## 4 Results and Discussion
### Air Flow and Thermal Comfort  
The air supplied from the desiccant cooler was allowed to generate a narrow jet flow towards the opposite wall in the dining room. As depicted in Figure 7, after the collision, it was supplied to the living room and kitchen, and exited through the outlet installed on the ceiling, after the cooling was complete. The large airflow velocity in the vicinity of the jet flow increases the possibility that a human body would feel an unwanted local cooling, i.e., a human body would feel a draft and thermal discomfort. To evaluate this, checking the draft-related thermal comfort indicators, such as the EDT,  
Figure 6: Humidity distribution at a height of 1.1 m from the ground in a residential space with hybrid desiccant cooling: (**a**) relative humidity; (**b**) humidity ratio.  
was deemed necessary. In the region excluding the jet flow, there was no flow observed to evenly supply cooling air; thus, the need to check the local thermal comfort distribution was inferred.  
Applying Equation (1), the PMV can be obtained upon the inclusion of metabolism and clothing information, along with the dry-bulb temperature, globe temperature, and humidity obtained through the measurement. Herein, the PMV was calculated by applying 1.0 met (60 W/m\({}^{2}\)), the metabolism of working in an office environment, and 0.5 clo, the standard of summer clothing. The PMV was determined to range from \(-\)3 to 3, whereas the thermally comfortable point should be set as 0; nevertheless, a value between \(-\)1 and 1 can be judged as comfortable [15; 16]. As shown in Figure 8a, based on PMV, the desiccant cooling space was located at the boundary of the thermally comfortable area.  
Considering the structure of the desiccant cooling space shown in Figure 2, the thermal comfort was expected to be poor as a result of direct sunlight entering through the window. Actually, the globe  
Figure 8: Distribution of thermal comfort in residential spaces with hybrid desiccant cooling: (**a**) PMV; (**b**) EDT.  
Figure 7: Airflow distribution and supply angle: (**a**) three dimensional streamlines from CFD for normal supply (0°); (**b**) cooling air supply angle.  
temperature in Figure 5b could be seen to increase to 29.8 \({}^{\circ}\)C at the window. Taking into account the globe temperature for the calculation of the PMV, it could be seen that the value of the latter increased at the window, resulting in an average PMV value at the living room that was estimated to increase up to 1.2.  
Likewise, the airflow distribution in Figure 7a indicates that cooling air was not supplied smoothly even in the kitchen, resulting in a PMV of 1.22, which is higher by 1.0. Based on the PMV, the most comfortable area was apparently the dining room. However, in Figure 7a, the distribution of airflow caused the generation of a strong jet flow around the dining room, which raised the concern of possible thermal discomfort in relation to the airflow draft. To examine this, the EDT was evaluated using the following equation:  
\[EDT=(t_{a}-t_{m})-C(v_{ar}-v_{ref}) \tag{5}\]  
where \(t_{a}\) and \(v_{ar}\) represent the local temperature and velocity, respectively. In addition, tm is the spatially averaged temperature, \(v_{ref}\) is the reference velocity of 0.15 m/s, and \(C\) is a coefficient (having a value of 7 or 8 according to the literature for Celsius temperature [16; 17]) set in the analysis herein to be 8. For the EDT, a value between \(-1.7\) and 1.0 is judged as comfortable. According to these range criteria, the kitchen and living room can be considered as comfortable areas. Based on the PMV, the dining room that was included in the comfortable region had an EDT value of \(-2.3\), which was less than \(-1.7\), indicating that it was out of the comfortable area.