Design and performance evaluation of novel personal cooling garment

Personal cooling garments (PCGs) have been developed to reduce heat stress and improve human thermal comfort in hot environments. In this study, a new type of PCG, a PCM-liquid cooling vest (PLV), is developed to improve the ease of use of phase change material (PCM) garments. The PLV adopts the scheme of combining PCM with water pipes buried in the PCM. The PCM in the vest is used to cool the torso and the water pipe buried in the PCM circulates cold water from a microchiller to freeze the PCM. This PLV is designed and tested using mathematical modeling and human trial. Based on the simulation results, inorganic PCM with high density and conductivity, a high flow rate of cold water, and multiple parallel water pipes buried in PCM are recommended. Adjusting the tightness and wearing the insulation vest are effective methods to enhance the comfort and prolong the service time of the PLV, respectively. In the human trial, a PLV containing inorganic PCM and with a total mass of 1.8 kg is fabricated and used. The experimental results show that the fabricated PLV can provide effective cooling for at least two hours for users working indoors, without sacrificing the overall thermal comfort in the wearing mode. The cooling-storage can be finished within 40 min in the cooling-storage mode or within 60 min in the cooling-storage and wearing combined mode.