Draught sensitivity is influenced by general thermal sensation

Abstract

The effect of a cool thermal sensation on local discomfort due to draught was studied in a series of human subject experiments. While performing standing arm work, ten male subjects were exposed to mean air velocities increased step-by-step ranging from 0.05 m · s −1 to 0.40 m · s −1 at air temperatures of 11°C and 17°C. Two different levels of thermal sensation between slightly cool and neutral were scheduled. At each level of air velocity, the subjects were asked whether they could feel an air movement, whether it was uncomfortable and where it was felt. Most frequently, draught was felt at the head region comprising face, neck and upper back. The subjective responses showed that significantly more persons feeling slightly cool perceived air movements as uncomfortable than persons having a thermal sensation closer to neutral, provided the air velocity was the same. A relationship was established that specifies the relative increase in the percentage of dissatisfied due to draught at a cool thermal sensation in proportion to a neutral thermal sensation at equal mean air velocity.