The effect of PCM placement on torso cooling vest for an active human in hot environment

• Fabric-PCM model of cooling vest was modified to predict condensation on the inner PCM surface.
• Bio-heat model was adjusted for human activity in hot climate and integrated with Fabric-PCM model.
• Models were validated with experiments on thermal manikin and with published experimental data.
• Placing 8 packets on the back of torso resulted in best overall sensation and comfort.
• Thermal comfort improved by 94% when placing of 8 PCM packets on the back over the case with no PCM.

The distribution of phase change material (PCM) packets on a cooling vest worn by active human in hot environments is investigated using an integrated fabric-PCM and bio-heat model. The model considered the effect of added PCM weight and hot environments on the human metabolic rate, and incorporated the effect of condensation to check its occurrence in the vest. The fabric-PCM model predictions of local torso skin temperature were validated experimentally on a thermal manikin operated at constant heat flux mode while its predictions of skin and core temperatures when integrated with the bioheat model were validated with published experimental data on human subjects exercising in hot conditions.The validated model is used in a parametric study to determine the best arrangement of 8 PCM packets distributed on different torso segments to improve sensation and comfort of human performing moderate activity in hot climate. It was found that placing 8 PCM packets on the back resulted in the best overall sensation of 1.38 as compared to 2.69 when no PCM is used using a sensation scale that varies from very cold at −4 to very hot at +4.

Figure optionsDownload as PowerPoint slide