A brief review and introduction to (1) magnetic heating, (2) magnetic refrigeration and (3) magnetic power conversion systems - working with materials showing the magneto caloric effect - is presented. This review is mainly based on studies initiated by the Swiss Federal Office of Energy on each of these three technologies. Today applied conventional technologies are listed and the best suited for a replacement by the magnetic counterparts are evaluated.Magnetic heat pumps with ground heat sources operating for floor heating systems were found to be an ideal application. The predicted coefficient of performance (COP) for such an application exceeds the characteristic value of conventional heat pumps working at equal heating power and temperatures of the source and sink.In the area of refrigeration technologies the household refrigerator without a freezing compartment and the central chilling unit - which may be of large size - have been found to show very good prospects for a successful application. The COP values of such large-scale systems are very high. Systems with (high-temperature) superconducting magnets could even be an economic solution.The main objective of the third study was to search for different applications of heat utilization where magnetic power conversion may present a good alternative to conventional power conversion technologies. This principle can be regarded to represent the inverse of the magnetic heat pump or refrigeration principle. Magnetic power conversion machines based on permanent and superconducting magnets are analyzed for numerous heat source temperatures and magnetic field strengths of a machine.As a main result the COP or thermodynamic efficiency of the investigated magnetic systems are presented.
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