抄録
About 35 % of heat generated by a human body is dissipated by convection in a normal room condition. This convective heat dissipation causes upward air stream around the body. The characteristics of free convection around human bodies were surveyed through infrared thermograms, smoke wire photographs and hot wire anemometry in this study. Male students of a normal height and weight were chosen for the experimental objectives. Experiments were carried out under standing and seated postures, and also under naked and clothed conditions. A heated rectangular model of a height of 1.6 m and a total surface of 1.6 m^2 was also included in the objectives. The results of the three methods indicated that stable free convection existed already at the ankle level. Laminar air flow enclosed the lower parts of the subjects to the height of the thighs. The range of peak air velocities was 5 to 15 cm/s in this part. The range of boundary layer thicknesses was 1 to 3 cm here. The upper parts of the subjects were enclosed by the turbulent flow, the average air velocity of which was about 20 cm/s, and the boundary layer thicknesses of which ranged between 5 and 10 cm. The measured velocities of the clothed condition concentrated in the slower part, and the measured velocities of the naked condition concentrated in the faster part of each of the ranges. The velocity of the free convection corresponds to the allowable maximum air movement for comfort in an air conditioned room.
