FDNY Operating Engineer Practice Test

In a compression refrigeration system, the low-pressure side specifically refers to the section of the system where the refrigerant is at a low pressure and temperature, facilitating the absorption of heat from the environment being cooled. This low-pressure side begins at the metering device, which is responsible for controlling the flow of refrigerant into the evaporator.

Once the refrigerant passes through the metering device, it enters the evaporator where it absorbs heat, causing it to change from a liquid to a vapor. Following the evaporator, the vapor refrigerant moves to the compressor, where it is drawn in at low pressure and further compressed, increasing its pressure and temperature before it exits to the high-pressure side of the system.

Thus, the definition of the low-pressure side correctly encompasses the path from the metering device to the compressor suction, which aligns perfectly with the selection. This understanding is crucial for anyone working or studying in the fields of refrigeration and HVAC, as it highlights the system's operation dynamics and the importance of each component in the refrigeration cycle.