  The electrification of public transport vehicles offers the potential to
relieve city centers of pollutant and noise emissions. Furthermore, electric
buses have lower life-cycle greenhouse gas (GHG) emissions than diesel buses,
particularly when operated with sustainably produced electricity. However, the
heating, ventilation, and air-conditioning (HVAC) system can consume a
significant amount of energy, thus limiting the achievable driving range. In
this paper, we address the HVAC system in an electric city bus by analyzing the
trade-off between the energy consumption and the thermal comfort of the
passengers. We do this by developing a dynamic thermal model for the bus cabin,
which we simplify by considering it to be in steady state. We introduce a
method that is able to quickly optimize the steady-state HVAC system inputs for
a large number of samples representative of a year-round operation. A
comparison between the results from the steady-state optimization approach and
a dynamic simulation reveal small deviations in both the HVAC system power
demand and achieved thermal comfort. Thus, the approximation of the system
performance with a steady-state model is justified. We present two case studies
to demonstrate the practical relevance of the approach. First, we show how the
method can be used to compare different system designs based on a year-round
performance evaluation. Second, we show how the method can be used to generate
accurate setpoints for online controllers. In conclusion, this study shows that
a steady-state analysis of the HVAC systems of an electric city bus is a
valuable approach to evaluate and optimize its performance.
