Thermal comfort criteria for personal air supply in aircraft cabins in winter

Abstract

Personal air supply systems (PASSs) have shown great potential in buildings, but to date, the usefulness of PASSs in aircraft cabins in winter has not been examined. In this study, 40 subjects participated in experiments in a model aircraft cabin constructed at Chongqing University. The subjects were exposed to air from a personal air supply at flow rates of 0, 0.5, 1.0, and 1.5 L/s under eight different conditions: 28, 26, 24, and 22 °C while wearing winter clothing (≈1.23 clo); 24, 22, and 20 °C while wearing winter clothing with a jacket (≈1.55 clo); and 26 °C while wearing summer clothing (≈0.65 clo). The results indicate that the subjects were more thermally sensitive to the environment in the aircraft cabin than that in buildings. Because a higher draft rate (DR) at the face occurred under some conditions, a new DR model based on convective heat transfer at the face was constructed. The perceived air quality (PAQ) had a strong relationship with the airflow rate of the air supply and the standard effective temperature, implying that the PAQ is affected by the heat balance of the body. Thus, recommended adjusted thermal environment criteria for a personal air supply while wearing winter clothing that account for the thermal sensation, drafts, and PAQ are presented.