## 3 Methods  
### PMV Measurements  
Typical Korean summer weather, characterized by a temperature of 31 \({}^{\circ}\)C and a relative humidity of 57%, was the outdoor condition on the day of the experiment (see the red dot in Figure 3a). This experiment was conducted on 13 August 2019. In the aforementioned residential space, the desiccant air conditioner was operated from 11 a.m. to 5 p.m. Figure 3b shows the room temperature and return air temperature during the cooling operation period. After the hybrid desiccant cooling system was initiated at 11 a.m., it entered a steady state in approximately 40 min, with the average indoor temperature of the cooling space at 26.7 \({}^{\circ}\)C and the absolute humidity at 10 g/kg. Thermal comfort was measured between 1 and 2 p.m.  
Figure 2: A residential space with a hybrid desiccant air-conditioning system: (**a**) floor plan; (**b**) actual photograph of the residential space. As shown in Figure 3c, the indoor thermal environment entered the summer comfort zone of ASHRAE. In the desiccant cooling space, there was no noticeable difference in the thermal comfort of each space (kitchen, dining room, and living room in Figure 2) as observed in the ASHRAE comfort zone. The ASHRAE comfort zone (see Figure 3c) is defined by temperature and humidity. However, thermal comfort sensed by the human body is also affected by insolation, metabolism, and clothing, as well as airflow. PMV, the popular thermal comfort index that includes these indicators, is well-predicted by the following set of equations [15,16]:  
\[PMV=\ \left\{ \begin{array}{c}\left[0.303\text{-}exp(-0.036\ M)+0.028\right] \cdot\\ \left(M-W\right)-3.05\times 10^{-3}[5.733-6.99\ (M-W)-p_{a}]-0.42[(M-W)-58.15] \right\}\\ \qquad\qquad-1.7\times 10^{-5}\ M\ (5.867-p_{a})-0.0014\ M\ (34-t_{a})\\ \qquad\qquad-3.96\times 10^{-8}.f_{cl}[\left(t_{cl}+273\right)^{4}-\left(t_{r}+273 \right)^{4}]-\ f_{cl}\ h_{c}\ (t_{cl}-t_{a})\end{array} \right\} \tag{1}\]  
\[t_{cl}=35.7-0.028(M-W)-l_{cl}[3.98\ \text{-}10^{-8}f_{cl}[\left(t_{cl}+273 \right)^{4}-\left(t_{r}+273\right)^{4}]\Big{)}+f_{cl}\ h_{c}(t_{cl}-t_{a}) \tag{2}\]  
\[h_{c}=\left\{ \begin{array}{c}2.38\ |t_{cl}-t_{a}|^{0.25},\ 2.38\ |t_{cl}-t_{a}|^{0.25}<12.1\ \sqrt{v_{ar}}\\ 12.1\ \sqrt{v_{ar}},\ 2.38\ |t_{cl}-t_{a}|^{0.25}>12.1\ \sqrt{v_{ar}}\end{array} \right. \tag{3}\]  
and  
\[f_{cl}=\left\{ \begin{array}{c}1.00+1.29\ l_{cl},\ l_{cl}<0.078\ \text{m}^{2}\text{K}/ \text{W}\\ 1.05+0.645\ l_{cl},\ l_{cl}\geq 0.078\ \text{m}^{2}\text{K}/\text{W}\end{array} \right. \tag{4}\]  
where \(M\) and \(W\) in Equation (1) represent metabolism and effective power, respectively. Accordingly, \(f_{cl}\) in Equation (4) is the clothing surface area coefficient, \(t_{cl}\) in Equation (2) is the clothing surface temperature, and \(t_{a}\), \(t_{r}\), and \(h_{c}\) in Equation (3) are the dry-bulb temperature, globe temperature, and heat transfer coefficient, respectively. Moreover, \(p_{a}\) represents the vapor partial pressure, which can be obtained from the humidity, whereas \(v_{ar}\) means airflow velocity. A PMV meter (testo PMV 400) was used to measure the temperature, average radiation temperature, air speed and humidity in the space shown in Figure 2. As for the measuring points (shown in Figure 4a),  
Figure 3: Indoor and outdoor conditions at the time of thermal environment measurement (13 August 2019): (**a**) outside air conditions at the time of measurement indicated in the distribution of outside air conditions in July and August 2019; (**b**) room temperature change over time on the day of measurement; (**c**) thermal environment of the cooling space displayed in the standard ASHRAE comfort zone. the kitchen, dining room and living room were divided into 3, 4 and 9 sections, respectively. The height was 1.1 m from the ground, which is a breathing position that senses the thermal comfort when seated in a chair in an office environment [28]. The temperature sensor was separately calibrated before the experiment.