Does car air conditioning refrigerant naturally dissipate over time? If so, how long does it take for car refrigerant to be “used up”? If a car is low on refrigerant could the cause of the low refrigerant be natural dissipation of the refrigerant?
Refrigerant is not consumed or used up in normal day-to-day operations, but some cars due exhibit a slight loss over time. While some will argue that on the molecular level no system is completely sealed, when your vehicle leaves the factory, its air conditioning is essentially leak free. This doesn’t mean it’s going to remain that way forever. The bulk of your AC system components are made of metal, but rubber seals and hoses are used at connection points. Over time these rubber pieces are susceptible to degradation and may cause minor leaks. They are leaks that may take years to become apparent to the driver.
If your vehicle is less than five years old and its AC system is inoperative due to refrigerant loss, then it likely has a significant leak other than what is mentioned above, such as an AC condenser, compressor or evaporator.
It really becomes a matter of plumbing at that point. Find the leak, temporarily evacuate the system of any remaining refrigerant, repair and refill to the factory-specified amount.
Source: https://www.theglobeandmail.com/drive/culture/article-what-causes-ac-refrigerant-loss-in-a-car/