37. Transitioning to Low Global Warming Potential Refrigerants

[music] Ashrie Journal presents. [music] Welcome to this episode of the Ashrie Journal podcast. I am Ryan Shanley, Ashrie Senior Manager Standards, and today I will be discussing ultra-low GWP global warming potential refrigerants with our guest Doug Reindel and Stet Samborn. So you guys want to go ahead and introduce yourselves. Hey Reindel, it's Doug Reindel. I'm a professor at the University of Wisconsin-Madison, and I also direct the organization here called the Industrial Reperturation Consortium. Been a long time Ashrie member and an Ashrie fellow, and I'm also a member of the Ashrie Standard 15 Committee. Great to be here. My name is Stet Samborn. So I'm vice president for engineering at Smith Group. I lead our engineering team at a San Francisco, so definitely on the design side. New buildings and retrofits, and then relative to refrigerants work and general decarbonization, I sit on Ashrie's task force for building decarbonization executive committee. So overseeing a lot of the work of how we're incorporating decarbonization throughout the structure of Ashrie and helping give direction to various committees on areas that we can all collectively support efforts around decarbonization. Great, so to get our discussion started off, May Doug, if you want to just kind of give a little background and refrigerants, may just like what the different safety classes are, then they'll help inform what some of the issues that will come up with trying to transition to ultra-low GWP refrigerants might be. - Yeah, so Ashrie has a standard Ashrie 34 that establishes the designation, the number designation for each refrigerant uniquely, and it also establishes a safety group classification for each refrigerant. This safety group classification is an alpha numeric string that describes the toxicity of the refrigerant and also its flammability. So you'll hear us refer to A1 or A2L or A3 refrigerants. Those, the A is the toxicity flag, and it's using a 400-part per million threshold if the refrigerant has health effects at concentrations that are less than 400-part per million, it's considered a higher toxicity refrigerant, and for the refrigerants that have health effects that are equal to or greater than 400-part per million, it's classified as a lower toxicity or a class A refrigerant. The flammability is the next index of the safety group classification, class one refrigerants, don't propagate flames, and that's measured in a laboratory setting at a specified temperature, usually 60 degrees centigrade, and then class two and two L are flammable refrigerants, slightly flammable, and the distinction between the two and the two L is the flame speed. So there's a specific lower flammability limit threshold that set, and also a heated combustion limit that set, but the two L is a slower flame speed propagation, it's a threshold of 10 centimeters per second, and then the class three flammable refrigerants are considered higher flammability. Those are lower flammability limits that's a lower concentration threshold, which they will ignite, and they're usually faster flame propagation to higher heat of combustion. So, class three, or what we would call the highest flammability, and class one are no flame propagation. And just to give everyone kind of an idea, when we had discussed this topic earlier, between ourselves, there was a lot of references that will come up again to a refrigerant titled R290, which is classified as an A3, which means it is very flammable, and eventually it just decided to look at the ashrie refrigerant tables, and see, okay, what's R290, and it was propane, so that made sense, obviously, that's very flammable. - Yeah, and that standard 34 that sets the numbering for each refrigerant. So, you know, we might also talk about R600A, that's isobutane, and that's another A3 refrigerant that's used in some products today, most notably like domestic refrigerators. - Okay, so since what we're kind of discussing is regarding the global warming potential of refrigerants, obviously climate change is a big issue, that is facing the entire planet, and so what we kind of want to discuss is, what does it look like to try and transition from current refrigerants, which have a higher GWP global warming potential to lower GWP, and some of those are A3s, which as we've noted are very flammable, so kind of what does that look like to try and move from less flammable refrigerants to more flammable refrigerants in order to reduce the global climate impact? - I could jump in and lay some context, 'cause I'd say that this whole process is multifaceted, and there's been a tremendous amount of work that's already been done in the market, in a transition to allowing the A2Ls, as Doug mentioned, there was actually a lot of learning that happened in terms of what needs to happen from stakeholders and manufacturing around that safety, not just for safety. And right now for the context of why A3s are even, you know, on the table for discussion, really Brian goes back to your point about sort of climate impact. We're seeing from the design side a request from owners, developers, large portfolio owners that have either ESG, environmental reporting requirements, or broader sustainability goals within their own portfolios. They're asking for what I would call whole life carbon solutions. You know, traditionally A3 has been at the forefront of energy efficiency, you know, for a very long time, and energy efficiency sort of translates more to that operational carbon impact. Where are you getting your energy from? Is it combustion on site, or is it, you know, from the power grid? There's been a lot of focus on that operational component. From a portfolio standpoint, as folks are looking at whole life carbon, they're looking at all the other mechanisms that have a climate impact. And so that includes fugitive emissions, you know, leakage of refrigerants, end of life loss of refrigerants that may not be recaptured during the decommissioning of a product, and things like that. So now, all of a sudden, there's a lens of looking at our broader impact beyond just the energy efficiency or the operating efficiency of our buildings. And so that's kind of spurred the conversation of, what can we do beyond traditional refrigerants? And even the A2Ls that the market has already begun to transition to. But I mean, Doug, who was heavily involved in that transition of even looking at the A2Ls, and so that process itself, I think leads to a really good roadmap of what needs to happen from a research standpoint, from a safety and analysis standpoint, and market adoption as we look at some of these more flammable A3-class refrigerants. - You know, I also think that that's a good sort of background. And there's, I mean, going back a little bit farther, depending on how you count, we're in, you know, the fourth or fifth phase out of different classes of refrigerants. And so one of the issues that I'm hearing is there's owners that just have phase out fatigue. And, you know, they're looking at now with the AMAC, the phase down of HFC refrigerants, and those refrigerants by and large have a fairly high global warming potential. And then they look at what's available in sort of this new class of refrigerants, the A2Ls, the GWPs are sort of three-digit. And they're, I think, sort of challenging themselves because they look at their roadmaps into the future and they go, do we want to transition again? And are these A2Ls a step into the low or ultra low GWP refrigerants? And so instead, I think you've been hearing maybe some of the same sort of thoughts and think phase out fatigue is another factor here. - Yeah, absolutely. I mean, we're working with our clients, you know, there's several layers that they're thinking about in terms of their operational capability within their own portfolio. You know, you have like an initial procurement of a building, you know, and the equipment that they might be buying out on day one. But they're looking at equipment that's been installed on their campuses or within their portfolios for 15 years, 30 years. And so there's layers of this transition, the impact, how they even plan their broader operations and maintenance across their portfolio. And so this transition to A2Ls, and as Doug mentioned, you know, we might be talking about refrigerants that have GWPs of 500, 700 within that range. They're kind of looking ahead at what the regulatory pressures that they're seeing either through phase out or, you know, kind of vision to the future of what reporting might be required for whole life carbon impacts, including scope three emissions. And they're kind of like, do I really want to have an interim step because they've already taken several steps. And so the questions that we're getting from our clients are, can we just jump all the way to whatever the end goal is? Just tell me what the end goal is. I just want to go to the end goal. I want to, you know, I don't want to have to have 18 steps. Will the real refrigerant please stand up? Exactly. And the challenge there is that the end goal hasn't gone through necessarily the same safety reviews in North America that we've gone through for all the other transition steps. And so that's kind of the crux is that from they're getting pressure from just being able to maintain their operations and put a roadmap for maintenance and keeping everything going. They're trying to look at the big picture. At the same time, you know, the market in North America doesn't really have product available in all classifications of equipment to jump right into. And so it's a challenge. It's a market transition challenge. And to add a little more context on some of the push towards this transition, about two months ago in March, the three of us were actually invited to a meeting with the White House Climate Policy Office 'cause the US government currently is kind of looking at how can we get ahead of this? 'Cause as Step mentioned, this seems like it would probably be the end point instead of trying to just progressively move to lower GWP refrigerants and steps. And so there's a number of things that, you know, would not probably immediately come to mind as to what may be needed from regulation standpoint. I know at one point there was mention of department transportation. regulations because there are limits on how much of a refrigerant can be on a truck, for example, based on the affordability. So those may need to be revised if, say, a 18-wheeler is going to be transporting a bunch of air conditioning units full of A3s. They may need to revise those regulations and kind of figure out how to do that safely. And so one of the major questions I was supposed to ashrie is, ashrie has two standards, which are standard 15 and 15.2, which are safety standards for refrigeration systems. And the 15.2 is focused more on residential. 15 is more commercial focused. And the question was kind of, well, what are the standards doing to incorporate these A3s into the safety considerations? What is the timeline for that? What else can be done to support this? So if Dougherst, that you want to talk a little more about that? I'll maybe start off instead. You can chime in. I think, you know, one of the things that we agreed on in the meeting that you had mentioned, Ryan, was that, you know, safety is the number one priority. We have to, you know, whatever we're going to transition to, it has to be done safely. And, you know, we hold the safety of the public and those that occupy buildings and facilities that use these refrigerants, you know, that sort of paramount. So that's a recognition. And when you talk about transitioning to these ultra low GWP refrigerants, which by and large are A3, the higher flammability classification. Okay, how do we do that? How do we utilize these safely? And so 15.2, which is really think single family dwellings, town homes, residential type dwellings, that's the target for that standard. And that was newly published in 2022. And as it stands right now, that standard doesn't even permit A3 refrigerants to be used. And so, you know, we have to look at, okay, what do the application of these refrigerants mean for residential dwelling? And there's technology that's being used elsewhere outside of North America that are modular units that have all of the A3 refrigerant, like propane, contained within the outdoor unit. And then they're using secondary foods to go into the residence. And I know steps very familiar with those. But, you know, for us in North America, at least, you know, for standard 15.2, that's not even a allowed refrigerant for use. And so, you know, we need to look at, okay, what does that mean for that application? What are the setback requirements? You know, how do we apply this class of refrigerants? And mostly propane is going to be mostly propane for that. How do we do that safely? And then for standard 15, actually standard 15 has what I would call reasonable allowances for use of A3 refrigerants in non-residential applications. And so, there are A3 refrigerants that are finding use in some applications. But I would still say that it's pretty limited. And, you know, there's a need to dig more deeply into what are the safety considerations if we continue to grow the use of these ultra-low GWP refrigerants that are higher flammability. Yeah, I think one of the interesting things that come out from the median at the White House was really how, as a coalition of agencies and entities and groups, can we move the work needed to take this forward? You know, how can we collectively? And so, it's not just Astray, it's in combination with UL, it's in combination with the national labs. There's actually been some incredible research that the national labs, including Oak Ridge National Lab, have already done in optimization of equipment with A3 refrigerants like propane. Heat exchanger optimization, trying to get the charge volumes as low as possible and still see high efficiency. I would say there was a very strong interest in propane in the market, mainly because, as Doug mentioned, there's a number of products, sort of indirect system products that are available in Europe. Really, I'd say in the last year, have come online that you could purchase. And so, what are the impacts on how does that go through the same regulatory regime in North America? Because as I mentioned, it's not even when Astray, you know, say Astray 152 adopts sort of that safety standard, then the testing methodology needs to follow up with that so that, you know, manufacturers can put their products through a testing regime and get a stamp of approval that it's either gone through, you know, UL listing or similar sort of regulatory review from a testing standpoint. I think something that folks don't also realize is that in parallel to that, we're not, you know, as Astray, we're not just interested in what refrigerant goes into the product, but we're also in parallel trying to drive efficiency of equipment across the board as we march towards reduced operational carbon. And so, as we introduce new refrigerants into classes of equipment, we need to then in parallel look at what the impacts of that on efficiency standards, like 90.1, 90.2 are going to be because, you know, I obviously have a very strong fondness for indirect hydronic-based systems. It's like where my passion lives from a design standpoint. But every time we add another loop to a system, you know, another heat exchanger, another transition, you know, you do take an incremental hit on efficiency. And so, we want to make sure that as we're looking at these new types of equipment that can be deployed, they were able to do so that still continues the Astray's drive towards increased efficiency across the board. And so, it's another layer, and I'd say to that onion, if you will, of trying to pair both the safety standard with enhanced performance. The nice thing is that propane or R290, I prefer to call it R290. The nice thing there is that from a performance standpoint, it actually does quite well, especially when we look at cold climates for making space heating and domestic hot water applications. So, it has really great performance characteristics that will help augment that conversation, especially for making some elevated temperature water upwards of 160 degrees Fahrenheit are achievable, which is especially appealing as we look at retrofits where we're trying to do boiler replacements, and, you know, multi-family buildings in homes and cold climates, it's really attractive. But that goes back to Doug's point about what are those safe installations? It's very different to think about a built piece of equipment that's going to sit inside the envelope of a building versus outside. How far away, you know, propane amongst its many benefits is also has some challenges from a deployment standpoint. It's heavier than air, it tends to pool. So, anybody who's used to having a large propane tank as part of their combustion based heating system knows that you have to be very careful about leaks selling into basements or window wells or stairwells that go down below grade. You know, those are all risk factors. And so, we need to make sure that we're moving in a safe direction and that we have some uniformity from that safety standpoint so that everybody is called plain by the same rules. So, that's an interesting point that, you know, we think about other fuels, whether it be natural gas or propane that we use for heating, particularly in cold climates, and one of the benefits of those fluids that are used for heating is they typically have an odorant that's added to them. So, when there is a leak, the homeowners know about it, they know that they need to call for help and don't turn on any lights or use the phone that sort of thing. And so, one of the challenges, and we've been talking about it with, you know, the renewed interest or re-interest in A3s is that is it possible to find odorants that could be added to the refrigerant because we know that the traditional odorants that are used in propane or natural gas get stripped out from the refrigerant circuit with filter dryers. And so, there's actually kind of a push to identify are there odorants that could be added to the refrigerant that don't materially affect its thermodynamic performance and don't create other sorts of issues in the system that we don't want, and that would be livable. They would survive circulating within the system and not get taken out by like filter dryers. And so, you know, those are important things too to help its safe use in applications where now people are, I think they're pretty readily attuned to natural gas leaks and propane leaks and they know what to do. Can we find a similar sort of strategy with hydrocarbon refrigerants that propane, for example? So, I kind of bring to a question regarding that the reason we're looking at A3s is because of their ultra low GWPs, but there are some class one or two L refrigerants, which also have ultra low GWPs. So, there's ammonia, air, ironically in my opinion, carbon dioxide, R1234, YF. So, why are those kind of not good alternatives to look at? Is it because of safety issues, efficiency, primarily those sort of things? Well, maybe I'll start, you can jump in. So, I dealt a lot with ammonia, a lot of experience with that, but it's pretty much been relegated to the industrial sector. So, food processing facilities, large refrigerated distribution facilities, it's ubiquitous, that's the refrigerant they use. So, you know, in that sort of space, they've been using that refrigerant for 150 years. They don't know this thing called refrigerant phase out and they kind of just, they live in their own world and they keep using that refrigerant. And, environmentally, it has a zero global warming potential and zero ozone depletion potential, but from a safety group classification, it is a B2L higher toxicity, slightly flammable, kind of like the A2Ls. And some of the data that's compiled in ash ray standard 34, one of the measures is what's called the OEL, the occupational exposure limit. And for ammonia, it's pretty low. It's 25 parts per million. So, in high concentrations, we don't want to have people, you know, potentially being exposed to that refrigerant. So, that's sort of the bad news. The good news is that people know it's there. It's a very distinct odor. Most people can smell it at, you know, single-digit concentrations and they generally want to go in the other direction. And so we call it self alarming. In terms of application, well, our standards prohibit the use of ammonia as a direct refrigerant in a non-industrial environment. So we wouldn't even allow it. Could it be used as an indirect refrigerant? Yes, it could. There's really not been the effort put into the development of technology to use it in other than industrial applications. And you know, it has some challenges, you know, for example, it doesn't get along well with copper. And so if you think about your conditioning construction of your conditioning equipment, you know, copper coils, copper, copper tubing, copper piping, that sort of thing. And with ammonia, that's just not possible. So there is a bit of a, we'll call it a system performance hit. It's an efficient refrigerant thermodynamically. But now when we have to use things like aluminum heat exchangers or stainless steel heat exchangers, it doesn't do quite as well from a, from a heat transfer standpoint compared to a copper heat exchanger. So, you know, ammonia's out there. I think it's, you know, it has its niche whether it will grow into non-industrial uses. We'll see CO2, a lot of activity in CO2, it's starting to pick up in the US. I think there's two issues that I continue to see in here. One is, I mean, the efficiencies are pretty poor quite honestly. And to stats point, if we're looking at, you know, whole life carbon, you know, we have to factor in what is the operating efficiency of the refrigerant, even though it's GWP is one. I mean, CO2 is the benchmark. The, the other issue is you get really high design pressures. And particularly for systems that are going to run transcritical. And so that becomes not only a design issue and a cost issue, but it, you know, that has its own inherent safety issues. And I guess I would say the, the third kind of piece of this is that because of its, you know, comparatively poor operating efficiency, there's a lot of additional components that get integrated into these systems to try to prop up their efficiency and make them less energy hoggish. And that just makes them more costly and more complicated. And so that's a challenge. The last thing I'll say on YF is it is being used primarily in mobile air conditioning systems, not so much in what I would call traditional HVAC applications. And I don't expect that to change a lot quite honestly, but you know, we'll see what the future holds. Yeah, the really interesting thing around all of these refrigerants is that it's not, and I think that's certainly the perspective of those of us that that volunteer with Ashré is that we're not trying to pick a single winner that's going to be the refrigerant that solves all problems. It's really trying to open up the field so that we can find the refrigerants that are the best match for the types of conditioning that we're trying to do. So like when we look at transcritical CO2 heat pumps, which have really within the last five years broken into the market in any sort of meaningful way, you know, it's mostly focused on domestic hot water production. You know, the transcritical CO2 heat pumps love a very large lift. They excel at making very hot water relative to traditional refrigerants that we've been using for air to water heat pumps. But at the same time that pros of the challenge if we try to integrate that a transcritical CO2 heat pump say into a space conditioning, space heating configuration because the delta T on our system isn't typically large enough to keep a CO2 heat pump happy. And so a lot of as Doug mentioned, there's a lot of things that you may have to do to that system to allow it to accept a lower delta T. And with that, you're operating outside of its sweet spot. And so there's an efficiency hit. CO2 also doesn't tend to perform on the space cooling side as well as refrigerants that we're used to using. And so we're looking at whole life performance, both heating and cooling and or domestic hot water production. So it's really about finding the refrigerant that matches the type of load that we're doing. And I think that's where I don't think anybody who's an advocate for R290 or propane heat pumps, I don't think anybody's saying let's throw away CO2 heat pumps. I really think it's about finding the right refrigerant for the right application and then doing so safely. I'm a huge advocate for finding a pathway for R290 mainly because it from a space conditioning standpoint, especially in cold climates, it performs quite well. So it hits two buckets at the same time, high performance from an operating standpoint, as well as the sort of global warming potential impact. But I'm also a huge fan of CO2 heat pumps. I agree, though, with Doug, some of the challenges that operating at those high pressures are the inherently the components within the heat pump cost more. There's more robust connections. You're typically going to welded connections inside the apparatus. So from a manufacturing standpoint, that presents challenges, which then for my clients, that means that there's a higher price point. Now, some of them are totally willing to do that. They're willing to hit that environmental standard. They are absolutely willing to pay that up front premium. As I mentioned, we're not trying to find the silver bullet for all solutions. And when we start to think about the ubiquity of equipment from a building type standpoint, not every building type is looking for that high quality domestic hot water production, like maybe a multi-family project. We have a lot of rooftop equipment out there in those single story, two story, either office buildings or warehouse buildings. That's a lot of equipment. And it doesn't pair well when we think about commodity products with the ultra-sophisticated high cost and dealing with certain refrigerants. And so I think that's what brings our attention towards finding a family of solutions that can be applied in use types that are really the most appropriate for them. And it ties back to the safety standard to pair with that. So for rooftop air handlers, those are direct systems that typically are taking air, heating it, cooling it, throwing it right into the building. And so that presents some safety challenges from a standpoint. If we're using propane, do we, and there's a leak within the equipment or a heat exchanger fails? Do we really want to, are we pushing that refrigerant in an unsafe way into the building? And so I think that kind of comes back to a number of the discussion points that we had both at the White House. And then part of it for a group that's reconvened as recently as this past week on Monday in California as part of the codes and standards conference of looking at what are the testing standards and tests that, and R&D really, that are needed to make sure that we're finding the safe way in each of these applications to deploy A3 refrigerants. And I think maybe that kind of leads us into some questions about what are the current kind of barriers to adopting A3s more widely? A lot of people may not be aware of this, but Ash Ray also has some involvement with the International Standards Organization, which has sort of a corresponding series of standards to Ash Ray standard 15, which are the safety standard for a refrigerant system. And the same kind of work is actually going on there currently, and several members of Ash Ray SSPC 1534 are involved in those efforts as well. So it's kind of this outside of North America as well that this is kind of just coming up and starting to be looked at. I know that you've mentioned that there's some rollout of R290 systems in Europe, but it's not really all that extensive there either. I think you may have mentioned the last year or two. Yeah, really the driver in Europe has been the FGAS regulations that have kind of pushed the industry in Europe towards propane as a solution in sort of these air to water or indirect systems as we are calling them. But there's actually some differences in how Europe goes about regulating refrigerant to a safety standpoint. One of the biggest challenges or differences is that a lot of that safety risk is put on the onist of the designer or installer of that equipment. If I look at the available products on the market in Europe for air to water heat pumps, each manufacturer has their own recommendations for spacing requirements for how close to a window, the unit can be aged, how close to a window well or to a stairwell. And effectively it says, do a paper review, safety review of your design installation and see if you feel like it's a safe installation. That presents some challenges in the market for deployment. So as a design professional trying to install this, specify this equipment, having each manufacturer have a different guide for how it gets installed makes it incredibly difficult for us to put a design forward that can be open bid, for instance, to multiple manufacturers. What is the, if I'm putting equipment on the roof, what is the spacing between equipment? What's the density of the equipment that I can put on a roof or outdoors adjacent to my building? If each, if that's based on a manufacturer recommendation versus a safety standard, then there's a lot of challenge for us to design something, you know, that you could substitute a manufacturer, for instance, in the field for cost concerns. If that meant that every time we did that, we had to redesign because now we have a different basis that we're referencing, then it makes it especially challenging for deployment in the US. So from a design perspective, that's our big challenge. I don't think that's a hurdle that we can't overcome, but having the standard in place allows us to point and say, this has been tested, there's a consensus standard based on that spacing requirement or concentration or charge limits. That gives us more certainty in the market as a designer that those solutions have been vetted, and it's a little bit different in how the European standard has been rolled out. And referring to the standard specifically for ash race standard 15.2, Doug, you mentioned currently, does not permit the use of a three refrigerants at all. So one of the things I know is being looked at is what can be put in there currently. That is generally agreed as a safe refrigerant charge limit for the use of a threes in residential applications. And there's also some proposed research going on to kind of help determine those limits and other data that's really needed in order to be able to update the standards to properly advise on the safe use of these refrigerants and equipment containing them. Yeah, and I think that sort of mentioned a couple of considerations and the 15 committee and 15.2 committee have already started really trying to dig into some of these questions and ultimately what we're gonna need to do is some research to be able to provide a decisions that are supported based on some sound research and risk associated with, for example, as Stett mentioned, if we have a unit that's located outdoors, how far does it need to be set back from the residents? What do we do with other equipment that might be located in that area if there's potential ignition sources? In some locations, in the northern parts of the U.S., there's a lot of homes, single-family dwellings that have basements, those basements have window wells, a lot of these outdoor units are located in close proximity to window wells, so what happens in that situation? And even in light commercial stepping aside from 15 point two for a moment, you have other similar sort of low points where if a leak of refrigerant from a unit can infiltrate those low points, now what hazards are created by that? So there's a number of questions, and of course in residential dwellings, not all of these units are located outdoors, some of them are in sort of interstitial spaces, and that creates a bunch of additional questions, how restrictive do the locations need to be distances, and you know, what are the hazards associated with that so that these can go in and be operated safely? And it's going to be a little bit of a different shift too from not only an installer's point of view, but also the homeowner because if those systems are going to find deployment, they're going to be secondary fluid systems, and so now we're going to have to have a hydronic system that will in cold climates will use glycoil as the working fluid that would go to cooling coils or heating coils for conditioning the space, so there's going to be some differences in approach with that technology as it sort of finds its way into the U.S. market. And it kind of goes back to the discussions that are happening in 15.2 is really trying to take those different application types and carve out what's a pathway, what needs to be validated, what research needs to happen for each one of those types, because what's come up really consistently across all of our working group meetings is that risk assessment is going to look different for the different application types, and the question about charge limit, the question about spacing, the questions about, you know, adjacency to other ignition sources, the recommendation, the result, or the enabling code sections that come out of that are really going to be tailored to that risk profile, and so rather than trying to find a single solution and a charge limit that makes everybody happy, I have a feeling it's going to come out that the different applications are going to have different limits, and I think that that's going to be born out of the research, and luckily we've gotten really great sort of lessons learned from the A2L transition, and the partners are already coming together to do that research, and to identify the research gaps, and that's everything from fire marshals, sort of fire service to UL, to ash ray, government agencies, even EPA Snap has a role to play in figuring out this pathway to adopt A3 refrigerants, and so I'd say on the upside, there's a lot of attention and excitement around sort of the market transition, but the most important part is to do it in a way that is transparent, has everybody at the table, and so we don't go down the road, and then all of a sudden get pushed back eight years from now, when we're trying to do a code adoption, and have some, you know, fire marshals were saying, "Hey, we weren't at the table, and we didn't know about this, we're not on board at all," and so having them at the table early on is going to help identify some of those other market barriers Ryan mentioned, and in terms it's not just a codes and standard element from an ash ray standpoint, from 15, but it's the broader impacts of what barriers might occur as we look at this, and so those charge limits the questions about separation distance, even labeling, is there going to be a new class of labeling that might be required on a building that includes these systems so that first responders are aware that these systems are present? There's a lot of questions that come up even beyond just the performance of the equipment itself. So I know in our meeting at the White House it came up that there are some applications currently that are using A3s with pretty wide adoption, so a lot of mention of domestic refrigerators, vending machines, and kind of the commonality between these seem to be that there are low charge limits, factory seals, so there isn't technician on-site inserting and removing refrigerant and maintaining it in that manner. So do you think there are other applications that could be looked at kind of as like low hanging fruits, so to speak, where there might be similar kind of characteristics of equipment, where there might be able to be quicker adoption of A3s? So I would say yes, and you know you highlighted a few of them, that the producers of equipment like vending machines, they've sort of went in that direction to A3s because they had to meet energy efficiency, increasingly stringent energy efficiency requirements, and really that was the option for them to do that without drastic changes to their product that would have really increased cost, and so you know what they have to work within now are some pretty low charge limits, 150 grams in the U.S. at least is sort of that threshold currently. So they've done that, they've produced the products, and you buy for example a home refrigerator now, chances are it's using a hydrocarbon, either R600A which is ISO butane or R290 which is propane, but looking at other markets, so in the commercial refrigeration, the supermarket refrigeration, there is increasing interest in deploying technologies that use hydrocarbons, these would be low charge modules that are commonly referred to as monoblocks, that would condition whether it be a cooler freezer type of refrigerated case, and they would reject heat either through a water cool loop or air cool. The interesting thing, I had a conversation with a designer earlier this week, and it's giving them some tools that they maybe had really had previously to think about, and if you look at supermarket refrigeration, maintaining low space, dew point temperatures is important for them to minimize things like the parasitic effects of defrosting those cases more frequently when they're in high humidity environments, and they have air cooled monoblocks that provide some space heat where they can now maybe maintain lower space dew point temperatures as a form of sort of free reheat that they're getting from the refrigerated cases, so I think designers, the ones that are sort of leading on this are starting to think in different ways and saying, okay, rather than take and try to duck this heat outdoors, how can I use it for an express purpose to give me leverage somewhere else in this footprint that we call a supermarket, so those discussions are starting right now and they're finding maybe, hey, I need to think in a different way and this actually might give me a tool that I didn't have previously. I think one of the other things that's really exciting about the conversations that have already started around the use of some of these refrigerants is that there's a really great research opportunity for optimization of charge and how we go about designing heat exchangers, how we go about designing the whole system that becomes a monoblock heat pump. Before the A3 conversation or before that sort of risk factor came in, I would say that the standard refrigeration cycle component sizing has followed a pretty linear improvement process, but there's already been in charge of it looking at even heat pump style water heaters for the residential market. You know, Oak Ridge National Lab has done some really phenomenal research on looking at heater optimizations and different circling designs that keep the refrigerant charge down to that 150 gram or lower limit while still providing the enhanced performance that we're looking for. And so there's actually a really great opportunity as we're looking at this to also focus on innovation enhancements and manufacturing enhancements for these designs that actually can allow us to say get more options even within the reduced charge limits. And I have a feeling that even as we go through this safety review and if a charge limit is set up, there's a ton of work that can be focused on getting more capacity for heating or cooling or to mask out water production under even within a certain charge limit. So I think that's something that's often overlooked is that everybody tends to focus on the direct relationship between charge limit and capacity, but realizing that there's actually another opportunity for innovation in optimizing those refrigeration circuits to stay within that bound but get more capacity out of the system. So this is a great chance where manufacturers and the national labs can collaborate and with additional funding from the Department of Energy or the White House where we could actually do quite a bit of work to get more options out of reduced charge limits and it's not just about a safety enhancement at that point. Anytime that we're looking at refrigerants, whether it's a GWP of 7 or 700, less refrigerant, tighter configurations, typically are going to be less leakage through the course of operations of that equipment. And so charge optimization inherently brings environmental benefits when we're looking at just reducing even the potential for leakage during normal course of operations. And so there's kind of a dual benefit. The putting a cap on the limits also to a certain extent is going to drive innovation on just reducing charge overall which has broader impacts on sort of reducing our climate impact. I know a few times mentioned kind of transitioning from A1 refrigerants which were non-flammable to A2Ls which are lower flammability but still flammable and I know that transition has kind of taken quite a bit of time. Do you think there's lessons that can be learned from that that could be applied to transition A3s? Well, I would say yes but to maybe put a finer point on it. You know, we're still, I would say we haven't really started the transition in terms of field installation of these A2L systems. I mean they're in their early phases of starting to get equipment that's been designed for utilizing those refrigerants and then rolling out and really the long runway was to determine the hazards associated with using me slightly flammable refrigerants that we didn't have in the past to deal with in commercial buildings or residential dwellings and thinking about things like food service. Well, what happens if I have a refrigerant leak in a kitchen where I have open flames? I mean, there's a bunch of issues that we didn't really have to take into account or didn't think hard about necessarily with A1 refrigerants. And so that process of doing the risky valuation, doing the flammability testing, a lot of flammability testing was done. HRI, Oak Ridge, other people that were involved. One of the parameters that we have to implement to ensure that these systems have the opportunity to be safely used in the built environment. And then we have to craft the language for those that would be incorporated into standard 15. The product safety standards that are published like the UL standards, then the equipment has to be designed and constructed to meet those safety requirements. And then the model codes have to adopt them so that they can be either adopted by jurisdictions to say, okay, this is what we will allow. And so all of those pieces take time. But I think what the lessons learned in all of the flammability testing, product testing that was done with A2Ls, that gives us a bit of a roadmap for repeating that in A3s. And I think going back to something instead and mentioned earlier, there are some differences where we're going to have to have infrastructure to do the testing. That's more robust than what we had for two L refrigerants with a higher flammability. The equipment manufacturers are going to have to have their own infrastructure to be able to develop products and test products and do that safely in their laboratories. And so what we've done with two Ls provides sort of a roadmap. And it's going to be a little bit different. Going back again to something else that I mentioned, getting the key stakeholders involved really early, going to help limit sort of speed bumps that we ran into with two Ls and getting to the stage that we're at right now. So I think we've learned a lot. Hopefully we won't repeat the same sort of old column mistakes, but the same divergence that we had previously in the redirects that we had to come back and address things. Yeah, I think just to echo that, when the A2L transition, which I agree with Doug, we are still in. It's not done because we're from the design side. We're just now being able to specify equipment with A2L refrigerants and actually find it on the market to put in. But during the A2L beginning to the transition, that roadmap was being invented, figuring out what tests needed to be done, who needed to be in the room, what the process was leaving going to look like was that entire roadmap was being invented while it was being driven down. And that inherently brings challenges. I'd say one of the benefits of having that process have already happened, and B is that we've learned things to avoid, things that we don't want to duplicate, but things that were very successful. And there was a number of working groups that actually were very successful that supported the A2L research transitions. And those groups are reconvening, as we speak, to dive into A3s and then being enhanced with the elements that maybe didn't go so well during the A2L transition. And so I'm really optimistic, in general, I'm an optimistic person, but I'm generally optimistic that the process can be done safely, and I think it can be done faster than potentially what was done for A2Ls. And we need to. The need for climate action is upon us. We need to find solutions that have whole life-carbon benefits. Strongly feel like when I'm in the room, and I hear the conversations that are happening, that there's a willingness to dive in, to do the work, and to figure out the safe transition, to make it available as an option on the market. And again, it won't be the only option. And that's the important thing to keep in mind that even as we look at A3s and a transition, there are great solutions on the market today that can help, at least in the interim, reduce our total impact on our designs. So, although we have an eye on where the target is, action today has impact today. And whether that's decarbonization project on a building or fuel switching, converting to heat pumps that are already available in the market. So there have been pickups on the road, but I actually think that looking at the critical mass of super smart people that are diving into this right now, across our national labs from the manufacturer's perspective, even taking lessons learned from their rollout in Europe, and from a manufacturing and testing standpoint, what needs to happen here in the US. I would say a critical mass amount of attention. Right now that I think supersedes are even as larger than what the A2L transition add in terms of the pace at which a large collective body wanna dive into this really quickly. As to those super smart people who you mentioned, I'd really like to take this opportunity to thank you for having this discussion with me today. I know it's been very important to me, both this and other conversations we've had. I've learned a lot, and it's just a really interesting topic. And I think not something people would really think of immediately when you're talking about addressing climate change. You know, my first thought would not be leakage of refrigerants from systems and such. So I really just want to thank you for taking time for your exceedingly busy schedules to have this discussion with me. Thanks for inviting us Ryan to have a great rest of your day. Thanks Ryan, and I will say that Doug and I are two people of hundreds that are diving in and focusing on this. And I personally just want to give a shout out. A lot of the folks that are working on these standards committees and doing this work is all volunteer. And, you know, you have to give a shout out to Ashley volunteers for diving in and doing the hard work on, you know, standard 15, 15.2, you know, standards group 34, all the standing committees of putting hard work in front of us around decarbonization, but you look around and there's just an incredible group of people that are doing this work. So my personal shout out and thank you to all the Ashley volunteers that are helping to move us forward on decarbonization. I agree. And thank you for reminding me that none of this will be possible without our volunteers. And we're always looking for more. So always. We'd love for more people to get involved. Help take some of the load off of you guys. Thank you very much. The Ashley Journal podcast team is Editor Drew Champlin, Managing Editor, Kelly Guelazo, Producer and Assistant Editor, Allison Hambler, Assistant Editor, Sarah Owning, Associate Editor, Tony Pulevsky, and Technical Editor, Rebecca Matasovsky, Copyright, Ashley. The views expressed in this podcast are those of individuals only and not of Ashley, its sponsors or advertisers. Please refer to Ashley.org/podcast for the full display.