Page 43 - CleanIndiaJournal June Digital Issue

FM - HVAC

by mechanical issues in the
air conditioning system or
deficiencies in fresh air intake.
This can affect passenger health
by causing respiratory issues,
allergies and other problems.
Inadequate ventilation
causes air to become stagnant,
leading to the collection of
dust and harmful gases inside
the compartment. Nitrogen
oxides from power cars and
diesel engines are a problem in
particular. Moulds may grow
in the damp areas of the air
handling units.
Subodh Sagar, CWE, Central Railways (centre) felicitates Bapat (right) and Rajput (left). The quality of ambient air is
the biggest determinant of indoor
the entire compartment. If there hygrostats. Across the world, air quality. Filtering fresh air
are leakages in the duct system, only these two parameters are can help to some extent. Indian
contamination of the inside air measured in train compartments. Railways is looking for HEPA
may take place. Whenever the temperature filters that can filter out PM 2.5
Fresh air screens are provided or humidity fluctuates beyond effectively, and at a price that is
above the main door in the RMP given limits, the microprocessor reasonable. Trials can then be
unit. Fresh and recirculation air automatically kicks in to restore conducted to gather data on their
effectiveness in train coaches.
flaps are also provided. normalcy.
Exhaust air units are installed Fresh air intake of 20-30% is Duct cleaning
in the roof at the end of each maintained. A relative humidity
coach. A radial fan and air box of around 60% needs to be When dirt in the ducting
are provided for this purpose, maintained at all times; above system is dislodged, it becomes
but they do not function very this level, dehumidification a contaminant. Abroad, the
efficiently. begins. Cooling begins when average frequency of cleaning
temperatures exceed 28 °C. recommended for coach air
Role of sensors ducts is every 3-10 years. Indian
Railways cleans ducts every
LHB coaches have sensors to Air quality issues 1.5-3 years. Vande Bharat train
measure room temp, ambient Poor indoor air quality sets already have UV lamps for
air and supplied air, as well as in coaches is caused either disinfecting air. CIJ

Clean India Journal•JUNE 2023 43
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