Ventilation of the carriages ensures air extraction and fresh air inflow from the street. Natural and forced ventilation are used in the cars. Natural ventilation of passenger cars is installed during the assembly of the car; it works without the use of electricity. Forced is a combination of fans and air ducts and is powered by electricity.
Car ventilation functions
Passenger cars are equipped with compulsory ventilation systems for passenger cars, the functions of which are:
- Ensuring the exchange of air, saturating it with oxygen and removing carbon dioxide, dust, stench;
- Air movement in the locations of passengers;
- Provides the necessary air pressure inside the car, preventing the suction of dust and hot air from the street (in summer);
- Partially lowers the air temperature in the car.
Types and mechanisms of car ventilation
Natural ventilation of the carriages is carried out through the vents, it is free and efficient. But it can be used only in summer, and dust and rain drops into the carriage through the windows. Another drawback: these are drafts, which are necessarily formed in the carriage with several open windows. Therefore, all passenger cars are equipped with deflectors - exhaust mechanisms.
They are also not perfect: the intensity of air extraction is weak, drawing out air, they do not replace it, and the atmosphere in the carriages is discharged. Deflectors are mounted on the roof of the car; they suck air only during the movement of the car. The air, passing through the deflector, creates a vacuum in it, which is compensated for by air from the carriage room.
Given the low efficiency of the deflectors, they are used as additional ventilation equipment. Typically for venting air from toilets. Air is supplied through windows or a forced ventilation system. When the car is stationary, the deflector does not work and only the windows are used.
Forced ventilation of a passenger carriage can be with or without recirculation. Air ducts are mounted above a false ceiling. In addition to air ducts, the system includes intake louvers, filters, a unit, a diffuser and an air heater. The ventilation system of the passenger car with recirculation ensures the admixture of clean air from the atmosphere. It is cooled or heated and fed into the carriage. Such systems are complex, because it is necessary to equip an air duct for air return, a mixing chamber, and a filtration system.
