The use of waste heat by means of heat exchangers is already realized in many modern DMUs but not yet in EMUs.

Energy saving

While for DMUs, the use of waste heat by means of heat exchangers is already implemented in some modern stock and barriers for a further diffusion are low, the extension of the measure to EMUs meets the following barriers:

Complexity

Compared to DMUs, the heat sources in EMUs are less concentrated along the train: motors, transformers and inverters are distributed along the entire train length. Furthermore the temperature of the individual heat source is relatively low (e.g. some 80-120 °C in the case of electric traction motors). To use this heat in an effective way requires a relatively sophisticated concept for the air flow of the heat exchanger. This will increase initial and maintenance costs as well as liability to defect.

The use of waste heat from traction equipment on the basis of heat exchangers is only feasible for MU stock because waste heat cannot be transported along the train.

DMUs: use of waste heat from traction equipment is a common feature in modern stock.

EMUs: not yet in use.