The HVAC industry is transitioning to new refrigerants as required by the American Innovation and Manufacturing Act of 2020. This legislation gradually phases out existing refrigerant classes and introduces new requirements for those used in air conditioners and heat pumps. The new refrigerants have a lower global warming potential than the current ones.
As part of this transition, the U.S. Environmental Protection Agency (EPA) has set specific dates for new equipment to use the new refrigerants, commonly referred to as A2Ls. Residential and light commercial air conditioners and heat pumps manufactured after January 1, 2025, must use these new refrigerants. Equipment produced before this date has a one-year grace period to be installed, with a final installation deadline of January 1, 2026.
For products not requiring field assembly, like window air conditioning units, the final sale date is set for three years after the manufacturing compliance date, making the deadline January 1, 2028, without a compliance date for installation. The EPA is also considering a one-year extension 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 these new regulations and can continue to be used until the end of their lifecycle. Components used for servicing and repair are also exempt from these regulations. The supply of refrigerants like R-410A and R-134a for servicing needs will remain available even as production and imports decline over the next decade, similar to previous refrigerant transitions in the 1990s and early 2000s.
Differences with A2Ls
All refrigerants are classified by toxicity and flammability. A2L refrigerants retain the non-toxic classification of their predecessor (R-410A) but have been reclassified to Class 2L for lower flammability, compared to Class 1 (no flame propagation) for R-410A. This requires redesigning HVAC equipment, and it is crucial for home builders to plan for this transition, engage with suppliers and installers, and ensure an adequate supply of equipment to avoid bottlenecks and delays.
To address the increased flammability, equipment manufacturers are adding safety features, revising transportation and handling procedures, and updating installation instructions. Key mitigation measures include:
- Enhancing refrigerant line testing and requiring specific joint types and nail plates at framing members.
- Controlling refrigerant concentration in buildings to stay below flammability limits.
Manufacturers may also install leak detection sensors in air handlers, activate main fans to reduce refrigerant concentration, and use shut-off valves to limit refrigerant leaks. Systems without leak detection sensors will require careful sizing of refrigerant quantities to ensure safety.
Additional documentation requirements include permanent labels on equipment indicating the installer and refrigerant weight. The primary A2L refrigerants expected in the market are R-32 and R-454B, with each equipment manufacturer specifying their use.
Multifamily Buildings
For multifamily buildings, where refrigerant lines penetrate fire-rated floor assemblies, building codes may require refrigerant lines to be placed in fire-rated shafts or other fire safety measures. Developers should coordinate designs with their MEP firms, as shaft requirements can impact plan layouts and architectural designs.
Centrally Ducted Systems vs. Mini Splits
Different mitigation strategies will be specified for centrally ducted systems versus mini splits. Builders should consult their vendors and follow installation instructions to ensure all required safety measures are implemented to prevent exceeding refrigerant concentration limits in case of a leak.
Design Software
Software programs for sizing equipment and energy modeling should use updated specifications for new equipment with A2L refrigerants.
Actions for Home Builders
Home builders should have a transition plan that includes:
- Coordinating a switch-over timeline with vendors and installers.
- Ensuring a sufficient supply of existing equipment before the switch-over and new equipment afterward.
- Collaborating with mechanical system designers (for multifamily buildings, evaluate the need for fire-rated shafts).
- Ensuring HVAC contractors are knowledgeable about new installation requirements and safety measures.
- Making sure installation instructions are available from manufacturers for specific units.
- Coordinating among all parties involved and establishing a feedback loop.
Building Code Updates
Information about building code status regarding A2L refrigerants in each state can be found using the interactive map from the Air-Conditioning, Heating, and Refrigeration Institute (AHRI).
Additional Resources
Additional resources are available from Us and Trane.
Understanding R-454B Refrigerant
Switching from R-410A to R-454B: A Guide to Refrigerant Safety and Sustainability
