JUST when it looked like so-called natural refrigerants were to be the long-term answer in many applications, two of the world's leading chemical companies have revealed details of a potential new range of low GWP blends. These are based on the technology behind the refrigerant HFO1234yf which is currently being adopted as a replacement for R134a in car air conditioning systems.
At Chillventa this week DuPont announced the development of Opteon XP10 a blend based on HFO1234yf and a number of other as yet unspecified gases but thought to be readily available HFCs. Meanwhile, Honeywell has revealed some of its work with five HFO blends that could eventually provide a low GWP alternative to many of today's common refrigerants.

DuPont's XP10, formerly known as DR-11, has been designed as a lower GWP (close to 600) alternative to R134a in new and existing medium-temperature commercial refrigeration systems. The gas is non-flammable and thermodynamic properties are said to be similar to 134a.

Pilot projects with ALDI Süd and Penny in Germany and Spar in Austria have been completed and DuPont says it is considering an initially limited commercial launch of Opteon XP10 between 2012 and 2013 in Europe.

Meanwhile, Honeywell is working on a number of HFO blends based on 1234yf, 1234ze (currently being used as a propellant and solvent) and a possible as yet unnamed third generation HFO. The blends being developed include replacements for R404A, R134a and R410A. GWPs will be 50-99% lower than existing refrigerants, says Honeywell, and will be non-flammable or have mild (A2L) flammability.