VW says CO2 as a refrigerant — also known as R744 — has lower greenhouse gas effects than conventional refrigerants, with a GWP (Global Warming Potential) value of 1, or 99.3 percent below the European Union-specified GWP limit of 150. The German automaker says the technology will be rolled out progressively over its entire vehicle fleet.
German media sources report four other carmakers — Daimler, Audi, BMW and Porsche — will also switch to CO2 technology in mobile air conditioning systems as an alternative to R-1234yf, R744.com reports.
R-1234yf was developed by Honeywell and DuPont, intended as a more environmentally friendly refrigerant and an alternative to R134a, which is being phased out in the EU and will be banned in 2017.
In September 2012, however, Daimler announced it would stop using R-1234yf because of safety concerns. In some head-on collision test scenarios, the refrigerant burst into flames, Daimler said.
Honeywell and DuPont have defended the product, arguing there are other flammable materials under the hood of a car. The companies said R-1234yf was not flammable in similar testing conditions, SAE International reports.
According to the EPA, R-134a does not deplete the ozone layer, but has a GWP that is approximately 1,400 times greater than that of CO2.