Compressor – HVAC Glossary
A compressor is a mechanical pump in an HVAC system that pressurizes refrigerant and circulates it through the cooling cycle, serving as the heart of the air conditioning process.
A compressor is a mechanical device that functions as the central pump in heating, ventilation, and air conditioning (HVAC) systems. This component pressurizes refrigerant gas and propels it through the cooling cycle, enabling the heat transfer process that makes air conditioning possible.
How a Compressor Works
The compressor receives low-pressure refrigerant gas from the evaporator coil and compresses it into a high-pressure, high-temperature gas. This pressurized refrigerant then flows to the condenser coil, where it releases heat and converts back to liquid form. Without the compressor’s pumping action, refrigerant would not circulate through the system, and no cooling would occur.
Types of Compressors
Several compressor designs exist for different HVAC applications:
- Reciprocating compressors use pistons to compress refrigerant, similar to an automobile engine
- Scroll compressors employ two spiral-shaped scrolls that compress refrigerant as they rotate
- Rotary compressors use rotating mechanisms to pressurize refrigerant in a circular motion
- Screw compressors utilize intermeshing helical rotors for large commercial applications
Signs of Compressor Problems
When a compressor malfunctions, several symptoms may appear. The system may fail to cool adequately, produce unusual noises like grinding or clicking, or refuse to start altogether. Hard starting, where the unit struggles to begin operation, often indicates compressor wear. Tripped circuit breakers can signal electrical issues within the compressor motor.
Maintenance Considerations
Compressor longevity depends on proper system maintenance. Clean air filters prevent debris from entering the system and causing damage. Adequate refrigerant levels prevent the compressor from overheating or running inefficiently. Regular professional inspections can identify potential problems before they lead to compressor failure, which represents one of the most expensive HVAC repairs.
The compressor typically resides in the outdoor condensing unit of split air conditioning systems. Its location exposes it to weather elements, making protective housing and proper installation important for long-term performance.
