Future developments in magnetocaloric refrigeration and heat pumping.

Since the earliest days of engineering magnetocaloric devices for applications near or above room temperature, a total of about 70 prototypes have been developed in different parts of the world. Despite the fact that we have seen an exponential growth in the number of publications in this field, it is not easy to relate these activities to the S-curve of technology development. A multitude of articles based on minor modifications to already-know compositions and a large number of repetitions of earlier scientific or engineering achievements tend to blur the transition from science to technology, with future directions being unclear. There is strong competition among involved institutes and industries, but with a low level of open, trust-based international collaborations. Simultaneously, important technical problems remain unsolved or, in some cases, even untouched. It is therefore not a coincidence that we tend to see relatively small steps towards the commercialization of magnetocaloric technology. However, there are different
engineering solutions that can really foster developments towards the first real market applications. This contribution does not represent a scientific paper, but rather a critical review of activities and achievements in the development of magnetocaloric refrigeration and heat pumping. It addresses some of the very important scientific, technical and non-technical factors. These can provide a basis for future improvements. Moreover, the most important technical obstacles are discussed and potential solutions
are outlined by pointing out their weaknesses, advantages, limits, as well as their future applicability.