Friday 11 October 2013

article

Don't Treat Today's Refrigeration 

Systems with Yesterday's Techniques

Today's refrigeration technicians are confronted with refrigeration systems that are vastly different than those serviced last century, but they still continually use the "tried and true" repair/maintenance techniques that used to be very effective.

The hydrofluorocarbon (HFC) refrigerants and polyolester (POE) oils of today's systems have different chemical make-ups than their predecessors--hyrdrochlorofluorocarbon (HCFC) or chlorofluorocarbon (CFC) refrigerants and mineral oil. Essentially the new refrigerants are more stable than the old refrigerants, but the oils are less stable.

Grandpa probably wanted nothing but refrigerant and oil in his refrigeration systems, but today's service technicians don't have that choice. The new refrigerants and oils for the 21st Century already have many built-in additives that were never present in the old refrigerants and oils.

The chlorides used in the CFC refrigerants had excellent anti-wear characteristics. Unfortunately chlorides are one of the reasons CFC refrigerants have been deemed bad for the environment. To fill the anti-wear void created when chlorides were eliminated from the new HFC refrigerants, oil manufacturers put in phosphorus and other additives. Plus there is a full range of aftermarket products that a service technician is enticed to add into a system. Generally, additives within a system fall under three different categories:

Additives that are built into today's new HFC's by the refrigerant and oil manufacturers that promote lubricity and anti-wear. These additives usually get consumed during the life of the unit resulting in sludge formation and increased wear or oxidation over time that damage the system.
Additives that are not intentionally added to the system, but get into the system during the manufacture or installation of the equipment. (such as acid, air, or moisture)
Aftermarket additives introduced by a technician that remain in the system and increase the formation of sludge or alter the equilibrium chemistry of the oil.
In general, the refrigerant and oil manufacturers have ensured that their proprietary compositions of additives are compatible within each other. However, combining these chemical additives with acid neutralizers, untested flushing fluids or leak stopping chemicals is a recipe for disaster. Many technicians also fail to realize that water and air in a system is more of a problem with the new synthetic oils.

In general, the refrigerant and oil manufacturers have ensured that their proprietary compositions of additives are compatible with each other. However, combining these chemical additives with acid neutralizers, dyes, or leak stopping chemicals can be a recipe for disaster. Many technicians also fail to realize that water and air in a system are more of a problem with the new synthetic oils.

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