In the last post we looked at the challenges associated with the formation of copper oxides within the refrigerant circuit when dry nitrogen is not used during the brazing process. In today’s post, the focus is on “air” within the refrigerant system. Air is a common catalyst that does tremendous damage and yet is easy to prevent if good work practices are followed.
When the refrigerant system is energized, the refrigerant flows in an environment that is under pressure and operating at high temperatures. When air is combined with refrigerant in the presence of heat and pressure it will form acids within the refrigerant circuit.
Refrigerant manufacturers combine carbon, fluorine, chlorine and hydrogen in the process of producing refrigerants R22 and R410A. The oxygen (air) element becomes the unwanted catalyst within the refrigerant system. The oxygen will hydrolyze (i.e. combine) in an uncontrolled manner with the hydrogen element already present in the refrigerants, and will form water vapor (moisture.)
When moisture combines with R22 in the presence of heat and pressure, it will form hydrochloric acid. When it combines with R410A in the presence of heat and pressure, it will form hydrofluoric acid. These acids which are both highly corrosive begin to circulate through the refrigerant system. The end result is extensive damage causing component and equipment failure.
Following proper procedures during the evacuation process may seem like a minor detail. However, NOT following proper procedures will ultimately be a major detail that costs your customers substantial dollars in preventable service and maintenance. And it may cost you a valuable customer and a hard-earned positive reputation.