Terry McIver
Gillis Hougton Maiorana

A2L Refrigerant in Focus at ACCA "Next Level"

Nov. 4, 2023
Experts described the points to consider regarding the HFC phasedown, the importance of refrigerant reclamation and an understanding of "mildly flammable" A2L refrigerant.
Terry McIver
Gillis Hougton Maiorana

Air Conditioning Contractors of America (ACCA) presented the “NEXT LEVEL” 2023 conference in Indianapolis October 16-17. Among the presentations to be featured in coming editions of Contracting Business and on ContractingBusiness.com was a panel discussion on the ramifications of the switch to mildly flammable, A2L refrigerants, as HFC refrigerants continue to be phased down over the remainder of this decade.

Panelists were Don Gillis, technical trainer for A2L refrigerants, The Chemours Company; Kate Houghton, vice president, sales and marketing for Hudson Technologies; and John Maiorana, sales and product support manager, Arkema.

What will A2L-friendly Equipment Look Like?

Don Gillis: “I don’t see a big change coming  internally on those products. I came from Copeland not too long ago, and as far as the internal compressors are concerned, you’ll start seeing things rated for A2L refrigerants, like tools will be. On a circuit board for example, you’ll start to see coded spade terminals; anything
that could possibly cause a spark has been considered. As far as pressure temperatures with R454B and R-410A, pressures/temperatures are almost exact, and it’s the same POE oil. The contactor will be encased.”

John Maiorana: if the A2L content exceeds a certain poundage of charge, a sensor (a sniffer) will go off if it detects a threshold of a leak. You could technically still have a very small leak that will not trigger the sensor, but leaks within the window will trigger the sensor, and it will go to the motherboard as a sequence of operation. The biggest technical change from a R-410A piece of equipment to an A2L, is that the sensor will be located within the air handler. But in some cases, a manufacturer will allow you to move that sensor within the coil, depending on if it’s a slant or an air handler or furnace.  We can’t see this equipment right now and will probably not see this equipment in all actuality until the second quarter of 2024.

How Should Contractors Approach the 30% Cut in HFC Production?

Kate Houghton: “It’s a big deal. The new equipment will not start to be installed towards the end of next year, so we can continue to install HFC equipment  right through probably the end of 2024, while there is 30 percent less HFC because of the reduction that is happening on January 1, 2024.  Looking at [the contractors’] base of installed equipment, you could install a system in June of next year with a 10-15 year lifespan, and you’re still going to have to service it with HFC refrigerant. Understand that the AIM Act covers all HFCs. It’s not just a reduction in R-410A, it will also be a reduction in R-134A, R-404A, R-407, all of the various HFC refrigerants. It’s not going to be about who has allowances and how those allowances are used, that’s going to affect the various refrigerants differently. We encourage you to think about reclamation.”

Reclamation Needed

Kate Houghton: “We hear about how the refrigerant reclamation industry has changed in recent years. We hear contractors are very worried about mixed refrigerants. Maybe you have only one cylinder on your van, or maybe you get to a system and you don’t know who serviced it before you. Was the refrigerant serviced correctly or not? The fear of turning in mixed refrigerants has probably held back reclamation. Most programs now don’t charge for mixed refrigerants, and in fact, many programs pay for mixed refrigerants.

“So, if you’re being assessed charges under your reclaim program and the partner you’re working with I encourage you to look around, because there are plenty of programs that have removed those charges.

“We also hear that it’s difficult to do reclamation in the field, and it takes time to set up the equipment. But thinking about the systems and
equipment that was optimized for R-22 is not necessarily optimized for R-410A. It’s very important to be looking at your equipment and determine how you’re going to go about reclamation and providing training on recovery. There are ways to reduce recovery time, and ways to start recovery before you start working on everything else. Every pound of HFC refrigerant is very, very valuable, and is part of getting your economic value back, by doing recovery and the right things will be critical to be able to service that equipment moving forward.

Mild Flammability Explained

Don Gillis: “A2L refrigerant is closer to an A1 (non-flammable) refrigerant than anything else. It had so low of a flame propagation or mild flammability that they had to make a new classification and put the “L” behind it. It just means ‘lower velocity’. The difference between an A2L and an A2, quite honestly is, if it's less than 10 centimeters per second, it's non-flammable. If it's more than 10 centimeters per second, it's flammable. A2 refrigerants are flammable, A3 refrigerants – propane and other hydrocarbons – are highly flammable. That's really in a nutshell what it looks like.”

John Maiorana: The Air-conditioning, Heating and Refrigeration Institute (AHRI) uses three measurements of flammability: how fast it burns (burn velocity); how much you need to burn, which is the lowest flame limit; and then once it burns how much heat energy is created, which is very important. When we hear the word “flammability,” people categorize everything together and there’s clearly a distinction. As Don mentioned, [A2L refrigerant] had such a minute flammability that they had to create a new category for it.”

“The EPA has allowed hydrocarbons to be used at 55 grams or less in domestic refrigerators. Does that mean that a domestic refrigerator manufacturer has to go in that direction? No, but they can choose to. Where finding that most domestic refrigerators will be using hydrocarbons, whether it be propane, isobutane, or a blend, but you’re not going to be seeing them in window air conditioning units or packaged units or unitary equipment.”

Don Gillis: “One of the biggest misconceptions I’ve seen since I came on board at Chemours, is about hydrocarbons in A2L refrigerants. It’s blown me away how many people are under that belief. There are NO hydrocarbons or propane in A2L refrigerants.”

Is Refrigerant Testing Going to be Required for Technicians?

Don Gillis: “There’s talk of that. If you want to hear “journeyman Don’s” take on it, there hasn’t been a license for A3s R-290 since it came out. You can go to True, ACCA, or Emerson, and take a test, but it’s not recognized on the federal or state level. I believe that before you test an A2L, you would almost think that there would be an A3 refrigerant test in play. And the thing I understand, when John mentions that it’s the same R-290 we use in gas grills, yes, it’s the same flammability rating, but they remove the stench [for refrigeration uses], because when you have stench, that causes impurities. So that’s a different slippery slope for people who walk into a mechanical room, can’t smell it if it’s leaking, and turn on a light switch. It takes a lot less propane in the air to cause a flame.”

John Maiorana: There is no consensus on if testing will be required or not. EPA Section 608 does have questions and terminology regarding
flammability, but Sec. 608 is not a safety exam, it’s an exam to test environmental awareness. The OEMs and wholesales aren’t going to require you to take a test to buy that piece of equipment that uses an A2L refrigerant, but code officials more than likely will.

Don Gillis: “[Any required testing] will come from your local jurisdiction, such as a fire department. Things could change if people start to ignore good practices. It boils down to getting back to the basics, what we should have been already doing and is now, in some cases, going to be required. If you’ve followed good practices before, you’re going to be alright.”

Will There be a Change in How to Handle A2L Cylinders?

Kate Houghton: “The cylinder code is still being finalized, but there will be different cylinder markings. There will be differences related to those cylinders in terms of pressure relief and a burst disc. With any cylinder, you need to treat it with care and handle it safely. The valve threads will be different; they will be left-handed, not right-handed. So, you’ll be able to distinguish an A2L mildly flammable cylinder from a standard cylinder. (Ed. note: A2L refrigerant cylinders will also bear a red marking, such as a band or red upper section. They will also have a pressure release valve. If the cylinder becomes over-pressurized, the valve will release an amount of refrigerant that will reduce the excess pressure.)

Something else that’s important: none of the A2L refrigerants are drop-ins for R-410A. If you have an existing R-410A system, there is no drop-in replacement refrigerant. There is nothing that you can put into that system other than R-410A.  And when you have an R-410 and an A2L cylinder -- whether it be R-32 or R-454B -- you are going to have that separation.

John Maiorana: The Department of Transportation dictates the construction of the cylinder, and they do say you will not be able to lay the A2L cylinders down. The new pressure valve is where the burst disc was located, maybe closer to the neck. That can’t and should not be seeing liquid, because if that were to activate, all the liquid would come out.

Don Gillis: Nothing’s changed about the trucks. There is still a maximum of 440 pounds of pressurized tanks in your truck. That includes acetylene [tanks] and anything else that’s more flammable; and, no ventilation [is allowed] in your vans.

You can petition UL for having tanks on their side. That’s what Chemours did, and that will be stamped on the side of the tank if allowed.

Good practice has always been to have the rupture disc or the new relief valve in the 12 o’clock position. The idea is to not have an accidental rupture. You’re also supposed to have a vapor barrier there. Follow the guidelines that appear on the box moving forward.

Has the Supply of Recovery Cylinders Gone Back to Normal?

Kate Hougton: The availability of 30- and 50-pound recovery cylinders was very, very tight. I would often hear from contractors that they can’t do recoveries because they couldn’t get cylinders or swap cylinders. The industry has moved past that. Recovery cylinders are readily available.

Temperatures in Arizona or Similar Climates Can Cause Van Temperatures to Reach as High as 160 degrees. Is that going to be an issue with the A2L cylinders?

Don Gillis: With A2L refrigerants, specifically R-454B, it’s going to be set at a much higher pressure, about 600 psi or so. The temperature threshold, is roughly 160 degrees Fahrenheit. But the cylinder will release [excess] pressure. If you haven’t had a rupture disc pop on  you before, you’re probably not going to have an issue here. [The pressure relief valve] is just another safety step.”