A2L refrigerants and the AIM Act for new HVAC design

The American Innovation and Manufacturing (AIM) Act directs the EPA to phase down the production and consumption of high-global-warming-potential (GWP) hydrofluorocarbon refrigerants on a declining schedule. It also enables sector-based rules that limit the GWP of refrigerants allowed in new equipment.

The practical effect: the high-GWP refrigerants that dominated the last two decades, like R-410A, are being designed out of new commercial HVAC equipment.

The replacements for many applications are A2L refrigerants — lower-GWP options such as R-454B and R-32. “A2L” is a safety classification meaning lower toxicity and mild flammability. New equipment is being engineered specifically for these refrigerants.

For new design, this means selecting equipment on a current A2L platform rather than a refrigerant being phased down — a forward-looking choice that protects the owner’s service and parts availability.

A2L refrigerants are far less flammable than the A3 hydrocarbons, but they are not non-flammable like the old A1 refrigerants. That introduces requirements: charge limits per space, leak detection and mitigation on some equipment, and adherence to updated equipment standards and building/mechanical code provisions for A2L systems.

Modern equipment is designed to meet these requirements, but the design and installation have to respect them — it is a real consideration on systems with refrigerant in occupied spaces, like VRF.

Specifying new equipment on a phased-down refrigerant risks rising refrigerant cost, shrinking supply, and a shorter useful window before service becomes difficult. Specifying a current A2L platform aligns the equipment with where the market and regulations are going.

This is part of the refrigerant strategy on any new build — and it intersects with the repair-or-replace decision, where an old refrigerant is often the deciding factor.

In a design-build engagement, refrigerant strategy is decided alongside equipment selection in the basis of design — choosing an A2L platform, confirming the code and charge requirements for the application, and documenting it for the owner.

Getting this right at design time protects the owner from a refrigerant problem that would otherwise surface years later as a costly retrofit. It is standard in how we scope design-build and refrigerant management.