The Refrigeration Cycle

Refrigeration works by mechanically circulating refrigerant through a evaporation and condensation cycle. Low temperatures and pressures encourage evaporation, while condensation occurs in areas if high temperature and pressure. One side of the loop is inside an area of low temperature like a refrigerator, and one side is on the outside air. This two sided design of the loop allows the transfer of heat.

As a basic overview of the mechanics, as the low pressure liquid refrigerant expands at the evaporator inlet, it absorbs heat and evaporates into a low pressure gas. The compressor then pumps the gas through an accumulator which builds pressure for discharge into the condenser.

The accumulator protects the compressor from trying to pump solid or liquid freon. All Denver HVAC systems should come with an accumulator to protect air conditioning compressor life. Compressors are the most commonly ordered part by Denver air conditioning companies. Compressors are especially susceptible to varying load conditions and frequent compressor on/off cycling.

Condensers remove heat from the gas until it condenses back into a high pressure liquid. Some optional parts common in a Denver air conditioner are drain valves, heat exchangers, and liquid line valves.

The expansion device is between the condenser and evaporator. A liquid line strainer should be installed before this part to prevent problems from the buildup of dirt or moisture. The pressure between these valves is maintained by thermal expansion. As the refrigerant liquid is sucked into the evaporator, its pressure drops and the liquid absorbs heat as it expands and evaporates.

Once the desired interior temperature is reached, the thermostat sends a signal to the central air conditioning or refrigeration unit to shut down. The system turns back on when rising heat in the evaporator enlivens the circuit.