It is desirable to understand the characteristics of heat and water vapour transfer from the body surface as fundamental physical properties if human physiological responses are going to be investigated and discussed under thermal environments. This is because, in order to maintain core temperature at an appropriate level, the body not only continuously produces heat energy but also simultaneously releases sensible and latent heat energies from its surface to the environment. As for the characteristics of sensible heat transfer from the body surface, while significant differences in the radiative heat transfer coefficient are not seen between locations in the body, significant differences in the convective heat transfer coefficient are remarkably seen. The convective heat transfer from the extremities, such as upper and lower limbs, is larger than that from the trunk. Mass transfer from the body to the environment is quite similar to heat transfer that its coefficient from the extremities is greater than that from the trunk. For evaluating heat and water vapour transfer from the body, experiments with subject participants and experiments using thermal manikins or sweating thermal manikins, which represent not only body shape but also heat production and sweating of human, have been conducted. Measurements employing a thermal manikin provide high representability and also give detailed data from each location of the body. Therefore, the thermal manikin is an effective and useful device in the research field related to thermal environments. Heat and water vapour transfer from the body surface to the environment occurs through clothing in daily life. Therefore, clothing is considered to be one of the important thermal environmental factors, because the heat and water vapour transfer characteristics of clothing have significantly strong impacts on temperature regulation and thermal comfort of human. There are two ways for evaluating the heat and water vapour transfer characteristics of clothing: one is to obtain them experimentally using thermal manikins and the other is to obtain them employing estimation equations defined by ISO. Heat transfer characteristics of clothing are affected by the thermal properties of its materials as well as largely affected by flow promoted by the wearing conditions (gaps and openings etc.), body movements, and the environment. Water vapour transfer characteristics of clothing are affected by flow promoted by wearing conditions, the body movements, and the environment in the same way as the heat transfer, and are, in particular, strongly influenced by the material’s absorbent properties against water and water vapour.

The Thermal Environment and Clothing Physical Properties

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发表日期：

2025年

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Takako Fukazawa

摘要

It is desirable to understand the characteristics of heat and water vapour transfer from the body surface as fundamental physical properties if human physiological responses are going to be investigated and discussed under thermal environments. This is because, in order to maintain core temperature at an appropriate level, the body not only continuously produces heat energy but also simultaneously releases sensible and latent heat energies from its surface to the environment. As for the characteristics of sensible heat transfer from the body surface, while significant differences in the radiative heat transfer coefficient are not seen between locations in the body, significant differences in the convective heat transfer coefficient are remarkably seen. The convective heat transfer from the extremities, such as upper and lower limbs, is larger than that from the trunk. Mass transfer from the body to the environment is quite similar to heat transfer that its coefficient from the extremities is greater than that from the trunk. For evaluating heat and water vapour transfer from the body, experiments with subject participants and experiments using thermal manikins or sweating thermal manikins, which represent not only body shape but also heat production and sweating of human, have been conducted. Measurements employing a thermal manikin provide high representability and also give detailed data from each location of the body. Therefore, the thermal manikin is an effective and useful device in the research field related to thermal environments. Heat and water vapour transfer from the body surface to the environment occurs through clothing in daily life. Therefore, clothing is considered to be one of the important thermal environmental factors, because the heat and water vapour transfer characteristics of clothing have significantly strong impacts on temperature regulation and thermal comfort of human. There are two ways for evaluating the heat and water vapour transfer characteristics of clothing: one is to obtain them experimentally using thermal manikins and the other is to obtain them employing estimation equations defined by ISO. Heat transfer characteristics of clothing are affected by the thermal properties of its materials as well as largely affected by flow promoted by the wearing conditions (gaps and openings etc.), body movements, and the environment. Water vapour transfer characteristics of clothing are affected by flow promoted by wearing conditions, the body movements, and the environment in the same way as the heat transfer, and are, in particular, strongly influenced by the material’s absorbent properties against water and water vapour.