Propane AC a success on German trains
18th March 2025
GERMANY: In a world first, a passenger train with a propane air conditioning system has completed successful trials in Germany.
While the use of flammable refrigerants has previously been taboo for railway air conditioning, Germany’s federal environment agency UBA has revealed that a passenger train equipped with a propane system has operated in scheduled service for a year.
Prior to the trial project, the propane air conditioning module was tested on the test bench and subjected to extensive safety investigations.
In the project, a propane system module was installed in a Class 440 regional train. In parallel, the standard air conditioning system was operated using R134a. The architecture of both systems was similar. Both systems were operated on the train for over a year.
The evaluation showed that the propane air conditioning system was at least as powerful and energy-efficient as the R134a system in regular train operation. Simulation calculations also suggest that integrating a heat pump could also be energy-efficient, although this would need to be verified in practice.
The propane air conditioning system is now operating on ICE 3neo, Germany’s new 320 km/h high-speed train.
