[00:00:00] Speaker A: Foreign.
[00:00:03] Speaker B: Hello and welcome to the Consulting Specifying Engineer podcast.
I'm your host, Amara Roskas, and today we're talking about refrigerants for H VAC Systems with Chris Forth. This podcast is now two years old, so it's great to be here and thank you, Chris. I appreciate you joining me today.
[00:00:26] Speaker A: Thank you for inviting Amara. This is a pretty exciting topic for me these days.
[00:00:32] Speaker B: Exactly. And Chris has some deep knowledge on this topic, so let me give you a little bit of insight into his background.
Chris Forth is the Vice President of Regulatory Codes and Environmental affairs at JC Residential and Light Commercial. He is an H VAC industry veteran with more than 30 years of experience who has worked in engineering, product management, and in the regulatory and code space. Chris is heavily involved in industry codes and standards development, as well as advocacy efforts to facilitate the safe transition to low global warming potential refrigerants at the state, federal and international levels. So, Chris, a lot to cover here.
What makes these A2L refrigerants different from traditional refrigerants?
Why are they becoming more widely adopted? Give me a little bit of background here.
[00:01:28] Speaker A: Yeah, certainly there's a lot of things going on at the same time. Amar, the biggest issue, right, the biggest driver of the change is really regulation.
So back In December of 2020, there was a law passed called the American Innovation and Manufacturing act, or AIM for short, that mandated that manufacturers of H VAC equipment that use current, what we call high global warming potential refrigerants transition their equipment to lower global warming potential refrigerants. And that timing, the first big tranche or phase, happened just January 1, 2025. So six months ago, seven months ago is all we're talking. So relatively recently, and because there was still the current refrigerants out in the market.
Right. That's why some of your, your listeners are probably just starting to see some of these newer low GWP refrigerants starting to enter the market. So that's the, that's the biggest driver.
[00:02:36] Speaker B: Okay, so let's put this into a little bit of perspective for the specifying engineer.
What are those key considerations associated with A2L refrigerants?
[00:02:48] Speaker A: Yeah, the big one. In order for a refrigerant to have lower global warming potential, right, it has to break down. So the whole issue with some of the current refrigerants is they tend to stick around in the environment a long time. And so with these lower global warming potential refrigerants, they break down sooner, which is a very good characteristic to have.
However, the Side effect of these refrigerants breaking down makes them more flammable. Now one thing I want to be clear on is from a flammability perspective, there's different levels that we're talking about. Unfortunately, human nature tells us, hey, when we think of flammability, we probably jump to what our minds think of something really highly flammable, like a propane or something. Right? That is not what we're talking about here. We're talking about what ASHRAE has classified as A2L refrigerants, meaning they're low toxicity, that's the A. And then the 2L is the flammability.
And, and I, and as I speak about these going, you know, across the country and different groups and so forth, when I say mildly flammable, I often get a few chuckles, as you can might imagine. But it really is True because these two Ls are classified by ASHRAE, they have unique characteristics.
One of the characteristics I think people can relate to is the burning velocity, which is how fast something burns. In the case of A2LS, they literally burn as slow as a half a mile per hour. Just to put it in terms of mile per hour that everyone can relate to. I mean you can walk faster than that. So that's really what we're talking about here. And These refrigerants, these A2Ls, they also self extinguish. So if there was an ignition source, typically a live flame that's there and that live flame's removed, they self extinguish. So we're not talking anything like propane or anything of that magnitude.
[00:04:44] Speaker B: That makes perfect sense. I appreciate that explanation.
And you mentioned Ashrae.
How do codes and standards like Ashrae 15 or UL60335, 2040 or some other building code, how does that shape the requirements for using A2LS in a commercial H vac system?
[00:05:06] Speaker A: Yeah, that's a great question. There's a lot of numbers. Quite a mouthful. Right, so the UL standard you mentioned, 60335240 is the design standard for which manufacturers like myself have to design the equipment to. And the shortened version, the 2:40 is the first standard. When it was first published to the third edition, was the first time a 2Ls were really covered.
So prior editions of the safety standard did not cover A2LS in these applications. So for a manufacturer like Johnson Controls Residential Light Commercial, we have to design the equipment to these new standards. That includes things like refrigerant charge, the safeties, the refrigerant detection system and so forth.
Ashrae 15, which covers the commercial side of the installation, so it's an application standard, covers how this, these A2L products get installed. Right. So what's, what's the dispersal volume? So the building volume, the refrigerant volume, those all go into the math and the calculations as to, you know, when a RDS refrigerant detection system is required and when it isn't required.
So those standards are really critical for specifying engineers to understand. And because they are newer and they always evolve their continuous maintenance standards, your audience really needs to stay on top of these. And that's, that's very critical.
[00:06:40] Speaker B: Okay, so speaking of refrigerant detection systems, what are those key components of a well designed, designed refrigerant detection system?
[00:06:50] Speaker A: Yeah, good, good question. So I think, you know, most engineers will think, well, hey, there's a sensor. Well certainly there's a sensor, but there's also controls that come with that and they have to work together as a, as a system. So detecting certain threshold levels, like the refrigerant concentration levels, which have to be set below certain mandated levels. Right. Typically a certain percentage below the minimum ignition. Right. What we call the lower flammability limit.
And once that's detected, if there is a leak and the RDS reacts, then there has to be controls that react within a certain timeframe and move a certain volume of air. Right. So the point of the RDS is to disperse any concentration that might ignite. And because the RDSS have both the pre configured sensor and the controls, they function together to make sure that there's no concentration that could be met, you know, allowed to be created by a leak that would allow for some sort of external ignition. Right. And just because there's a leak, there also has to be a suitable ignition source for there to be any event.
And for A2L's, the minimum ignition energy is quite, quite high. Again, not like propane. Right. Takes quite a bit of energy, a live flame basically to ignite those. So the RDS is pretty critical, right? It's very critical. It's required by the standard in some cases.
But having those work together as part of the UL 60335240 standard and in some cases the 15 standard. Right. Depending on how the application works is, you know, required by the code. So that's what your audience will really need to be aware of is both of those standards.
[00:08:41] Speaker B: Okay, okay, so I'm going to flip the coin here a little bit and talk about the negative aspects what are some of the common pitfalls or misunderstandings that engineers face when designing around a 2L refrigerant requirements? What does that look like?
[00:08:57] Speaker A: Yeah, that's a great question. So A2Ls, because they are different than the previous refrigerants, which were A ones, right? They do have different requirements. We mentioned RDs and I'll tell you one of the pitfalls. When our engineering customers call us, they usually will call us when they have specific questions, particularly the first couple of jobs they do.
Well, hey, do I always need an RDS and the engineers first, you know, reaction is if it's an A2L, I have to have an RDS. Not true. And I'll give you just kind of a high level example. In buildings or spaces where there's a lot of internal volume, what ashrae15 calls the dispersal volume, right?
If the refrigerant volume is low enough, that could leak into that internal volume, that space.
Then it, that volume space may be large enough that it could never reach a concentration that could be ignited.
So what I always convey to our customers, right, is hey, make sure you understand the building space, right? How much is there internal to the building?
The duct openings, right? How much free air is there? And of course you have to know the equipment. How much charge are you talking about, right? Is it a couple pounds? Is it a couple hundred pounds? Depending upon the equipment type.
Those are all things that's very critical to just basically determine if an RDS is needed.
And I would say the other big thing for your audience is to be aware of the local code requirements, right? So the code you mentioned are national, right there.
The 240 is a design standard, right? Ashrae 15 is an application standard, but local jurisdictions can adopt those and modify those.
So where the job is being installed is very important. They have to know what. There may be some unique things. Like for example, in some jurisdictions for A2L refrigerants, and any refrigerants in general, they require like locking caps on service ports. That's not a universal requirement across the country, but depending upon the versions of the Uniform Mechanical Code or the International Mechanical Code, so forth, there's unique requirements. So what I always tell the engineers, hey, make sure you touch base with your ahj, know your local codes, know the standards, and really those are things that, you know, your audience is probably doing already to some degree with the current older refrigerants, but with the new 2Ls, you know, it's mandatory. Some of those are things have to be done.
[00:11:41] Speaker B: Right? Solid Advice for any project, really.
[00:11:46] Speaker A: Exactly. Exactly.
[00:11:47] Speaker B: Yeah. Okay, so what's the latest on the R454B refrigerant shortage and what can specifying engineers do to address that?
[00:11:58] Speaker A: Yeah, that's a really hot topic of the day. So 454B is one of the new A2L refrigerants that, you know, from an OEM we just started production with on January 1st of this year.
Due to a number of, I'll call it factors, there is a perceived shortage of. Of two Ls like 454B in the market. I say the good news, really. You know, Amar, in the last few weeks there's been a lot of inroads, right? But initially what had happened was there was a, you know, a shortage, not necessarily of the refrigerant 454B, but of the disposable service cylinders. There was a. There's only one Manu main manufacturer in the U.S. they had some overwhelming volume by some OEMs that transitioned early.
And then we also had some unfortunate, I call it kind of panic buying facilitated by threats of tariffs and. Tariffs, right. Kind of similar to what we saw with the. Call it the toilet paper panic buying, you know, during COVID So from a specifying engineer perspective, I think the best thing that they can do, right, is make sure your equipment supplier does have gas that comes in the product. Right. So when I build a rooftop unit, right. For a commercial application, those products come fully charged. Right. So in many cases you're, you know, the contractor and the specifying engineer won't need additional gas unless there's some kind of damage or so forth. But if it's a split system and depending upon the piping length, they may need to have some refrigerant there at the job site startup, right. If they, if it's a long line length, they may have to have top off charge. So having plenty of notice and making sure those, you know, refrigerant supplier, whoever it might be, and for this aftermarket is there. And I'll tell you, I'm happy to say almost all the OEMs, you know, JC, you know, Johnson Controls, residential light, commercial, we've done things to help facilitate that as well.
We provided some additional cylinders to our distribution partners and they in turn have added some, sold some of those downstream. I would call it a. Not a normal kind of channel for providing service gas, but that's what the industry's done, come together, right, to help the contractor, to help, you know, these jobs and so forth to make sure, there's gas there at startup. So others have added additional charge to split systems, right. Be it residential or commercial, to make sure there's less needed, you know, at the job site. But, you know, any good, you know, building manager, right, is always going to have gas on hand, at least some amount on hand. They should work with their local supplier to make sure well ahead of the job, they do have access to that gas. And one of the things that I will tell them is it may not always come in the same container. Meaning by that when I say container, I mean cylinder. So the shortage on the 454B initially was just all around the cylinder, the service cylinders that are, you know, disposable. But what we've done and other OEMs have done is use refillable cylinders or which are an ample supply. Right. So those can be reused and they're great to have around for reclaim. So just having that flexibility around. And like I said, I want to emphasize the situation has really improved here in the last, you know, 20, 20 days or so.
[00:15:36] Speaker B: Well, Chris, based on your enthusiasm, I'm guessing that you eat, sleep and breathe this topic.
What's something you do to stay current on the latest H vac issues or trends?
[00:15:52] Speaker A: Well, I mean, one of the things, it's kind of a consequence of my job, right. I always have friends and family that need help with their air conditioning or heating systems, right. So, hey, Chris works for John's controls, right. So he can help us. So what I, what I've done and I've come to help people, I get involved in some actual installs for family and friends. Not, I want to say we follow all the codes and standards. Just want to put that disclaimer out there, right.
But getting involved in that really gives me a good feel, feel for what the contractor sees, what the engineer has to design around.
And having that real life experience, you know, is pretty helpful. And I've seen some pretty, I'll say, comical things right out there doing some of that work. And I, I'll have to tell you, I've learned a ton of things. It's made me, you know, a better engineer on, on my front. Right. And with my work, I add a lot of credibility to things. But when you go to the field, right, your audience may not always get that opportunity and I would always encourage them, hey, if you can go down and see some real, real life installs, participate, if you're able, is well worth the time and effort to do that.
[00:17:13] Speaker B: Okay, so your advice is to eat, sleep and breathe the topic.
[00:17:18] Speaker A: Yeah, I pretty much get tied to it. So yes, I'll. I'll concede that's correct.
[00:17:23] Speaker B: Awesome. Well, thank you, Chris. I appreciate these insights.
[00:17:28] Speaker A: Well, I've enjoyed speaking with you, Mara. Thank you. And I hope your listeners did as well.
[00:17:35] Speaker B: This is where we need to wrap things up. There have been a lot of questions about refrigerants since the new requirements went into effect.
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