HFOs are eco-friendly refrigerants designed to replace older, harmful AC refrigerants with a lower global warming potential.

What are Hydrofluoroolefins (HFOs)?

Hydrofluoroolefins (HFOs) are the latest generation of refrigerants designed to be more environmentally friendly. With very low Global Warming Potential (GWP) and zero Ozone Depletion Potential (ODP), HFOs are effective in reducing the environmental impact associated with older refrigerants. They’re used in various HVAC applications, including air conditioning (AC) systems, heat pumps (HPs), and even as blowing agents in insulation foam.

Environmental Impact of HFOs

Older refrigerants like R-22 (Freon™) and R-410A have contributed to climate change due to their high GWP. R-22 also has a high ODP, meaning it depletes the ozone layer. Even though R-410A has no ODP, its GWP is significantly high. Recognizing this, the Environmental Protection Agency (EPA) passed the American Innovation and Manufacturing (AIM) Act of 2020, which mandates phasing out high-GWP hydrofluorocarbons (HFCs) in favor of low-GWP refrigerants like HFOs.

Why HFOs are Superior to HFCs

HFOs offer numerous advantages over older HFC refrigerants:

• Environmentally Friendly: HFOs have zero ODP and low GWP.
• Energy-Efficient: HFOs contribute to energy savings due to their efficiency.
• Lower Greenhouse Gas Emissions: Adoption of HFOs helps reduce the environmental impact associated with refrigerants.

Transition to HFOs in HVAC

Starting in 2025, many HVAC systems will transition to R-454B, a mixture of HFOs and HFCs with a GWP of 466, which is considerably lower than R-410A’s GWP of 2088. While current HVAC systems using R-410A can continue to be serviced, new systems after 2025 will be designed to use R-454B to align with updated environmental standards.

Trends and Future Developments in HFOs

R-454B is expected to become the standard refrigerant in residential HVAC systems, and other HFO blends will likely replace HFCs in commercial and industrial cooling applications. With a GWP of 466, R-454B falls well below the EPA’s 700 GWP limit, helping ensure a more sustainable future for HVAC systems.

Trane and other manufacturers are leading this transition by developing products compatible with these new refrigerants, helping reduce the frequency of future regulatory transitions. HVAC professionals are also receiving training on installing and servicing systems with these newer refrigerants to ensure a smooth transition for homeowners and businesses alike.