By Barney Richardson
This manual, introduced at the beginning of 2022, provides an understanding of the Pressure Equipment Regulations (PER), SANS standards and good engineering practice in refrigeration.
While the use of the F-gases continues through the phase-out of HCFC and HFC refrigerants, the appearance of flammable refrigerants has changed how we work.
A worldwide phase-out of the HCFC refrigerants is moving ahead with approximately a 45% reduction in South Africa of HCFC gases to date. This was mainly achieved by the foam blowing industry with quick phase-out of R141. The refrigeration and air conditioning industries need to catch up on the phase-out of the use, in particular, of R22.
South Africa as partner in the Kigali amendment will soon start the HFC phase-out plan for HFC consumption.
Practitioners must be aware of safety aspects and changes in design concepts with the phase-out of HCFC and HFC refrigerants. The new use of flammable refrigerants such as R290 and R600a in small refrigeration units and R32 in room air conditioners places a responsibility for safe work procedures.
The procedures and methods used for the common refrigerants also apply to flammable refrigerants classified as A2L, A2 and A3. It is just that extra care must be taken when working on a unit using these flammable gases. In all cases the prevention and detection of gas leaks from joints and connections is important.
Full safety checks and procedures must be followed at all times and for all refrigerants, even when they are classed as low toxicity or non-flammable. For safety reasons and compliance with the PER an installer must be a registered practitioner and be competent when working with and handling flammable refrigerants.
A fire extinguisher either with dry-powder or with CO2 must be available close to the work area.
As mentioned in a previous column, there are certain factors to be considered and these are worth stating again. When doing service and repair, a two meter flame hazard zone in all directions of the outdoor condensing unit and indoor refrigeration or air conditioning unit is required. If the area is a confined space like a plant room the area must be well ventilated. These are the same procedures that apply to the common refrigerants and will still apply to the three classification levels for flammable refrigerants.
Then there is the refrigerant concentration limit (RCL), (ASHRAE standard 34 – 2019) this limit in air is determined in accordance with this standard and intended to reduce the risks of acute toxicity, asphyxiation, and flammability hazards in normally occupied, enclosed spaces. This refers to the amount of refrigerant allowable in a space if there is leakage. With an A2L refrigerant like R32 which has a lower flammability, the concentration can be calculated.
It is advisable before starting any service, maintenance, or repair work on a unit or system an assessment should be done:
- Check what the history of servicing has been
- Check the classification of the refrigerant charge into the unit or system
- Confirm that there is no source of ignition from an electrical power tool present
- There are no flammable materials are stored close by
- Welding only takes place when all gas is recovered and with the greatest of care
- Ensure a dry-powder or with CO2 fire extinguisher is available
- Have visible safety signage in place
- Ensure that the work area is adequately ventilated
- Ensure that a flammable refrigerant detector is present
- Always wear recommended personal protective gear(PPE).
Flammable refrigerants are with us now and will become more widely used for refrigeration and air conditioning. All practitioners must be prepared and registered as competent to work with these gases.
About the author
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.