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Eco-friendly HVAC units look to keep rail cool
Unlike traditional heating, ventilation, and air conditioning (HVAC) units, a new generation of eco-friendly HVAC systems use natural refrigerants like CO2.
In doing so, they not only reduce carbon emissions but also energy consumption.
The Challenge
New HVAC units must be installed within the space already available and cannot add any additional weight to the vehicle.
The HVAC system must be designed with the close collaboration of the HVAC supplier, vehicle integrator and train operator.
How we do this?
To address these challenges, the Shift2Rail Programme delivered several prototype HVAC systems based on heat pumps that use CO2 as a natural refrigerant.
New generation HVAC prototypes
Field Testing
Main Outcomes*
Wabco Faiveley prototype
Prototype installed on one end vehicle of a DB single-deck train.
- Met established comfort conditions
- 7% lower annual energy consumption
- No significant maintenance requirements
Knorr-Bremse prototype
Prototype installed on Bombardier vehicle used by DB for regional/commuter services.
- Achieved satisfactory level of comfort
- 7% lower energy consumption
- Higher efficiency at ambient temperatures below 23°C
- Slightly higher maintenance requirements
*Compared to state-of-the-art HVAC unit using R134a refrigerant
The potential benefits of CO2-based HVAC systems
- Reducing emissions
- Decreasing energy use
- Increasing vehicle comfort
- Improving passenger satisfaction
Who benefits
There is a clear opportunity for:
Final users
Railway operators
Suppliers
To develop a new generation of eco-friendly HVAC systems tailored to the unique needs of the rail sector.
Did You Know?
Conventional HVAC systems that use artificial refrigerants produce climate change causing greenhouse gases.
Fast Fact
Other sources of natural refrigerants, such as propane, could offer even lower energy consumption than CO2.
Key Finding
Heat pumps using CO2 as a refrigerant are the most promising HVAC technology.