The design of the passenger compartment’s air conditioning system is based on the specifications of the Association of German Public Transport (VDA). The level of comfort in the outer limits, where ambient temperatures are either extremely hot or extremely cold, is adjusted. Instead of a predetermined absolute interior temperature, a defined reduction or increase to the external value is used. Thermal management has been optimised down to the last detail.
This means that all heat-emitting components are networked together to optimise the energy required for cooling. The performance of heating and air conditioning also varies depending on the number of passengers on board. This is determined via the axle load sensors.
Since the city bus passengers usually spend only a short time in the vehicle, this slight comfort limitation in favour of energy consumption and therefore range is perfectly reasonable. On the other hand, since drivers spend their entire work day in the city bus, their requirements are somewhat higher – especially recognising that maximum driver fitness needs to be safeguarded. With this in mind, the air conditioning of the driver’s work station is regulated separately and independently of the passenger compartment.
Overall, the energy required for the eCitaro’s heating, ventilation and air conditioning is close to 40 per cent lower than for the current Citaro with an internal combustion engine.