Experimental Study on the Efficacy of a Novel Personal Cooling Vest Incorporated with Phase Change Materials and Fans.

Xiaoyang Ni,Qin Hu,Tianyu Yao,Ying Zhang,Albert P.C Chan,Yijie Zhao

doi:10.3390/ma13081801

Abstract

In recent years, personal cooling has aroused much attention because it can achieve both localized high-level thermal comfort and build energy savings. In this study, a novel hybrid personal cooling vest (PCV) incorporated with phase change materials (PCMs) and ventilation fans was developed, and its efficacy was investigated by human trials in a hot-humid climate chamber. Three generally accepted indices (thermal load, Q; thermal sensation, TS; and physiological strain index, PSI) and a new proposed index (cumulative heat storage, CHS) during human trials were comparatively studied between the two human trial groups, i.e., the PCV group (wearing the PCV) and the CON group (without PCV). Results found that TS, PSI, and CHS were significantly reduced by the PCV, which suggests that the PCV can significantly improve both the perceptual and physiological strain. In addition, a strong linear relationship (r2 = 0.8407) was found between the proposed index of CHS with PSI, which indicates the applicability and reliability of CHS for assessing physiological heat strain.

Highlights

Construction workers in Hong Kong are under the high risk of heat stress and heat related accidents in the hot and humid summer [1,2]
Personal cooling is one of the methods suggested for decreasing heat stress and improving thermal comfort of outdoor workers; since, in such conditions, air-conditioning systems are not effective [4,5,6,7]
We developed a hybrid cooling vest for construction workers in Hong Kong and investigated its cooling performance with human trials in a climate chamber

Summary

Introduction

Construction workers in Hong Kong are under the high risk of heat stress and heat related accidents in the hot and humid summer [1,2]. Personal cooling is one of the methods suggested for decreasing heat stress and improving thermal comfort of outdoor workers; since, in such conditions, air-conditioning systems are not effective [4,5,6,7]. Current personal cooling systems are of primarily three types, these include air cooling systems, liquid cooling systems, and phase change cooling systems. Though the air cooling system or liquid cooling system can provide enough cooling power for the construction workers, they restrict the worker’s movement and bring inconveniences due to the large amount of weight of the compression systems and pumps [8]. Though the phase change cooling systems are more portable, its cooling capacity is generally limited, and it needs other cooling devices

Methods

Results

Conclusion