Fluorocarbons & Sulphur Hexafluoride: Air conditioning - Mobile

Air conditioning has become standard equipment on most vehicles, enhancing traveling comfort and safety. Modern systems feature integrated cooling, heating, demisting and defrosting, air filtering, and humidity control.

MAC ( Mobile Air Conditioning ) improves:

  • passenger comfort and driver alertness when driving in high ambient temperatures
  • driver's visibility and passengers' security by de-misting and de-fogging windows during rainy or humid weather.

Energy-efficient air conditioning is essential for energy efficient vehicles. Keeping windows closed by using air conditioning during hot weather also saves energy, while preserving driver alertness.

There are a wide range of factors that affect the global warming contribution of a car, many of which result from how the car is used in practice.

The current design of mobile air-conditioning systems require a non-flammable, low toxicity refrigerant and, until 2011, HFC-134a is the dominant refrigerant used for passenger cars, trucks, trains, and buses.

Directive 2006/40/EC relating to emissions from air-conditioning systems in motor vehicles and amending Council Directive 70/156/EEC phases-out refrigerant HFC 134a in new vehicle types from 1 January 2011 and new vehicles from 1 January 2017. This is for passenger and light commercial vehicles, and requires a refrigerant with GWP < 150 to be used. Servicing of existing vehicles that contain HFC- 134a is not restricted except that repairs must be made if an abnormal amount of refrigerant has leaked from the system before refilling.

The Directive introduced leakage requirements for HFC 134a systems for new vehicles (until phase-out) setting maximum annual leakage rates of 40 grams per year for single evaporators and 60 grams per year for dual evaporators.

Several companies initially made announcements on the introduction of trans-critical CO2 systems. However the challenging technical and reliability issues, and the poor energy performance in warm and hot climates in comparison to HFC-134a meant that car companies thoroughly investigated a range of refrigerant options and selected a new low GWP fluorocarbon refrigerant HFO 1234yf.

By 2011 car companies in Europe, USA and Japan have announced the use of HFO 1234yf due to its technical and environmental performance in comparison to HFC 134a and trans-critical CO2.

More Info

Regular Conferences keeping track of MAC technologies progress are announced in the Coming Events section of our website, and in our monthly Newsletter.