The switch from CFC 12 to HFC-134a

The use of an HFC (HFC-134a) in car air-conditioning is well established, with MAC installation in around 80% of cars in USA and Japan for many years. In the EU the penetration of a/c systems in cars was previously low, about 10%, but will reach 80% in the next few years.

The availability of HFC-134a for car MAC systems enabled a rapid switch from CFCs (CFC 12) in the mid 1990s using MAC systems of essentially the same design and high level of safety. Other refrigerants did not offer this possibility. Based on these factors, it is clear that car companies made the appropriate choice when switching from CFC 12.

The use of HFC-134a has contributed to an enormous reduction in the environmental impact of individual cars with MAC systems:

  • Eliminating emissions of ozone depleting CFCs
  • Reducing the global warming of the car MAC system by about 92%, based on the elimination of CFC emissions
  • Reducing the global warming of the car in total by about 45%, based on the elimination of CFC emissions

Reduced Refrigerant Emissions

During the switch to HFC-134a major efforts were made to reduce refrigerant loss to atmosphere, which are today considerably less than those for an equivalent CFC 12 system in 1990. Improvements have been made in leakage rates from the system through better assembly, inspection, and component design. Reduction in refrigerant loss has also been achieved through better recovery and recycle procedures adopted by service engineers. The end-of-life vehicle directive requires recovery of HFC-134a when the vehicle is scrapped.

Impact of increasing MAC installation rates

The overall contribution of emissions from HFC-134a car MAC systems to global warming, even at an 80% market penetration rate, is less than the contribution of CFC 12 systems at a 10% market penetration rate, which was the approximate rate for the EU in 1990.

The requirement to improve HFC-134a refrigerant loss to meet the Directive emission requirements, has been achieved through improved component design, assembly and inspection. The trend towards reduced refrigerant charge due to eg microchannel heat exchangers, has contributed to reduced refrigerant loss in the event of emission due to vehicle accidents or residual losses with end-of-life recovery.