Responsible Refrigeration
BARNEY RICHARDSON
Barney Richardson is the director of South African Refrigeration and Air Conditioning Contractors Association ( SARACCA ) and sits on various other boards within the HVAC industry , including the South African Qualifications and Certifications Committee for Gas ( SAQCC ) Gas .
RECOVERY OF REFRIGERANT
By Barney Richardson
There is a lot of talk about this topic relating to both air conditioning units and refrigeration plants . But what does it mean ?
To prevent overfilling , cylinders should not be filled to more than 80 % of their internal volume and capacity mass as shown on
the cylinder .
Refrigerants are an important part of cooling in air conditioning and refrigeration as part of the heat transfer process . Recovering the refrigerant in a safe and efficient way reduces the amount of harmful HFC and HCFC refrigerants entering the atmosphere and environment .
Then there is the Montreal Protocol and amendments alongside the regulation published by the Department of Environment Forestry and Fisheries . These all emphasise regulation of the release of refrigerants . This is all beneficial to the environment through preventing global warming and Ozone depletion .
Before recovering refrigerant and before starting the recovery machine , do the following :
Be aware of the type of machine , does it recover only vapour or will it recover vapour and liquid ? Check the manufacturers ’ procedure for operation . This is important because you don ’ t want liquid to enter the compressor .
Examine the service valves . Are they are open or closed ? Purge the connecting hoses , then recover any refrigerant that may still be in the machine . A new filter drier must be used for
each new refrigerant recovery operation . The service / recovery cylinder must be evacuated so that it is empty before starting the
Barney Richardson transfer of refrigerant into the cylinder . Also check the oil in the compressor . The oil should have been changed after the previous recovery .
Qualified practitioners use these recovery machines before starting a repair or modification as part of maintenance on an air conditioner or refrigeration system . The refrigerant recovered into a service cylinder must be checked for contamination before reuse . The refrigerant suppliers offer a testing service .
Only a recovery machine must be used to recover refrigerant from a refrigeration circuit . The release of refrigerant is wrong and illegal . A vacuum pump cannot be not used for recovery of refrigerant and must only be used to evacuate a refrigeration system in preparation for pressure testing and charging with the recovered refrigerant or new refrigerant .
Refrigerant recovery machines are used to remove refrigerants from refrigeration equipment in compliance with standards . The practitioner can recover refrigerant from the refrigeration circuit into the service cylinder and when the repair is complete , recharge the client ’ s equipment with the recovered refrigerant provided it is not contaminated .
To prevent overfilling , cylinders should not be filled to more than 80 % of their internal volume and capacity mass as shown on the cylinder . See the photograph for a typical service cylinder with the filling capacity for common refrigerants . A scale should always be used to weigh the cylinder while filling , to ensure that over-filling does not happen .
Should the cylinder become over-filled , the internal pressure can increase with even a small rise in temperature and create a dangerous situation with possible bursting or explosion that will cause serious damage and injury .
Where the refrigeration system is large , the smaller recovery units may not cope with the volume of refrigerant and recovery could take hours . A Gas offers a service for large capacity refrigeration systems from which refrigerant can be recovered efficiently and quickly . RACA
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RACA Journal I January 2021 www . hvacronline . co . za