As an addition to yesterday’s passive, solar powered air conditioning article, I found out today that NIST researchers (in collaboration with Chinese scientists) have a strong word to say in refrigeration technology that could revolutionize the inside components and operating cycle of that electricity guzzling, big, old fridge of yours. Well, ok, it may not be as old as I said, but the idea behind it surely is.
As I said, NIST researchers discovered a special metallic alloy made of manganese, iron, phosphorus and germanium, that works as a near-room-temperature magnetocaloric. Magnetocalorics are alloys that heat up when exposed to magnetic field. When the field is removed, their temperature drops drastically, reaching almost absolute zero in its lowest point. Until now, magnetocalorics haven’t been very useful to the refrigeration technology because the materials they were made of were the prohibitively expensive and rare metal gadolinium and arsenic, a deadly substance.
Conventional refrigerators and air conditioners contain HFCs (hydrofluorocarbons), that are greenhouse gases, contributing to global warming if released into the atmosphere. In addition to this, traditional refrigeration is becoming increasingly difficult to improve. “The efficiency of the gas cycle has pretty much maxed out. The idea is to replace that cycle with something else,” says Jeff Lynn of NIST’s Center for Neutron Research.
The metal mixture they found already competes in efficiency with gas compression: “Understanding how to fine-tune this change in crystal structure may allow us to get our alloy’s efficiency even higher,” says NIST crystallographer Qing Huang. “We are still playing with the composition, and if we can get it to magnetize uniformly, we may be able to further improve the efficiency.”
Members of the collaboration include scientists from NIST, Beijing University of Technology, Princeton University and McGill University. Funding for the project was provided by NIST.
What would be the benefit of this technology for you? A quieter, much more energy-efficient refrigerator and air conditioning, and a much lower electricity bill. And let’s not talk about the tremendous benefits to the environment.
I wonder: what if we put a strong permanent magnet instead of the electromagnet there, and isolate it by using a bit of the energy generated by the heat the magnetocaloric alloy produces when exposed to the field? Wouldn’t we produce a much more efficient refrigerator? Even if we used grid electricity to cut off the permanent magnet’s field by shielding it with something, wouldn’t we save a lot more energy than using an electromagnet?
Think about that, and if you have an opinion, comment below.