Overview of the effects on vehicle air conditioning systems and mobile systems OFF-Highway F-GAS IN CHANGE – WHAT'S IN AHEAD FOR MOBILE SYSTEMS
Vehicle air conditioning systems were operated with the refrigerant R12 until the 1990s. R12 belongs to the chlorofluorocarbon (CFC) group of halogenated hydrocarbons. These gases have a high ODP (Ozone Depletion Potential), causing depletion of the ozone layer in the atmosphere and consequently increased UV radiation reaching the Earth's surface.
The global phase-out of CFC production began with the Montreal Protocol of 1987, which was signed by many countries, including the United States and the Commission of the European Communities. The use of R12 in vehicle air conditioning systems was prohibited from 1996 onwards, and R134a became the primary replacement refrigerant. This refrigerant is a hydrofluorocarbon (HFC) containing no chlorine and therefore has no ozone depletion potential.
However, the disadvantage of R134a is its high GWP (Global Warming Potential). Its greenhouse effect is 1,430 times greater than that of carbon dioxide. Since 2011, refrigerants with a GWP greater than 150 have no longer been permitted in newly introduced vehicle types, and since 1 January 2017 their use has been prohibited in all new vehicles. This was established by Directive 2006/40/EC and applies to motor vehicles of categories M1 and N1. Regulation (EC) No. 842/2006 provides the general framework for the regulation of fluorinated hydrocarbons, which is further specified for motor vehicles by Directive 2006/40/EC.
Regulation (EU) No. 517/2014 introduced new rules governing the availability of hydrofluorocarbons (F-gases) by implementing a quota system. An average value in tonnes of CO₂ equivalent was established based on the quantities of F-gases placed on the market between 2009 and 2012. This average value was defined as 100% in 2015, with a gradual reduction to 21% by 2030 through restrictions on the quantities placed on the market. As a result, the availability of F-gas-based refrigerants is decreasing, leading to price increases and creating pressure across all applications using these substances to switch to alternatives.
The new Regulation (EU) 2024/573 further tightens these reduction steps and aims for a complete phase-out by 2050.
Previous regulations and directives do not yet impose specific restrictions on the use of F-gases in mobile equipment. This includes heavy-duty commercial vehicles, vans, non-road mobile machinery and equipment used in agriculture, mining and construction, as well as trains, underground railways, trams and aircraft. The European Commission intends to publish a report by 1 July 2027 to assess whether cost-effective, technically feasible, energy-efficient and reliable alternatives to fluorinated greenhouse gases are available for mobile refrigeration and air conditioning systems. The outcome may have direct implications for the mobile sector.
Regulation (EU) 2024/573 also updates the threshold values for leak inspections. Leak checks are required for systems containing fluorinated hydrocarbons (e.g. R134a) with refrigerant charges exceeding 5 tonnes CO₂ equivalent and for HFOs (e.g. R1234yf) with refrigerant charges exceeding 1 kg. From March 2027 onwards, these leak inspections will also become mandatory for mobile off-highway applications. They can be incorporated into regular maintenance intervals.
The regulations in the United States (US AIM Act 2020) differ from those in Europe. In the U.S., the prohibition on placing refrigerants with a GWP greater than 150 on the market will apply from January 2028 to the MVAC (Motor Vehicle Air Conditioning) sector, including non-road vehicles such as agricultural machinery, construction equipment, mining vehicles and municipal vehicles. Hydrocarbons such as propane (R290) are not approved for MVAC applications. Propane belongs to safety class A3, indicating higher flammability. Currently, only R1234yf and R744 are approved for mobile applications in the United States. Although R1234yf is also flammable, it belongs to safety class A2L, meaning it is mildly flammable with a low burning velocity.
In summary, there is a clear trend towards R1234yf becoming the standard refrigerant for mobile applications. However, the European legal framework is still awaiting a decision regarding PFAS substances. PFAS are per- and polyfluoroalkyl substances as well as gases that are proven or presumed to degrade into PFAS. HFO refrigerants such as R1234yf decompose in the atmosphere to form TFA (trifluoroacetic acid), which belongs to the PFAS group. The ongoing discussions at EU level regarding a PFAS initiative under the REACH Regulation may therefore have significant implications for refrigerants. A corresponding regulation is currently expected between 2027 and 2028.
Since both R1234yf and propane (R290) are flammable substances, a risk assessment should be carried out during system design. The disadvantage of propane is its high flammability, classified as safety group A3 according to DIN EN 378-1. It is therefore subject to specific safety requirements. With appropriate safety measures in place, systems can be operated safely depending on their intended applications, as demonstrated by the practical experience gained from systems that have been in operation for many years.
