Matthew Morrissey

Real evaporative cooling efficiency of one‐layer tight‐fitting sportswear in a hot environment

Real evaporative cooling efficiency, the ratio of real evaporative heat loss to evaporative cooling potential, is an important parameter to characterize the real cooling benefit for the human body. Previous studies on protective clothing showed that the cooling efficiency decreases with increasing distance between the evaporation locations and the human skin. However, it is still unclear how evaporative cooling efficiency decreases as the moisture is transported from the skin to the clothing layer. In this study, we performed experiments with a sweating torso manikin to mimic three different phases of moisture absorption in one‐layer tight‐fitting sportswear. Clothing materials Coolmax® (CM; INVISTA, Wichita, Kansas, USA; 100%, profiled cross‐section polyester fiber), merino wool (MW; 100%), sports wool (SW; 50% wool, 50% polyester), and cotton (CO; 100%) were selected for the study. The results demonstrated that, for the sportswear materials tested, the real evaporative cooling efficiency linearly decreases with the increasing ratio of moisture being transported away from skin surface to clothing layer (adjusted R2 >0.97). In addition, clothing fabric thickness has a negative effect on the real evaporative cooling efficiency. Clothing CM and SW showed a good ability in maintaining evaporative cooling efficiency. In contrast, clothing MW made from thicker fabric had the worst performance in maintaining evaporative cooling efficiency. It is thus suggested that thin fabric materials such as CM and SW should be used to manufacture one‐layer tight‐fitting sportswear.

The effect of wind, body movement and garment adjustments on the effective thermal resistance of clothing with low and high air permeability insulation

Using a thermal manikin, the total clothing thermal resistance (IT) of two clothing ensembles with the same air-impermeable outer layer but with either high or low air permeability insulation was determined at three different walking (0, 1 and 2.5 km.h−1) and wind (0.1, 1 and 2.5 m.s−1) speeds. Three clothing ‘configurations’ (outer garment sealed, outer garment open, outer and mid layer garment open) were also tested. The IT of the high-permeability insulation was lower than that of the low-permeability insulation, indicating more heat transfer by radiation and the possibility of natural convection between clothing layers. When the outer garment was opened to favor ventilation, the IT of the high-permeability insulation was reduced by between 15% (surface-weighted average) and 25% (locally) more than that of the low-permeability insulation, but when the outer garment was ‘sealed’, the IT of the high-permeability insulation was not reduced by a greater extent. The use of high-permeability insulation may allow clothing designers to create more comfortable clothing by encouraging ventilation, particularly by creating localized cooling.

Clothing systems for outdoor activities

Abstract Participation in outdoor activities can improve mental, physical and social well-being. Such activities also present significant physiological strain and risks such as hypothermia; therefore, correct choice and usage of clothing is extremely important. The aim of this review is to critically analyse the literature regarding outdoor clothing systems, focusing on the layers comprising a typical clothing system. Additionally, alternative systems, potential improvements and future trends are discussed.

A new method to assess the influence of textiles properties on human thermophysiology. Part I

Purpose – The purpose of this paper is to determine the validity and inter-/intra-laboratory repeatability of the first part of a novel, three-phase experimental procedure using a sweating Torso device. Design/methodology/approach – Results from a method comparison study (comparison with the industry-standard sweating guarded hotplate method) and an inter-laboratory comparison study are presented. Findings – A high correlation was observed for thermal resistance in the method comparison study (r=0.97, p<0.01) as well as in the inter-laboratory comparison study (r=0.99, p<0.01). Research limitations/implications – The authors conclude that the first phase of the standardised procedure for the sweating Torso provides reliable data for the determination of the dry thermal resistance of single and multi-layer textiles, and is therefore suitable as standard method to be used by different laboratories with this type of device. Further work is required to validate the applicability of the method for textiles wit...

Assessment of body mapping sportswear using a manikin operated in constant temperature mode and thermoregulatory model control mode

Regional sweating patterns and body surface temperature differences exist between genders. Traditional sportswear made from one material and/or one fabric structure has a limited ability to provide athletes sufficient local wear comfort. Body mapping sportswear consists of one piece of multiple knit structure fabric or of different fabric pieces that may provide athletes better wear comfort. In this study, the ‘modular’ body mapping sportswear was designed and subsequently assessed on a ‘Newton’ type sweating manikin that operated in both constant temperature mode and thermophysiological model control mode. The performance of the modular body mapping sportswear kit and commercial products were also compared. The results demonstrated that such a modular body mapping sportswear kit can meet multiple wear/thermal comfort requirements in various environmental conditions. All body mapping clothing (BMC) presented limited global thermophysiological benefits for the wearers. Nevertheless, BMC showed evident improvements in adjusting local body heat exchanges and local thermal sensations.

The effect of metallisation, porosity and thickness on the thermal resistance of two-layer fabric assemblies:

In this study, we evaluated the thermal resistance of various combinations of commercially available, metallised and conventional, mid- and shell-layer materials, and additionally investigated the effect of plasma metallisation of the non-metallised materials. The evaporative resistance of the shell layers was measured, and did not increase due to plasma metallisation. Metallised mid- and shell-layers increased the thermal resistance of fabric assemblies, and this increase was greatest when the thickness and optical porosity of the mid-layer were suitably high.

Exercise intensity dependent relevance of protective textile properties for human thermo-physiology

During firefighting, thermoregulation is challenged due to a combination of harsh environmental conditions, high metabolic rates and personal protective clothing (PPC). Consequently, investigations of thermoregulation in firefighters should not only consider climate and exercise intensity, but technical properties of textiles too. Therefore, laboratory textile performance simulations may provide additional insights into textile-dependent thermoregulatory responses to exercise. In order to investigate the thermo-physiological relevance of textile properties and to test how different garments affect thermoregulation at different exercise intensities, we analyzed the results of a standard laboratory test and human subject trials by relating functional properties of textiles to thermo-physiological responses. Ten professional, healthy, male firefighters (age: 43 ± 6 y, weight: 84.3 ± 10.3kg, height: 1.79 ± 0.05m) performed low and moderate intensity exercise wearing garments previously evaluated with a sweating torso system to characterize thermal and evaporative properties. Functional properties of PPC and the control garment differed markedly. Consequently, skin temperature was higher using PPC at both exercise intensities (low: 36.27 ± 0.32 versus 36.75 ± 0.15℃, P < 0.05; moderate: 36.53 ± 0.34 versus 37.18 ± 0.23℃, P < 0.001), while core body temperature was only higher for PPC at moderate (37.54 ± 0.24 versus 37.83 ± 0.27℃, P < 0.05), but not low-intensity exercise (37.26 ± 0.21 versus 37.21 ± 0.19, P = 0.685). Differences in thermal and evaporative properties between textiles are reflected in thermo-physiological responses during human subject trials. However, an appropriate exercise intensity has to be chosen in order to challenge textile performance during exercise tests.

Air and water perfusion-based personal cooling systems (PCSs) to protect against heat stress in protective clothing

Abstract: The heat exchange processes of both air- and water-based personal cooling systems (PCSs) such as air-ventilation and water-perfusion clothing in thermal protective clothing systems are examined. Some critical design parameters used when designing PCSs are outlined. In addition, the three most common methods of evaluation of the performance of PCSs are presented and future trends of PCSs are discussed.

Recent developments in reflective cold protective clothing

Purpose – The purpose of this paper is to present some new results about reflective cold protective clothing (i.e. those featuring metal coatings), and compare and contrast the data with other recent research work. Design/methodology/approach – The authors used a thermal manikin and a guarded hot plate to determine the thermal resistance of different textile assemblies and garment featuring plasma-deposited metal-coated insulation and interlayers. Findings – Depending on the exact approach, the authors show that metal coatings can increase the thermal resistance of textile assemblies by ∼30-75 per cent. Practical implications – New data on reflective cold weather clothing show that metal coatings could be an important addition to cold weather clothing, especially those featuring high air permeability/optical porosity insulation. Plasma-deposited metal coatings cause the lowest increase in weight. Originality/value – This paper provides new data about the efficacy, in terms of thermal resistance, of metal ...