What A2L Is and Why It
Matters to You

Overview

A2L Is Here—What You Need to Know

Starting in 2025, the US government will require newly-installed residential HVAC equipment systems to meet new Global Warming Potential (GWP) limits established by the EPA Technology Transition Final Rule.

---

What is a refrigerant?

A refrigerant is a compound typically found in either a gaseous or fluid state that can easily absorb and reject heat. HVAC systems use refrigerant to help transfer heat from the inside to the outside of a space or vice versa.

---

What is the A2L Refrigerant classification?

A2L is a refrigerant safety classification assigned by (American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). ASHRAE Standard 34 assigns an identifying reference letter and number to each refrigerant, which classifies the refrigerant according to the hazard involved in its use. The capital letter (A) designates a toxicity class. Refrigerants assigned an A have lower toxicity, while refrigerants assigned a B have higher toxicity.

The second and third digits of the ASHRAE safety classification (2L) represent the flammability classification of the refrigerant as assigned by ASHRAE Standard 34. There are three ASHRAE flammability classifications and one subclass. Those classifications are 1 (no flame propagation), 2 (lower flammability), and 3 (higher flammability). The subclass is 2L, mildly flammable.

Following the 2020 American Innovation and Manufacturing (AIM) Act passed by Congress and subsequently signed by President Trump, the Environmental Protection Agency (EPA) is no longer allowing usage of high-GWP refrigerants in certain applications.

Only systems using A2L refrigerants are being manufactured for Residential Air Conditioning and Heat Pumps as of January 1, 2025. This equipment can be sold through December 31, 2025 and individual components of the system (parts) can be sold after that for servicing existing systems. New installations from January 1, 2026 on will need to be designed for and utilizing A2L refrigerants.

A2L refrigerant cannot be used in systems not designed for those A2L refrigerant, nor is it possible to use A1 classified refrigerants in A2L equipment.

---

Disclaimer: The advice offered here is intended as a basic guide only and not to be used as, or substituted for, professional tax preparation advice. We strongly advise you seek professional support for assistance and advise you to consult with a certified tax preparation specialist or CPA as appropriate.