By now, most of the HVACR industry is familiar with the HFC phasedown portion of the U.S. EPA American Innovation and Manufacturing (AIM) Act that was signed in 2020 and finalized in 2021.
The first phasedowns started Jan. 1, 2020, with a 10% reduction in HFC refrigerant production, importation, and consumption, and was followed by an additional 30% reduction that began Jan. 1, 2024. As these regulations work to achieve a total 85% HFC phasedown from historic baseline levels by 2036, Technology transition rules will start to impact the industry as early as Jan. 1, 2025.
Technology Transitions
Often referred to as “sector controls,” Technology Transitions are the second of three main sections of the AIM Act.
They focus on limiting the use of HFC refrigerants and supporting A2L adoption by calling for global warming potential (GWP) limits for refrigerants based on specific applications, including refrigeration, air conditioning, heat pumps, and more.
three new-generation refrigerants
Three new-generation refrigerants help create a clear path to making refrigerant transitions that comply with the rules
Although the Technology Transitions program is rather complex (providing rules for which refrigerants or GWP limits apply for which applications and when) focusing on just three new-generation refrigerants helps create a clear path to making refrigerant transitions that comply with the rules and support more sustainable operations.
While several new refrigerants have been developed recently, many of the HVACR industry’s applications and equipment can be covered by focusing on these three refrigerants: R-454A, R-454B, and R-454C.
R-454A (AR4 GWP = 239)
Developed to replace legacy refrigerants such as R-404A, R-454A is an HFO blend offering zero ozone depletion potential (ODP) and a GWP of 239, lower than R-404A’s GWP of 3,920. R-454A is classified as a mildly flammable, low-toxicity A2L, suitable for low- and medium-temperature commercial refrigeration applications.
The AIM Act Technology Transitions set a maximum GWP of 300 for several types of systems with charge limits up to 200 lbs., such as remote condensing units for food retail walk-ins and cascade systems. These systems are ideal for R-454A, given the refrigerant’s improved performance and reduced GWP compared with R-404A.
R-454B (AR4 GWP = 467)
Regarding refrigerants of the future at work today, R-454B is likely the one you’ve heard the most about. Establishing itself as the predominant replacement for R-410A in new air conditioners and chillers, R-454B started being used earlier this year.
R-454B will be used in most equipment manufactured after Dec. 31, 2024. Offering a GWP of 467 compared with R-410A’s GWP of 2,088 (a 78% reduction), R-454B has been selected by most air conditioning and heat pump manufacturers worldwide.
R-454C (AR4 GWP = 148)
R-454C, with a GWP of 148, offers compliance with AIM Act regulations and is suitable for new systems
R-454C, with a GWP of 148, offers compliance with AIM Act regulations and is suitable for new systems in applications requiring a GWP of <150.
Two examples are small standalone units and larger system architectures with a charge size of >200 lbs. being developed for supermarkets.
For Use in New Equipment Only
R-454A, R-454B, and R-454C are HFO-blend refrigerants and have slightly different R-32 and R-1234yf components percentages. All three are individually optimized for peak performance and carry an A2L mild flammability safety classification.
As A2Ls, these refrigerants can only be used in new equipment designed to mitigate leaks and flammability risks and must be installed according to OEM instructions and in compliance with applicable safety standards and building codes.
Easy as A, B, C
In anticipation of AIM Act regulations and the continued adoption of R-454A, R-454B, and R-454C, the HVACR industry has ramped up A2L training and engineering support significantly over the past few years.
So, while sorting through the regulatory changes and becoming familiar with the new refrigerant options may seem complex, focusing on these three A2Ls will hopefully make your refrigeration transition, and your business’s future growth as easy as A, B, C.
