RACA Journal I May 2026 www. refrigerationandaircon. co. za 37
SUPPORT voices
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 understanding theoretical and practical aspects of the industry. I will endeavour to enlighten. We are going back to basics as I have questions coming in that indicate that the basic understanding necessary to work in industry is not in place.
All images supplied by Grant Laidlaw
This is a continuation of the question in RACA Journal April: Clement asks: Hi Grant, I see that in the air-conditioning space we have some technicians who, when working on R32 units they remove the R32 and use R410a. They do not know how to deal with the safety aspects of R32. Can you please discuss the use of flammable refrigerants?
Hi Clement, I have looked into R290 in the previous issue and will now expand on this topic. Working with flammable refrigerant and cylinders requires strict safety procedures due to their high flammability. The primary danger is fire or explosion if the gas leaks and finds an ignition source. Proper training and adherence to safety protocols are critical for anyone handling these materials.
Flammable refrigerants can only pose an explosion risk if the concentration is between the lower and upper flammability limits
( LFL and UFL). When following the safety standards, the concentration of leaked refrigerant will not get above LFL where ignition sources can ignite it, even in extreme situations. The necessary safety precautions and system design depend on the refrigerant charge.
Should a national standard not suffice, safety standards should be implemented as follows: For example: we would use the national standard SANS 10147, but one can reference the international Standard EN378.
In general ignition, sources inside the equipment must be avoided. Most hydrocarbons are non-toxic, with the main safety risk coming from their flammability, although gaseous hydrocarbons are heavier than air and will displace air within low lying areas and in the lungs.
Only authorised persons certified for the installation and maintenance of refrigeration systems containing flammable refrigerants should engage in installation and maintenance.
Flammability and classes of refrigerant The above table illustrates the classes of refrigerants and describes their flammability.
Refrigerant charge limitations The limiting factor associated with the use of hydrocarbon refrigerants is the refrigerant charge size, the occupancy category and the room size.
RACA Journal I May 2026 www. refrigerationandaircon. co. za 37