USA: Honeywell has revealed details of its new lower GWP refrigerant replacement for R134a in new medium temperature commercial refrigeration, chillers and heat pumps.
Solstice N15, designated R515B by ASHRAE, is an A1 non-flammable refrigerant blend with a GWP of just 293 under AR4.
A blend of R1234ze (91.1%) and R227ea (8.9%), R515B is said to have zero glide and low discharge temperatures with an efficiency to match R134a.
R515B is designed for new equipment and is not a retrofit product for existing systems. Honeywell lists its applications as remote condensing units, supermarket multiplex systems, stand-alone units, medium temperature side of cascade systems, flooded systems and high ambient air conditioning.
It has already been approved for use by Danfoss in its new Turbocor TG490 compressor for air- and water-cooled chiller applications.
The blend’s component R227ea is little used as a refrigerant due to its very high GWP of 3220. It is used here in a small proportion to suppress the mild flammability of the low GWP HFO R1234ze. While R1234ze is classified as an A2L refrigerant, it is only flammable above 30°C. EN 378, which is harmonised with the EU PED directive, does not recognise R1234ze as a hazardous substance, but as a PED group 2 fluid.
R227ea was originally introduced to replace the CFC R114 and as a zero ODP alternative for the fire suppressant Halon 1301. It is also used in metered dose inhalers and in some foam blowing applications.