Simulation on energy use for mechanical ventilation and air-conditioning (MVAC) systems in train compartments

Unlike the conventional automotive, modem railway trains are designed with non-openable windows; and a mechanical ventilation and air-conditioning (MV AC) system is installed in each train compartment for better indoor air qua lity as well as to provide a thermally comfortable environment. The ventila tion rate is no doubt a critical element in the design of a MVAC system, es pecially in Hong Kong where the daily passenger load is extremely heavy. Ea rlier studies illustrated that carbon dioxide can be controlled at 1000 ppm by increasing the ventilation rate to 25.2 m(3) h(-1); however, it will al so lead to an increase in energy consumption. In this paper, the electrical energy consumption at various ventilation rates was studied, and the cost of maintaining a low carbon dioxide level was estimated. These provide soli d information for the local railway companies to improve the air quality in side the train compartments. (C) 2000 Elsevier Science Ltd. All rights rese rved.