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German Automakers To Use Air-Conditioners Based On Carbon Dioxide

Shift away from hydrofluoroolefin-1234yf hinges on flammability concerns

by Marc S. Reisch
March 14, 2013 | A version of this story appeared in Volume 91, Issue 11

German automakers say they will forgo deploying a fluorine-based refrigerant in the air-conditioning systems of their future cars in favor of using carbon dioxide.

Delays associated with the decision mean the automakers will miss a 2013 European Union deadline to start replacing the current refrigerant, hydrofluorocarbon (HFC)-134a, with a more environmentally benign one. HFC-134a has a global warming potential (GWP) that’s 1,430 times greater than an equivalent amount of carbon dioxide, whose GWP is 1.

The German firms Daimler, Volkswagen, Audi, and BMW were set to start using hydrofluoroolefin (HFO)-1234yf, which has a GWP of 4, this year. But in September Daimler released tests that it said proved the new refrigerant could cause a fire in a collision.

Now Daimler, like other German carmakers, plans to develop systems based on CO2. A Daimler spokesman tells C&EN that CO2 “from our point of view is currently the most promising solution.”

CO2 air-conditioning system suppliers will need time to scale up production, according to Ray K. Will, a director with consulting firm IHS Chemical. Indeed, Daimler says it plans to use HFC-134a for several more years.

The German decision doesn’t bode well for HFO-1234yf-maker DuPont. The firm says delaying the introduction of low-GWP coolants in Europe until 2015 isn’t good for the environment, noting that it will “result in higher greenhouse gas emissions equivalent to putting 400,000 additional cars on the road.”


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