Building owners, general contractors, and engineers across the United States are at a critical juncture for phasing out high-Global Warming Potential (GWP) refrigerants. With the looming January 1, 2025, deadline prohibiting the manufacturing of mid-size cooling equipment using high-GWP Hydrofluorocarbons (HFCs), the shift to designing systems using lower-GWP alternatives, such as A2L refrigerants, is not just imminent but imperative.
Despite the federal timeline trailing by a few years, the extensive lead times required for older systems make it essential for industry professionals to begin the transition to systems designed for these environmentally friendlier refrigerants. This proactive approach not only ensures compliance but will also avoid scheduling delays and, therefore, cost increases.
The high-GWP HFC phasedown deadline in Colorado for larger cooling systems, like chillers, has passed (January 2024), and the deadline for smaller cooling systems, like ductless systems, is still a couple of years away (2026). Now is the time to address replacement refrigerants in air handling units (AHUs) and other medium-sized units. (Here’s a link to a detailed phasedown schedule.)
What is an A2L, and why is it better?
An A2L refrigerant is a type of hydrofluoroolefin (HFO) with a low flammability rating. These refrigerants are categorized as “A2L” according to safety standards due to their low flammability and low toxicity. The main environmental advantage of A2L refrigerants over higher-GWP HFCs is their significantly lower impact on global warming. GWP is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific period, compared to carbon dioxide. HFCs have high GWP values. For context, R-410, probably the most commonly used HFC refrigerant, has a 2088 GWP, and the new GWP standard for replacement refrigerants is under 700.
Here’s a chart comparing GWP in older refrigerants and their newer replacements.
As you can see, A2L refrigerants like R-454B have much lower GWP values that meet the new standard of less than 700. Going forward, that means that A2L refrigerants are a more sustainable option. Their adoption is a key part of the effort to reduce the climate impact of the refrigeration and air conditioning sectors, aligning with international agreements like the Kigali Amendment to the Montreal Protocol, which aims to phase down the use of high-GWP HFCs globally.
If the deadline is January 2025, why should we design for A2L refrigerants now?
We’re still months away from the 2025 deadline to stop using HFC-cooled systems, but the lead time on obtaining those older systems is very long, about 45 weeks or ten-and-half months. If you’re designing a project to include an older system using R-410 or a similar HFC system and ordering that system today, you might not receive the unit before 2025. By the time the unit arrives, it might already be obsolete according to the new standards.
We saw this scenario last year when the deadline for transitioning away from high-GWP HFCs in larger units was January 1, 2024. Some owners who opted for older-model replacement chillers in their designs ended up having to scramble to find newer models for their jobsites because the older models arrived after the deadline. Besides needing to order and wait for newer models to arrive, which lengthened the project schedule, the project teams also had to redesign the original plans for the newer models. The result was an increased cost.
We recommend that customers with mid-size units, go ahead and design for replacement equipment that uses A2L refrigerants.
Next?
A2L refrigerants aren’t a perfect replacement for high-GWP refrigerants. Yes, they have a lower GWP that currently meets the new regulations, but they’re still flammable, toxic, and very difficult to store and deliver.
We expect a completely synthetic refrigerant to emerge in the next decade with low GWP, low flammability, low toxicity, and a low or nonexistent climate impact. Several chemical companies are working toward that synthetic solution.
In the meantime, A2Ls are our best option for HFC replacement. Let’s start designing for the transition to A2L refrigerants. Contact Caryn Becker to talk about your system and what to do.
Kevin Stoddardis Director of Preconstruction at U.S. Engineering Construction (USEC) in Denver, Colorado. He has extensive experience in both mechanical and electrical engineering consulting. Possessing a keen understanding of the intricacies of mechanical and electrical design coordination, he effectively bridges the gap between these disciplines, facilitating seamless communication and decision-making processes.
