Airconditioning in Automobiles

An automobile air conditioner has the following:

Compressor: This is the heart of your a/c system. The compressor intakes the refrigerant (the gas) and pressurizes it so that it cools the air. An engine belt runs it.

Condenser: The condenser is like a miniature. The condenser has its own electric cooling fan, too. The hot, compressed air passes through the condenser and gets cooler.

Evaporator: The evaporator does just the opposite task as the condenser. When the cooler liquid passes through its tubes, air is forced through and gets really cold. When it warms, the refrigerant starts turning back into a gas.

Thermal Expansion Valve: To save from excess cooling, the a/c system has a valve that controls the flow of super-cool refrigerant to the evaporator. 

Drier or Accumulator:  The compressor compresses the gas form of your refrigerant. However, some liquid could make it back that far. The drier catches this liquid before it can damage the compressor.