## 4 Discussion
### Psychometric Chart: Visualization of Thermal Comfort Across Floors  
Psychrometric charts provide a detailed visualization of air property relationships under specific conditions, tailored for various room types across multi-story buildings. Dry bulb temperature (DBT), relative humidity (RH), wet bulb temperature (WBT), and pressure levels were utilized to define comfort zones specific to each room type. These comfort zones account for variations in activity levels, occupancy, and thermal expectations, ensuring that they reflect the unique requirements of spaces such as classrooms, offices, and laboratories. Figure 4 provides a sample psychometric chart for various types of room usage on the eighth floor. For enhanced interpretability, curves for constant relative humidity (RH) values, including 10%, 30%, 50%, 70%, and 100%, are plotted to demonstrate how the moisture content varies with temperature changes. Additionally, wet bulb temperature (WBT) curves, such as those at 15 \({}^{\circ}\)C, 20 \({}^{\circ}\)C, and 25 \({}^{\circ}\)C, are incorporated to represent specific cooling scenarios, reflecting the interplay between latent and sensible heat under different conditions. Figure 4: Psychometric charts for 8 th-floor rooms (reference pressure = 1007.03 hPa). The generation process involved systematically defining the input parameters, calculating essential relationships, and visualizing the results. Each room type was assigned specific ranges for DBT, RH, and comfort zones (as detailed in Table 17) based on the purpose of and typical activities conducted in the space. Additional factors influencing thermal comfort--such as clothing insulation (clo values), radiant heat, and air velocity--were assumed rather than explicitly modeled. For instance:  
* Clothing insulation values ranged from 0.5-1.0 clo, representing typical indoor attire in tropical climates such as that of the Philippines. While clothing variations were not explicitly modeled, comfort temperature ranges were adjusted to account for expected attire. * Radiant heat was assumed to align with DBT values. However, environments such as computer rooms or laboratories, which include heat-generating equipment, may require additional considerations. * Air velocities were assumed to be within 0.1-0.5 m/s, which is suitable for most indoor spaces. For ventilated spaces such as multi-purpose halls, adjustments to comfort zones may be needed to reflect the higher temperatures associated with increased air movement. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  
Table 18 contains the summary of the assumed values for clothing insulation, radiant heat, and air velocity. Atmospheric pressures were calculated for each floor based on height, air density, and gravitational acceleration, and adjusted to APC's ground-level pressure of 100,928 Pa and a floor height of 2.71 m per level. These calculations were essential for accurately representing air properties under varying conditions throughout the building. The humidity ratio (HR)--a critical parameter for the psychometric charts--was calculated using Equations (9)-(11), as follows:  
\[H_{R}=\frac{0.622\ P_{r}}{P-P_{r}}, \tag{9}\]  
\[P_{r}=RH\times P_{s}, \tag{10}\]  
\[P_{s}=0.61708\times e^{\frac{17.27\ T}{T+207.3}}, \tag{11}\]  
where \(H_{R}\) is the humidity ratio; \(P_{r}\) is the partial pressure (in kPa), computed as the product of the saturation pressure \(P_{s}\) (in kPa) and relative humidity \(RH\); and \(T\) is the temperature (in \({}^{\circ}\)C). These calculations ensured that the air's moisture content was accurately represented across varying conditions. The psychrometric charts' subplots varied for each floor of Asia Pacific College and its corresponding room types, as summarized in Table 19. The charts in Figure 5 display constant RH curves, WBT curves, and defined comfort zones, offering a comprehensive view of the thermal conditions.