The U.S. HVAC industry is now operating under materially different refrigerant requirements than it was just a few years ago. What began under the AIM Act as a long-range phase-down has become enforceable federal regulation, reshaping equipment design, installation practices, and service standards.
Lower-GWP and A2L refrigerants are moving into the mainstream, influencing safety protocols, labeling, and system monitoring expectations. For contractors, facility managers, and BAS integrators, the focus has shifted from preparation to practical implementation.
As systems evolve, aligning refrigerant detection, airflow verification, and controls integration with updated standards is part of ensuring compliance and operational readiness.
FAQs:
What refrigerants replace R-410A in 2026?
R-454B and R-32 are the primary replacements for R-410A in residential and light commercial systems under the EPA’s 700 GWP limit.
Are A2L refrigerants flammable?
A2L refrigerants are classified as mildly flammable under ASHRAE Standard 34 due to their low burning velocity.
The refrigerant transition has entered a new phase
We first examined the broader environmental drivers and policy trajectory in our previous analysis of the refrigerant phase-out.
Hydrofluorocarbons (HFCs) have long powered building HVAC systems, but many of these refrigerants have high Global Warming Potentials (GWPs) that contribute to climate change. The American Innovation and Manufacturing (AIM) Act set broad goals to reduce HFC production and usage, but as of **January 1, 2025, the U.S. EPA’s Technology Transitions Rule requires that new residential and light commercial HVAC systems use refrigerants with a GWP of 700 or less (U.S. EPA, Technology Transitions Rule).
This means high-GWP refrigerants like R-410A are no longer permitted in newly manufactured comfort cooling equipment, and manufacturers have redesigned their systems accordingly.
Lower-GWP refrigerants are now mainstream
In response to the new regulations, the HVAC industry is moving toward several compliant refrigerants:
- R-454B — A2L refrigerant with a GWP around 466, emerging as a primary replacement for R-410A in new systems due to its lower environmental impact and similar performance characteristics (EPA SNAP Program Listings).
- R-32 — A2L refrigerant with a GWP near 675 that also meets the EPA’s ≤700 threshold and is being adopted in both ducted and ductless heat pump systems (EPA SNAP Program).
Both fall under the A2L (mildly flammable) category, which influences equipment design, labeling, and service practices across the industry.
Safety and performance go hand-in-hand
As the industry transitions to A2L refrigerants, leak detection and environmental monitoring become even more critical. Because A2L refrigerants have different safety profiles than legacy refrigerants, facilities need reliable detection systems integrated with building automation systems (BAS).
Kele provides many options in refrigerant leak detection, designed to detect escaping HFC refrigerant in HVAC systems and BAS environments, with selectable outputs and alarm relays to integrate into a control system for proactive safety management.
These tools are especially helpful as A2L refrigerants become more common, bolstering safety and minimizing environmental release.
What A2L means for technicians and facility managers
Systems designed around A2L refrigerants require updated training and awareness. Mild flammability classifications influence:
- Field handling and recovery practices
- Ventilation requirements during service
- Approved tool sets and protective measures
- BAS and sensor integration for safety monitoring
Leak detection products like those from Kele help provide continuous monitoring and actionable alarm data so technicians and facility teams can respond quickly and confidently.
Retrofitting existing systems isn’t always an option
Although some facility teams ask whether legacy R-410A systems can be converted to newer refrigerants like R-454B or R-32, the short answer is that most existing systems are not designed for retrofit. Differences in lubricant requirements, safety classifications, and component compatibility generally make replacement the safer and more practical path as equipment ages.
The long view: HVAC refrigerants beyond 2026
The refrigerant transition is no longer theoretical. Equipment specifications, safety practices, and compliance standards have materially changed. Building owners, contractors, and BAS integrators who understand A2L requirements and monitoring best practices will be better positioned to manage risk, ensure code compliance, and maintain long-term system performance.
