Revolutionizing Train Comfort: Deutsche Bahn and DLR Extend Innovative Climate Control Research

Deutsche Bahn (DB) and the German Aerospace Center (Deutsche Zentrum für Luft- und Raumfahrt or DLR) have been jointly researching how to achieve comfortable, effective, and energy-efficient air conditioning since 2020. Recently, they extended their successful research collaboration for another three years.

A regular ICE train car has been converted into a "Demonstrator Vehicle for Innovations in Passenger Comfort and Air Conditioning," or DIRK, equipped with sophisticated sensor technology to research technologies that enhance passenger well-being and reduce the energy needs of air conditioning. The car is located at DB Systemtechnik’s facility in Minden, Westphalia. Prof. Andreas Dillmann, Director of the DLR Institute of Aerodynamics and Flow Technology, and Christoph Kirschinger, Managing Director of DB Systemtechnik, DB’s engineering office, signed the new cooperation agreement today.

In the coming years, experts will use DIRK to study how aerosols in the air can be safely and effectively controlled. They will test new filter, ventilation, and air conditioning concepts in a joint EU-funded research project under real ICE car conditions. These evaluations will incorporate findings from previous practical studies in DIRK as well as theoretical work from the DLR Institute of Aerodynamics and Flow Technology. 

Prof. Meike Jipp, Head of Energy and Transport at DLR, said, "The railway is a key mode of transport for climate-friendly mobility that meets societal demands. Joint research by DLR and Deutsche Bahn helps to strengthen rail as a comfortable alternative to cars and planes. To encourage more travelers to switch to rail, comfort, air conditioning, and—especially post-COVID—safety play a crucial role. We aim to continue researching these factors and translating them into technological innovations."

Christoph Kirschinger, Managing Director of DB Systemtechnik, added, "Sensitivity to air quality and a comfortable indoor climate has significantly increased in recent years. With DIRK, we have been able to provide valuable insights into effective air treatment and distribution in train cars. This has not only enhanced passenger comfort but also enabled more efficient use of energy for heating and cooling. We intend to continue this research to evaluate new innovations that further increase passenger comfort and well-being. Our goal, as part of our 'Strong Rail' strategy, is to double the number of passengers on our long-distance trains in the coming years."

In DIRK, researchers are not only monitoring the temperatures of air and surfaces but also air movement, humidity at various points, and air quality, including CO₂ levels. Surveys with test subjects regarding their individual temperature perceptions at different air conditioning settings have also been conducted in DIRK. With its extensive documented measurements, DIRK is available to the entire rail sector for studies and as a reference model for comfort and air conditioning.

The research results from DIRK benefit both passengers and railway companies: They support onboard comfort as well as the efficient use of heating and cooling energy. After propulsion, air conditioning is the second-largest energy consumer in rail vehicles.

Source: Deutsche Bahn Press Releases