May 20, 2009

Scientists study ‘magnetic’ refrigerators

British scientists say they are a step closer to making environmentally friendly magnetic refrigerators and air conditioning systems.

Imperial College London researchers say magnetic refrigeration technology could provide a green alternative to traditional gas-compression refrigerators and air conditioners, requiring up to 30 percent less energy without the use of ozone-depleting chemicals or producing greenhouse gases.

A magnetic refrigeration system works by applying a magnetic field to a magnetic material, causing it to heat. That heat is removed from the system by water, cooling the material back to its original temperature. When the magnetic field is removed the material cools even further, and it is that cooling property that researchers hope to harness for a wide variety of applications.

The researchers said they discovered the pattern of crystals inside different alloys has a direct effect on how well they perform.

This is an exciting discovery because it means we may one day be able to tailor-make a material from the 'bottom up' "¦ so it ticks all the boxes required to run a magnetic fridge, said Professor Lesley Cohen, one of the researchers. 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.

The research, led by James Moore, is reported in the journal Advanced Materials.