New Holland CX720 Repair Manual page 3036

BODY AND STRUCTURE - ENVIRONMENT CONTROL Air-conditioning system
A/C CYCLE
2
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Air Conditioning Process
Refrigerant is drawn into the compressor as a cool, low-pressure vapor, compressed and then moves out as a hot,
high-pressure vapor to the condenser.
As the hot, high-pressure vapor passes through the condenser core, it gives off heat to the cooler outside air being
drawn past the radiator cooling fins.
The vapor is condensed to a liquid by giving off heat to the outside air. This liquid moves to the receiver/dryer under
high pressure.
Hot, high-pressure liquid is stored in the receiver/dryer until it is released to the evaporator by the expansion valve.
The liquid refrigerant passes through a metered orifice in the expansion valve and into the evaporator coil. As the
refrigerant passes through the orifice in the expansion valve, the refrigerant changes from a high-pressure liquid to a
low-pressure atomized liquid. Then, when it reaches the evaporator coils, it begins to cool, absorbing heat from the
air drawn across the coils and fins by the blower. The refrigerant now changes from a cold low-pressure liquid to a
cool low-pressure vapor and leaves the evaporator outlet moving to the suction (low-pressure) side of the compressor
to repeat the cycle.
As the heat loss is taking place, moisture (humidity) in the air will condense on the outside of the evaporator and drain
off as water through the drain hoses attached to the evaporator drain pan, thereby reducing the humidity level of the
cab. Also, dust or pollen not removed by the cab filters will collect on the wet evaporator fins and coils and will be
washed off with the condensed moisture.
In summary, the heat in the cab is removed by the refrigerant in the evaporator and is transferred from the refrigerant
to the outside air by the condenser unit.
Lubricants
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