Association, Inc.

Issue No. 4, 2006

SAE J-2727—Simpler Leakage Test for the MAC Directive

The MAC Directive

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.

Future EU Leakage Test Method

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 Europe after 2008.

The Adequacy of the SAE J-2727 Standard

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 (Scottsdale, Arizona, June 2006). The formulation of the revision is currently underway and a finalised version is expected to be released soon.

JAMA believes that the revised SAE J-2727 will provide a simpler, more cost- effective leak measurement test methodology that will enable manufacturers to comply fully with the requirements of the MAC Directive.