New Refrigerants are (Almost) Here - What You Need to Know | NAHB

The HVAC industry is beginning to transition to new refrigerants required by the American Innovation and Manufacturing Act of 2020, which gradually phases down the use of existing classes of refrigerants and establishes new requirements for the refrigerants used in air conditioners and heat pumps. The new class of refrigerants has a lower global warming potential than current ones.

As part of this transition, the U.S. Environmental Protection Agency (EPA) has set transition dates for new equipment required to use new refrigerants, commonly referred to as A2Ls.

Residential and light commercial air conditioners and heat pumps manufactured after Jan. 1, 2025, must use the new refrigerant. The equipment manufactured prior to this date has a one-year grace period to be installed — a Jan. 1, 2026, installation deadline.

For products that do not require field assembly, such as window air conditioning units, the rules establish the final date of sale as three years after the manufacture compliance date — a Jan. 1, 2028, sale deadline — without a compliance date for installation.

EPA is evaluating an extension of transition dates by one year only for Variable Refrigerant Flow (VRF) systems with capacities of 65,000 BTU/h (19 kW) or more.

Existing air conditioning and heat pump equipment is not subject to EPA regulations and can continue to be used through equipment end-of-life. Components used for servicing and repair also are not subject to EPA regulation. The supply of R-410A, R-134a, and other refrigerants to meet servicing needs will remain available for the foreseeable future even as overall production and imports decline through the middle of the next decade, as was the case in prior refrigerant transitions in the 1990s and early 2000s.

All refrigerants are required to be classified by toxicity and flammability. A2Ls retain the same toxicity designation — non-toxic — as their predecessor (R-410A). However, the flammability has been reclassified as Class 2L (lower flammability), compared to Class 1 (no flame propagation) for R-410A.

A2L refrigerants require redesign of the HVAC equipment. It is important that home builders actively begin to plan for the transition, and engage with their suppliers and installers to ensure an adequate pipeline of equipment in the upcoming months and to avoid potential bottlenecks, delays and last-minute change orders. Each equipment manufacturer will have their own roll-out strategy and timeline, but these changes are imminent and will happen over the coming months.

To address the slight increase in flammability, equipment manufacturers are adding safety features to equipment, revising transportation and handling procedures, and updating installation instructions.

Primary mitigation measures for the building include:

In many cases, equipment manufacturers will add a leak detection sensor installed in the air handler unit and programmed to activate the main fan to quickly circulate the air throughout the home to reduce refrigerant concentration. Other safety strategies can include the use of shut-off valves also activated by leak sensors and designed to limit the quantity of the refrigerant that can leak out. For systems without leak detection sensors, the quantity of the refrigerant in the system, including the lines, will need to be sized more carefully such that a refrigerant leak into the smallest space (e.g., bathroom) directly served by the system would not exceed the established concentration limit.

Additional documentation requirements include a permanent label on the equipment listing the company that installed the system and the weight of the installed refrigerant.

Although there are several A2L refrigerants approved for use, the primary two refrigerants that you should expect in the market are R-32 and R-454B. Each equipment manufacturer will specify which refrigerant is used for their equipment.

For multifamily buildings where refrigerant lines penetrate fire-rated floor assemblies, the building code may require that the refrigerant lines be placed in a fire-rated shaft or other fire safety measures be implemented. Developers should coordinate designs with their MEP firms. The shaft requirements can impact plan layouts and architectural designs.

Different mitigation strategies will be specified for centrally ducted systems vs. mini splits. Again, builders should reach out to their vendors for information and follow installation instructions to make sure all required safety measures are implemented so that concentration limits are not exceeded in case of a refrigerant leak.

Software programs for sizing equipment and for energy modeling should use updated specifications for the new equipment with A2L refrigerants.

Have a transition plan in place that achieves the following goals:

Information about the status of building codes regarding A2L refrigerants in each state can be found using this interactive map from the Air-Conditioning, Heating, and Refrigeration Institute (AHRI).

Technology Transitions HFC Restrictions by Sector | US EPA

Frequent Questions on the Phasedown of Hydrofluorocarbons | US EPA

Safe Refrigerant Transition | AHRI (ahrinet.org)

A2L Refrigerants Transition | ICC (iccsafe.org)

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