Metro Ventilatingvalve / product

Nowadays,many metros have been built underground where there are large flow of
people but lacking of ventilation .Also, the poor air quality does great harm to people’s
health.However ,the cost of air purification is very high.Metro Ventilatingvalve uses
the air pressure difference which is produced by the running of a subway to take away
the dirty air of platforms. At the same time, the fresh air at the metro entrance will be
added into the underground. In this way ,we can improve the poor air quality of platforms
without any additional energy consumptions.