The modern refrigerator can be found in almost every home in the developed world. These refrigerators keep food and beverages cooled or frozen, and have become widespread since the discovery of Freon in 1928. They do, however, have some disadvantages – particularly that they have remained inefficient, bulky and unreliable despite developments and steps forward. As a result, the refrigeration market has been ripe for disruption for decades.
Now, with the development of the new technology, “magnetic cooling,” we may be on the verge of just such a disruption.
The Disrupting Technology
A team of Canadian-Bulgarian researchers developed a particularly promising magnetic cooling approach, using solid magnetic substances called magnetocaloric materials to act as the refrigerant in miniaturized magnetic refrigerators. These materials are the key to the development of a “green” cooling technology.
The magnetocaloric influence is “the thermal response of a magnetic material to the change of an external magnetic field, which manifests as a change in its temperature.” Mohamed Balli said, a researcher in the physics department at the University of Sherbrooke in Quebec.
The researchers soon found they could create a giant magnetocaloric effect by simply rotating a crystal of Holmium-Manganese-Oxide within a constant magnetic field, without needing to move it in and out of the magnetic field zone.
This discovery is an important step toward the development of magnetic cooling technology, which will offer lower energy consumption and eliminate the use of hazardous fluids. As Balli points out, “Using the rotating magnetocaloric effect means that the energy absorbed by the cooling machine can be largely reduced. It also opens the door to building simplified, efficient, and compact magnetic cooling systems in the future.”
GE developed an alloy of nickel and manganese for magnets that exhibits the magnetocaloric effect at room temperature. The researchers set up a series of magnets in 50 cooling stages that have been successful in lowering temperatures by 80 degrees Fahrenheit, beyond the point of freezing.
Advantages and Implications
GE’s system and the mew technology at the University of Sherbrooke both offer major advantages over traditional fluid-compression refrigeration. Specifically:
- They reduce energy consumption by at least 30 percent;
- They eliminate coolant leaks;
- They avoid ozone layer damage from chlorofluorocarbons;
- Installation and service will be simpler;
- Units will last longer;
- They will be easier to dispose of, without harming the environment.
Looking ahead, the following are potential developments:
- First, magnetic cooling will prove to be a big breakthrough for energy efficiency and reliability;
- Second, once it is further developed and improved, magnetic cooling technology will be adapted to a broader range of applications;
- Third, this new technology will extend the benefits of refrigerators, frozen food, and air conditioning around the world, making billions of lives better (and coupled with advances in solar power technology has the potential to provide “free cooling”);
- Fourth, universal availability of refrigerators and air conditioning will play a major role in adaptation to climate change.
- Applied Physics Letter, June 9, 2014, Vol 104, Issue 23.
“Anisotropy-Enhanced Ginat Reversible Rotating Magnetocaloric Effect in HoMn2O5 Single Crystals.” By M Balli, S Jandi, P Fournier and M M Gospodinov. © 2014 by AIP Publishing LLC