A classification methodology applied to existing room temperature magnetic refrigerators up to the year 2014

Magnetic refrigeration at room temperature is a promising technology with the potential of competing with traditional vapor compression technology. It promises high energy conversion efficiency values, and is environmental friendly. In fact it can operate with zero ODP (Ozone Depletion Potential) and low GWP (Global Warming Potential) fluids. Furthermore the process and the plant configuration are very simple and the device promise to be very compact, with low noise and vibrations. The literature shows many prototypes developed and built both with proof of principle purposes and with performance oriented purposes. Very different embodiments and arrangements can be conceived, operating with similar or identical conceptual behavior. An existing classification methodology is discussed and applied to a wide set of prototypes and test sections known in the literature up to the year 2014. In this short review, most used configurations and trends are described according to the proposed classification criteria. The method is able to highlight common and uncommon solutions, and to show conceptual differences and similarities between different embodiments, irrespective of the engineering solutions chosen by the designer.