Should Refrigeration Oil Be Added from the Low Pressure or High Pressure Side?
2 Answers
Refrigeration oil should be added from the low-pressure side. A dedicated filling device injects it through the low-pressure line port. The functions of refrigeration oil are as follows: 1. Lubrication: Refrigeration oil lubricates the compressor during operation, reducing friction and wear, thereby extending the compressor's service life. 2. Sealing: It acts as a sealant in the compressor, ensuring tight seals between the piston and cylinder walls, as well as between rotating bearings, to prevent refrigerant leakage. 3. Cooling: While lubricating moving parts, refrigeration oil carries away heat generated during operation, maintaining lower temperatures for these components, thus improving compressor efficiency and operational reliability. 4. Energy Regulation: For refrigeration compressors equipped with energy regulation mechanisms, the oil pressure of refrigeration oil can serve as the driving force for the energy adjustment mechanism.
Previously, my car's AC wasn't blowing cold air. When I took it to the repair shop, the technician told me that the refrigerant oil should be added from the low-pressure side because the pressure there is lower, usually only a few dozen psi, making the operation simple and safe. The high-pressure side has much higher pressure, reaching up to two or three hundred psi, which can easily cause the oil to spray out, lead to uneven oil distribution, or even result in system leaks. He mentioned that when adding oil himself, he uses specialized tools to slowly inject it through the service port, and the oil only circulates to the compressor after the system is running. Adding oil from the high-pressure side is not only laborious but may also damage the seals, making the AC worse. After he handled it, my AC returned to normal, and he reminded me to regularly check the oil level to avoid shortages and reduce repair hassles. I recommend not attempting DIY fixes and instead seeking professional help to ensure safety and accuracy.
