Along with the refrigerant that is being discharged, compressors will discharge which of the following as it leaves the compressor?

• A. Oil
• B. Water
• C. Moisture
• D. Acid vapors

Answer: (A)

Lubrication is needed to keep the compressor’s moving parts from rubbing and heating up. The oil that does this lubrication is carried along with the refrigerant as it moves through the compressor. When the gas exits, it often contains small oil droplets in the discharge stream, which is why oil is typically discharged from the compressor along with the refrigerant. Oil separation and return are then used to pull the oil back to the crankcase so the compressor stays lubricated.

Water or moisture isn’t normally ejected as a standard part of the discharge; moisture in the system is dealt with by dehydration and drying components, not by the compressor’s discharge. Acid vapors would only appear if the refrigerant degraded or the system overheated or became contaminated, which isn’t a normal condition of the discharge stream.