Measurement of Leak Flow Rates of Mobile Air Conditioning (MAC) Components - How to Reach a Generic Approach

The components of mobile air conditioning (MAC) systems follow different emission laws. Hoses are typically following a diffusion law that needs to identify solubility coefficient, permeability coefficient, and dependence on the temperature. Shaft seal, fittings, valves show different behaviors dominated by viscous law, the diffusion representing a limited part of emissions. Two hundred development tests carried out on those different components are used to elaborate behavior laws for hoses and hose materials, the effect of clearances for fittings is also studied. The paper concludes at what conditions it is possible to elaborate a generic approach allowing to limit the number of measurements.