Global Warming Potential

By Anne Fonda

Refrigerants in your AC unit or heat pump transfer heat from one area to another during the cooling or heating process. Environmental regulations have evolved to require more sustainable refrigerants. Refrigerants are now limited in the United States based on their global warming potential (GWP). Refrigerants that are ozone-depleting substances (ODS), like R-22, have been banned in the U.S.

Scientists determine a refrigerant's GWP by comparing its global warming impact to the amount of carbon dioxide that would cause an equivalent global warming impact.  The higher the GWP, the greater the climate impact. 

AC refrigerants are greenhouse gases (GHGs). Greenhouse gases absorb and trap the heat in the atmosphere creating the same heating effect that a greenhouse does. But instead of warming plants in a greenhouse, GHGs trap the sun’s heat in the Earth’s atmosphere. 

Some GHGs are essential for life, like water, which occurs naturally in the atmosphere. But releases of refrigerants used in air conditioning our homes and carbon dioxide from the burning of fossil fuels to produce electricity across the globe can lead to additional greenhouse gases. The result is a changing climate, with shifts in snow and rainfall patterns, rising average temperatures, and more extreme climate events such as hurricanes, heat waves, and floods.

Common types of refrigerants can include:

CFC refrigerants have the highest ozone potential (ODP) and very high GWPs and have already been phased out. HCFC refrigerants, such as R-22 (HCFC-22) or Freon™ have also been phased out in new equipment by the Environmental Protection Agency (EPA) because of their ODP.

R-410A refrigerant is a blend of hydrofluorocarbon (HFC) refrigerants R-32 and R-125 that replaced R-22. But the global warming potential of R-410A is 2088. The EPA set a limit of 700 GWP for chillers, air conditioning, and heat pumps in 2025 under the AIM Act.

HFO refrigerants are very short-lived chemicals in the atmosphere, having lifetimes as short as several days. HFOs have carbon double bonds (unsaturated). HFCs do not contain a carbon-carbon double bond. HFOs have a zero ODP and ultra-low GWP. This makes them more sustainable refrigerants.

The HVAC industry’s transition to these more sustainable refrigerants is in the beginning stages. Based on EPA mandates, HVAC manufacturers will begin phasing out equipment production using R-410A and transition to production of equipment that uses HFO refrigerants and blends. 

American Standard is transitioning to low-GWP refrigerants because it’s the right thing to do for the planet, but also because of federal regulations.

HVAC technicians can still service your air conditioner or heat pump that utilizes an older refrigerant, so don’t worry that your existing HVAC system is obsolete. Just know that when it comes time to replace your air conditioner or heat pump, it may utilize a more sustainable refrigerant with a lower GWP.  

The HVAC industry is adopting two new refrigerants that meet the AIM Act 700 GWP limit for air conditioning and heating systems.  Some of the new low-GWP refrigerants include: 

Replacing older units that use R-22 or R-410A with new central air conditioning systems that use a low-GWP refrigerant will greatly reduce the global warming contribution from the refrigerant. But the bigger climate impact will be the improved energy efficiency of the new equipment, which will reduce carbon dioxide emissions from energy as a result. New air conditioners and heat pumps utilizing new refrigerants will emit fewer greenhouse gases. 

Big transitions like this don’t happen overnight. In addition to making changes in manufacturing and product design, we will strive to fully educate our team of American Standard dealers, sales force, and homeowners like you. 

Over the next months and years, American Standard will be transitioning to R-454B refrigerant for many of our new residential products. R-454B is an HFO mixture with the best in-case GWP refrigerants with the benefit of higher efficiency than R-410A with zero ODP. R-454B has a GWP of 466, which is 78% lower than that of R-410A.

Most HVAC manufacturers are transitioning to R-454B as well, making it the new industry standard.

Questions about the transition to low-GWP refrigerants and what it means for your HVAC system? Contact your local American Standard dealer for expert advice. 

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need. 

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Steve Kujak, Director Next Generation Refrigerant Research