To design comfortable clothes in hot environment it is important to obtain information about regional sweating rate and regional evaporation rate with the changes in the temperature. The puｒpose of this study is to investigate the relationship among body weight loss, regional sweating rate and regional evaporation rate at air temperatures of 28, 31, 34 and 37℃ with the relative humidity of 50%. Ten adult male subjects wearing shorts sat on a stool in a sitting position for 30 minutes. Sweating rate were measured with a ventilated capsule device and evaporation rate with an Evaporimeter in 5 body regions (forehead, chest, back, forearm and thigh) and body weight loss was measured with an electrical balance.
The results were summarized as follows: ①The regional sweating rate increased significantly as the air temperature increased. ②The regional sweating rate and the regional evaporation rate showed a similar trend. However the difference between both values increased as the air temperature increased. The regional evaporation rate showed significantly lower values.③ No significant difference between total sweating rate estimated from the regional sweating rate and body weight loss was observed in insensible perspiration zone. However, as the air temperature increased, total sweating rate was significantly higher than the body weight loss. ④ No significant difference between total evaporation rate estimated from regional evaporation rate and body weight loss was observed in insensible perspiration zone. However, as the air temperature increased,total evaporation rate was significantly lower than the body weight loss.⑤Total evaporation rate estimated from the regional evaporation rate corresponded to the body weight loss through correcting the regional heat transfer coefficient.
This study demonstrates that the regional sweating rate was quantitatively different from the regional evaporation rate and in order to estimate the average evaporation rate from regional evaporation rate it is necessary to correct the regional curvature factor.