Optimizing the Performance of Phase-Change Materials in Personal Protective Clothing Systems

Abstract

Phase-change materials (PCM) can be used to reduce thermal stress and improve thermal comfort for workers wearing protective clothing. The aim of this study was to investigate the effect of PCM in protective clothing used in simulated work situations. We hypothesized that it would be possible to optimize cooling performance with a design that focuses on careful positioning of PCM, minimizing total insulation and facilitating moisture transport. Thermal stress and thermal comfort were estimated through measurement of body heat production, body temperatures, sweat production, relative humidity in clothing and subjective ratings of thermal comfort, thermal sensitivity and perception of wetness. Experiments were carried out using 2 types of PCM, the crystalline dehydrate of sodium sulphate and microcapsules in fabrics. The results of 1 field and 2 laboratory experimental series were conclusive in that reduced thermal stress and improved thermal comfort were related to the amount and distribution of PCM, reduced sweat production and adequate transport of moisture.

Meta-analysis of the effects of microclimate cooling systems on human performance under thermal stressful environments: Potential applications to occupational workers

“…Air circulation around the body is one of the key issues of the cooling efficiency of ACG-Ns Zhao et al, 2013). The melting temperature, latent heat capacities, coverage area, and mass of phase change materials can affect the cooling efficiency of PCMCGs (Gao et al, 2010;Reinertsen et al, 2008). In addition, ACG-Ns tend to become bulky when they blow air and PCMCGs are cumbersome and heavy (Chan et al, 2013;Hadid et al, 2008).…”

Laboratory assessment of cold weather clothing

“…An impact of PCM was demonstrated by Reinertsen et al (2008), but in this case the PCM was present in large amounts (several pounds) in a situation similar to an ice vest. In this case enough heat storage capacity was present and the PCM allows a more comfortable action temperature of the substance than in the case of water/ice.…”

A Review of Technology of Personal Heating Garments

“…How much heat is released from PCMs greatly depends on the temperature gradient from the skin surface through clothing ensembles to the outer environment and how much PCM is added to the garment. PCMs incorporated in garments by coating, lamination and fibre spinning technology have small heating effect due to their low mass [48,49,50,51]. A packaged PCM garment is heavy and may be only suitable for those people who take part in activities or are exposed where additional weight is not an issue or where gain during exposure overweighs possible performance loss.…”