BMW picks CO2 air conditioning

BMW has chosen CO2 as the refrigerant for its next-generation air conditioning systems.

Carmakers need a refrigerant that is less harmful to the environment. They have until 2011 to comply with EU rules that will ban the use of the current chemical, R134a, in air conditioning systems.

BMW spokesman Rudi Probst told Automotive News Europe that the carmaker has chosen a CO2-based solution because the other option was a chemical solution, “which we are not happy with technically.”

Other German automakers will announce at next week’s IAA in Frankfurt whether they have chosen CO2 as the refrigerant for their future air conditioning systems, sources at leading suppliers told ANE.

Suppliers and automakers have spent years debating whether CO2-based systems are better than those that use competing refrigerant solutions, such as R152a.

When asked for further details about its system, BMW declined comment. The automaker referred questions to the German auto industry association, the VDA, where, said BMW, all the German carmakers were “working together on the issue.”

The VDA did not return phone calls or e-mails asking for comment.

Other German automakers would not comment.

Suppliers such as Behr, Denso, Delphi, Visteon and Valeo have been waiting for automakers to decide which refrigerant they want. The choice affects a market worth more than 5 billion euros in 2006, according to analyst Frost & Sullivan.

Thomas Aney, an analyst at Dresdner Kleinwort in Frankfurt, believes automakers purposely delayed their decision on future air conditioning systems.

“It’s just the same as what we saw when there was a deadline for tire pressure monitoring,” he said. “The car companies just waited and waited until the last minute, and then they pushed the price.”

EU rules will outlaw R134a on new cars sold after 2011.

The majority of cars produced in Europe last year included air conditioning. The feature is in nearly every car sold in the premium, upper-medium and large segments.

Scientists have developed a scale called global warming potential (GWP) to rate how damaging to the earth's ozone layer a specific coolant is.

CO2 refrigerant, which is known as R744, has a GWP of 1, the lowest level. R134a has a GWP of 1,430, or 1,430 times more damaging than CO2. Unlike the CO2 emitted from cars' exhausts, the CO2 in the air conditioning systems is contained. Even if some CO2 leaks from the system, the effect on the environment is small.

R152a has an intermediate GWP level of 124.

CO2-based systems will be up to 25 percent more energy-efficient than the best of today’s R134a systems, said Nurdal Kuecuekkaya, vice president of climate systems at Visteon.