Honeywell’s Solstice N13, aka R450A, is already being trialled in CO2 cascade systems

USA: The EPA is to list refrigerant R450A, a substitute for R134a, under the USA’s SNAP programme. The listing would also see CO2 being accepted for use in refrigerated transport applications.

R450A, developed by Honeywell as Solstice N13, is seen as being acceptable in a variety of refrigeration and air conditioning applications under the SNAP (Significant New Alternatives Policy) programme.

In addition to CO2 in refrigerated transport, the listing would also see the new R123 substitute R1233zd(E) being accepted for use in non-mechanical heat transfer and in flexible polyurethane foams and the low GWP propellant HFO1336mzz(Z) in a variety of foam-blowing end-uses.

R450A is seen as a suitable substitute in a wide range of new and retrofit applications including retail food refrigeration systems, refrigerated transport, water coolers, cold storage warehouses, industrial process refrigeration, reciprocating, screw and scroll chillers, centrifugal chillers, household refrigerators and freezers and industrial process air-conditioning. It has also been listed for use as retrofit only in vending machines.

A blend of 42% R134a and 58% HFO1234ze(E), R450A is non-flammable, has a zero ODP and a GWP of about 601.

It is currently being trialled by Honeywell in a number of installations, where it is best suited as an alternative to R134a in chillers and as the MT refrigeration element of distributed CO2 cascade systems. Such a system is being trialled at a new large Auchan hypermarket near Paris in a new design low-energy refrigeration system. It was also recently employed as a drop-in in the conversion of a medium temperature R404A refrigeration system in a Dia supermarket in Valencia.


Also sold by Honeywell as Solstice N12 Refrigerant, 1233zd(E) was previously listed as acceptable for use in centrifugal chillers in August 2012. It has been promoted as a low GWP replacement for R123 and is being used for the first time in Trane’s Series E CenTraVac lunched in June.

Its additional listing makes 1233zd(E) acceptable for use in the organic Rankine cycle and as a blowing agent in flexible polyurethane foams.


Previously listed as a refrigerant in a number of other refrigeration and air conditioning end-uses, CO2 is, for the first time, being added to the acceptable refrigerants under the SNAP programme for use in refrigerated transport.

Related stories:

Spanish store first to test new R404A “drop-in” – October 5, 2014
SPAIN: A low GWP refrigerant, originally developed as a replacement for R134a in chillers, is being tested as a “drop-in” replacement for R404A in a Spanish supermarket. Read more…

Trane first with 1233zd chiller – June 30, 2014
FRANCE: A new non-flammable, low GWP refrigerant HFO1233zd(E) is being used for the first time in a new Trane chiller. Read more…