Behind the Low-GWP Refrigerant Transition: R-454B and A2Ls

In 2010, the HVAC industry transitioned from ozone-depleting hydrochlorofluorocarbon (HCFC) refrigerants like R-22 to hydrofluorocarbon (HFC) refrigerants such as R-410A. Now, it will make a similar transition to a new generation of low-GWP (global warming potential) refrigerants. The available low-GWP refrigerants fall into a category called "A2L," which refers to a class of refrigerants with low toxicity and low flammability. The fact that A2L indicates low flammability has some people concerned, and we want to help dispel any misconceptions.

The first thing to understand during this transition is that not all flammable refrigerants are the same. This makes it an opportune time to solidify our understanding of A2L refrigerants such as R-454B, and how they differ from other flammable refrigerants.

• A2L refrigerants are nothing new. In fact, they are currently used today in systems you may already be familiar with, like room and window air conditioning units. They are just now being allowed in larger-size units, which is an industry first.
• Flammability classes are not created equal. However, the differences in flammability properties of various refrigerants are significant. For example, R-454B is considered an A2L category lower flammability refrigerant and its flammability properties are significantly different than refrigerants in higher A2 or A3 flammability classes, which include propane blends. Check out the video to see how the flammability properties of different refrigerants compare.
• Safety protocols are largely the same. With this lower-flammability A2L classification, many of the best practices commonly used with R-410A refrigerants are still applicable with R-454B. We have developed service and installation training to help Luxaire® partners in the field during this transition. Talk with your technical services rep for more information.

Opteon^TM XL41 (generically known as R-454B) has been selected as the refrigerant replacement for R-410A in all Luxaire® residential, light commercial and commercial ducted HVAC applications. Why?

• R-454B has the lowest GWP with the best outlook for long-term viability. This reduces the likelihood that another refrigerant transition will be necessary with a future regulatory change.
• R-454B temperatures and pressures are much like R-410A, resulting in similar system designs and a reduced learning curve for equipment service technicians.
• R-454B provides up to a 78% reduction in global warming potential (GWP) while still enabling the opportunity for optimized unit efficiency and decreased energy use.

Legal disclaimer: Recommendations above are based on current guidance from regulatory bodies but are subject to change, and HVAC trade professionals should make decisions based on their own research, training and compliance standards.