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Climate Change:
Mobile Air Conditioners

Why care about mobile air conditioners?

HFC-134a (also called R-134a, Genetron 134a, Freon 134a, or Norflurane) is a gas that is widely used in air conditioners in cars and other cooling equipment. In vehicles, it replaced Freon-12. Freon-12 was phased out of use because it adversely affected the ozone layer in the earth’s upper atmosphere. While HFC-134a was an improvement for the ozone layer, it is a gas that has a high global warming potential. This means that it has the potential to trap much more heat in the atmosphere than carbon dioxide (CO2) does – 1,430 times more!

See the MPCA’s Web page on High Global Warming Potential Gases for more information about chemicals like HFC-134a.

What new requirements apply to mobile air conditioners?

Air conditioning systems contain many parts. The coolant can leak out at connections (fittings) or through the hoses. Legislation passed in Minnesota in 2007 requires that automobile manufacturers report the average amount of HFC-134a that leaks from motor vehicle air conditioners.

Scroll down to see lists of air conditioner leakage information for vehicles sold in Minnesota.

What vehicles are included?

This requirement applies to most new passenger cars, pick-up trucks and SUVs starting with model year 2009. They include light duty vehicles (up to 8,500 lb gross vehicle weight rating (GVWR)) and medium duty passenger vehicles (up to 10,000 lb GVWR). Heavy duty vehicles (over 10,000 lb GVWR) are not included.

When does this apply?

This requirement applies to new motor vehicles sold in Minnesota on or after January 1, 2009.

Instructions and reporting form for manufacturers

Submit the reporting form summarizing the results of the air conditioner leakage rate calculation to the MPCA by October 1, 2008 for vehicles to be offered for sale as of January 1, 2009. When a new model will be offered for sale, the report is due at least 90 days prior to the first date it will be available.

NOTE: For vehicles that are manufactured by one company but sold under another company’s nameplate or brand, it is acceptable for the manufacturer to prepare the report for all the vehicles it produces. To ensure that all makes and models are reported and to avoid duplication, manufacturers and purchasers/marketers should agree on who will be responsible for their data prior to a report’s being submitted.

The Excel report form is a workbook with includes two spreadsheet tabs. One tab contains more detailed instructions for completing the report. The other tab is the report form itself. You will need to complete a report for each model or group and save the file. Submit completed forms to mac.hgwp@pca.state.mn.us.

• Letter to Motor Vehicle Manufacturers, Reporting Leakage Rates of HFC-134a from Mobile Air Conditioners, August 29, 2008
• Instructions and Reporting Form – Mobile Air Conditioning (MAC) Leakage Rate Disclosure

For further information, contact Barbara Jean Conti, at barbara.conti@state.mn.us or 651-757-2288.

Mobile Air Conditioner Leakage Rate Data

“Vehicle air conditioning systems may leak refrigerants. Information provided in the chart compares the potential global warming effects of refrigerant leakage from different makes and models of vehicles.”

These lists contain air conditioner leakage rate information that was submitted by the car manufacturers. The leakage rates provided are an average for the type of vehicle over the course of a year. The leakage rate is determined by the types of connectors, the compressor, and hoses in the air conditioner assembly. Please note that any individual vehicle may have a different leakage rate – which may be better or worse – due to a variety of possible factors. Those factors may include how the air conditioner system is assembled or road damage.

The average refrigerant leakage rate reported for the 2009 model year cars is 15.1 grams per year, or just over 0.5 ounces. The average percentage loss is about 2.4% of the full system charge. Those amounts may not sound like a lot. However, because there are so many cars, emissions from leaks can really add up.

• Model Year 2009 leakage rate list – alphabetical order by make (manufacturer)
• Model Year 2009 leakage rate list – ranked by percent loss from system
• Mobile Year 2009 leakage rate list - ranked by leakage amount
• Model Year 2010 leakage rate list – alphabetical order by make (manufacturer)
• Model Year 2010 leakage rate list – ranked by percent loss from system
• Mobile Year 2010 leakage rate list - ranked by leakage amount

What will happen next?

In the future, replacements for HFC-134a will likely be made available. Currently, using replacement chemicals in your vehicle may void the warranty. Mobile air conditioner designs may have to be changed to be effective and safe using different refrigerants. Manufacturers are evaluating the potential to change the refrigerant to a chemical called HFC-152 or a system that uses compressed carbon dioxide. More recent research looks at HFO-1234yf, another chemical that has a lower global warming potential than HFC-134a.

Where can I find more information about vehicle emissions?

• US EPA Green Vehicle Guide
• US EPA and US Department of Energy joint motor vehicle information
• California’s Mobile Source Program - Contains both general information and material specific to California
• California’s “Drive Clean” rating system and driving guide
• MPCA’s motor vehicle information
• Environmental Defense Fund’s Clean Fleets Partnership Program