Pretty much anyone involved in any capacity in HVACR is aware that the world of refrigerants has begun its next evolution. At present, the ultimate and ideal vision is for new equipment to be charged with sustainable refrigerants like hydrofluoroolefins (HFOs), which offer zero ozone depletion potential (ODP) and a global warming potential (GWP) that is significantly lower than the legacy products they replace. I say “at present” because you can never be 100% sure with evolutions. Inherent in evolutions is the possibility that something even better will be discovered or innovated that raises the bar on that ideal. Or an unforeseen challenge or development may arise that takes that ideal down a half step for the sake of practicality and ensuring that, at the end of the day, the changes deliver the greatest possible benefit to the greatest number of people. But, for the most part, in terms of refrigerants, the industry is headed toward an HFO-centric — and more specifically, a low-toxicity, low-flammability A2L-centric — future. In a world that continues to demand and expect more, the criticality of these solutions is undeniable because of their environmental and performance advantages over existing alternatives.

Evolutions take time, and to be successful, they must be done strategically and realistically. This is why when people ask, “Dr. Chuck, when do you think the industry will be fully transitioned to next-generation HFO-based refrigerants?” I respectfully tell them that I don’t have an answer. The other reason I don’t give a definitive answer is because “deadlines” can cause panic. Imagine you own an HVAC shop with 100 or more customers operating on systems charged with R-22 or its common alternative, R-410A, a hydrofluorocarbon (HFC). Then someone tells you everything will be HFO-based by a certain date. Whether that date is a few years or several decades away, the thought of what your business would need to do can be overwhelming.

The more productive and reassuring way to gauge the current refrigerant transition timeline is to look at history. This is not the first time the industry is experiencing such a transition. In the early years, ammonia, sulfur dioxide, and carbon dioxide were common refrigerants —at least until growing concerns over health, safety, and efficiency drove science to come up with something better. That solution came in the form of R-12, a chlorofluorocarbon (CFC), and R-22, a hydrochlorofluorocarbon (HCFC) — both familiar under the brand name Freon.

For generations, these refrigerants were embraced because they addressed safety concerns and solved several performance issues of their predecessors. R-12 and R-22 enjoyed a good run until a hole was discovered in the ozone layer, putting CFCs and HCFCs on the spot. Once again, chemists went to work to develop a better solution, focusing the industry on HFCs, which offered excellent performance properties and zero ODP. The 1987 Montreal Protocol worked to accelerate the adoption of HFC refrigerants by implementing a global phasedown of HCFC production and consumption. While HFCs helped fix the ozone layer, they were later found to quietly contribute to a rise in global warming.

The need to innovate beyond high-GWP refrigerants — and the solution found in the development of HFOs — is the impetus behind the transition we find ourselves in presently. These new HFO refrigerants offer stellar performance properties and zero ODP, and they have a significantly lower GWP than the products they replace. As ratification of the Kigali Amendment to the Montreal Protocol took effect, a gradual reduction in HFC consumption and production was set in motion. In the U.S., the American Innovation and Manufacturing (AIM) Act also supports this strategic transition. This past January, the industry experienced a significant initial reduction in the HFC phasedown under the AIM Act. The next phasedown step will require an additional 30% reduction in HFC production and consumption, starting Jan. 1, 2024.

FIGURE 1. The Biden administration set a timeline for the phasedown of HFCs as part of the American Innovation and Manufacturing Act.
Images courtesy of The Chemours Co.

History demonstrates the industry has a track record of successfully transitioning to new refrigerants. Many of us have been around long enough to have experienced at least one, if not more, of these transitions — so we know that, while there may have been challenges, the end results were positive. For example, the transition from R-22 to R-410A and similar HFCs raised concerns, because R-410A operated at a higher pressure. But the industry got past that with proper training and by adhering to best practices. Currently, there is concern about A2Ls being mildly flammable. Here again, safety education and concentrated efforts to train technicians are proving effective.

Through all our refrigerant transitions, the industry is still going strong. In fact, with each transition, we’ve innovated and invested to bring about better solutions. This is where we find ourselves currently with HFOs. Moreover, by taking a systematic, robust approach to phasing down high-GWP refrigerants, the HVACR industry takes a leading role in creating a healthier, sustainable planet.


Our industry and our world operate under the influence of several megatrends that continue to put focus on emerging next-generation refrigeration. One is fast-tracking the move toward decarbonization. Another is circularity — that is, maximizing use of renewable energy and minimizing waste through reclaiming and the infinite reusability of materials. Third is the shortage in skilled workforces, which makes it imperative for businesses to ensure the labor they have possesses a diversity of capabilities. In the case of refrigerants, for example, this means having technicians who can work with HFCs, Class A1 and A2L HFOs, and even CFCs and HCFCs. Lastly, from wholesalers to retailers to end users, there is increasing demand not only for products that support a greener environment but also for assurance those products are manufactured responsibly.

These megatrends will continue to influence the refrigerant transitions. However, so will the business of HVACR. Refrigerants and equipment operating with them need to support more than the environment. They need to perform well by cooling effectively and efficiently. They need to minimize energy consumption, offer low or no toxicity, and maximize safety for the people working with them. Price points need to make them accessible to most businesses, and the supply chain needs to be able to support demand. Lastly, solutions need to offer the versatility to support everyone from mom and pop shops to global corporations.

All these needs can work hand in hand with the megatrends, but it requires striking the best possible balance of all the factors. This is where continual refinement of refrigerant chemistry becomes critical. At Chemours, this process started with the first products in our Opteon line of HFO-based refrigerants. HFOs feature zero ODP and lower GWP values than the HFCs they are designed to replace. Chemours Opteon XP products, such as Opteon XP40 (R-449A) and Opteon XP10 (R-513A), are nonflammable refrigerants offering retrofit solutions for replacing higher-GWP legacy HFCs, such as R-404A, while maintaining an A1 safety listing.

From here, chemists continued to develop ways to further lower GWP and maximize performance, operating efficiency, and energy savings. This resulted in the Chemours Opteon XL line. These products have an ASHRAE and ISO Safety classification of A2L and deliver very low GWP solutions. Opteon XL10, for instance, has a GWP of less than 1.

Due to their low flammability, A2Ls are used in new equipment only. And with their lower GWP, A2Ls are being adopted more and more in refrigeration systems around the world, chosen for their ability to support regulatory compliance as well as performance attributes. These include increased system efficiency, lower energy consumption, low toxicity, and improved safety for use in a broad range of applications. In addition, A2Ls can lower operating costs throughout the life cycle of the refrigeration equipment.

The Path Between Now And Then And Beyond

We know that this transition is headed toward an industry fueled by A2L refrigerants, but a question remains: How and at what pace will we get there? The integration of several factors, all of which have already started to come into play, helps create our road map.

Current equipment

Even though OEMs have not manufactured equipment for R-22 for quite some time, there are plenty of systems in operation that still use the refrigerant. However, due to regulations, existing supply to service this equipment can only be sourced from reclamation or existing stockpiles. Many R-22 systems that have been consistently and properly maintained still have decent life in them. However, these are entering the final stage of their life cycle. Given their age plus an uncertain supply in the refrigerants they require, servicing R-22 systems will become increasingly challenging and costly. When it comes to R-12, there is very little demand, because most equipment has aged out of being operational. As these trends continue, we’ll see more and more retrofits and total system replacements incorporating the use of HFOs.


I often say, “The gas follows the equipment.” We can manufacture all the HFO refrigerants we want, but they’ll be inconsequential if there’s no equipment to make use of them. Earlier this century, most major OEMs were beginning a transition of their own by investing in the qualification and production of new components and systems charged with HFOs. Initially, OEMs focused heavily on equipment using class A1 (nonflammable) refrigerants such as R-449A and R-513A as strong replacements for the higher-GWP R-404A and R-134A. Today, components and refrigerants are readily available to support members of the industry in transitioning, via gas retrofits, from HFC-charged systems to operating with HFOs.

While retrofits currently represent the best transition solution for many HVACR businesses when considering available budget, time, workforce training, and other factors, most OEMs have now geared up for industry players who are ready to invest in new equipment using the new-generation A2Ls. For example, Opteon XL41 (R-454B) has already been selected by several OEMs, including Carrier, Johnson Controls, and Rheem. Some expect this equipment to start rolling out in early 2024. Here, it’s important to remember OEMs have dozens of SKUs, so they, too, will follow a manageable process for rolling out new products based on market need.

FIGURE 2. This chart shows the phasedown schedule.

Willingness and readiness

Because we are managing the transition through a phasedown, not an immediate phaseout, willingness of industry members to accept and become comfortable working with the mildly flammable A2Ls will also help determine how quickly we reach the finish line. This is why companies like Chemours and others in the industry are implementing strong educational and training programs that increase acceptance and accelerate adoption. The transition is coming, so you can expect to see more technicians becoming prepared.


Refrigerant manufacturers also have multiple interests to support, including environmental commitments, regulatory compliance and their own bottom lines. Considering how the AIM Act phasedown is structured, it will be more economically strategic for manufacturers to produce larger quantities of HFOs while tapering off HFCs. Plus, there’s the rule of supply and demand. As more HFC-charged equipment falls out of use, manufacturers need to avoid having stock sitting on the shelves. In addition, refrigerant manufacturers such as Chemours have been immersed in this transition for over a decade and understand our responsibility to encourage use of HFOs —especially A2Ls — and ensure there is supply to meet demand. This is why, based on intelligent predictions of market needs, Chemours recently invested in expanding our Opteon capacity production by approximately 40%.

One final note on supply. If you continue to use and service HFC-charged equipment, beware of counterfeit refrigerants and illegal imports. As phasedowns progress and reduce the supply of available HFCs, the risk of illegal materials coming into the country increases. To an extent, we saw this happen when HCFCs were phased out in the U.S. Plus, after HFC phaseouts began in the European Union in 2015, authorities seized hundreds of metric tons of illicit HFCs in 2019 and 2020. The risk with illegal imports is that you just don’t know what is in that canister. They are often mixed with other substances and contaminants, not only diminishing system performance but also making them dangerous to the people who use them and the equipment they go into. Always get your supply from a trusted source.

How to Prepare

There is no single plan to prepare for the refrigerant transition. The options are as varied as the roles played by members of the industry. However, taking the following into consideration can help guide what steps you take, and when you take them, to ensure you are best prepared.

  • Your corporate responsibility mission. The systems you use, sell or support should be charged with a refrigerant that is in line with your commitment to the health and sustainability of the planet.
  • What matters to your employees. Consider the people working for you. Will pride in working for a green company impact productivity, job satisfaction and retention?
  • Customers and clients. Comfort, safety, being “green and clean.” All come into play in attracting and retaining customers and clients.
  • Your client’sbottom line. Newer-generation refrigerants and the systems that work with them have been developed to lower energy consumption.
  • Market awareness. Keep an eye on supply trends and make sure the systems you use can be supported based on refrigerant supply.
  • Technician training. While A2Ls may look, feel, and work like R-410A or R-404A, there are key differences due to their low-flammability rating. Now is the time to ensure technicians are properly trained to work with A2Ls as well as their predecessors.


The concept of refrigerants in transition should be an exciting one for all of us because of where we are headed. The next-generation A2Ls that will become the industry standard combine innovative chemistry and sustainable technology to help our world live better. This transition will lead to a healthier, sustainable planet. The transition to A2Ls also offers tremendous opportunities for the industry in every application, covering the entire cold chain to commercial and residential air conditioning to industrial cooling and more. It provides customers and clients with higher-performing, safer and greener solutions. Lastly, because the transition is happening through a strategic, manageable process, it supports individualized solutions, business growth and a thriving industry.