www . refrigerationandaircon . co . za RACA Journal I November 2024 31
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GRANT LAIDLAW
Grant Laidlaw is currently the owner of the Air Conditioning and Refrigeration Academy ( ACRA ) in Edenvale . He holds a Bachelor of Business Administration and an associate degree in educational administration . He has a National Technical Diploma and completed an apprenticeship with Transnet . He has dual-trades status : refrigeration and electrical . He has been involved with SAIRAC for over two decades and served on the Johannesburg committee as chairman and was also president between 2015 and 2018 . Currently he is the SAIRAC national treasurer .
WELCOME TO THE SOLUTIONS PAGE
By Grant Laidlaw
Many people ask for assistance in the understanding of theoretical and practical aspects of the industry . We are going back to basics as I have questions coming in that indicate that the basic understanding necessary to work in the industry is not in place .
Andre asks : Hi Grant . We attended the Dreosti Lecture which was very interesting , and we seem to be moving forward with refrigerants with low global warming potential and no ozone depletion potential . However , what about all the split units out there using R22 and R410a - even R32 . What are we going to do once these units are removed ? All the refrigerant , oils and other contaminants will end up polluting our environment . Can you give some input around the problem and how to deal with this issue . Thanks .
Hi Andre . Yes , a very interesting question . Let us give this a name – ‘ End of life ’ – and start by looking at the impact to the environment when improper end of life procedures are not followed .
Looking at an average R22 split unit air conditioner we find that the HCFC- R22 will release 0.08 ODP kg and a considerable amount of carbon dioxide .
Metals and other rare materials , as found in fridges and air conditioners , are depleting raw materials and should thus be part of the circular economy .
The most critical and known hazardous substances of fridges and air conditioners are the refrigerants HCFC-22 , HFC-134a , R-410A , HFC-32 , other HCFC or HFC-based mixtures and ammonia solutions containing chromium-vi . The most important critical blowing agents found in refrigerators are CFC-11 and HCFC-141b . Other hazardous substances are : mercury , printed circuit board components , lead , cadmium , hexavalent chromium and PBB and PBDE in plastics used as flame retardants .
The benefits of proper dismantling include the protection of the ozone layer and climate system ( global warming ) by not releasing toxic gases into the ecosystem , saving of depleting raw materials and the economic benefits from the resale of valuable materials .
Aside from the damage to the environment caused by improper dismantling we find considerable negative health effects on humans which can be avoided .
• Lead is released when heated and the effect on humans are kidney damage as the heavy metal accumulates in body tissue through making contact without the necessary protection .
• The Cadmium used in colouring of plastic casing as well as contacts when burnt or heated up can cause brain damage and even death .
• Mercury found in switches , contacts and sensors when heated or shredded releases nerve toxin which is deadly in small doses and it is also pollutes water , soil and air .
• Hexavalent chromium found in plating and in colouring of plastic casing as well as in ammonia refrigerants when heated up as well as when plastics are melted and burnt causes cancer . Hexavalent chromium is also used as an anticorrosion agent .
• Both the flame retardants polychlorinated biphenyl ( PCB ) and poly-brominated biphenyl ether ( PBDE ) used in plastic casing and housing , plastic wiring and cables and printed wire boards when burnt or shredded cause cancer .
“ Other hazardous substances are : mercury , printed circuit board components , lead , cadmium , hexavalent chromium and PBB and PBDE in plastics used as flame retardants .”
www . refrigerationandaircon . co . za RACA Journal I November 2024 31