Oil analysis for refrigeration installations

Oil sample analyses are similar to blood tests because you can learn a lot about the system from which the sample was taken if you know how to read and interpret the results.

Oil suppliers and laboratories that conduct oil sample analyses know the procedures, but they are not always aware of how those results can influence the operation of the refrigeration system and what issues might arise. Oil analysis should be performed at a laboratory that adheres to contamination limit standards for refrigeration systems, as these differ from those for engine or gearbox oil. There are specialized laboratories that perform oil sample analyses for refrigeration systems and can provide results in accordance with the contamination limit standards for these systems. Analyses should only be conducted at such laboratories.

The issues that can arise in refrigeration installations and air conditioning units, and which can be detected through an oil analysis, include: water contamination, high acid content (except in NH3 systems), contamination with engine oil, hydraulic oil, and gear oil, contamination with other refrigerants, compressor bearing failures, etc.

Here are some indicators of potential problems in refrigeration installations and air conditioning units:

• Leaks at seals and joints
• Valve blockages
• Substantial sediment deposits
• Short operating life of compressor bearings