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Key Performances of Mobile A/C Systems With Alternate Refrigerants
Published May 20, 2007 by Institution of Mechanical Engineers in United Kingdom
Prior to the 1990 years the transition from refrigerant R12 to R134a was lead by the Montreal Protocol to protect ozone layer and the new technology was largely disseminate in the worldwide market by year 1995. Then the Kyoto Protocol (supporting reduction of greenhouse effect) has increased the interest about low Global Warming Potential (GWP) refrigerants (for direct emission which is the larger part of today's mobile A/C system environmental contribution) and more concern about the system energy efficiency (for indirect emission). According to this new industry trend, a European regulation was drafted in July 2003 and finally voted and published in June 2005. From that time the deadline to introduce on the market a new type of car with a new refrigerant is fixed at 1st January 2011 and remaining time to have a validated technology able to fit with regulation has become very short. At the last Phoenix Forum (June 2006), all the car manufacturers announced that the deadline to choose a new refrigerant is estimated as June 2007. This situation is unusual because of the short time to decide and the increasing number of potential refrigerants to be investigated. By early 2000s the R744 (carbon dioxide as refrigerant) was the main stream of the development. It was also several times announced in new papers that the major real market launches occurred by early 2005. In the meantime, a significant progress in the development of newly formulated alternative bases which have been communicated prior to MAC summit in February 2006. This has lead to at least 3 new possible candidates including Fluid H from Honeywell, DP-1 from DuPont and AC-1 from Ineos. Today all automotive A/C suppliers or customers are facing an increasing level of development work for which they need to find a minimized common agreement in order to minimize risk and manage time to market. This paper is giving an initial view (based on early 2006 results) of the key performances which are affecting the mobile A/C system behavior.