LoginNatural convection, which arises around an occupant by his own metabolic heat, plays an important role in convection heat dissipation of the body in a room environment. The present research aimed at to know how local airflow penetrates through the natural convection layer, how it is perceived at a body surface, and finally causes sensations of warmth and air motion. As a basic study of it, horizontal local airflow was directed at the representative two locations on subjects surfaces, which are the back of the neck and the left side of the ankle. The subjects votes on the feeling of temperature and air motion at the two locations were compared.
This experiment was carried out at a room temperature of between 22 and 23 degrees C in winter 2002 with twenty subjects of male and female students. The applied airflow was combinations of different temperatures and velocities, which were blown from a distance of 0.4m from a nozzle of a diameter of 0.05m. During the experiments, changes in weight, pulse rate and temperature of each subject were recorded. The later two factors changed irregularly, and no tendency was found from them. The decreases in weight were clear, but these decrease were almost equal among the experimental conditions. The experiment appeared to be carried out in a stress free condition.
The subjects votes indicated that the airflow caused stronger thermal sensation at the ankles than the backs of the neck. However, the airflow and the thermal comfort were perceived more strongly at the back of necks than the ankles. The airflow was felt comfortable rather than uncomfortable even in the high air velocity range
A study on Perception of Local Airflow in Winter
Year:
2003
Bibliographic info:
The 4th international conference on Cold Climat HVAC, Trondheim, Norway, June 16-18, 2003,
Paper 55, pp 1-9, 17 Fig., 2 Tab., 8 Ref