摘要：KOTATSU is a well-known heating facility in Japan. It heats the lower extremities of a body by an infrared heater or a wood coal fire in a box. The objective of this paper is to clarify the thermal effect of KOTATSU on a person. Experiments were carried out under the following combined conditions: air temperatures were 11°C, 14°C, 17°C, and 20°C and infrared lamp levels were 'off', 'low', 'middle' and 'high' which correspond to 0W, 86W, 91W and 181W infrared heater consumption power, respectively. Five male and six female subjects participated in these experiments. The following results were obtained: 1) The skin temperature at the lower extremities of the body rose and that at the upper extremities dropped respectively, at the same time when a subject was seated at the KOTATSU. 2) The corrected operative temperature for indicating the effect of KOTATSU was introduced by the authors in the basis of heat balance equation between the human and its environment. This index correlates with the modified mean skin temperature and the thermal sensation for the whole body. Consequently, it is a suitable index to evaluate the thermal environment when a subject is seating at the KOTATSU. 3) The heating facility KOTATSU at 'middle' IR heater level has the equivalent effect of 8°C air temperature rise at 11°C air temperature, and also has more than 2°C effectiveness at 14°C air temperature even if the infrared lamp of the KOTATSU is turned off. 4) The corrected operative temperature fairly indicates the effect of thermal environment with KOTATSU in spite of non-uniform environment.
关键词：heating facility ; KOTATSU ; operative temperature ; human body
