## 4 Results and Discussion
### Effects of Air Supply Angle on Thermal Environment
A comparison of the results is shown in Figure 11.  
Figure 9: Airflow distribution when the cooling air supply angle is increased by \(45^{\circ}\): (**a**) 3D streamlines; (**b**) comparison of velocity distribution at a height of \(1.1\) m above ground. From a comparison of the black and gray bars in Figure 11, it could be inferred that the guide vane was adjusted to supply the cooling air at a 45\({}^{\circ}\) upward angle (black bar), after which the cooling performance became spatially more uniform. As reflected in Figure 11a, the PMV for the entire cooling space slightly exceeded 1.0 when cooling air was supplied upward by 45\({}^{\circ}\). This means that it had entered a slightly hot area; thus, if the cooling effect is to be even across the space based on PMV, then the cooling capacity should be slightly increased. When air was supplied vertically to the outlet surface (light gray bar, Figure 11b), the ADPI was significantly below the comfort standard of 80% in the dining room, and the average of the cooling space was also less than 80%. If the cooling air was supplied at a 45\({}^{\circ}\) upward angle (black bar), the ADPI would enter the comfort zone at more than 80% in all the cooling spaces. If the cooling air was supplied upwards at 45\({}^{\circ}\), the ADPI would have a positive effect, but there was a problem in raising the average PMV of the space to more than 1.0. To find the most advantageous discharge angle in both indicators, the effect was examined by changing the discharge angle of the cooling air from 0\({}^{\circ}\) (vertical injection) to 80\({}^{\circ}\) upward at intervals of 10\({}^{\circ}\). For each case, CFD analysis was performed, and the thermal comfort was evaluated by combining the CFD results and measurement data. Figure 12 shows the changes of PMV and ADPI according to the discharge angle change. PMV is not very sensitive to the discharge angle compared to ADPI, but it does show the most uniform thermal  
Figure 11: Comparison of thermal comfort between the vertically supplied cooling air and that supplied 45\({}^{\circ}\) upward: (**a**) PMV; (**b**) ADPI. Figure 10: Changes in discomfort areas evaluated by EDT (EDT \(<-1.7\) or EDT \(>\) 1) according to the change in the cooling air supply angle: (**a**) normal supply; (**b**) 45\({}^{\circ}\) upward supply. comfort distribution, as the PMV values of all the cooling spaces gather near the discharge angle of 40\({}^{\circ}\) (Figure 12a). In terms of PMV, a discharge angle of about 40\({}^{\circ}\) is considered appropriate. The ADPI (Figure 12b) showed that more than 90% of all the areas were in the range of 10-60\({}^{\circ}\); therefore, it was determined that it would be appropriate to set the discharge angle between 10\({}^{\circ}\) and 60\({}^{\circ}\). Considering both thermal comfort indicators, the best thermal comfort distribution can be obtained when the discharge angle is 40\({}^{\circ}\) upward. In a conventional air conditioner, the best discharge angle was found to be 33\({}^{\circ}\) upward when considering the ADPI and energy efficiency [21]. Herein, taking into consideration the effects of PMV and ADPI, the optimum discharge angle obtained for the hybrid desiccant air conditioner, which is 40\({}^{\circ}\) upward, was similar or slightly higher.