Heat Distribution Analysis in Urban Transit Cabin Using Real-Scale Environmental Chamber

초록

Thermal comfort in urban transit cabin is very important since more than 90% of passengers’ complaints are about thermal comfort.<br>However, there is no solution to reduce the number of complaints due to the lack of study about the thermal comfort in the urban transit cabin. In this study, the temperature distribution in an urban transit cabin was measured to find a solution to relieve the thermal comfort problems in winter seasons. An urban transit cabin was placed in a very large real-scale environmental chamber for railroad passenger cabin was used to control the ambient temperature from -20 ºC (-4 ºF) to 10 ºC (50 ºF). 15 sets of thermocouples were installed at 0.1 m (0.33 ft), 1.1 m (3.6 ft), and 1.7 m (5.6 ft) height from floor inside the cabin. Temperature at each point were monitored and saved by using a data logger. When only heaters, which<br>are located at passenger seats, were operated without operation of any other equipment, the temperature was higher at 1.7 m (5.6 ft) or 1.1 m (3.6 ft) than at 0.1 m (0.33 ft) since warmer air, which has lower density, moves upward while cold air moves downward. Two fans were installed inside the cabin, and the effect of wind direction was also studied. When there is air flow, the averaged temperature was lowered. However, temperature difference between 1.7 m (5.6 ft) and 0.1 m (0.33 ft) was much smaller. It means the air mixing is very important to enhance the thermal comfort inside the cabin. The effect of passenger load was also extensively studied.