Preferred velocities with individually controlled facially applied air movement at high humidity

Thirty subjects participated in three 3-hour experiments performed in climatic chamber at air temperature of 26°C and 1) 70% RH without air movement (0.05 m/s), 2) 30% RH without air movement and 3) 70% RH with air movement supplied isothermally by personalized ventilation from front/above toward the upper chest and the head. The subjects could control the supplied flow rate. They performed work on PC. Pollution level in the room was unchanged. Lack of air movement was perceived as unacceptable at 70% RH while at 30% RH it was rated as acceptable. The acceptability of air movement introduced at 70% RH was slightly higher than at 30%. The preferred velocity ranged between 0.6 and 1.5 m/s. The provided control of the personalized flow was exercised more often at the beginning of the exposure. Female subjects used longer time and needed more adjustments of the personalized flow in order to obtain the preferred conditions.