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 .
AUTHORISED PRACTITIONERS AND FLAMMABLE REFRIGERANTS , R290 AND R600A
By Barney Richardson
I have previously written about the training providers setting themselves up for training in the hydrocarbon ( HC ) refrigerants . This is mainly for R290 , which is a propane gas , but also for R600a which is an Isobutane .
Both gases are very similar and require special care when working with these flammable refrigerants . Both these refrigerants are classified by ASHRAE as A3 with high flammability and low toxicity .
Class A signifies a refrigerant where toxicity concentration is less than 400 ppm .
Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit ( LFL ) of less than or equal to 0.10 kg / m 3 at 21 ° C and 101kPa or a heat of combustion greater than or equal to 19kJ / kg .
R600a is used and has been used in domestic and small refrigeration units for a number of years . But now R290 is becoming more attractive in refrigeration systems and is found in a variety of applications including commercial refrigeration and water chillers . Soon we will see this refrigerant in room air conditioners
The International Electrotechnical Commission in June 2019 published IEC 60335-2-89 , edition 3.0 ; this raised the charge limit for A3 flammable refrigerants in self-contained units to 13 times the lower flammability limit for R290 refrigerant . This therefore allows the refrigerant charge to increase from 150g to 500g .
The low flammable refrigerants classed as A2 and A2L such as R32 will also see an increase in the charge limit from 150g to 1 200g .
The IEC working group has also proposed an update to standard EC 60335-2-40 for room air-conditioning units and systems .
WHAT DOES THIS MEAN FOR US HERE IN SOUTH AFRICA ? As mentioned before , the Western Cape Provincial Government has an initiative to concentrate on R290 as a refrigerant in conjunction with German support via the Bavarian State Government . An RAC Project is being put together and is in the planning stage for skills training in hydrocarbon refrigerants use .
An Authorised Refrigerant Gas Practitioner registered with SAQCC Gas has a specific category designated category A2 for practitioners who are semi-skilled for refrigeration work . These category A2 Authorised Refrigeration Gas Practitioners are assessed in their particular skill for domestic refrigerators charged with R600a .
Practitioners are trained in particular on the safety aspects of a flammable gas and to ensure procedures are followed in particular on domestic refrigerators . For this equipment , spark proof switches must be used particularly when original components are replaced in a repair .
As the use of hydrocarbon gases becomes more common and used in different applications , the skills requirement will be more important particularly when considered with the greater charge limit proposed above .
As mentioned above , the International Electrotechnical Commission has released a proposal to update the safety standard for room air-conditioning units and systems including heat pumps using flammable refrigerant . This proposal will allow for larger charges of flammable hydrocarbon refrigerants like R290 in these applications . This means that Installers will soon have to acquire the skills for safety standards required when working with hydrocarbon refrigerants like R290 . RACA
www . hvacronline . co . za RACA Journal I November 2020 43