DuPont-R1234yf-(2)USA: The US EPA has evaluated the new HFO refrigerants as having similar or lower global warming potential than CO2.

The HFOs 1234yf, 1234ze and 1233zd are amongst a number of fluorinated greenhouse gases and fluorinated heat transfer fluids being added to the Environmental Protection Agency’s Greenhouse Gas Reporting Rule.

The changes are designed to increase the completeness and accuracy of the carbon dioxide equivalent emissions calculated and required to be reported by suppliers and emitters.

Against the baseline GWP of 1 for CO2, HFO1234yf has been assigned a GWP of just 0.31. HFO1234ze(E), an HFO proving to be promising as an alternative for R134a in chillers and other stationary equipment, has been assigned a GWP of 0.97.  Its “cousin”, HFO1234ze(Z), which is being touted as having potential for use in for high temperature heat pumps, has a GWP of just 0.29.

Honeywell’s HFO1233zd(E), a possible replacement for R123 in centrifugal chillers and previously carrying a GWP of 6, has received a reduced GWP rating of 1.34.

Earlier this year, the influential Intergovernmental Panel on Climate Change (IPCC), was the first to confirm that both R1234yf and R1234ze(E) had GWPs less than 1, putting their environmental impact below that of carbon dioxide. 1234yf had previously been calculated to have a GWP of 4 and 1234ze and 1233zd as having GWPs of 6.

The final rule is effective on January 1, 2015.

Related news:

IPCC confirms HFO GWPs are less than 1 – February 3, 2014
USA: The Intergovernmental Panel on Climate Change (IPCC), has confirmed that both R1234yf and R1234ze(E) have global warming potentials below that of carbon dioxide. Read more…

Finally, a replacement for R123? – October 17, 2013
USA: While much has been made of the new HFO refrigerants 1234yf and 1234ze, another lesser known HFO could provide a much needed alternative to R123 in chiller applications. Read more…