An evaporator unit for use in the air conditioning system of a mass transit vehicle
that includes a housing mounted inside the air conditioned section of the vehicle
having a return air inlet connected to a supply air outlet by a flow passage. The
evaporator coil of the air conditioner is mounted in the flow passage to cool the
air moving through the passage. A heater coil is mounted behind the evaporator
coil to selectively heat the air moving through the passage. A dehumidifying coil
is mounted in front of the evaporator coil that utilizes ambient air to dehumidify
the indoor air when the ambient air temperature is at a temperature below that
at which the air conditioner cannot reliably operate.
