Automobile air conditioning systems are a closed, pressurized system. It consists of a compressor, condenser, accumulator that is sometimes called a receiver dryer, and an expansion valve or an orifice tube and finally an evaporator. These components work together in your automotive ac system to create an output air temperature in the low 40° Fahrenheit range. How automobile air conditioning works In a basic air-conditioning system, the heat is stored and transferred in the following steps. First the refrigerant leaves the belt driven clutch operated compressor as a high pressure, high temperature vapor.

It is moved towards the condenser, where the vapor becomes a high pressure, high temperature liquid. It is changed from a gas to a liquid by the heat that is removed by the condenser component and the condenser fan that blows across it. After the condenser the refrigerant is then circulated to the accumulator or receiver dryer where moisture and contaminants are removed. This is also where most of the Freon is stored until it is needed.

The expansion valve or orifice tube controls the flow of the refrigerant into the evaporator that is mounted inside the passenger compartment. It is this step that converts the freon from a high pressure to a low pressure. And this is where the automotive a/c system is the coldest. In fact if this step is not controlled properly the evaporator can turn into a block of ice.

You may have heard people talk about low out put of cold air due to ice and not really understand why. You would think ice is a good thing on a hot summer day! But if the evaporator freezes airflow through it is actually reduced and along with it the air temperature from the ducts is not as cool as it could be. Heat absorption from the air inside the passenger compartment by this low pressure Freon causes the liquid to vaporize and move out of the evaporator as a gas.