R32, R452B, and R454B replacements for R410A are all classed as 2L: mildly flammable. These A2L refrigerants offer only moderate limitations in charge for direct expansion systems and no limitations for indirect expansion systems such as chillers, when located outdoor or in technical rooms.
R-454B is a blend and it must be charged like R-410A. The components of R-454B leak at different rates, while R-32 is a single component refrigerant and can be added in the field without concern of composition change.
R32 falls into the “lower flammability” or Class 2L "mildly flammable" category. Under ISO 817, any refrigerant and air mixture that is capable of self-propagating a flame falls into one of the three flammable categories.
A2L refrigerants like R-454B are considered mildly flammable, difficult to ignite, and have a low flame speed.
A3 refrigerants, like propane (R290) and isobutane (R600a), are highly flammable and are considered even more environmentally friendly than A2Ls. Class A3 refrigerants include R-170 (ethane), R-290 (propane), R-600 (butane), and R-600A (isobutane).
The A2L subgroup is made up of refrigerants with a low flammability. Flame propagation speed is low, less than 10 cm/s. These refrigerants are already playing a significant role as we move away from the old high-GWP HFCs.
R-22a is a hydrocarbon refrigerant blend with primary components including flammable substances such as propane and butane. In some cases, it may also contain small amounts of other hydrocarbons or a pine-scented odorant. This refrigerant is a highly flammable, colorless gas that is heavier than air.
Additionally, both R32 and R454B are classified as mildly flammable (A2L), so proper training and safety protocols for handling these refrigerants are necessary. Key Takeaway: R32's single-component nature simplifies maintenance, while R454B requires careful handling to maintain its blend integrity.
Changes to the Dangerous Goods Legislation, effective in 2021, has new categories for A2L refrigerants. R32 is a synthetic greenhouse gas. If released to the atmosphere it can contribute to climate change. R32 is a flammable refrigerant.
The auto ignition temperature for R-454B is 928 °F (498 °C). The surface temperature limit for R-454B is 1290 °F (700 °C)4. For comparison, a cigarette burns at 752-1652 °F (400-900 °C), depending upon puffs of air drawn through the cigarette.
Disadvantages:Different from R22 and R410A, the R32 is slightly flammable. But combustion will not occur unless three critical conditions are met, refrigerant concentration, constant oxygen, and an ignition source. In real practice, it's hard to meet all the combustion conditions.
No, R-454B does not contain propane. It is a blend of R-32 (68.9%) and R-1234yf (31.1%), both of which are fluorinated refrigerants, not hydrocarbons like propane.
MULTICOOL-HC32 is a high purity mixture of propane R290 and R170 ethane. It is a refrigerant with a reduced global warming potential (GWP). It is designed to replace R410a and R32 in most stationary residential and commercial air conditioning systems.
It is a hydrofluorocarbon (HFC) with a low global warming potential (GWP) and is considered a more environmentally friendly alternative to older refrigerants such as R22 or R410a. R32 has a good thermodynamic performance and is flammable, which makes it safe to use by a qualified professional.
Beginning in late 2024, R454B will replace R410A in all newly manufactured HVAC systems to meet these environmental goals. This change is in line with the EPA's SNAP (Significant New Alternatives Policy) program, which ensures that the alternatives meet both environmental and safety standards.
In the first half of 2024 we'll phase out our R-410A dedicated models and introduce -01 refrigerant versatile models, compatible with both R-410A and R-454B refrigerants.
R-454B has a GWP of 466, which is 78 percent lower than R-410A's GWP of 2088. R-454B is non-toxic and mildly flammable, with an ASHRAE safety classification of A2L.
Flammability of R32 has 80% burning velocity less than R290 and slightly flammable when compare with R410A. Although, R32 discharge gas temperature is higher than R410A around 20°C and this can damage compressor's motor at some heat pump condition especially at high compression zone.
LG leads the way with R32 refrigerant
Now builders can take advantage of the many benefits of R32 refrigerant for their homeowners with LG solutions and technologies as a refrigerant that reliably keeps homes warm and cool.
Trane is phasing in the transition to R-454B in 2024, starting with the adoption of R-454B refrigerant in its residential products, beginning with the XR15 SEER2 heat pump.
Will R-454B work in existing R-410A systems? No. R-454B is NOT a drop-in replacement for R-410A. Although many of the characteristics of R-454B are similar to R-410A, the use of R-454B is restricted by code and regulation to systems for which it was specifically designed.
Like its predecessor R-410A, R-454B poses no danger to the ozone layer. These advantages that led Lennox to adopt R-454B as our primary 2025 Compliant Refrigerant for whole-home systems and R-32 for our ductless mini-split systems.
Common examples of flammable refrigerants include R-290 (Class A3), R-152a (Class A2), and R-32 (Class A2L).
Notice that R-11 has the highest ODP of 1. R-11 is the most destructive refrigerant and we compare all other refrigerants against it. Note also that R-11 is a CFC, which we have already discussed is the most destructive refrigerant to ozone.