Good refrigeration practice for CFC systems

It is a well known fact that an engineer required to work on an ammonia system will be very careful not to allow undue discharges of refrigerant because of its toxicity. Since CFCs are non-toxic it has been common practice to discharge them to atmosphere. This must now be regarded as malpractice and cease forthwith.


It was also past practice to use the dilution or triple evacuation method, in which a small amount of refrigerant is used to dilute the atmosphere within the system, discharging between evacuations. This method can still be employed, but instead of releasing the refrigerant to atmosphere it should be reclaimed by decanting to a cooled refrigerant cylinder.

Alternatively, the more practical deep evacuation method should be adopted.

Cleaning condensers

The practice of cleaning condensers with a refrigerant should be discontinued. Proprietary brands of degreasing and cleansing agents which are environment friendly are readily available.

Should it be necessary to apply pressure to ensure penetration to fins and pipework, then nitrogen should be used.

Decanting refrigerant

Special care must be taken not to overfill the cylinder, and to use only those which are free from any contamination by oil, acid or moisture.

Do not mix grades of refrigerants. Always use a cylinder for the specific refrigerant for which it is designated.

Removal of refrigerant from sealed systems

This can be achieved by fitting a line tap valve to the system and connecting to a recovery cylinder.

Removal of contaminated refrigerant

Contaminated refrigerant which may have resulted from a compressor burnout or a water cooled condenser leak must not be used to recharge the system. It must be recovered and sent away for reprocessing or disposal.

It should be decanted into special recovery cylinders available from the manufacturers or suppliers of refrigerants. Never use service cylinders for reclaiming contaminated refrigerants.

When removing refrigerant charges or decanting from systems, adequate protective clothing and goggles must be worn. All safety procedures must be observed.

It is advisable to include an isolating hand shut-off valve at the cylinder end of the charging line to minimize purging. Ensure that the valve is open before discharging from the system. Use charging lines without the Schreader inserts.

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