The federal AIM Act will phase down HFC refrigerants 85% by 2036, which means that the HVAC industry will soon begin transitioning to lower-GWP refrigerants such as R-32 and R-454B in many types of comfort cooling equipment. However, these alternatives to R-410A are mildly flammable (A2L) and many state building codes do not yet allow their use in stationary comfort cooling equipment.

But that is changing quickly. Florida, Oregon, North Carolina, and Washington were the first states to update their building codes to allow the use of A2L refrigerants in larger air conditioners and heat pumps, and many more have now jumped on the bandwagon. Indeed, on July 5, New York’s governor signed legislation that allows the use of A2L refrigerants in the state’s building codes, and according to AHRI, Arizona, Colorado, Maine, Missouri, and Tennessee have also passed similar building code legislation this year.

Other states are in the process of updating their building codes to allow the use of A2Ls as well, which is a good thing, as time is of the essence. That’s because the Environmental Protection Agency (EPA) is considering banning the use of R-410A in new residential and commercial air conditioning equipment starting January 1, 2025. That is not a lot of time, but that date aligns with California’s HFC phasedown regulations, which require a 750 GWP limit for new air conditioning equipment starting in 2025, while VRF system manufacturers have until 2026 in order to comply with the new limit. Ironically, California’s building code does not yet allow the use of A2L refrigerants.

The reason for this patchwork approach to building codes is that in the U.S., there are several building codes available, including the International Code Council (ICC) and the International Association of Plumbing and Mechanical Officials (IAPMO), and states typically adopt one or the other. The ICC has already updated its standards for the use of A2L refrigerants in its 2024 edition, so states that follow those guidelines are free to adopt those standards at any time. IAPMO has also adopted A2Ls for the 2024 Uniform Mechanical Code (UMC).

Each state also approaches the code-making process differently. Most have a statewide code process that includes proposing amendments to the code. Those proposals then go through an administrative process and, if approved, result in changes to the state code. Other states, such as Illinois and Texas, do not have a statewide code.

Regardless of the process, building codes are changing quickly to allow the use of A2L refrigerants across the U.S., and contractors and technicians would be smart to learn how to install and service these new units sooner rather than later. They will also need to purchase A2L-compatible tools, such as manifold gauges, recovery machines, and vacuum pumps.

There are many training resources available to contractors and technicians, such as refrigerant manufacturers, OEMs, and industry associations. ACCA, for example, offers A2L training through a program that was developed based on the ASHRAE and UL safety standards. It provides an introduction to the new refrigerants; instruction on how to handle them safely; and a review of tools that will be needed to work on equipment with A2L refrigerants.

The ESCO Group’s training program for A2L refrigerants consists of a manual (available in print or online), an e-learning-style course, instructor PowerPoint presentations, and a closed-book safety certification exam. ESCO also offers train-the-trainer courses for those who want to offer low-GWP refrigerant safety courses.

If your state has not yet updated its building codes to allow the use of A2L refrigerants, it will happen soon. There is no question about that, as EPA is already hard at work creating the rules necessary to phase down the use of HFCs such as R-410A in the U.S. The A2Ls are coming, and it’s only a question of time before you will be asked to work on equipment containing these new refrigerants.