AIR CONDITIONER
Basic maintenance is about the same as the cooling
system; clean leaves and bugs from the front of the car. Good
air flow is very important.
It seems to be a good idea to use the air conditioner in the
winter to help defrost the windshield. Use the air conditioner
at least once per week if possible.
Some loss of freon after a few years may be "normal".
Seals wear and lose pliability after being subjected to heat
and vibration. Under hood temperatures "cook" hoses
and coupling seals.
We suggest an air conditioning checkup at the first sign of
diminished cooling.
Anatomy of an automotive air conditioner
Compressor
The "heart" of the system, pumps refrigerant through
the air conditioning system. Refrigerant (freon) is a hot
gas when it leaves the compressor and must be cooled and
allowed to "condense" to a liquid state. The compressor
starts the "process" over by compressing the freon
gas and sending it to the condenser. The freon gas has removed
heat from inside the vehicle. The condenser will give up
this heat to the air.
Condenser
The hot gaseous freon goes from the compressor to the condenser.
The condenser looks similar to, and is mounted in front
of the radiator. Air flowing through the condenser cools
the freon. The freon gives up heat to the air and changes
to the liquid state. From there it flows to the receiver-drier.
Receiver / drier
The liquid freon is "stored" in the receiver-drier
for a time until it flows to the expansion valve. While
being stored, the freon comes in contact with a desiccant
material that removes moisture that may be in the system.
Freon must be dry. Water and freon molecules can combine
to form acids that do damage to the system.
Expansion valve
The expansion valve controls the amount of freon flowing
into the evaporator. Like a water valve, it controls the
flow of liquid. The amount of freon allowed to enter controls
the temperature in the evaporator.
Evaporator
The evaporator looks somewhat like a small radiator. Liquid
freon, under high pressure, is metered into the evaporator
(which is at a much lower pressure) and allowed to change
from a liquid back to the gaseous state. The blower motor
directs the air inside the cab across the evaporator. Heat
is removed from this air when this change of state occurs,
cooling the inside of the vehicle.
