Please enter your location or click here to select our default site experience.

A2L - R454B Transition


In 2025, EPA regulations will mandate a change to refrigerants that have a lower global warming potential (GWP). For Carrier and its associated brands, that means a transition from R-410A to R-454B, which has one fourth the GWP of R-410A*.

R-454B is in a specific class of refrigerants known as A2L, whereas R-410A is a class A1 refrigerant. Without going into all the technical details, R-454B offers similar operating temperatures, pressures, and oil compatibility as R-410A – reducing the learning curve associated with the new refrigerant. However, there are two key precautions that must be taken into account:

• R-454B and R-410A (or any refrigerant for that matter) cannot be mixed or cross-contaminated

• R-454B, as with all A2L refrigerants (including R-32), has a mildly flammable characteristic – meaning:

(1) a direct flame source and a high concentration of refrigerant is required to create a flame

(2) that if it were to ignite, the flame would likely be unsustainable and

(3) the spread rate would be less than half a mile per hour – slower than a typical walking speed.

These differences do require that additional measures be taken from a servicing perspective to avoid cross contamination and/or make certain no sparks are inadvertently generated.

Service technicians use a variety of equipment on the job – vacuum pumps & recovery machines, recovery cylinders, gauges/manifolds, leak detectors, scales, hoses, etc. This document will guide you through the changes needed to support these new refrigerants being introduced.

* Puron® and Puron Advance™ are trade names for R-410A and R-454B and are used exclusively with Carrier and Bryant branded products.