Issue No. 4, 2006
Directive 2006/40/EC relating to emissions from air-conditioning systems in motor vehicles (also known as the MAC Directive) requires manufacturers to ensure that, from certain dates, leakages from those air-conditioning systems (using fluorinated greenhouses gases with a global warming potential higher than 150) do not exceed 40 grams of fluorinated GHG per year for single evaporators and 60 grams per year for dual-evaporator systems.
Article 7 of the MAC Directive also indicates that, with a view to enabling compliance on leakage requirements, the Commission will adopt, by 4 July 2007, a harmonised leakage detection test for measuring leakage rates of fluorinated greenhouse gases with a global warming potential higher than 150.
The Commission is currently looking at a leakage test method that would involve the use of a costly gas-analyzer system and require the following:
These requirements are currently being integrated into SAE J-2763, which is being developed by the Society of Automotive Engineers (SAE). It is intended to apply to all new passenger cars sold in
The existing SAE J-2727 standard is, however, already used globally and can be adapted to meet forthcoming EU requirements. Indeed, the market- monitoring tests conducted by ACEA and JAMA have shown that refrigerant leakage actually amounts to only about 8-12g per vehicle per year, a leak level which is substantially below the limit of 40g per vehicle per year. This suggests that high-precision measurement (as required by SAE J-2763) is not necessary for compliance with the MAC Directive, and that the use of a modified SAE J-2727 standard would therefore be adequate.
JAMA has also found a certain level of correlation between the leak quantity data of SAE J-2727 and the monitoring tests’ leak quantity data. A modification to the SAE J-2727 standard is now being formulated in order to increase correlation with the monitoring tests. SAE is also studying a modification of the leak quantity rating by multiplying the SAE J-2727 rating results with the coefficient derived from shed-test results.
A revision of SAE J-2727 was proposed and discussed during the 7th Alternative Refrigerant Systems Symposium (