The MRT Environmental Control System (ECS) includes tunnel ventilation, smoke exhaust system, air-conditioning and ventilation, Shop Floor Control System (SFCS), etc. In particular, the tunnel ventilation system mainly consists of two types of equipment:

1. Tunnel Ventilation Fan (TVF) are located at two sides of underground stations (as shown in Figure 1).
2. The jet fans are located above the track level of the underground cut and cover tunnel section.

Due to the train’s piston action, the tunnel is ventilated during normal mode. The air in the tunnel is exchanged with external air via the track’s exhaust system and wind pressure drainage pipes (pressure relief air wells) at both ends of the station.

During congestion, the tunnel ventilation system in each station provides several ventilation operation modes. These operation modes include delivering external air to the next tunnel and discharging air from the tunnel damper (TD) (as shown in Figure 2) to outdoors.

In addition, detailed designs and relevant simulated smoke control of the underground tunnel ventilation are in accordance with design conditions.

Devices which make up the smoke exhaust system include: smoke extraction fans (as shown in Figure 3), Smoke Exhaust Dampers (as shown in Figure 4), smoke exhaust ducts, fire dampers (FD), static pressure detectors, etc.

The activation of smoke exhaust dampers and smoke extraction fans is controlled by smoke detectors. The configuration of the smoke exhaust system must comply with applicable domestic laws and regulations. The motors in smoke extractor fans need to be able to run nonstop for at least an hour when the ambient temperature is over 250℃. In the event of a fire, the air conditioning is automatically shut off and the smoke exhaust system is activated to release fumes and smoke into the atmosphere.