They're Using Magnets To Heat & Cool

They're Using Magnets To Heat & Cool ENERGY Alternative Fuels 26-2-37 Magnetic heating and cooling? The idea is still four or five years away from commercialization, according to researchers and developers, but magnet-based heating and cooling systems will likely find their way eventually onto farms. The concept was originally conceived in the 1920's, but other forms of refrigeration were more efficient and attractive at the time, so it got put on the shelf. However, recent efforts by scientists at Astronautics Corporation of America, Madison, Wisconsin, and the Ames Laboratory, a U.S. Department of Energy lab operated by Iowa State University, have refined the process to the extent that it now promises to be more efficient and more environmentally friendly than the chloroflurocarbon gas refrigeration systems we're now using. What makes the system unique, says Karl Gschneidner, one of the Ames Lab scientists involved in the project, is that it can be used for both heating and cooling. The newest version of magnetic refrigeration uses gadolinium, a rare-earth metal discovered in 1880 that gets hot when exposed to a magnetic field. Instead of a gas refrigerant, it circulates water (to which antifreeze can be added to keep it from freezing) inside a closed loop through magnetic beds containing fine spheres of gadolinium and hot and cold heat exchangers. Heating the solution as it flows through the gadolinium magnetic beds has the same effect as compressing gas in a conventional refrigeration system. The water-antifreeze solution is cooled by being circulated through a demagnetized chamber. Esssentially no energy is lost during the magnetizing and demagnetizing processes, so the system can be up to 60 percent efficient, compared with no more than 40 percent energy efficiency for current systems. Magnetic heating and cooling is expected to be more expensive to produce, at least initially, but Ames Lab sources project energy savings will pay for the system in about five years. While Ames Laboratory is conducting research to perfect the materials for the system, the Astronautics Corporation is developing ways to commercialize the equipment. Contact: FARM SHOW Followup, Karl Gschneidner, Ames Laboratory, 255 Spedding Hall, Iowa State University, Ames, Iowa 50011 (E-mail: cagey@ameslab.gov).

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