GERMANY: Mercedes to use CO2 air conditioning

By Graeme Roberts | 20 October 2015

To comply with new EU-mandated environment requirements taking effect in 2017, Daimler's Mercedes-Benz said it would equip European market S- and E-Class models as the first production passenger cars with CO2 air conditioning systems. Cars using a new, alternative refrigerant will have a special fire protection system.

The automaker said CO2 as a refrigerant necessitates the redesign of crucial components because systems operate at a pressure of more than 100 bar – some 10 times higher than that of today's systems. This means that all components including the hoses and seals need to be redesigned.

Mercedes claims to be the first automobile manufacturer to award development contracts and place production orders for CO2 air conditioning systems and their components and has worked with suppliers and regulators to determine standards.

Other models will use a new R1234yf refrigerant with a specially developed protective system tailored to the specific vehicle configuration. In the event of a severe frontal collision, the patent-pending system ensures that the resultant refrigerant/air mixture is separated from the hot engine components in the engine compartment and that these components are cooled and effectively keeps the mixture from bursting into flames. This is made possible by a gas generator, which releases inert argon gas specifically at the relevant hot spots. This effectively keeps the mixture from bursting into flames.

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