Technology.am (May 16, 2009) — Refrigeration and air conditioning units consume approximately 50% of the US energy use in the summer months. Scientists are trying to make environmentally-friendly ‘magnetic’ refrigerators and air conditioning systems.
Magnetic refrigeration technology could provide a ‘green’ alternative to traditional energy-guzzling gas-compression fridges and air conditioners. It would require 20-30% less energy to run than the best systems currently available, and would not depend on ozone-depleting chemicals or greenhouse gases.
The system works by applying a magnetic field to a magnetic material causing it to heat up. The excess heat is removed from the system by water, cooling the material back down to its original temperature. When the magnetic field is removed the material cools down even further, and it is this cooling property that researchers hope to harness for a wide variety of cooling applications.
The technology, based on research funded in the UK by the Engineering and Physical Sciences Research Council (EPSRC), has proved possible in the lab but researchers are still looking for improved materials that provide highly efficient cooling at normal room temperatures.
They researchers also need a material that exhibits dramatic heating and cooling when a magnetic field is applied and removed.
Professor Cohen, from Imperial’s Department of Phsyics, said: “We found that the structure of crystals in different metals directly affects how dramatically they heat up and cool down when a magnetic field is applied and removed. This is an exciting discovery because it means we may one day be able to tailor-make a material from the ‘bottom up’, starting with the microstructure, so it ticks all the boxes required to run a magnetic fridge. This is vitally important because finding a low-energy alternative to the fridges and air conditioning systems in our homes and work places is vital for cutting our carbon emissions and tackling climate change.”