Observation and Influence Examination of Free Convection around Human Body

Abstract

A human body transfers about 35 percent of its metabolic heat to the ambient air by convection. This heat causes upward natural convection around the body. The characters of the convection were observed by infrared photography and smoke wire photography technics. Its velocity reached to about 0.25 m/s at 0.3 m above the head, and its flow rate was about 40 1/s. As the results of it, the convection heat transfer coefficient at the lower leg was about two times of it at the torso. The concentration of occupant produce carbon dioxide was higher in the overhead region than in the lower region of.a room. It is important to consider the influecne of the natural convection in thermal comfort and ventilation design.