Mobile Air Conditioning: R&D is intensifying

The Mobile Air-Conditioning sector (MAC) is currently in the news. On January 31, 2006, the European Parliament and the Council reached agreement on a Directive (to be transposed at national level) "relating to emissions from air-conditioning systems in motor vehicles" requesting the following: - as of January 1, 2008: limits on the rate of refrigerant leakage for new models of cars; - as of January 1, 2011: banning of HFCs with a Global Warming Potential (GWP) higher than 150 for new models of cars; - as of January 1, 2017: banning of HFCs with GWPs higher than 150 for all cars. The final endorsement of this agreement by the Parliament and the Council is expected by mid-2006 and the entering into force of the Directive by 2007. The content of this Directive is not unexpected. This agreement does however confirm the need to carefully reexamine the previously available refrigerant options in the MAC sector in Europe: R134a (an HFC) is currently by far the most widely used refrigerant in automobile air conditioning; given its GWP (1300) its use in new European vehicles will be banned by 2011. Countries like the USA and Japan are placing the emphasis on the environmental impact of refrigerant leakage: about 20% of the refrigerant charge in MAC systems is released into the atmosphere annually. For this reason, an agreement between Europe and the USA on the harmonization of testing and engineering standards to curb greenhouse gases emissions from MAC systems was recently announced. The MAC Summit 2006 held in February 2006 in Austria demonstrated that research and development is intensifying in order to develop MAC systems meeting tomorrow's requirements: reduced climate impact thanks to the use of refrigerants with low GWPs but high energy efficiency, better tightness, lower refrigerant charge, safe use and low manufacturing cost. This summit also provided an opportunity to present emerging trends in refrigerant use worldwide: - R152a, an HFC with a GWP of 120, will still be authorized in Europe, but its flammability will deter use; - R290, a hydrocarbon, has an even lower GWP (20), but is even more flammable; these two refrigerants are not expected to represent a strong trend on the market; - R134a has a high GWP and is to be banned in Europe, but its energy efficiency is still being intensively investigated; - CO2 (R744) has a negligible GWP (= 1) but has a drawback: its operating pressure is 6 to 7 times higher than that of R134a, and thus requires suitably designed systems and until mass production can be achieved will incur additional costs. However, forecasts presented at the MAC Summit indicate that some 100 000 cars using CO2 could be sold in Europe by 2008, rising to 2 million by 2011. Furthermore, two major chemical companies, DuPont and Honeywell, both announced the development of new low-GWP refrigerants currently under testing. According to these companies, these refrigerants are expected to offer a comparable performance to that of HFC-134a. DuPont has tripled its R&D investment in this field and specified that its new refrigerants were expected to meet the EU Directive commitments, to be non-flammable and commercialized within 3-5 years. MAC Summit experts generally considered that at the moment, until sufficient data on these new refrigerants are available, CO2 and, to a lesser extent- outside Europe- HFC-134a systems were the main options: CO2 provides better energy efficiency at mild and mid-ambient temperatures (25°C and below) compared with HFC-134a but is less efficient at higher temperatures. They stressed that the efficiency of both systems has almost doubled over the past 10 years and that potential further improvements (20-45%) are expected soon.