# Design of Liquid-Air Hybrid Cooling Garment and Its Effect on Local Thermal Comfort
## 3 A Detailed Description of the Designed Cooling Garments and the Control Garment
### The Liquid Cooling System of the Cooling Garments  
#### 3.3.1 The Components of the Liquid Cooling System  
In the present study, an emerging semiconductor refrigeration pump was used to produce cooled water. The pump was compact and capable of providing a continuous cooling capacity [35]. Considering the problem of overcooling when wearing liquid-air garments, a thermostat was set in the whole device, and the role of the thermostat was to make the clothing more intelligent. The probe of the thermostat was connected to the outer wall of the liquid cooling tube, and when the liquid cooling tube was detected to be overcooled, it controlled the semiconductor refrigeration pump to stop the cooling.  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Clothing Length** & **Chest Width** & **Hip Width** & **Waist Width** & **Cross Shoulder** \\ \hline
58 & 100 & 100 & 116 & 40 \\ \hline \end{tabular}
\end{table}
Table 1: Clothing specification and size (cm).  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Style** & **Structure** & **Pipe Material** & **Material** & **Fabric Gram Weight** \\ \hline AAL & Upper and & Aluminum tube & Polyester, nylon, and cotton & \\  & lower splicing & & blended non-stretch fabric & 180 g/m\({}^{2}\) \\ \hline SAL & Upper and & & Polyester, nylon, and cotton & \\  & lower splicing & & blended non-stretch fabric & 180 g/m\({}^{2}\) \\ \hline YAL & Internal and & & Polyester, nylon, and cotton blended & \\  & external splicing & & non-stretch fabric, Polyester mesh fabric & 180 g/m\({}^{2}\), 73 g/m\({}^{2}\) \\ \hline CON & – & – & Polyester, nylon, and cotton & \\  & & & blended non-stretch fabric & 180 g/m\({}^{2}\) \\ \hline \end{tabular} Note: –, not applicable.  
\end{table}
Table 2: The material details of each style of liquid–air cooling garment.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Style** & **Pipe Material** & **Inner Diameter** & **Outer Diameter** & **Density** & **Length** & **Weight** \\ \hline AAL & Aluminum tube & 4 mm & 6 mm & 2.7 g/cm\({}^{3}\) & 8.4 m & 356 g \\ SAL & Silicone tube & 4 mm & 6 mm & 2.2 g/cm\({}^{3}\) & 8.4 m & 290 g \\ YAL & Silicone tube & 4 mm & 6 mm & 2.2 g/cm\({}^{3}\) & 8.4 m & 290 g \\ \hline \end{tabular}
\end{table}
Table 3: The material details of the liquid pipes.  
The circulation pump used a head of 550 mL/min (as shown in Figure 5a). The refrigeration pump was two miniature water-cooled pumps (Figure 5b) which contained a refrigeration piece, with a size of 100 \(\times\) 100 mm heat sink and a small fan; A SeetyXH-W1308 digital (Square Technology Ltd., Shenzhen, China) display thermostat was used (Figure 5c), whose temperature control range is \(-\)55-120 \({}^{\circ}\)C and whose temperature control accuracy is 0.1 \({}^{\circ}\)C. A mobile power supply (YNS-120 HK, Romance Technology Corporation, Shenzhen, China) with an output voltage of 12v and a capacity of 38,400 mah (Figure 5d) was used to supply power. Additionally, different parts of the torso have different acceptance of water temperature [36], and the dynamic change of water temperature can meet the cooling needs of various parts of the body in different periods. Therefore, the thermostat was set to, when the temperature monitored by the thermostat was greater than 28 \({}^{\circ}\)C, start the semiconductor refrigeration pump to open refrigeration; when the monitored temperature was less than 20 \({}^{\circ}\)C, it stopped the work of the semiconductor refrigeration pump, providing overcooling protection.