The electrification of passenger vehicles has been progressing significantly in the past years revealing new challenges for the design of heat-pump systems. Several approaches have been proposed for improving the energy efficiency of the systems, while regulatory rules and newly emerging technologies keep on posing new challenges for the system design. One of the important areas for system optimization is the acoustical response of the heat pump systems to the compressor noise. With the lack of significant noise coming from the engine, the heat-pump components are one of the main sources of unpleasant or loud sounds reaching the vehicle passengers. The situation gets even more important when it comes to newly used refrigerants like CO2 with the large pressure differences across components present in the system. In this paper the acoustic flow noise propagation from the source being the compressor on to the piping and the heat exchangers is investigated. Moreover, different modeling options from a component-level to system- level are presented and their results are compared.