A new or well-serviced air conditioning system is filled 100% with a refrigerating agent and contains neither air nor water nor dirt.
However, up to 10% of the refrigerating agent may escape from the air conditioning system annually as a result of "natural evaporation". Over a longer period, air and humidity enter the system. This is even more promoted by any possible leakages brought about by stones and porous O-ring seals.
The air conditioning system no longer delivers its full performance, but worse than that: water and refrigerating agent are acid-forming in the course of time. This acid then attacks the various components of the air conditioning system and may also cause corrosion. The damage done by this often entails high repair costs.
The mechanical operation of the air conditioning system produces dirt (resulting from abrasion of metal particles), which may cause damage to the system or even total failure.
