This tech tip was written by Dr. Chuck Allgood with Chemours. Thanks, Dr. Chuck!

While the ever-evolving world of refrigerants can often seem overwhelming with what seems like a never-ending parade of new gases being developed, taking a simplified approach may help clear the clutter.

It can be as easy as A, B, C—that is, R-454A, R-454B, and R-454C. These three refrigerants cover a very broad range of applications typically encountered by service technicians. We'll see them in residential and light commercial air conditioning, as well as commercial refrigeration (supermarket, C-store, etc.).

First off, all of these refrigerants are ASHRAE class A2L, meaning they have lower toxicity and lower flammability. We can also only use them in systems designed for A2Ls—they are not retrofit products. Also, all A2L systems will need to be installed per applicable safety standards and local codes.

R-454A is an alternative to R-404a for low and medium-temperature refrigeration applications. With a GWP of 239, R-454A meets the US EPA’s limit of GWP <300 and is targeted for use in systems up to 200 lbs of charge (where permitted by code), such as remote condensing units.

R-454B is the heir apparent to R-410A and has been selected by more than 80% of system OEMs. Residential AC and heat pumps with R-454B are being rolled out starting this year, and market adoption is expected to grow very quickly.

R-454C is similar to R-454A but with an even lower GWP of 148. It can be used per EPA AIM rules in larger systems and applications requiring a GWP of <150 in accordance with local codes.

There will always be innovations and improvements in the refrigerant world. At this time, keeping your focus on “Easy as ABC” will hopefully simplify this sometimes confusing subject.

—Dr. Chuck