followed by \(CS_{1}\) and \(PS_{1}\) pads, both with a porosity of 0.53. The \(PS_{2}\) pad had a porosity of 0.56 and the \(CS_{2}\) pad had the highest porosity (0.59). The specific surface area (\(\zeta\)) was computed using the surface area per mass factor (m\({}^{2}\) kg\({}^{-1}\)), which was obtained according to the methodology presented in Appendix A. The highest specific surface area was obtained for \(CS_{1}\) (374.7 m\({}^{-1}\)-0.62 m\({}^{2}\) kg\({}^{-1}\)), similar to that for \(CL\) (372.6 m\({}^{-1}\)).