Deutsche Bahn: two years of zero-emission train air conditioning

According to NASA, the last decade was the warmest since records began in 1880, and temperatures are continuing to rise worldwide. Air conditioning in rail transport has therefore become essential for the comfort and well-being of passengers. However, the cooling systems in particular, which have become necessary due to climate change, are a significant source of pollution and account for around 30 per cent of a train’s energy consumption.

High technology for a low CO2 footprint

Wabtec’s Green Air technology offers a solution to this paradox by using the refrigerant R290, also known as propane. Conventional HVAC systems use synthetic refrigerants such as R-134a, which has a global warming potential (GWP) of 1430. At 0.2 the GWP of R290 is significantly lower. Green Air technology reduces the carbon foot-print of the train air conditioning system with similar cooling performance and can be safely operated at temperatures of up to 50°C, making it suitable for all climate zones. In addition, R290 already fulfils the future requirements for fluorinated greenhouse gases (F-Gas Regulation) and the guidelines for handling per- and polyfluorinated alkyl substances (PFAS).

A proven solution for Deutsche Bahn

In June 2023, DB became the first operator to use Wabtec’s Green Air technology by implementing it in two DB ICE 3neo high-speed trains for air conditioning in the passenger compartments and driver’s cabs. In May 2024, it launched the second phase of the project by applying it in DB Mireo Plus trains on four regional routes.

Before the technology was integrated in DB trains, one of Wabtec’s tasks was to investigate and assess the risks of using a flammable refrigerant for air conditioning in trains. It was then necessary to develop technical solutions which would ensure safe operation over the entire service life of the air conditioning system. Green Air was tested and validated by external experts, including the Federal Institute for Mate-rials Research and Testing (BAM) in Germany and TÜV SÜD.

Thanks to its successful collaboration with DB, Wabtec has become the first provider of a solution with R290 for air conditioning systems. Green Air, which is available for new rolling stock, refurbishments and retrofits, offers a reliable and safe solution. It can be seamlessly integrated into the infrastructure of today’s train systems to comply with current and future regulations while drastically reducing their contribution to climate change.