Understanding R-454B Refrigerant

R-454B Refrigerant at a Glance

According to Carrier, here are the key facts about R-454B refrigerant:

Carrier identifies Puron Advance™ (R-454B) as its lower-GWP refrigerant for newer residential HVAC equipment. EPA lists R-454B as an acceptable substitute for residential and light commercial air conditioning and heat pumps, subject to applicable use conditions.

What is R-454B Refrigerant?

Carrier's Puron Advance™ (R-454B) is a next-generation HVAC refrigerant blend composed of 68.9% R-32 (difluoromethane) and 31.1% R-1234yf (tetrafluoropropene). It is classified as an A2L refrigerant, meaning it has lower toxicity and mild flammability. HVAC systems designed for R-454B incorporate equipment and safety features appropriate for the refrigerant.

R-454B is being used in new air conditioners and heat pumps as the HVAC industry transitions away from higher-GWP refrigerants such as R-410A. Carrier systems using Puron Advance are designed specifically for the refrigerant and its applicable safety requirements.

How HVAC Refrigerant Works

To understand the upgrade to R-454B, it helps to know what refrigerant does. According to Carrier, refrigerant is a chemical compound that circulates through an HVAC system in a closed loop, absorbing heat from indoor air through the evaporator coil and releasing it outside (condenser coil). This cycle of changing from liquid to gas is what keeps your home cool.

Jim Snyder, owner of Irish Air in Indianapolis, Indiana, explains how refrigerant works.

“Simply put, you need refrigerant for an air conditioner or heat pump to function properly,” Snyder said. “Refrigerant is what allows the system to move heat energy into or out of the home.

“During cooling, the refrigerant absorbs heat from inside the home and carries that heat to the outdoor unit, where it's released," Snyder said. "In heating mode, a heat pump reverses that process and moves heat from outdoors into the home. Refrigerant is an efficient way to transfer that heat energy, which is what makes modern air conditioning and heat pump systems possible.”

Learn more about the basics of AC refrigerant.

R454B vs R410A: Key Differences

When comparing R454B vs R410A, the primary differences are global warming potential, chemical composition and system design requirements.

According to Carrier, R-454B operates at pressures similar to R-410A but is not a drop-in replacement. Existing R-410A systems should not simply be charged with R-454B because equipment components, controls and safety requirements are designed around the specified refrigerant.

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• Global Warming Potential (GWP): According to Carrier, R-410A has a GWP of 2,088, while R-454B has a GWP of 466. Carrier describes this as a 75% reduction in GWP.
• Composition: R-454B combines R-32 with R-1234yf, including an HFO component.
• Performance: Carrier states that Puron Advance is designed to provide similar performance to R-410A while meeting lower-GWP requirements.
• System compatibility: R-454B cannot be used as a direct replacement for R-410A in an existing system. Systems must be specifically designed and approved for the refrigerant being used.

R-454B Installation and Safety

Because R-454B is classified as an A2L mildly flammable refrigerant, installation and service requirements differ from those for traditional A1 refrigerants such as R-410A.

Carrier systems using Puron Advance are engineered with safety features designed for R-454B. Carrier says its products containing Puron Advance incorporate a refrigerant detection and dissipation system that can detect a leak and activate a fan to help disperse refrigerant.

For homeowners, this means R-454B equipment should be installed and serviced by a qualified HVAC professional familiar with A2L equipment and the applicable safety requirements.

Does R-454B Require Different Oil?

R-454B systems use lubricants specified by the equipment manufacturer and compressor application. Testing of R-454B has demonstrated compatibility with certain polyolester (POE) and polyvinyl ether (PVE) lubricants used in HVAC applications, but homeowners should not assume that the oil from an existing R-410A system can simply be transferred to an R-454B system.

The correct lubricant, refrigerant charge and service procedure should always be determined from the equipment manufacturer's specifications.

R-454B Operating Pressure

R-454B operates at pressures similar to R-410A, but the refrigerants are not interchangeable. Pressure-temperature relationships, charging procedures and equipment requirements must be accounted for when servicing an R-454B system.

For this reason, technicians should use the manufacturer's specified pressure, charging procedure and service documentation rather than applying R-410A service practices directly to R-454B equipment.

R-454B vs. R-32 vs. R-290

R-454B is one of several lower-GWP refrigerant options considered for HVAC applications. R-32 and R-290 (propane) have also been used or evaluated in various applications, but refrigerant selection depends on factors such as GWP, flammability classification, efficiency, system design, safety requirements and regulatory requirements.

Carrier selected Puron Advance™ (R-454B) for its newer HVAC products as part of its transition to lower-GWP refrigerants while maintaining performance and meeting applicable regulatory requirements. Carrier's Puron Advance refrigerant has a GWP of 466 and is classified as A2L.