Auxiliary Heating Systems of Conventional and Heat Pump Type: Technology, Performance and Efficiency

A variety of different heating systems of heat-pump-type with refrigerant R744 have been investigated on the test bench for basic functionality, heating performance and efficiency. The experimental results served to validate calculations of Behr's simulation tool BISS that allows calculating the heat-up of different heating systems, considering the characteristics of the heating system, the engine and the passenger compartment. This paper gives an overview of the investigated R744 heating systems including heat pumps with ambient air or engine-coolant as heat source and dissipative heating systems to compare them with conventional systems such as the PTC heater and the fuel-fired heater. The main characteristics of the systems and the results of the heat-up-calculations are discussed.