What happens if too much refrigeration oil is added?
3 Answers
Adding too much refrigeration oil can have the following consequences: 1. Hindering heat exchange: When the amount of refrigeration oil is excessive and cannot be carried back to the compressor by the refrigerant vapor, the excess oil will adhere to the evaporator and related pipe walls, forming a thermal resistance that hinders heat exchange. 2. Reducing refrigerant circulation: Excessive refrigeration oil can accumulate at the lowest pipeline points, increasing the flow resistance of the refrigerant and reducing its circulation volume. 3. Decreased cooling capacity: Too much refrigeration oil in the cylinder can reduce the volumetric efficiency of the compression chamber (the excess oil occupies the volume meant for refrigerant vapor, decreasing the refrigerant circulation volume). This reduction in circulation volume significantly lowers the air conditioning cooling capacity, which is the primary factor affecting the performance of the air conditioning system due to refrigeration oil.
I've worked in auto repair shops for over a decade and often encounter problems caused by car owners randomly adding refrigerant oil. Adding too much refrigerant oil leads to excessive oil levels in the compressor, which actually worsens lubrication and accelerates compressor wear. The oil can also mix with the refrigerant, clogging the expansion valve and condenser pipes, significantly reducing cooling efficiency. Increased system pressure may damage seals, causing oil leaks that pollute the environment. Long-term operation under these conditions leads to higher energy consumption, louder AC noise, and even compressor burnout. The bigger headache is that repairs require dismantling the entire system, with costly cleaning and part replacements. Always check the oil dipstick before adding any oil—never rely on guesswork.
Last time my car's air conditioning wasn't cooling properly, so I tried DIY adding refrigerant oil. But my hands shook and I added too much. After just a few days of driving, I noticed the cold air from the vents became extremely weak. When I took it to the repair shop, the mechanic said the excess oil had clogged the evaporator and caused uneven mixing of the refrigerant, overloading the compressor. Fuel consumption also increased, costing me dozens more dollars per month on gas. Now I've learned a lesson: more refrigerant oil isn't always better. Overfilling can damage the system and easily cause strange odors and noises. It's best to regularly monitor your AC's condition and stop using it immediately if any abnormalities occur, then have it professionally inspected for safety.
