The Thermal Manikin; a Useful and Effective Device for Evaluating Human Thermal Environments

Abstract

Thermal manikin is a device, which simulates not only body shape but also human heat production and release. The device contributes to evaluate human heat transfer, thermal resistance of clothing, and protective tools for human safety with a high representativity. According to a study using the thermal manikin, for example, convective heat transfer from the human body has been found to be different in individual body location. The convective heat transfer coefficients in extremities are so larger than those in trunk and head that it is reasonable to put gloves on hands, e.g., to effectively protect the extremities from heat loss in a cold. In natural convection system, it has been experimentally confirmed through the thermal manikin that the convective heat transfer coefficient decreases with decrease in ambient pressure. Therefore, during exposure to a low ambient pressure, even if in a cold, temperature drop in skin surface can be suppressed because of the depressed sympathetic nerve activity and of the decrease in the convective heat transfer coefficient. A baby thermal manikin aged 0.5 year-old has been originally developed with aiming for infant’s safety and thermal comfort. There is a significant difference in convective heat transfer in the whole body between infant and adult because of difference in height; the coefficient is larger in infant than in adult. The baby thermal manikin has been employed for measuring the thermal resistance of clothings for infant. An estimation equation by means of the total weight of the clothing for infant has been derived to obtain the thermal resistance, because a high correlation has been confirmed between them.