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The US just passed a law to restrict climate warming refrigerants. Here’s how it’s going to work.

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Jay Stein's picture
Senior Fellow Emeritus E Source

Jay Stein, a Senior Fellow Emeritus affiliated with E Source, is one of America's leading energy technologists. Over the course of his over 40-year career he has played numerous roles, including...

  • Member since 2006
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  • Jan 26, 2021

Buried in the 5593 page COVID relief and omnibus spending bill signed into law on December 27th, is the most significant piece of US national climate legislation in years. Titled the American Innovation and Manufacturing (AIM) Act, it restricts the production and consumption of hydrofluorocarbon (HFC) chemicals, the most commonly used refrigerants in air conditioners, heat pumps, refrigerators, freezers, and heat pump water heaters. To get a sense of the significance of this new law, we can turn to Project Drawdown, a nonprofit organization that bills itself as the “world’s leading resource for climate solutions.” In a recent analysis, the organization ranked switching from HFCs to alternative refrigerants in the top-ten of its extensive list of 76 climate solutions. Furthermore, restricting HFC refrigerants is going to affect both the cost and efficiency with which we cool buildings, refrigerate food, increasingly heat water, and numerous other daily processes.

HFCs were introduced in the US in the early 1990s as a substitute for chlorofluorocarbons (CFCs), which, at the time, were the dominant refrigerants. CFCs were phased out by the US EPA because they were damaging the ozone layer. Replacing CFCs with HFCs was largely successful, as they were widely adopted, and the ozone layer is slowly recovering. Like virtually all technological solutions, substituting HFCs did result in at least one unintended consequence. HFCs are potent greenhouse gases, exhibiting hundreds to thousands of times greater climate impact than carbon dioxide. In response, most developed countries are on their way towards curtailing HFC production and consumption in accordance with an international agreement forged in 2016, and signed by the US as well as nearly 200 other countries. It’s taken until now for the US to finally incorporate that international agreement into law, and here’s how it’s going to play out.

A phasedown, not a phaseout

In 1992 when the EPA issued rules regarding CFCs, the agency called for them to be completely phased out by 2000. The AIM Act is different. As with CFCs, HFC production and consumption will be gradually reduced in steps, but unlike CFCs, HFCs will not be zeroed out. Instead, the Act calls for the annual climate impact of HFC production and consumption to be just 15% of the average for the years 2011 through 2013 (with a few minor adjustments) by the year 2036. In other words, HFC production and consumption will be greatly reduced in steps, but not eliminated, over the next fifteen years.

The AIM Act regulates annual HFC climate impact, not quantities

To phase down HFCs, the EPA will issue annual production allocations and establish an exchange program for manufacturers. In setting the baseline and the allowances, the Aim Act weights HFCs by a technical metric named global warming potential (GWP), which is the multiple of how much more atmospheric heat a given refrigerant traps than carbon dioxide. For example, the GWP of R-410A, the current standard HFC air conditioner refrigerant, is 1924. That means that if a pound of R-410A were to leak into the atmosphere, it would trap nearly 2,000 times as much heat as a pound of carbon dioxide. Each HFC refrigerant features a unique GWP, and the AIM Act regulates the product of the quantity of HFCs produced and consumed, multiplied by their individual GWPs. To meet the requirements of the AIM Act, manufacturers could use less HFC refrigerants, lower-GWP HFC refrigerants, or some combination of the two. In essence, the Act is phasing down the climate impact of annually produced and consumed HFC refrigerants.

The EPA is expected to ban the refrigerants currently used in air conditioners

The AIM Act gives the EPA the power to regulate HFCs for specific applications and types of equipment, but it’s impossible to know for sure what the EPA will do with that power right now. The passage of the AIM Act coincides with a change of management for the agency. Years ago, the EPA attempted to ban one of the most widely used HFCs for use in chillers, retail food refrigeration, and household refrigerators. Those rules were vacated by the courts in 2019. Look for the EPA to reinstate them in some form, if not their original form. As for home and light commercial air conditioners, the California Air Resources Board recently adopted regulations limiting refrigerants used in newly manufactured equipment to less than 750 GWP starting January 1, 2025. If the EPA follows California’s lead, as leading environmentalists are urging it to do, it will essentially ban manufacturers from making new equipment containing the HFC refrigerant that is currently the standard for home and business air conditioners.

The government isn’t coming after your HFCs

The AIM Act only applies to newly manufactured or retrofit equipment. It doesn’t apply to existing equipment, or even equipment yet to be manufactured between now and the yet-to-be-determined dates the EPA will likely set for specific refrigerants to be discontinued. If you own equipment that contains HFCs, you can continue to use that equipment until it fails. There will likely even be reclaimed HFC refrigerant available for servicing for the rest of its life. None of us need give a speech about the EPA prying our HFCs from our cold dead fingers.

Three types of refrigerants are likely to dominate

Although some equipment manufacturers haven’t tipped their hands yet, it appears that most will replace HFC refrigerants with one of three different chemical types:

  • Low-GWP HFCs. Just like the HFCs that are being phased down, these refrigerants are composed of hydrogen, fluorine, and carbon. However, they feature much lower GWPs, which in some cases, are 65% less than the high-GWP refrigerants they’re replacing. Whether they exhibit low enough GWP to remain in use over the long run remains to be seen. In the meantime, they are more efficient than the HFCs they would replace.

  • Hydrofluoroolefins (HFOs). These refrigerants are also typically composed of the same elements that make up HFCs, but they feature a different chemical structure. They remain stable in the confines of a refrigeration system but break down rapidly if they ever escape into the wild. As a result, most feature GWPs down in the single digits. They’re also similar in efficiency to the refrigerants they’re replacing, although, for some applications, savvy buyers will have an opportunity to boost efficiency. Their chief drawback is that they’re more expensive than HFCs. In some cases, HFOs cost ten times as much as the HFCs they replace. Also, many of them are a bit flammable (more on this below).

  • Naturals. These chemicals already exist in the natural environment, including ammonia, carbon dioxide, and propane. Beloved by environmentalists, they feature GWP ratings close to zero, they’re inexpensive, and in the right applications, they can be more efficient than HFCs. For some applications, like grocery store refrigeration, they’re rapidly becoming the go-to choice. For others, they’re held back by their requirements for specialized piping materials as well as their flammability. Ammonia, in particular, is limited largely to industrial applications due to its moderate toxicity.

The future is flammable

For those of us who grew up with the “Better living through chemistry” slogan, we might expect the refrigerant manufacturers to send a team of folks in white coats into a lab, and have them emerge a few weeks later with a new family of refrigerants that work as well or better than HFCs, but feature low GWP to boot. Turns out, it’s not that simple. What enables a chemical to exhibit low GWP is an ability to react with oxygen in the atmosphere, and that ability, all too often, makes it flammable. For nearly a century now, we’ve used only non-flammable refrigerants in the US in non-industrial applications. Before then, flammable refrigerants were widely used, which resulted in many fires and explosions. If we return to using flammable refrigerants in order to mitigate climate change, will we also return to the dangers and damages of those long-ago days? That’s unlikely, given that we’ve got better technology now, and many of the low-GWP refrigerants are far less flammable than those of a century ago.

For example, some of the most efficient and climate friendly new refrigerants under development are characterized as “mildly flammable,” meaning that they can be ignited, but not easily. For one, they will only ignite in specific refrigerant-to-air ratios. If refrigerant leaks into a room, and the refrigerant is overly diluted by air, or if there’s too much refrigerant in the air, the mixture won’t ignite. Secondly, ignition requires an open flame or similar high-energy source. Air conditioning manufacturers are developing new systems to enable these mildly flammable refrigerants to be used safely. Those systems will come standard with a factory installed refrigerant detector. If the detector ever sensed there was a refrigerant leak approaching the ignitable air-refrigerant concentration, the detector would turn on a fan to dilute the refrigerant with indoor air, and prevent it from igniting, even if there’s an open flame.

Building codes aren’t ready yet

Currently, few building codes in the US allow central or split air conditioners with mildly flammable refrigerants to be installed. Such codes are under development, but for the vast majority of the thousands of states, cities, counties, and other government entities that enforce their own building codes, if they follow their standard processes, those new codes won’t be in place until sometime in 2026 at the earliest. Now, remember, California is limiting the GWP for refrigerants used in air conditioners manufactured in 2025 or later. Nearly all the refrigerants currently under development for air conditioners that would meet California’s standards are mildly flammable. That means, unless something changes, in 2025 there will be some folks in California who want to install air conditioners and won’t be able to.

Chances are the situation won’t come to that, but it’s not certain. California is working on a process to amend its building codes to be able to approve air conditioners with mildly flammable refrigerants, although it’s uncertain how that process will play out. The state’s fire marshal office is still evaluating the new technologies and standards, and probably won’t come to any decision on whether to support them or not for at least another year. A major chemical manufacturer is working on a new nonflammable refrigerant for air conditioners that is expected to meet California’s new standard for GWP. Again, it’s too soon to know how that development will work out as manufacturers are still evaluating the new refrigerant’s performance and compatibility.

As long as we’re piling on the uncertainties, it’s worth noting that this predicament could extend beyond California. There’s a good chance other states will follow California’s lead and adopt similar restrictions on air conditioner refrigerants. In 2018 California enacted restrictions on the refrigerants used in chillers, and so far, six more states have enacted similar restrictions. Maybe even the EPA will follow California’s lead and institute nationwide air conditioner refrigerant regulations. Furthermore, even before California’s new regulations kick in, there will be early adopters who want to install the most efficient, most climate friendly air conditioners available. How are they going to respond when they find out that their local building department won’t allow them to do so?

Usually, policies regulating technologies are designed so that the needed building codes are in place several years before the new technologies are rolled out. That way, building code officials and equipment supply chains have time to prepare. In this case, the technology changes could well precede the building codes by at least a year. This isn’t going to be a catastrophe and somehow we’ll find a way to muddle through. Even so, there’s already a good deal of confusion and frustration, and that’s certainly not going to help build support for climate change mitigation policies.

Here’s what you can do

For readers who want to know how they can help ease along the transition to low-GWP refrigerants, there’s plenty of work to be done. Policy wonks and environmental advocates can urge the EPA to adopt more aggressive schedules and regulations to ban HFCs for specific sectors. They can also help support building code officials in their efforts to update codes by amending them with the latest national standards governing the use of mildly flammable refrigerants. Folks who are looking for new air conditioners and refrigeration equipment can ask retailers for the most efficient and climate-friendly units that local building codes will accept. Investors can look for opportunities amongst equipment and refrigerant manufacturers, as well as contractors who have the skills to work with low-GWP refrigerants. For the rest of us, we can show support for those policymakers and officeholders who are now part of this new era of climate change mitigation policies and legislation in Washington.

Mark Silverstone's picture
Mark Silverstone on May 4, 2021

Thanks for explaining some of the nuts and bolts of this Jay. I agree that it is  "the most significant piece of US national climate legislation in years."

I was aware of some of the flammability issues with the replacements. I am glad to hear that non or less flammable products may be available.

Of course the cynics will always find a way it could all go wrong.  Let´s hope the EPA works constructively with stakeholders to get this implemented. 

It indeed will make a difference if, as you say,  "we can show support for those policymakers and officeholders who are now part of this new era of climate change mitigation policies and legislation in Washington."

Jay Stein's picture
Jay Stein on May 5, 2021

You’re welcome, Mark. Thanks to you for your interest in my work. You brought up one point that I do want to call attention to. Please don’t be too relieved that there are non-flammable and mildly flammable refrigerants available for the residential sector. These are only short-term solutions. Over the long run, unless there are some new developments I’m not aware of now, we can’t get to GWPs in the single digits for this sector without going to highly flammable refrigerants. I explained why in my post titled Electrification Backers, the Refrigerant Revolution Needs Your Support. I’m working on an article right now that will highlight new technologies that will enable us to use these refrigerants safely in residential and light commercial buildings. I hope to see you in the comments section when that article comes out.

Mark Silverstone's picture
Mark Silverstone on May 6, 2021

Understood. I read something a while back about Mercedes-Benz testing a replacement car air-conditioning refrigerant.  They found that is was too flammable to use.

Jay Stein's picture
Thank Jay for the Post!
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