Kouhei Kuwabara

Experiments to determine the convective heat transfer coefficient of a thermal manikin

Abstract In order to determine an equation for calculating the convective heat transfer coefficient in humans, that can be used in an outdoor environment, experiments using a thermal manikin were carried out at an air velocity in the range of 0.7–4.7 m/s. The convective heat transfer coefficient of the naked human body almost agreed with that of the clothed human body with two clothing ensembles. Empirical formulae of the convective heat transfer coefficient for the whole and 10 parts of the body were calculated using experimental data at an air velocity in the range of 0.1–1.0 m/s, which are applicable formulae at an air velocity in the range of 0.1–4.7 m/s. The thermal insulation of the two clothing ensembles decreased with increasing air velocity.

Effective radiant temperature including solar radiation

An evaluation method for thermal sensations of the human body in an outdoor thermal environment was developed. Effective radiant temperature was proposed as the mean radiant temperature in an outdoor environment. The operative temperature and standard new effective temperature, SET*, in outdoor environments could be calculated using the effective radiant temperature. In order to examine the operative temperature and SET* based on the effective radiant temperature, experiments using subjects were carried out in an outdoor environment at Sapporo city. The SET* calculated from experimental data correlated well with the thermal sensation votes of the subjects. It was shown that a SET* based on the effective radiant temperature can evaluate the thermal sensation of the human body in an outdoor environment.