• organic acids (such as oleic acid)
• and inorganic (mineral) acids (such as hydrochloric acid)
The former is found in refrigerant oil in the compressor pump. They are soluble in oil and do not vaporize. The inorganic acids on the other hand, are more reactive and stronger compared to their organic counterpart. They are partly soluble in oil. They are found both is refrigerant oil and also in refrigerant and therefore circulate throughout the machine. They can pose more danger to the unit than organic acids. Acids do an irretrievable damage to the compressor. So when the new compressor is installed care should be taken that acid have been completely eradicated from the system.
Usually clean-up of a unit include changing the compressor and removing the oil and refrigerant, as the acid is primarily found in these. However there remains the fact that the acid has traveled with the refrigerant throughout the vapor-compression loop. The traces of acid has been left almost everywhere. This acid residue should be removed mandatory. It has been found to shorten the life of the A/c otherwise. There are evidences that a compressor burnout of a system has increased the frequency of subsequent burnouts. This is mainly on account of incomplete removal of acid. The inorganic acids eat up the lacquer insulation from the wire of the motor winding which increase chances of shorts and burnouts.