Investigating claims that a clothed person's mass loss does not always represent their evaporative heat loss (EVAP), a thermal manikin study was performed measuring heat balance components in more detail than human studies would permit. Using clothing with different levels of vapor permeability and measuring heat losses from skin controlled at 34 degrees C in ambient temperatures of 10, 20, and 34 degrees C with constant vapor pressure (1 kPa), additional heat losses from wet skin compared with dry skin were analyzed. EVAP based on mass loss (E(mass)) measurement and direct measurement of the extra heat loss by the manikin due to wet skin (E(app)) were compared. A clear discrepancy was observed. E(mass) overestimated E(app) in warm environments, and both under and overestimations were observed in cool environments, depending on the clothing vapor permeability. At 34 degrees C, apparent latent heat (lambda(app)) of pure evaporative cooling was lower than the physical value (lambda; 2,430 J/g) and reduced with increasing vapor resistance up to 45%. At lower temperatures, lambda(app) increases due to additional skin heat loss via evaporation of moisture that condenses inside the clothing, analogous to a heat pipe. For impermeable clothing, lambda(app) even exceeds lambda by four times that value at 10 degrees C. These findings demonstrate that the traditional way of calculating evaporative heat loss of a clothed person can lead to substantial errors, especially for clothing with low permeability, which can be positive or negative, depending on the climate and clothing type. The model presented explains human subject data on EVAP that previously seemed contradictive.
The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments' material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments.
PurposeThe paper aims to investigate thermal comfort properties, such as heat and moisture transmission through male business clothing systems, by using a sweating thermal manikin Coppelius that simulates heat and moisture production in a similar way to the human body and measures the influence of clothing on heat exchange in different environmental and sweating conditions.Design/methodology/approachTen different combination of male business clothing systems were measured using the sweating manikin, under three environmental conditions (10°C/50 per cent RH, 25°C/50 per cent RH and −5°C), and at 0 and 50 gm−2 h−1 sweating levels, in order to evaluate the influence of environmental and sweating conditions on thermal comfort properties of clothing systems.FindingsThe results show how business clothing systems influence on the dry and evaporative heat loss between the manikin surface and environment in different environmental and sweating conditions.Practical implicationsWhen using sweating thermal manikin Coppelius, water vapour transmission (WVT) through and water condensation on the clothing can be determined simultaneously with the thermal insulation (It) of clothing system. Measured thermal comfort properties of clothing systems evaluated with a sweating thermal manikin can provide valuable information for the clothing industry by manufacturing/designing new clothing systems.Originality/valueIn this investigation, the heat and moisture transmission properties of male business clothing systems were measured in different environmental and sweating conditions. In the past few years, clothing materials containing microencapsulated phase‐change materials (PCMs) have appeared in outdoor garments, particularly sportswear; therefore, we decided to investigate the thermal comfort properties of different standard male business apparel, as well as male business clothing that contain PCMs used as liner and outerwear material.
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