The new successor to R410A?

The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) has given Honeywell’s new stationary air conditioning refrigerant R466A (also known as Solstice N41) the official designation A1 – non-toxic and non-flammable.

The classification could be a key factor for manufacturers deciding which refrigerant to use in their systems in the medium-term. As a result of the HFC phase-down and the transition to refrigerants with a lower global warming potential (GWP), many manufacturers have already switched from R410A (with a GWP of 2,088) to R32 (675). In Australia, more than half of all small air conditioners imported now contain R32.

However, R32 is classified as A2L – mildly flammable – making it unsuitable for units with larger charge sizes, such as VRF units. There are also lingering questions about exactly how flammable A2L gases are.

R466A may be seen as a more favourable option, given its A1 classification and its ability to be used in a wider range of systems. Its GWP of 733 is comparable to R32.

Like R410A, Honeywell’s new refrigerant contains both R32 and R125, as well as CF3I (trifluoroiodomethane), a flammability suppressant.

Honeywell has indicated that Solstice N41 will be commercially available in 2020.

“We developed Solstice N41 to address the many regulatory and safety challenges facing the industry,” says George Koutsaftes, president, Honeywell Advanced Materials.

“This product is the first non-flammable refrigerant developed as an R410A alternative, and is also better for the environment, energy efficient, and cost-effective for the end user with minimal conversion required. Safety is paramount and the properties of Solstice N41 make it a groundbreaking technology for the industry.”

According to Honeywell, early testing indicates that Solstice N41 requires minimal changes to equipment, allowing original equipment manufacturers (OEMs) to easily convert their systems.

The new refrigerant is being tested by over 15 OEMs and leading compressor manufacturers and has accumulated more than 30,000 hours of testing in different applications such as commercial AC (VRF, rooftops) and residential AC (unitary).