From left to right: Dr. Kilian Bartholomé, Dr.-Ing. Olaf Schäfer-Welsen (both Fraunhofer IPM), Timur Sirman, Dr. Maximilian Fries (both MAGNOTHERM)
Magnetic cooling is seen as an important building block for environmentally friendly refrigeration of the future, as it promises up to 3 times higher efficiencies than existing systems - without using climate-damaging, explosive or toxic refrigerants. Instead, the cold is generated by a magnet and temperature-active metals called magnetocaloric materials. No market-ready magnetic coolers have yet been introduced.
Gas compressors have been used to provide cooling as well as heating for over 100 years and have been optimized for efficiency. However, they cause 10% of the global greenhouse gases and consume 20% of the globally available electrical energy. Regulations such as the European F-gas regulation ban the majority of refrigerants used and only allow explosive, toxic or otherwise problematic refrigerants.
MAGNOTHERM has now introduced the first magnetic beverage cooler, POLARIS, which makes the promises a reality and represents a major step towards market readiness.
The device delivers a cooling capacity of approx. 40 watts at a temperature span of 20 Kelvin and is capable of cooling a refrigerated volume of 75 liters to approx. 5°C. The device works purely magnetically and does not use any problematic refrigerants. A permanent magnet generating 0.85 Tesla magnetic field cyclically heats and cools the magnetocaloric material. A water-based system is used to extract the cold from the material and then pump it into the cooling volume.
"We are very pleased to be able to achieve a major milestone in the development of magnetic cooling technology with POLARIS. The team has worked very hard on this and I thank everyone who contributed to this success," said Dr. Maximilian Fries, Co-CEO and Co-founder of MAGNOTHERM.
The system is now being further developed for larger power classes and optimized in terms of efficiency. In particular, the magnetocaloric materials used are being improved and the use of recycled permanent magnets is being promoted. In this context, MAGNOTHERM is working together with the manufacturer VACUUMSCHMELZE from Hanau, which produces and sells magnetocaloric materials based on lanthanum-iron-silicon.
"In close cooperation with MAGNOTHERM, we are developing the next generation of magnetocaloric materials, which will make the system more powerful and efficient," says Dr. Alexander Barcza, product manager permanent magnets at VACCUUMSCHMELZE.
Future applications will include commercial refrigeration systems in food retail, heat pumps and air conditioning for buildings to liquefaction of green hydrogen.
"We are seeing tremendous interest from supermarkets that have high energy costs and are looking for an energy-efficient alternative to existing refrigerants," comments Timur Sirman, co-CEO and co-founder of MAGNOTHERM.
The first magnetocaloric beverage cooler POLARIS was presented, among others, to industrial representatives of the refrigeration industry during the final event of the "InnoCool - Consortial Study Caloric", organized by the German Refrigeration and Air Conditioning Association (DKV), GSI Technology and the Fraunhofer Institute IPM.
"Among the many caloric technologies, magnetocalorics is the most advanced technology," says Dr.-Ing. Olaf Schäfer-Welsen, Head of Department Thermal Energy Converters at Fraunhofer IPM. Deputy Dr. Kilian Bartholomé adds, "Caloric systems have great disruptive potential, but still have a long way to go in development. We are therefore very pleased to be one of the first here to hold a magnetocalorically cooled beverage in our hands."
MAGNOTHERM is a spin-off of the Technical University of Darmstadt and develops highly efficient and sustainable cooling systems based on magnetic materials. MAGNOTHERM has unique know-how in the field of magnetic materials after many years of research at the Functional Materials department of Co-founder Prof. Oliver Gutfleisch, where a patented process for stabilizing magnetocaloric materials was developed. The 25-member team has already developed two products, the MS30 and the MS90, which demonstrate the magnetocaloric effect and support material development, respectively. MAGNOTHERM is funded by several grant projects and recently received a commitment to the European Commission's competitive €2.5 million EIC Accelerator. Currently, MAGNOTHERM is in the process of fundraising for seed financing, after receiving pre-seed financing from KfW Capital in 2021.