How Often Should Refrigeration Oil Be Changed?

There is no uniform and fixed standard for the replacement cycle of refrigeration oil. The core principle is to determine the replacement time based on equipment type, operating conditions and oil quality test results. Here are the details by category:

Small household refrigeration equipment

For low-power devices such as household refrigerators and wall-mounted air conditioners, they usually run in a relatively stable condition with mild working environments. Under normal use, the replacement cycle of refrigeration oil can be extended to 3–5 years.

However, if your household equipment shows signs like reduced cooling efficiency, louder compressor noise or abnormal overheating of the unit, you can also inspect the oil quality in advance and consider replacing the oil.

Large commercial refrigeration equipment

Commercial devices such as supermarket cold storage, central air conditioners and industrial water chillers often operate under full-load conditions around the clock. Moreover, they may face harsh working conditions like frequent start-stop cycles, dusty environments and large temperature fluctuations, which will accelerate the wear and tear of refrigeration oil significantly.

Under regular operating conditions, it is recommended to replace the oil once every 1–2 years;

If the equipment operates in harsh conditions with high temperature, high humidity, heavy dust or frequent start-stops, the replacement cycle should be shortened to 6–12 months.

Core judgment basis: Oil quality test

For both household and commercial equipment, oil quality test results are the most reliable indicator for replacement. Conduct regular oil quality tests on refrigeration oil, and replace the oil immediately if any of the following conditions occur:

Appearance changes: The oil turns dark brown or black, or becomes turbid, emulsified or has impurity precipitates;

Performance exceeding limits: The acid value exceeds the standard limit, the viscosity fluctuates by more than ±15%, or the water content is above the standard;

Accompanying abnormalities: The compressor emits metal friction noise during operation, or the exhaust temperature remains high for a long time, and the problem is confirmed to be caused by poor oil quality after troubleshooting.

One additional note: If the refrigeration system has experienced leakage, water ingress, compressor failure maintenance or other similar issues, it is recommended to directly replace the oil with a new batch after repair. This avoids the impact of residual deteriorated oil on the subsequent operation of the equipment.