Leak flow rate of MAC systems and components 1 – Laboratory tests, fleet tests and correlation factor

According to the EU regulation 706/2007, the leak flow rate of a Mobile Air Conditioning (MAC) system must be tested based on a qualified method. The Center for Energy and Processes (CEP) has cooperated with ACEA (European Association of Car Manufacturers) in order to establish the test method. Laboratory tests have been undertaken on 40 MAC systems, more than 100 components, and field tests on 40 vehicles. In this paper the laboratory test protocol for leak flow rate measurements of HFC-134a concentration inside a test chamber using infrared techniques is presented. Leak flow rates in standstill and running modes have been studied. Comparing the laboratory tests and the fleet test results a correlation factor has been established to predict annual leak flow rates of MAC systems in real life conditions based on leak flow rates measured in laboratory.