Refrigerant Classification
Source Image: https://www.southernphc.com/articles/what-you-need-to-know-to-handle-a2ls-sately/
At Carlson & Stewart Refrigeration, Inc. we strive to design and install superior commercial and industrial refrigeration systems. One of the key components to delivering on this is selecting the best refrigerant for the desired application as well as keeping up to date on any potential changes or limitations to access certain refrigerant types, specifically with the refrigerant phase outs associated with the AIM Act. A few of us here at Carlson & Stewart Refrigeration, Inc. have already talked about some of the specifics of the AIM Act and the refrigerant phase outs coming, so I won’t spend any more time on that. Instead, I wanted to get into what makes the new A2L class of refrigerants different (or maybe not so different) from the A1 class of refrigerants that we are currently using.
Refrigerants are categorized by their toxicity as well as their flammability in accordance with ASHRAE Standard 34. These classifications are A1, A2, A2L, A3, B1, B2, B2L, & B3. The “A” in the naming convention indicates that refrigerant is non-toxic while the “B” indicates that refrigerant is toxic. The “1”, “2”, and “3” indicates how flammable the refrigerant is with “1” being non-flammable and “3” being highly flammable. Ammonia is a natural refrigerant that is categorized as a B2L refrigerant which indicates that it is a toxic refrigerant with some flammability level slightly above 1 while Propane is a natural refrigerant that is categorized as an A3 which indicates it is a non-toxic refrigerant that is highly flammable. Some common existing refrigerants such as R404a, R448a/R449a, and R410a are classified as A1, which indicates that these refrigerants are both non-toxic and non-flammable.
This leads us to the new A2L classification of refrigerants. These refrigerants are expected to take the place of the A1 refrigerants for new systems. With this change, there will be some detection, monitoring, isolation and/or ventilation tactics that need to be installed because of the low flammability potential of these new refrigerants. As shown in the image below, the A1 and A2L class refrigerants have very similar flame propagation, where A1 has a less than 90° flame propagation while the A2L has a greater than 90° flame propagation, I’ll be it slightly greater than but that is the big difference. Then the A3 refrigerant is well beyond that 90° flame propagation which is why it has the classification of highly flammable.
For any questions on the different classifications of refrigerants and how this may affect your operation, please contact Carlson & Stewart Refrigeration.