Experimental Study on the Effects of Air Flow from Cross-Flow Fans on Thermal Comfort in Railway Vehicles

Abstract

This study examines the effects of the periodic wind variations generated by cross-flow fans to offset the sensation of warmth under realistic conditions of occupant density and temperature change in commuter trains in Japan. Subjective experiments were performed in a stationary commuter vehicle at a rolling stock depot. The results of the study showed that (1) the temperature at which the subjects felt a neutral thermal sensation on average was 24.6 °C in the fan-off condition and 27.5 °C in the fan-on condition, (2) the temperature at which 20% of the subjects felt discomfort due to warmth was 24.3 °C in the fan-off condition and 27.6 °C in the fan-on condition, (3) the relations between air temperature and subjective evaluations under an occupant density of 0.3 m2 per person were almost the same as those under an occupant density of 0.2 m2 per person and (4) the draft risk model substantially overestimated the discomfort due to coldness at temperatures over 22 °C.