Navigating the Transition to A2L Refrigerants: What to Expect in 2025

Mar 11

As the HVAC industry moves toward more environmentally friendly refrigerants, contractors and businesses must stay ahead of regulatory changes. A significant shift is underway with the introduction of A2L refrigerants, designed to replace hydrofluorocarbons (HFCs) like R-410A. The transition is driven by the AIM Act and EPA regulations, which set deadlines for phasing out high-global-warming-potential refrigerants.

Key Updates on R-410A and HFC Bans

The EPA has extended the deadline for installing R-410A air conditioning and heat pump systems until December 31, 2025, provided the components were produced or imported before January 1, 2025. This affects residential and light commercial units under 65K BTU, while larger VRF systems over 65K BTU remain subject to the original January 1, 2026 installation prohibition. Further EPA rulemaking is anticipated for these larger systems.

For new construction, the ban on HFC refrigerants like R-410A begins:

January 1, 2026 for residential applications (one-year sell-through period)
January 1, 2028 for commercial applications (three-year sell-through period)

The Role of A2L Refrigerants

With these phaseouts, A2L refrigerants are becoming the industry standard. However, because they have mild flammability characteristics, their adoption requires safety training, new building code updates, and compliance with industry regulations. The International Code Council (ICC) has approved several A2L-related code changes in the International Building Code (IBC), International Fire Code (IFC), and International Mechanical Code (IMC), aligning with ASHRAE Standard 15-2019 and UL 60335-2-40.

Approved Code Changes for A2L Refrigerants

Several key proposals were approved to integrate A2L refrigerants into existing codes:

IBC and IFC Updates: Lower flammability refrigerants are now distinguished from higher flammability gases using the Globally Harmonized System of Classification and Labeling of Chemicals (7th edition).
IMC Updates:
- New safety standards for high-probability A2L equipment, aligning with UL 484, UL/CSA 60335-2-40, and UL/CSA 60335-2-89.
- Updated IMC refrigerant Table 1103.1 to match ASHRAE Standard 34.
- Restrictions on refrigerant charge limits, allowing only Group A1 or A2L refrigerants for high-probability direct systems.
- Machinery room requirements for A2L and B2L refrigerants now include temperature control, refrigerant detection, and mechanical ventilation, consistent with ASHRAE 15.
- New refrigerant piping standards based on ASTM A333-18.

What This Means for HVAC Professionals

The transition to A2Ls marks a significant shift in the HVAC industry. While safety concerns initially delayed widespread adoption, recent UL testing and analysis by the Air Conditioning, Heating, and Refrigeration Institute (AHRI) have confirmed that A2Ls can be safely integrated into residential and commercial applications. These regulatory changes, effective with the 2024 IBC, IFC, and IMC, will help accelerate the HFC phasedown while ensuring industry-wide compliance with safety standards.

As the deadlines approach, HVAC professionals must stay informed, complete required training, and ensure compliance with updated codes. The future of HVAC is evolving, and preparation now will ensure a smoother transition into the next generation of refrigerants.

Source: https://www.iccsafe.org/building-safety-journal/bsj-technical/code-changes-on-a2l-refrigerants/