The effect of ventilation on the thermal comfort properties of outdoor clothing systems with different mid-layer fabric structures

Modern clothing systems are continually making participation in outdoor activities more accessible, comfortable and safe. There has been considerable innovation in the engineering of clothing worn next to the skin and of outerwear designed to provide protection from foul weather. In this investigation, a novel application of highly permeable spacer fabrics has been studied, by incorporating spacer fabrics as insulating components in clothing systems. A preliminary investigation of the effects of a foam·based spacer fabric on human comfort indicated that the thermal resistance and moisture vapour permeability of such a material are highly dependent on air flow present in the clothing, and can offer some improvement in thermo physiological comfort over conventional insulation. Subsequently, a range of fleece and spacer fabrics were selected and characterised, using a variety of laboratory techniques to elucidate the effect of air flow on the thermal resistance and water vapour permeability of mid-layer fabrics with different structures. It was found that due to their high permeability, the thermal resistance and water vapour permeability of spacer fabrics was more significantly affected by changes in air flow over and in the structure of the fabric than conventional fleece fabrics. One spacer fabric and one fleece fabric were then selected from this range and made into bespoke garments. Using a thermal manikin, the thermal resistance of the garments and the additional heat transfer available through garment openings was measured. Spacer fabrics were found to improve the heat transfer capabilities of the garment openings. In order to evaluate the effect of the spacer fabrics on the thermal properties of clothing systems, the garments were assessed in wearer and field trials using both objective and subjective measures. Provided the exercise intensity was suitably high, the spacer fabric provided improved comfort, as evidenced by lower next-to-skin temperature and humidity recorded in the clothing. A suggestion for the future design of clothing based on the conclusions of this research is that for the widespread adoption of spacer fabric insulation to be plausible, design innovations that limit undesirable heat loss due to ventilation should be developed, and improvements to the sensorial properties of spacer fabrics should be made.EThOS - Electronic Theses Online ServiceGBUnited Kingdo