Abstract
Since the environmental aspects are of increased importance today, the automotive industry is developing environmentally friendly mobile air conditioning systems. Initial studies carried out in the early 90s showed the potential of CO2 (R744) as an alternative refrigerant for automotive a/c applications. Visteons development shows that the a/c system using CO2 offers efficiency benefits and additional comfort.
As the thermodynamic processes of the current production air conditioning system and the a/c system using the environmental friendly refrigerant CO2 (R744) are different, the components will change. The basic system structure remains the same. Visteon successfully investigated possible system architectures including the heat pump cycle during the past years. Due to the higher pressures of the transcritical CO2 cycle, the design requirements for the system components changed and new control algorithms are needed. Test results from vehicle tests with a/c- as well as heat pump systems prove the potential of CO2 as a future refrigerant for mobile air conditioning systems.