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A moveable sweating thermal manikin has recently been developed. Thermal and water-vapour resistances of three kinds of cold-protective clothing ensembles, laminated with polytetrafluoroethylene, polyurethane and without a laminate were measured, with the aid of the manikin in a cold environment of 5 degrees C with a relative humidity of 70% and an air velocity of around 1.5 m s(-1). Two sweating rates of 65 and 130 g m(-2) h(-1) were employed. Supplied heat fluxes in both of the sweat rates ranged from 350 W m(-2) to 400 W m(-2). To maintain a comfortable condition, the skin wettedness (w) (mean weighted value) had to be kept at < or = 0.6. The measurements obtained from the manikin when testing the three ensembles were w=0.3 (approximately) for the low sweat rate and w > or = 0.6 for the high sweat rate, irrespective of the property differences among the ensembles. In addition, the condensation in the ensembles in comparison with those calculated from an analytical equation is discussed. Condensation mass fluxes in the ensembles obtained by experiment and those from the calculation agreed sufficiently well. Thus, distribution of the condensation in the ensembles was estimated using the equation.

A new apparatus is developed to measure the Water vapor permeability resistance of textiles with and without temperature differences imposed on both sides of a specimen. Water vapor resistance is measured for a combination of temperature and pressure that simulates elevated altitudes. The effect of temperature on water vapor resistance is small. while that of pressure is significant, that is, water vapor resistance decreases with increasing simulated altitude due to an increase in the water vapor diffusion coefficient with increasing altitude. The amount of condensation in the specimen tends to increase with increasing simulated altitude. Moreover, water vapor resistance decreases apprecia bly due to increased condensation in the specimen. In addition, the reduced resistance further enhances the amount of condensation. These results indicate that decreased water vapor resistance enhances condensation in clothes and thus may cause further discomfort and a drop in body temperature at high altitudes.

A series of experiments is performed on the combined heat and water vapor transfer through fabric at simulated high altitudes. A considerable water vapor concentration difference is imposed between the water vapor source and the environment, so that condensation takes place in the specimen. A new analytical expression for the rate of condensation in textile materials is derived by considering the combined heat and mass transfer between the specimen and the environment. Although the amount of condensation in textiles can not be correlated well by primitive parameters such as temperature or water vapor concentration differences, good agreement can be obtained between the condensation mass flux measured experimentally and that calculated by means of the derived expression.If water vapor concentration in a garment exceeds saturation level) condensation takes place in the garment. When condensation occurs, heat released from the body to the environment is enhanced through the increased heat conduction of the liquid water. Thus, condensation is not only a significant discomfort factor in daily life, but also a significant survival factor in severely low temperature environments, such as polar regions and very high altitudes. Our previous work [3] experimentally indicated that the condensation mass flux increases with increasing altitude. This is due to both water vapor diffusion resistance and the saturated water vapor condensation decrease because of decreasing temperature with increasing; altitude. This indicates that a decrease in the water vapor resistance not only enhances condensation in clothes; but also discomfort and the chance of hypothermia due to the low thermal resistance of wet clothes. Therefore, condensation in clothing has to be prevented, especially at high altitudes.The water vapor transfer rate is determined by the concentration gradient, while the vapor saturation concentration is determined by the temperature level. Thus, both water vapor concentration and temperature gradient are determinant factors in water vapor transfer and condensation in clothing. Lotens et al. [6] developed a heat and water vapor transfer model with condensation and solved it numerically in order to estimate the condensation rate in clothes. They obtained good agreement for thermal resistance between their experiments and calculations, while agreement was less satisfactory for water vapor resistance or the amount of condensation in clothes by experiment. Therefore, more exact predictions of condensation are needed to develop comfortable and safe clothing systems. Lotens and Pieters [5] presented a set of heat and mass balance equations including condensation, which they solved numerically by an iterative method. To our

Differences between manikins may be present due to manikin body shapes (male versus female). In order to examine such differences a study was designed. Comparisons were carried out based on: (1) tight versus loose clothing; (2) serial versus parallel calculation models; (3) even versus uneven clothing (insulation) distribution; and (4) the effect of donning clothes. Differences were observed between female and male manikins depending on body shape. However, these differences were within the range that was observed in the Subzero project, and were comparable with differences between manikins of male body shapes. Manikins behaved differently according to clothing adjustments. Tight-fitting clothes resulted in smaller differences. The effects of donning clothes were more pronounced with the serial calculation model, while the results generated by the serial and parallel calculation models differed more if the insulation was unevenly distributed (24% and 12% respectively). In order to examine the effect of body size, two baby manikins were compared to an adult manikin. The experimental conditions involved air layer insulation measurements (AL), lying on the back on an insulating surface (OB), and lying on the back on an insulating surface, covered with a sheet (OBS, baby manikins only). The acquired AL insulation for all manikins were very similar. The insulation value of adult manikin tested under condition OB differed from the others. This was related to flexible joints allowing the arms and legs to be in contact with the insulating surface, while baby manikins retained their arms and legs in the air. The baby manikins performed similarly in OBS tests.