Elaboration of a Correlation Factor Based On Fleet Tests and Mobile Air Conditioning (MAC) System Laboratory Tests 2007-01-1187

The EU Commission has decided to establish a regulatory type test approval method for the guarantee of initial leak tightness of R-134a MAC systems in Europe. This method of test will be applicable as of July 2007. In order to establish the method of test the European Association of Car Manufacturers (ACEA) has launched a study for the development of a technically-sound method. The Center for Energy and Processes has carried out the study at three levels: a fleet tests of 40 vehicles, laboratory tests on 40 MAC systems identical to the ones installed on the fleet cars, and tests of 160 components. The paper describes the charge and recovery method in order to guarantee a precision of recovery of 0/-1 g for the fleet of vehicles. Results of the fleet tests show that the average emission level is of 10 g/yr. The paper describes also the laboratory method of test based on the measurement of the R-134a concentration inside mini-sheds using infrared techniques. A behavior law is elaborated allowing to refer the laboratory test results to the leak flow rates (LFRs) as measured on the fleet cars.