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Refrigerants Will Be a Big Deal in 2025

By Jay Stein on

Image by: Phyxter.ai

The refrigerant that charged up air conditioners and heat pumps for the last 15 years is going away in 2025, and replaced by two new more climate-friendly ones. Whether you’re buying a new system, or you want to help battle the misinformation and confusion that’s likely to ensue, here’s what you need to know.

On January 1st, 2025, a new US Environmental Protection Agency rule will effectively ban the refrigerant that’s been used in air conditioners and heat pumps for the last 14 years. R-410A is being banned because of its excessive contribution to climate change, and two new more climate-friendly refrigerants will be used in equipment manufactured after that date.

You may be wondering why, if you’re not in the heating and air conditioning business, you should care about these changes. After all, this isn’t the first time something like this happened. In 2010, the EPA banned R-22, which at the time had been the residential air conditioner standard for over fifty years, because it was depleting the ozone layer. That’s when R-410A became the new standard. If you’re like most people, you never knew what refrigerant was in your air conditioner, other than it was Freon, or something like that.

This round of refrigerant re-regulation is going to be different. Contractors and retailers are already telling customers what refrigerant is in their units. Not only will those customers be concerned, but they will be confused by a wave of misinformation that’s likely to surge. In the face of this confusion and misinformation, even if you’re not in the market for a new system, if you’re a regular reader of this blog, your friends and relatives will be turning to you for advice. Here’s what they’ll be concerned about.

First, for the first time since the late 1950s, when the domestic industry settled on R-22, there will be two standard refrigerants for newly manufactured air conditioners and heat pumps: R-32 and R-454B. Manufacturers are already selecting one of the new refrigerants for their product lines, and are using their selections in their sales pitches. Refrigerant is now another distinguishing factor between manufacturers, in addition to price, efficiency, and reliability. Some folks who don’t even have a working understanding of the refrigeration cycle will be sorting through that information to figure out which refrigerant is the best one for them. 

Second, both of these new refrigerants are slightly flammable. What enables refrigerants to be climate friendly is a tendency to break down rapidly in the atmosphere, and that tends to make them flammable. The new refrigerants are so slightly flammable that they’re unlikely to ignite. If they do, they’re unlikely to cause much damage. Furthermore, regulators and industry leaders developed a set of safety features that will further ensure they are safely used. Even so, since the founding of the home air conditioning industry in the 1930s, manufacturers only used nonflammable refrigerants. The introduction of even slightly flammable refrigerants is bound to make some consumers anxious.

What will you tell them? Hopefully, you’ll say that the EPA’s decision was necessary to keep refrigerants from becoming a major contributor to climate change. That they needn’t agonize over which of the two new refrigerants to choose because the differences between them are slight, and there are more important factors that will determine the success of any air conditioner or heat pump installation. And that if this equipment is installed properly, it is extremely unlikely it will jeopardize their health or property.

In these highly polarized times, in which both anxiety and misinformation are abundant,  it’s challenging to formulate and implement public policies to address climate change. This new round of refrigerant re-regulation is an example of the sorts of public policies that are both needed and will require public support to succeed. The more folks who understand why these policies are necessary, and why this isn’t a radical environmentalist plot to incinerate Americans in their homes, the more likely it will be that the general public supports these regulations, and climate change policies in general.

Do you want to help build such understanding and support? Then, simply, read on. 

The situation

In October, 2023, the US Environmental Protection Agency issued a rule designed to reduce the climate impact of residential air conditioner and heat pump refrigerants. This rule had its origin in scientific studies over a dozen years earlier that found that as the climate warms, and humanity gets richer, the amount of air conditioning we’re using is rising rapidly. As we install more air conditioning systems, charged with refrigerants, more of those refrigerants are leaking into the atmosphere. 

The refrigerants we currently use are powerful global warming agents, thousands of times more potent per pound than carbon dioxide. The scientists conducting those studies concluded that before long, atmospheric warming attributed to refrigerants would be equivalent to a substantial portion of the warming attributed to carbon dioxide itself. The only meaningful public policy remedy would be to switch to refrigerants that contributed far less to climate change. That insight led policymakers to craft an international agreement, which led to US Federal government legislation, which then culminated in the EPA rule.

The metric the EPA uses to regulate refrigerants is Global Warming Potential. It expresses how much more a refrigerant warms the climate than does carbon dioxide, which features a GWP of 1. A refrigerant with a GWP of 1,000 would be about a thousand times per pound a more potent greenhouse gas than carbon dioxide.

Starting in 2025, the EPA will require all newly manufactured air conditioners and heat pumps to contain refrigerants featuring a GWP of 700 or less. R-410A, the current standard for this equipment, features a GWP of 2090, so it can’t clear this bar. Of the refrigerants the EPA approved for this sector, equipment manufacturers are largely choosing between two, R-32 (GWP 675) and R-454B (GWP 470).

This new rule only applies to equipment manufactured in 2025 or later. Already installed equipment can continue to operate indefinitely with the refrigerant it was originally charged with. No one need chain themselves to their air conditioner to keep it from being dragged away by jackbooted thugs from the EPA.

There will likely be enough R-410A to continue to service existing equipment indefinitely, but if you’d like to switch over your existing equipment to one of the new lower-GWP refrigerants, you won’t be able to. With few exceptions, equipment is manufactured to work with a single refrigerant and can’t be charged with another.

Of course, when everyone puts up their 2025 calendars, there will still be air conditioners and heat pumps manufactured in 2024 still in stock. Split systems (with separate indoor and outdoor units) manufactured before 2025, and containing R-410A, can continue to be installed until the end of 2025. Window units and other self-contained systems can continue to be sold until January 1, 2028. How long R-410A equipment remains available, it’s impossible to say.

Mild flammability explained

Ever since the emergence of the home air conditioning industry about 90 years ago, manufacturers produced equipment charged with non-flammable refrigerants. But about a dozen years ago, when scientists began to search for a low-GWP alternative to R-410A, they came to a distressing realization: it wasn’t possible to identify a residential refrigerant that was both low-GWP and nonflammable. What enables a refrigerant to exhibit a low-GWP rating is that if it leaks into the atmosphere, it reacts with oxygen and breaks down quickly. Such reactivity tends to make things flammable.

When those scientists came to accept that the next refrigerant generation would be flammable, they developed a new category, mildly flammable, and identified chemicals that fit within it. Although mildly flammable refrigerants can be ignited, they will only do so within a limited range of air-refrigerant mixtures. Too much air, or too much refrigerant, and the mixture won’t ignite. A good way to keep a mildly flammable refrigerant from igniting is to mix it up with more air.

Also, for a mildly flammable refrigerant to ignite, there has to be a high energy flame present, like a candle or a cigarette lighter. A static electricity spark, a hair dryer, or a toaster won’t start a fire. Should a fire start, the flames are slow moving and they go out when the high energy flame is extinguished. Indeed, the flames are so lethargic, their burning velocity is much slower than a baby can crawl. Although it might seem scary to use them, mildly flammable refrigerants have been used for several years now in millions of air conditioning and heat pump systems around the world. I’m not aware of any reports of these refrigerants causing catastrophic fires.

Even with the minimum risk they pose, US regulators and the HVAC industry spent over $7 million developing measures to enable mildly flammable refrigerants to be used safely. They include special techniques for joining pipes and fittings, and enhanced leak testing. Any system containing more than 3.91 lb. of refrigerant will be required to include a refrigerant leak detector, and in some cases, systems containing less refrigerant will also feature leak detectors. 

Since there’s usually about 2-4 lb. of refrigerant per ton of equipment capacity, nearly all systems larger than a ton or two require leak detectors. Should these detectors ever sense a significant leak, they’ll turn on the system’s central distribution fan to dilute the leaked refrigerant with air, and turn off any gas furnaces or water heaters. 

These safety features don’t come for free. While it’s too soon for a comprehensive study on how much they add to the cost of a system, I’ve seen anecdotal reports that range from a few hundred dollars to a few thousand dollars. 

With these safety measures in place, it’s unlikely that mildly flammable refrigerants will harm anyone or cause catastrophic property damage. What’s more concerning are the logistics of getting these systems installed. Currently, few domestic contractors have worked with either of the new refrigerants or their safety systems. System buyers will want to be sure their installers are trained and are following the installation instructions.

Also, these refrigerants are new to building code officials. Early installations may get caught up in red tape as building inspectors work to enforce recently implemented codes and standards. Nearly all building code jurisdictions in the US recently adopted new codes enabling them to approve installations containing mildly flammable refrigerants. There are, however, a few laggards. To see if your state’s building departments are ready, you can check out this map from the Air-Conditioning, Heating, and Refrigeration Institute. Alternatively, you might find it easier to just call up your local building department.

Meet R-32

R-32 consists of a single chemical named difluoromethane, which is composed of carbon, hydrogen, and fluorine. Although it was only recently approved in the US to be used in air conditioning systems as a single chemical refrigerant, it’s long been used as a component in approved mixtures. R-410A, the standard for residential air conditioning for the last 15 years, is a 50-50 mixture of R-32 and a flame retardant. Because R-32 is mildly flammable, it couldn’t be used on its own in the US until approved safety systems for these refrigerants were developed.

R-32’s GWP is about one-third that of R-410A, and it’s about 5% more efficient. Those improved characteristics come at a price. R-32 is about 60% more expensive than R-410A according to eRefrigerants.com. Given the amount of refrigerant most residential systems hold, it would probably add less than $100 to the cost of an installed system.

Manufacturers already committed to use R-32 in their products include Daikin, Fujitsu, and LG, all of which are Asian-based, and have been using the refrigerant in their products for years. Goodman and Amana, which are recognizable North American brands but owned by Daikin, also opted for R-32.

Meet R-454B

R-454B is a blend containing 68.9% R-32 and 31.1% of an ultra-low GWP refrigerant from a new family known as hydrofluoroolefins. These refrigerants are composed of hydrogen, carbon, and fluorine, just like R-32, but feature a different chemical structure. Hydrofluoroolefins are remarkable in that they exhibit single-digit GWP, but are often mildly flammable. The particular hydrofluoroolefin used in R-454B was developed by the Dupont corporation for the automotive market, and is widely used. If you bought a car in the last few years, it probably came charged with it. It costs about 2½ times as much as R-32.

R-454B’s GWP is about 30% lower than R-32’s, but it is slightly less efficient, perhaps as little as 1% less. Because it contains a hydrofluoroolefin, R-454B costs about 25% more than R-32 and about twice as much as R-410A.

Many of the major North American air conditioner and heat pump manufacturers adopted R-454B, including Trane, Carrier, Lennox, and Rheem.

Which one is best?

So, if we’ve got two refrigerants, one of them has got to be better than the other, right? Which one is best depends on your what you want to achieve. Do you want the cheapest refrigerant? Then R-32 is your choice, although for a typical split system, choosing R-454B would at most add just a few hundred dollars to the overall installed cost of an R-32 system. That doesn’t seem like a big deal for a purchase that runs somewhere between five and twenty thousand dollars. 

Do you want the most efficient one? Again, R-32 would be your choice. How about the lowest GWP? Here, R-454B has the edge. However, the overall lifetime climate impact of an air conditioner or heat pump depends on much more than refrigerant GWP. You’ve also got to take into account overall system efficiency, annual operating hours, the cleanliness of the local electric grid, how much refrigerant the system contains, how much refrigerant leaks during its lifetime, and how much refrigerant is reclaimed at the end. In some cases, R-32, with its higher efficiency, could well contribute less to climate change. Indeed, the HVAC manufacturer Daikin calculated out such a scenario, although the difference in climate emissions between the two refrigerants was less than 1%.

For any given system, it’s not worth breaking out the laptop and going through all the calculations that Daikin did. You’ll probably find that the difference is slight. The equipment selected and installation quality will have a far bigger influence on system outcomes than refrigerant choice. Also, it’s not as though an installer is going to ask which refrigerant you prefer. Equipment will come from the factory designed and manufactured to work with only a single refrigerant.

My suggestion is that you find an installer who does high quality work and select equipment from the manufacturers that installer likes to work with. In the end, it will matter little whether that equipment is charged with R-32 or R-454B. Your time and energy are better spent finding an excellent contractor.

Practice non-attachment

Don’t get too attached to either of these refrigerants. There’s at least one more round of re-regulation coming from the EPA, and probably several. When that next rule goes into effect, and by how much it lowers the GWP bar, no one can currently say. With a GWP of less than 500, R-454B might survive the next round, but not the one after that. Ultimately, it’s likely that propane, or some other similar hydrocarbon, with a GWP close to zero and no fluorine, will emerge as the long-term standard refrigerant for residential air conditioners and heat pumps. It remains to be seen what sort of safety systems will be required for such highly flammable refrigerants.

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Lessons Learned From Smoke Season 2023 About Protecting Indoor Air Quality

By Jay Stein on

Source: Anthony Quintano (https://www.flickr.com/photos/quintanomedia/52958921436/)

When the smoke from Canadian wildfires spread through much of North America during the summer of 2023, it gave rise to an important question: How do you keep indoor air fresh when the outdoor air is polluted?

The 2023 wildfire season was an eye opener for many people, albeit a bloodshot one. Usually, it’s only the Western US that has to deal with wildfire smoke, but this year, smoke from Canadian forest fires poured down into eastern states, some over a thousand miles away. Many people sought refuge in buildings, where unbeknownst to them, the operators of those buildings faced a dilemma.

While at the time, building air may have been cleaner than outdoor air, indoor air is rarely pristine. It often contains carbon dioxide (exhaled by occupants), pathogens like viruses (also exhaled), volatile organic compounds (outgassed from furniture and carpets), and particulates (microscopic particles from burning fuel in gas stoves and fireplaces). Plus, whatever pollutants are outdoors find their way indoors. In homes we often mitigate these contaminants by opening windows, but commercial buildings—like offices, schools, and stores—are equipped with ventilation systems that automatically bring in outdoor air to dilute contaminants. That works fine when the outdoor air is clean, but what are building operators to do when the outdoor air is filled with smoke?

I spent a good deal of time this summer ruminating on this question and found that it begs a much bigger one. Of course, it makes sense to avoid breathing wildfire smoke. It contains particulates (abbreviated as PM2.5 in air quality apps and web sites) that are so tiny they penetrate deep into our lungs. Particulate pollution has been linked to numerous disorders, including asthma and cardiovascular disease.

But wildfire smoke isn’t the only outdoor air pollutant we need be concerned about. In some ways, other air pollutants are more insidious. Most are gasses, and many are odorless and colorless. We don’t immediately feel the irritation they’re causing, so they don’t get the same level of attention as wildfire smoke. Gaseous air pollutants include ozone, volatile organic compounds, and nitrogen oxides, and they also have the potential to damage both our respiratory and cardiovascular systems. Ozone is especially dangerous. According to the American Lung Association, “exposure to unhealthy levels of ozone air pollution makes breathing difficult for more Americans all across the country than any other single pollutant.”

Overall, the concentrations of virtually all US outdoor air pollutants dropped over the last few decades, but that progress isn’t uniform across the country. There are still plenty of places that all too frequently experience poor air quality. According to the American Lung Association, nearly 120 million Americans “live in places with failing grades for unhealthy levels of ozone or particle pollution.” Building operators in these high pollution areas can’t count on having a consistent supply of clean outdoor air. 

What are these building operators to do? For one thing, they can install high-efficiency filters to remove both particulates and pathogens, like viruses. For another, they can install special filters designed to remove gaseous contaminants, like carbon dioxide and ozone, directly from indoor air. Air cleaned by a combination of high-efficiency filters, and special gas-removing filters, is often cleaner than outdoor air.

Building operators using such filter combinations don’t have to rely on having clean outdoor air to dilute indoor contaminants and can dramatically reduce their outdoor air intake. They also avoid the energy consumption associated with heating outdoor air up and cooling it down to room temperature. Not only do those energy savings help pay for such advanced filters, but they also reduce the extent to which buildings contribute to climate change. Which brings us full circle, as it’s climate change that’s now exacerbating our outdoor and indoor air pollution problems.

Smoke gets in your eyes

The most dangerous component of wildfire smoke is particulates, but wildfires are not the only source of particulate pollution. Others include factories, power plants, and gasoline and diesel motors. Particulates have been linked to cardiovascular disease, including heart attacks, strokes, chronic obstructive pulmonary disease, and asthma. According to the American Lung Association, they are responsible for nearly 48,000 premature US deaths annually. Some of the worst metropolitan areas for particulate pollution in the US include Los Angeles and Long Beach, Fairbanks, Phoenix and Mesa, and Detroit, Warren, and Ann Arbor.

Particulate pollution also finds its way into buildings, by seeping in through cracks and open windows, and being drawn in via fresh air intakes, but outdoor air is not the sole source of indoor particulates. Internal sources include cooking (heated food puts out particulates, and if you’re cooking on a gas stove, there’s also the combustion gasses), fireplaces, burning candles, and dust. 

Of all the forms of indoor air contamination, particulates are the easiest to remediate. They can be removed from indoor air using high-efficiency filters, but few buildings are outfitted with such filters.

Lost in the ozone

Ozone is a gas molecule containing 3 oxygen atoms. It forms in the lower atmosphere when volatile organic compounds and nitrogen oxides mix, and are exposed to heat and sunlight. Volatile organic compounds typically come from burning fossil fuels, such as gasoline, diesel, and natural gas, and when fuels and solvents evaporate. Major nitrogen oxides emitters include cars, trucks, furnaces, and boilers. Wildfires also increase ozone levels.

The presence of ozone in the upper atmosphere is a good thing, as it absorbs ultraviolet rays. But here in the lower atmosphere, where we all live, it reacts with the linings of our lungs and airways, causing inflammation and respiratory system damage. Ozone is linked to asthma and chronic obstructive pulmonary disease. Children and the elderly are most susceptible. Some of the worst metropolitan areas, according to the American Lung Association, include: Los Angeles and Long Beach, Phoenix and Mesa, Denver and Aurora, Houston and The Woodlands, and New York and Newark.

Just like particulates, outdoor ozone penetrates into buildings. It’s also emitted indoors by printers, photocopiers, and some air purifiers. Fortunately, ozone reacts with interior surfaces, like walls and furniture, and breaks down, so indoor ozone levels are often about one-quarter of outdoor levels. Even at those reduced levels, because we spend more time indoors than outdoors, many people inhale potentially detrimental amounts of indoor ozone.

Climate change is making things worse

For decades after the EPA issued regulations authorized by the Clean Air Act, both particulate and ozone concentrations declined. In recent years, progress on both of those pollutants seems to have stalled out, probably due to climate change. 

In the case of particulates, climate change is driving up temperatures, which drys out vegetation, leading to more wildfires. The number of days in which particulate pollution hit unhealthy levels in numerous US counties started rising dramatically about a decade ago, with many scientists warning the worst is yet to come.

The story is similar for ozone. In the West, climate change is driving hotter, dryer, sunnier summers, with more frequent stagnant air conditions. These are exactly the conditions that exacerbate ozone formation. According to the American Lung Association, “climate change is undercutting the progress we would have made” on ozone. Both particulates and ozone will continue to increasingly threaten our health, both outdoors and indoors, for the foreseeable future.

Filtration first

The first thing building operators can do is to install high-efficiency filters to remove particulates. Filter manufacturers express the effectiveness of their products using the Minimum Efficiency Reporting Value scale, which ranges from 1 to 20. The higher the MERV rating, the more effective a filter is at removing a wide range of particles from an airstream. 

According to the US EPA, “upgrading to a filter rated MERV 13 or higher can be especially important during smoky periods to effectively remove fine particle pollution from smoke in the indoor air.” Most HVAC system filters feature MERV ratings from 6-8, which can remove some smoke-related particles, but probably not enough to effectively protect respiratory health.

Ozone, and other gaseous contaminants, can’t be removed from indoor air using ordinary filters. In theory, they can be removed using air filters infused with activated carbon. However, those filters are expensive and they require frequent replacement. Accordingly, they’re rarely used.

How to manage indoor air quality without using outdoor air

Once high MERV filtration is in place, building operators in places with high levels of ozone pollution may want to take the next step, and clean their indoor air without bringing in much outdoor air. The technology that makes this strategy possible is known as sorbent filtration. Sorbents are materials that gas molecules naturally adhere to on contact, and can be incorporated into filters formulated to absorb carbon dioxide, formaldehyde, and ozone. When sorbent filters are saturated, such that they can no longer absorb any more gas molecules, they are regenerated by forcing hot air through them. The absorbed gas molecules are then released from the sorbent filters and expelled outdoors.

While sorbents have been used for decades in spacecraft and submarines, currently, there’s just one manufacturer of such filters for buildings: enVerid, a young company based near Boston. It not only makes the filters but also incorporates them into modules containing fans, particulate filters, regeneration heaters, controls, and dampers (see picture below). Buildings that install these modules could potentially eliminate nearly their entire outdoor air intake and the pollution that comes with it. 

Source: enVerid

Another problem with bringing in outdoor air is that it takes a lot of energy to warm it up to room temperature in the winter, and cool it down in the summer. Reducing the amount of air brought in avoids much of that energy consumption.

The National Renewable Energy Laboratory, a US Department of Energy lab that specializes, in part, in building energy efficiency, monitored three enVerid module installations: a wellness center and two office buildings. The NREL researchers found that the sorbent filters enabled building operators to reduce outdoor air intake quantities, reduce energy consumption, and meet or exceed their indoor air quality goals. How much energy individual buildings saved depended on numerous factors, including how their HVAC systems were functioning, and the local climate. In a Miami wellness center they determined that the enVerid modules reduced cooling energy by 37% during a 3-month test period.

In new construction, sorbent filters might add little or no cost to a project. Since they reduce heating and cooling loads, the cost of the heating and cooling equipment they displace is often similar to the cost of the modules. In existing buildings, the economics are more complicated. It’s possible that the sorbent filters could pay for themselves in 10 years, based on energy savings alone. In buildings where the occupants are sensitive to ozone and other air contaminants, the health benefits could exceed the sorbent filter costs in much less time.

Here’s what you can do

If you’re interested in protecting the air in buildings, you’ve got different opportunities depending on who you are. If you’re designing a new building in an area with high levels of ozone and particulate pollution, your opportunity is clear. By specifying a combination of MERV 13, or higher, and sorbent air filters, you may be able to produce a building that better protects the health of its occupants and consumes less energy than a typical building, at little to no additional upfront cost. How can you tell if your buildings is in a high-pollution area? Check the American Lung Association’s annual State of the Air Report. It contains data for high ozone and particle pollution days for nearly every county in the US.

If you’re an operator of an existing building, or a commercial building occupant, you can figure out whether you need upgraded air cleaning systems by monitoring indoor air quality with handheld or portable monitors. For example, the Awair Element monitors carbon dioxide, volatile organic compounds, and particulates, and is available online for $209. For policy wonks, you can advocate for national and local governments to adopt indoor air quality standards for commercial buildings.

For the rest of us, who want to be able to seal up our homes on high ozone days and still breathe easily, you may be wondering when a sorbent filtration system will be available for residences. I posed this question to Christian Weeks, enVerid’s CEO, and he told me such a product is technically feasible, and his company is working on it. If the market for a premium residential indoor air quality product develops, he told me, it might be available in just a few years.

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When will we get the heat pump thermostats we need?

By Jay Stein on

We want dual-fuel heating systems—electric heat pumps combined with gas furnaces for backup—to minimize our carbon footprints and utility bills. Currently, no one makes thermostats that would enable these systems to do these things, but if governments and manufacturers take action, that could change.

It was a dark and stormy night. In a house near Denver, Colorado, the indoor temperature dropped below 68℉, and the thermostat activated the heating system. This particular heating system combined both a heat pump and a natural gas furnace into a configuration known as a dual-fuel system, which is gaining traction as an archetype for inexpensively electrifying existing homes. 

This home was also equipped with a thermostat typical for duel-fuel systems that determined which heater to run based on outdoor temperature. As is common, the outdoor temperature control was set at 35℉, just to make sure the house would stay comfortable. Above that temperature the heat pump would run, and below it the furnace would. No one knew for sure that was actually the right temperature to maintain comfort. It was based on a rule of thumb, which in-turn was based on the performance of heat pumps made decades ago. 

When the outdoor temperature dropped below 35℉, the thermostat fired up the natural gas furnace. Unbeknownst to everyone sleeping peacefully in the house, operating the heat pump at that moment instead of the furnace, would have caused less carbon dioxide to be released, and it would have cost less to run. The thermostat wasn’t smart enough to figure that out. As a result, the family wasted money and an opportunity to reduce CO2 emissions.

It’s likely that the family would have wanted a smarter thermostat if they could have gotten one. When consumers are asked what motivated them to buy heat pumps, two of their top answers usually are that they wanted to cut their energy costs and reduce their environmental impacts. Given these sentiments, you’d think that for dual-fuel systems you’d be able to equip them with thermostats capable of either minimizing CO2 emissions or utility bills. Think again. They’re not available at any price.

In theory, we already have most of the technology needed to make such thermostats. To minimize emissions, the thermostat would need to know how clean the local electric grid is at any given moment (it changes frequently over the course of the day), and how efficient the heat pump is (which also varies). The thermostat would also need to know the emissions associated with the natural gas grid and the efficiency of the gas furnace (both are relatively constant). Provided with such information, the thermostat need only make a simple calculation.

Determining the least cost heater requires a similar calculation, with one major difference. Instead of knowing grid cleanliness, the thermostat would need to know the cost of electricity and natural gas at any given moment. Combining that cost information with equipment efficiency, the cost of operating both heaters could be calculated, and the least-cost one identified. It’s not possible to minimize both emissions and costs simultaneously, since only one thing can be minimized at a time. It would be possible for such a thermostat to include an algorithm that balanced emissions and costs based on the user’s preferences.

Performing such calculations wouldn’t require technology much more sophisticated than current smart thermostats, like those from Nest and Ecobee. Instead, we don’t have CO2– and cost-minimizing thermostats for two reasons. First, several of the needed information streams don’t yet exist. For example, there isn’t a good way for thermostats to know what the actual energy prices are at any given moment. Second, it’s hard for manufacturers to build markets for products that are so new consumers don’t even know they need them.

There are folks working on developing smarter heat pump thermostats, both in government laboratories and in manufacturers’ offices. Because there’s so much untapped value for these controls to access, it’s likely they will eventually come to market. That emergence will come a lot sooner if: utilities and equipment manufacturers get to work on developing the necessary information streams; the federal government invests in research and funds manufacturers’ development efforts; and lastly, environmental advocates get the word out on how these thermostats would save both money and emissions.

Why dual-fuel systems matter

The gas furnace is the most common heating device in the US. Over 40% of US homes are equipped with one. Millions of these homeowners are going to want to take advantage of the Inflation Reduction Act’s heat pump tax credits, but will find it’s expensive to retrofit heat pumps, with costs often running as high as $30,000. 

One trick to cut these costs down to just a few thousand dollars or less is for homeowners to wait until their air conditioners fail, replace them with heat pumps that cost little more than new air conditioners, and leave their gas furnaces in place as backup. This strategy avoids the expense associated with upgrading air distribution ducts and electric panels, both of which are often required. It might not be the ultimate long-term electrification strategy, but in the short-term, while we build public support, workforce volume, and manufacturing capacity, it’s an attractive one. To learn more about this strategy, see Replacing a central air conditioner? Get a heat pump instead. As more homeowners learn about it, they’re likely to drive a lot more heat pump installations.

If we’re going to maximize the benefits we get for our investments in these heat pumps we need better thermostats. The way virtually all dual-fuel thermostats currently work is that when there’s a call for heat, they turn on either the heat pump or the gas furnace based on either indoor or outdoor air temperature. These controls are fine for homes, where heat pumps are backed up by electric resistance heat, propane or fuel oil. These fuels are so expensive and carbon intensive that simply maximizing heat pump operation will come close to minimizing energy costs and CO2 emissions. 

Natural gas is different in that it’s much less expensive and carbon intensive than those other fuels. Whether or not it’s beneficial to run a heat pump instead of a gas furnace at any given moment depends on several factors that can vary by the hour, including heat pump efficiency and energy costs. Making a decision on which heater to run based on a single temperature setting can’t possibly account for such variability.

This lack of effective thermostats is not a reason to delay heat pump purchases. A dual-fuel system installed in most locations in the US, using controls readily available now, over its lifetime, will likely cost less to operate, and cause fewer CO2 emissions, than a standalone gas furnace. The problem is that when people install dual-fuel systems equipped with current thermostats, they’re not getting all the money and emissions savings available. Indeed, we’d all benefit from those savings.

The quest for a dual-fuel heat pump thermostat that minimizes greenhouse gas emissions

A dual-fuel thermostat that minimizes CO2 emissions is actually not that far from fruition. That’s because an information stream for quantifying marginal carbon dioxide emissions currently exists. It’s offered by WattTime, a nonprofit organization founded by UC Berkeley researchers. WattTime puts out an Application Programming Interface (an arrangement that enables multiple computers to communicate with each other, usually over the internet, abbreviated as API) containing real-time electric grid marginal emissions factors, updated every five minutes, for virtually the entire continental US, and most of Canada, Australia, and Europe. 

As the electric grid goes through the day, solar power ramps up and down, wind power does the same, and grid operators respond by firing up and shutting down various fossil fuel and other generators. The mix of all these different electric power sources also varies depending on where you are on the grid. WattTime figures out, for numerous locations, what generation sources will power the next devices to draw electricity from the grid, and quantifies their emission intensity in pounds of CO2 per Megawatt-hour of electricity consumed. See the graph just below for an example of what an ordinary day of such data looks like.

Image courtesy of WattTime

Already, several companies offer products that make use of WattTime’s data to reduce CO2 emissions. Enel X Way enables electric vehicle owners to charge only when the cleanest power is available. The recently released Google Nest Renew thermostat is able to shift heating and cooling operation to times when less CO2 would be emitted.

Since a CO2-minimizing thermostat would only be a bit more complex than what Google is doing with its Nest Renew product, it seems that it should be feasible. I asked Geoff Hancock, a WattTime product manager when he thought it would come to market, and he responded “This is inevitable. My feeling is that a WattTime-enabled heat pump could be commercially available in two years.” Currently, similar concepts are being investigated by several groups, including Oak Ridge National Laboratory and the Western Cooling Efficiency Center.

Accessing heating equipment efficiency

Whether you want a dual-fuel thermostat to minimize operating costs or CO2 emissions, it would need to know what the heat pump efficiency is whenever there was a call for heat. That’s tricky to do, as heat pump efficiency varies largely based on outdoor temperature. The colder it is outside, the harder the heat pump has to work to extract heat from outdoor air. For example, at 40℉, some heat pumps provide about 4½ units of heat to a home for every unit of electricity input, but only about 2¼ at 10℉. These numbers vary quite a bit between different heat pump models. To determine heat pump efficiency at any given moment, the thermostat would need to know both the outdoor air temperature and the characteristics of the installed heat pump.

Knowing the outdoor air temperature is the easy part. Some thermostats already include outdoor temperature sensors. Others are able to get the local temperature from weather services over the internet. 

Knowing how the efficiency of a heat pump varies with outdoor temperature is more complicated. Heat pumps are currently tested for their heating efficiency at a few standardized outdoor air temperatures between 17℉ and 47℉, with the option to also test at 5℉. The results of these tests are compiled by the Air Conditioning, Heating, and Refrigeration Institute, an industry trade group. One way to enable thermostats to access equipment efficiency information would be for AHRI to put out an API containing those efficiency test results. Installers would need to simply enter the heat pump’s make and model number into the thermostat,

Once the thermostat could access both outdoor air temperature and the efficiency test results, it could readily determine moment-by-moment heat pump efficiency. The thermostat would also need to know the furnace efficiency, but that’s a much simpler proposition. Furnace efficiency ratings are also compiled by AHRI and they vary little with external conditions. Installers would only have to program a single efficiency number into the thermostat.

Accessing real-time marginal utility costs

Most people never know what the actual price is of the electricity and natural gas they consume. Mostly they just pay the bottom line number on their bills. I have occasionally figured out my marginal cost of energy—the cost of the next kWh and therm we consume—and it’s tedious work. Even then, I only know my cost of energy at the end of the billing cycle, well after I’ve actually consumed it.

A cost-minimizing thermostat would need to know the marginal cost of electricity and natural gas in real time, and both can change monthly, or even more frequently. For example, between November of last year and this March, my gas marginal rate changed by 34%. My electric rate changed only by 1%, but soon my utility will switch me over to a time-of-use rate. When that happens, my electric rate will change several times a day, by as much as 67% during the heating season.

A cost-minimizing thermostat would need to access real-time utility costs via an API. Such an API doesn’t exist now and it would be a major undertaking to develop one. There are hundreds of utilities in North America, and most offer multiple rates. An API administrator would need to continually monitor all those utilities and rates for filings and notifications, and then quickly make hundreds of updates. This might be a job for artificial intelligence.

Once a thermostat had access to both equipment efficiency and real-time utility rates, it would be a simple calculation to determine which heater to run at any given moment.

The state-of-the-art for dual-fuel heat pump thermostats

The most advanced dual-fuel heat pump thermostat that I’m aware of is the one that Mitsubishi Electric provides with its intelli-HEAT heat pump. According to Mitsubishi, this heat pump can be combined with most natural gas furnaces, and it uses artificial intelligence to reduce both energy costs and greenhouse gas emissions. Obviously, it’s not capable of the cost minimizing calculations described immediately above—many of the needed information streams don’t exist yet—but it does some impressive things nonetheless.

For example, if the thermostat senses that during the heating season the room temperature is dropping, even with the heat pump operating, and that situation persists for nearly a half-hour, it will switch to the gas furnace to take over. Its artificial intelligence feature over time learns the conditions at which the heat pump can’t maintain comfort, and switches more quickly to the furnace. This is a much more effective means to increase heat pump operating hours, while maintaining comfort, than to use a single outdoor switchover temperature.

Mitsubishi Electric is working to improve the intelli-HEAT thermostat’s capabilities to reduce operating costs, anticipating that eventually the information streams needed will become available.

The old chicken and egg problem

To gain more insight on when a a CO2-minimizing thermostat might come to market, I contacted Daniel Meyers, the founder and CEO of Flair. His company makes several innovative thermostats, including one that enables mini-split heat pumps to be controlled from smart phones. He told me “I’d love a business justification to incorporate a carbon driven algorithm for selecting equipment but I don’t think there are currently any market mechanisms that are easy to plug into.” In other words, just like any manufacturer, he’s reluctant to invest in a product for which market demand doesn’t yet exist.

In the annals of corporate product development, this is a classic problem: What comes first, the market demand or the product? Customers can’t demand a product they don’t know they need, and they often don’t know they need it until someone makes it and markets it to them.

Building a market for cost- and CO2-minimizing thermostats is going to take some nudges from policymakers, manufacturers, utilities, environmental advocates, and investors. For example, utilities and heat pump manufacturers could get to work developing the APIs these thermostats need. The US Department of Energy could kick in money for research, and for manufacturers to develop and test prototypes. State and municipal heat pump program administrators could signal to manufacturers that when these thermostats are available, they will require their installation for dual-fuel systems. Environmental advocates could begin educating consumers about the benefits of these thermostats. It’s time for all these groups to get to work.

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Big Changes Afoot for Heat Pumps

By Jay Stein on

Heat pumps are becoming more efficient, less expensive, and more climate friendly. Understanding the legislation and regulations driving these changes is vital for consumers, policy wonks, investors, and electrification advocates.

There’s a perfect storm going on in the heat pump market. Policymakers and environmental advocates are touting this equipment as a solution to both climate change, and European dependence on Russian natural gas. Simultaneously, a plethora of legislation and regulations are emerging that are roiling the industry. These include new efficiency metrics, efficiency standards, federal tax credits, and refrigerant rules. Combined, they will make heat pumps more efficient, less expensive, and more climate friendly. They are also causing quite a bit of confusion for nearly everyone.

If you are a consumer in the heat pump market, an environmental advocate who wants to speak knowledgeably about building electrification, or just someone who wants to impress friends at cocktail parties, never fear. Read on to learn how the heat pump market is changing and why those changes will help mitigate climate change.

What you need to know about heat pump efficiency ratings

Whether you are planning to replace your air conditioner with a heat pump, or you are looking to influence public policy, you need to have a working understanding of two efficiency ratings: Heating Seasonal Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER). The US Department of Energy requires that all heat pumps sold in the country be labeled with these ratings, and they are the basis for determining eligibility for virtually all government and utility efficiency programs.

They’re similar to the Environmental Protection Agency’s “miles per gallon” ratings for cars, and are determined by laboratory tests under standardized conditions. Two ratings are needed because heat pumps both heat and cool. HSPF expresses heating season efficiency and SEER expresses cooling season efficiency. The higher the ratings, the more efficient the equipment.

Manufacturers do a lot of research and development to boost their ratings, and charge more for higher rated products. Also, they’re used by designers, contractors, policymakers, and building code officials. The Air-Conditioning, Heating, and Refrigeration Institute, an industry trade group, provides an online directory that compiles the ratings. AHRI also governs how the ratings are determined, and continually upgrades them to be more representative of actual in-field performance.

Heat pump ratings V2.0

Now that you’ve got a working understanding of HSPF and SEER, I’m going to pull the rug out from under you. As of New Year’s Day 2023, they were superseded by new ratings named HSPF2 and SEER2. You might think of them as version 2.0.

The new ratings are similar to their predecessors in most ways, with one notable exception: they were modified to more accurately reflect the amount of work heat pump indoor fans do to push air through ducts. The SEER2 and HSPF2 ratings include five times more indoor fan power than the old ratings. That change results in lower, but likely more realistic, ratings.

There’s no simple formula to take a piece of equipment rated under the old system and calculate its new ratings. Instead, manufacturers redesigned and tested their products based on the new ratings. That said, we do have an approximation of how much lower they are. 

According to AHRI, if you had a group of ducted heat pumps, and you calculated their average HSPF, the average HSPF2 of that sample would probably be about 15 percent lower. The average SEER2 would probably be about 5 percent lower than the average SEER. Again, these ratios wouldn’t be precise for any individual unit, but for a group average, they’d probably be close. Also, this exercise is theoretical and you couldn’t actually do these calculations yourself. As new equipment comes out, it’s only being labeled with the new ratings, and not the old.

How much more representative of actual in-field performance are the new ratings? We don’t know yet. Researchers working for a coalition of utilties and other associations are currently collecting data to answer this question. Their final report is expected to be released later this year.

For heat pump buyers, the most important thing to know is to not directly compare the old ratings to the new ratings. Just because a new heat pump’s HSPF2 is lower than the HSPF of an older heat pump, doesn’t mean that the new heat pump is less efficient. Instead, just ignore the old equipment with the old ratings, and focus on equipment with the version 2.0 ratings.

Heat pumps get more efficient

Another change that took effect on January 1, 2023, was that new heat pump minimum efficiency standards kicked in. Just as the the US DOE sets minimum efficiency standards for light bulbs and washing machines, it also sets standards for heat pumps. Starting this year, the kinds of heat pumps most commonly used in US homes, manufactured after January 1 and sold in the US, must be rated at least 14.3 SEER2 and 7.5 HSPF2.

The new standards are about 7% better than the ones they superseded, but it’s hard to say for sure, since the old minimums were based on the old rating system. Heat pumps manufactured before January 1, 2023, can continue to be sold indefinitely.

For heat pump buyers, there’s not much to do. If you’re looking for the cheapest system you can buy, just know that the least-efficient and least-expensive systems will be a bit more efficient and a bit more expensive than they were last year. 

You might be able to get a screaming deal if you head over to the dealer’s showroom immediately and see if they have any of last year’s units still in stock. Not that I would recommend doing that. With the incentives available from both the federal government and other local programs, you may well find that high-efficiency heat pumps cost little or no more than their minimum-efficient counterparts, and cost less to operate.

New federal tax credits make heat pumps cheaper

Starting in 2023, and continuing for the next decade, the federal government is increasing the income tax credits available for heat pump installations. For most taxpayers, those credits are now worth 30% of the cost of their heat pump project, up to $2,000. Sounds simple, right? Turns out, there are a lot of complications: not all heat pumps are eligible for the credit, there are limits to how much money one can claim in a given year, and there are special programs for low-and-medium income folks.

Of all these complications the one that’s likely to lead to the most confusion and frustration is the slate of eligibility requirements. To ensure that the tax credits are only being spent on efficient heat pumps, the federal government outsourced to the Consortium for Energy Efficiency the job of setting the bar. CEE is a non-profit organization that has long worked with efficiency program administrators to coordinate with industry, trade associations, government agencies, and each other. 

CEE regularly compiles minimum eligibility ratings for a wide variety of efficiency technologies, including heat pumps. If you’ve ever gotten a rebate from a utility energy efficiency program, there’s a good chance that CEE established the efficiency specifications. 

Why is CEE specifying efficiencies when we already have the DOE doing that? They serve different purposes. The DOE specifies the minimum efficiency equipment that manufacturers can produce. CEE specifies which equipment qualifies for incentives from efficiency programs.

If you want to take a look at CEE’s 2023 specifications for heat pumps, you can do so here. Warning: It’s not set up for industry novices. Whether or not a heat pump qualifies depends on what kind of equipment it is (ducted, ductless, or single-packaged), where in the country it’s being installed (North or South), and whether it meets up to five different criteria. 

If you’re interested in determining whether a given heat pump qualifies for the federal tax credit, you can collect the data you need from the AHRI directory, but it’s not easy. There’s a lot to collect and some calculations are required. To make things easier, CEE is joining forces with AHRI to develop a directory that lists qualifying products. You can find that directory here, only at the time of writing, it’s not been populated yet. Until it is, check with the manufacturers regarding their products’ eligibility.

Out with the old refrigerants, in with the new

Heat pumps, just like air conditioners, refrigerators, and freezers, are filled with refrigerants, which by expanding and condensing, move energy from cold to hot. Should refrigerants leak out into the atmosphere, which they do with alarming frequency, they can contribute to a variety of environmental problems, including climate change.

The EPA is planning to restrict the use of the refrigerant that currently dominates the heat pump market in favor of new refrigerants that contribute far less to climate change. The agency proposed such a rule in December, 2022. It’s expected this rule will be finalized later this year and will go into effect January 1, 2025. It will only affect newly manufactured equipment, and not the refrigerants contained within existing equipment.

There are currently two commercially available and EPA-approved refrigerants that can meet the proposed rule: R-32 and R-454B. Both are slightly more efficient than the current refrigerant and otherwise perform similarly in heat pumps. Even so, they represent an important departure from the refrigerants used in the US for the last century.

What enables refrigerants to have low climate impact is they readily react with oxygen in the atmosphere and break down. That capability also tends to make them flammable, and virtually all US building codes explicitly outlaw flammable refrigerants inside buildings. However, these new climate-friendly refrigerants are classified as “mildly flammable.” They can be ignited, but not easily. For example, they’re about as flammable as ammonia, which you may be storing under your kitchen sink.

To enable mildly flammable refrigerants to be used safely, industry researchers developed new sensors, controls, and piping techniques, but there’s still a lot of work left to do to incorporate them into standard practice. Designers and installers are being trained, and the nation’s building codes are being amended to include rules for the new safety equipment and techniques.

As states and other jurisdictions get ready, manufacturers are developing products that can meet the new regulations. Daikin, the world’s largest air conditioner and heat pump manufacturer, is already shipping products charged with R-32 to a half-dozen states: Florida, Oregon, Washington, North Carolina, Maine, and Vermont. By late 2024, it’s likely that qualifying products from virtually all the major manufacturers will be widely available.

For heat pump buyers, be aware that over the course of 2025 and 2026, contractors and building code departments are going to be working with new techniques and regulations. Both buyers and policymakers will want to check to ensure that local building codes will be ready to accept equipment with mildly flammable refrigerants. Most building code departments will be ready, but a few won’t. Be prepared for some confusion and resistance as the industry gets used to working with these new refrigerants.

Final thoughts

Now you know why heat pump industry professionals are living on ibuprofen and antacid tablets. You also know many of the things you’ll need to successfully install or advocate for public policies for heat pumps.

One conclusion I urge you not to take away from this post is that you’d be better off waiting for the new more climate-friendly refrigerants to be in place. Yes, those future heat pumps will contribute less to climate change. But the benefits of replacing heat from burnt fossil fuels with heat pumping, far outweigh the benefits of more climate-friendly refrigerants. We’ll all be better off to have more heat pumps sooner rather than later.

Besides, if you want to wait for this market to settle down, you’re going to be waiting a long time. Heat pumps are benefitting from lots of research and development. There are sure to be more new standards, technologies, and refrigerants in the future. Don’t wait for them. The heat pumps we have now are more than good enough to drive down energy costs and mitigate climate change.

The More Heat Pumps the Merrier

By Jay Stein on

Concerns about climate-warming refrigerants leaking from heat pumps are valid. Even so, the benefits of installing heat pumps instead of natural gas furnaces far outweigh the drawbacks.

The number of cities moving to ban natural gas heating in new buildings, and encourage builders to install heat pumps instead, keeps growing. Early leaders include New York and Seattle. In California alone, 54 jurisdictions adopted codes that either restrict natural gas usage or outright require heat pumps in new construction. 

Following their lead, policymakers and environmental advocates responding to Russia’s Ukraine invasion, advanced heat-pump-boosting plans to lessen Europe’s dependence on Russian natural gas. One of the most prominent proposals came from the journalist and environmentalist Bill McKibben, who in an article titled Heat Pumps for Peace and Freedom, implored President Biden to “immediately invoke the Defense Production Act to get American manufacturers to start producing electric heat pumps in quantity, so we can ship them to Europe…” Biden hasn’t commented publicly on McKibben’s proposal, but separately, the White House did release a statement announcing support for the European Commission’s plan to increase heat pump deployments.

Some critics of amplifying heat pump installations noted that the vast majority of heat pumps currently produced in the US are charged with refrigerants that are potent greenhouse gases, and those refrigerants leak. As a result, or so they claim, turbocharging heat pump production and installation is bound to increase climate change.

While it is correct that the leaking refrigerant problem is serious, let’s not let the perfect be the enemy of the good. Research shows that the potential benefits to be gained by installing heat pumps instead of gas furnaces far outweigh the drawbacks of leaking refrigerants. Also, more climate-friendly refrigerants are on the way. Federal regulations, expected to take effect in 2025, will drive manufacturers to produce new climate-friendlier heat pumps. The push to install more heat pumps is a good thing that needn’t be slowed down over refrigerant concerns.

A new study that settles the question

For years now, leaders at the Natural Resources Defense Council, a US-based legal and scientific environmental advocacy group, heard concerns about the heat pump refrigerant problem. To investigate to what extent leaking refrigerants undermine the climate benefits of replacing natural gas furnaces with heat pumps, the organization funded a study by researchers working at the University of California, Davis.

The UC researchers used computer simulation to project the hour-by-hour energy consumption of an average US home in 99 US cities, first with a high-efficiency natural gas furnace, and then with a high-efficiency heat pump. Next, they used a database from the National Renewable Energy Laboratory to convert that energy consumption into carbon dioxide emissions. They also added in the leakage of natural gas and refrigerants, from gas pipes and heat pumps.

What they found was that for a weighted average of the US population, over a 15-year equipment lifetime, installing electric heat pumps instead of gas furnaces would reduce equivalent carbon dioxide emissions by a bit more than half. That projection assumes current refrigerants and starting out with the current mix of electric generation on the grid. The researchers expected savings to increase in the future as the grid gets cleaner and refrigerants are more climate friendly. The UC researchers also found that the savings would have been greater had there been no heat pump refrigerant leakage, but that leakage only reduced savings for current units by about 10%. As time goes on, that penalty decreases to just a few percentage points. 

Given these findings, the researchers concluded “…policies to expand heat pump deployment will only modestly impact refrigerant emissions from the residential sector, a change that is far outweighed by the significant reductions in carbon dioxide and methane emissions gained by deploying increasing numbers of heat pumps.”

More climate-friendly refrigerants are on the way

The US EPA is currently preparing new regulations that will essentially ban the refrigerant (R-410A) that is currently used in the vast majority of heat pumps and air conditioners sold in the US, and only allow newly manufactured equipment to be charged with a new generation of relatively climate-friendly refrigerants. It’s widely expected that those regulations will be released this summer, that they will only allow refrigerants that exhibit a bit less than about 40% of the climate warming impact of the current standard refrigerant, and that they will go into effect January 1, 2025.

Although the allowed refrigerants will be more climate friendly and efficient than the current standard, most of them are classified as “mildly flammable.” They can be ignited, but not easily. For example, they’re about as flammable as ammonia, which you may be storing under your kitchen sink.

To enable mildly flammable refrigerants to be used safely, industry researchers developed new sensors, controls, and piping techniques, but there’s still a lot of work left to do to incorporate them into standard practice. Designers and installers are being trained to work with this equipment, and the nation’s building codes need to be amended to include standards for the new safety equipment and techniques.

For the last century, virtually all US building codes explicitly outlawed flammable refrigerants inside buildings. In the US, there are thousands of building code jurisdictions, at the state, county, and municipal government level. Amending the codes for all these jurisdictions is a major undertaking. 

Leading the effort is the Air Conditioning, Heating, and Refrigeration Institute, a trade association which represents more than 300 companies. AHRI is advocating both statewide code amendments and state legislation, that empowers building code officials to accept the new slightly flammable refrigerants. According to Helen Walter-Terrinoni, AHRI’s vice-president for regulatory affairs, “Either code amendments or legislation is in place for markets representing one-third of annual sales. We expect to get to two-thirds by the end of next year.” 

Of the remaining code jurisdictions, there could well be some laggards. According to Elizabeth Ortlieb, a director with Alpyne Strategy, “I’ve seen recent reports that say it is unlikely that building codes in all 50 states will accommodate mildly flammable refrigerants by 2025.”

As states and other jurisdictions get ready, manufacturers will follow by shipping products with refrigerants that can meet the new regulations. Daikin, the world’s largest air conditioner and heat pump manufacturer, is already shipping products charged with the new refrigerants to a few states, including Florida, Oregon, and Washington. By late 2024, it’s likely that products from virtually all the major manufacturers will be widely available.

Let’s do the tighten up

In addition to advocating for climate-friendly refrigerants, both environmentalists and industry leaders are looking to prod installers and service people to take a more active role in preventing leaks. As Kristen Taddonio, a senior climate and energy advisor at the Institute for Governance and Sustainable Development, puts it, “What matters is the lifecycle climate performance of the system, including efficiency. If leaks are minimized, and the refrigerant is reclaimed at end-of-life, refrigerant should not contribute much to climate change.” 

By law, contractors are not allowed to intentionally vent refrigerant to the atmosphere and are required to reclaim refrigerant from retired equipment for reuse or destruction. However, far less refrigerant is being reclaimed then should be in theory, so it’s assumed that the missing refrigerant is being released. 

Recovering refrigerant from decommissioned systems is hard and expensive work, and when contractors go to sell what they’ve recovered, they find that it’s not all that valuable. Probably, if the economics were more attractive, more would be recovered. Both the policy makers and environmental advocates that I spoke with called for government action, including paying incentives to contractors to recover refrigerant, as well as more rigorous law enforcement. Furthermore, as more EPA regulations kick in, prices will likely go up, which should also make recovery more profitable. 

It’s getting better all the time

It’s clear that the climate change benefits of greater heat pump utilization far outweigh the impacts of their leaking refrigerants. Furthermore, as regulations come online, and new heat pumps come charged with climate-friendlier refrigerants, the net benefits of installing heat pumps will grow ever greater. In the event governments come up with the right means to motivate greater adherence to refrigerant recovery laws, that will be icing on the cake.

In the meantime, the refrigerant problem isn’t being ignored. To put it into context, according to Project Drawdown, a nonprofit organization that conducts rigorous assessments of climate solutions, the combined benefits of its Refrigerant Management and Alternative Refrigerants solutions are 25 times greater than those of its High Efficiency Heat Pumps solution. 

Given the results of the UC California study, how can that be? Refrigerants are used in many more applications than heat pumps, including transportation, refrigeration, and industrial food processing. There are also plenty of homes out there that incorporate air conditioners but not heat pumps.

While the problem of climate-warming refrigerants isn’t yet solved, we are making progress. The vast majority of refrigeration sectors have either already transitioned to climate-friendlier refrigerants, as the automotive sector has done, or the EPA is well underway developing new regulations that will be released over the course of the next few years. Lastly, this is just the world’s third wave of climate-driven refrigerant re-regulation. It’s unlikely to be the last.

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