Oklahoma Service Technician Practice Exam

The primary function of a compressor in an HVAC system is to compress the refrigerant and raise its pressure. This process is essential for the refrigeration cycle to work effectively. When the refrigerant enters the compressor, it is in a low-pressure gaseous state. The compressor reduces its volume, which increases its pressure and temperature. This high-pressure gas is then able to move through the condenser coils, where it releases heat and transforms into a liquid.

This compression process is critical because it allows the refrigerant to absorb heat from the indoor air when it evaporates in the evaporator coils, and later release that heat outdoors. The entire efficiency of the HVAC system depends on this effective function of the compressor, which is why it is often referred to as the heart of the system.

The other options do not accurately describe the compressive role of the compressor. For instance, cooling the refrigerant is a function associated with the condenser, while circulating air is the job of fans or blowers. Filtering impurities from the air pertains to air filters within the system, not the compressor. Thus, understanding the compressor's role in raising refrigerant pressure is fundamental to grasping how HVAC systems operate.