Air Conditioning Repair Certification (ETI) Practice Exam

The primary function of the compressor in an air conditioning system is to compress the refrigerant. This process is critical because the compressor increases the pressure and temperature of the refrigerant vapor as it circulates through the system. When the refrigerant is compressed, it transforms from a low-pressure gas into a high-pressure gas, enabling it to release heat effectively when it enters the condenser.

This step is essential for the refrigeration cycle to function correctly, as the compressor effectively prepares the refrigerant for the heat exchange process that follows. By raising the pressure, the compressor also ensures that the refrigerant flows smoothly through the rest of the system components, including the condenser and evaporator, maintaining the air conditioning system’s efficiency and overall performance.

The other functions listed do not correctly identify the compressor's role in the system. While cooling air, circulating air, and condensing refrigerant are crucial aspects of air conditioning operation, they are carried out by other components such as the evaporator and condenser.