Magnetic cooling attracts attention

German company Magnotherm has made a significant advancement in the development of refrigerant-free cooling systems, demonstrating that magnetocaloric materials can be protected by applying a copper coating and corrosion inhibitor to the alloys used in technology that is claimed to be 40 per cent more energy efficient than vapour compression.

After three months of continuous operation, the materials showed no signs of degradation or mechanical failure when used with water as the heat exchange medium. This achievement brings La-Fe-Si (lanthanum-iron-silicon) alloys – a key component of Magnotherm’s technology – one step closer to commercialisation.

Magnotherm was founded in 2019 as a spin-off from the Technical University of Darmstad and has secured €6.3 million in financing to support the series production of refrigerators using magnetic cooling technology.

Unlike traditional gas-compression refrigeration, magnetic cooling technology utilises the magnetocaloric effect in iron-based rare-earth materials, such as La-Fe-Si alloys. 

These materials heat up when magnetised and cool down when demagnetised. A circulating heat exchange fluid captures the heat and cold generated by this process and transfers it through water-based heat exchangers.

Magnotherm CEO Timur Sirman said the breakthrough “underscores Magnotherm’s ability to lead the way from fundamental feasibility to real-world applications”.

The company claims its cooling tech is 40 per cent more energy efficient than compressor-based systems, with coefficient of performance (COP) ratings ranging from five to 10.

A higher COP indicates more effective cooling with less energy consumption. These systems operate across a wide temperature range, from -100°C to +80°C between the cold and hot sides, and function at low pressures of 2-3 bar, which Magnotherm says makes them safer and easier to maintain.

As global energy consumption for cooling continues to rise and pressure on synthetic refrigerants increases due to ozone, climate and PFAS concerns, magnetocaloric and other methods represent promising potential solutions across multiple industries, including space cooling, goods refrigeration, and air-conditioning.

The work behind this achievement was led by Magnotherm chemist Dr Falk Münch and has been published in the peer-reviewed journal ACS Applied Engineering Materials, under the title Stable Operation of Copper-Protected La(FeMnSi)13Hy Regenerators in a Magnetic Cooling Unit.