"Magnetic Fridge" Could Be 40% More Efficient
by Justin Thomas, Virginia on 04.25.06
Researchers at the University of Cambridge have discovered a material that gives a whole new complexion to the term 'fridge magnet'. When this alloy is placed in a magnetic field, it gets colder. Karl Sandeman and his co-workers think that their material - a blend of cobalt, manganese, silicon and germanium - could help to usher in a new type of refrigerator that is up to 40 percent more energy-efficient than conventional models.
The 'magnetic fridge' envisaged by the Cambridge team would use a phenomenon called the magnetocaloric effect (MCE), whereby a magnetic field causes certain materials to get warmer (a positive MCE) or cooler (a negative MCE). Although the effect was discovered more than 120 years ago, it is only recently that magnetocaloric materials have been known with the right properties for use in everyday refrigeration. But several factors have so far prevented such applications.
For one thing, some of the materials - typically metal alloys - that show the strongest MCE contain the element gadolinium, which is very expensive. And some of the best potential alternatives contain arsenic, raising health concerns.
Sandeman and colleagues have now found a material that is neither toxic nor costly, and which generates significant cooling at around room temperature. The key to the magnetocaloric behaviour is a sudden change in the magnetic state of the compound - a so-called magnetic transition. The material is magnetic because it contains metal atoms that themselves act like tiny bar magnets. As it is warmed up from subzero temperatures, there comes a point where these atomic magnets abruptly change the way in which they are lined up.
Via: Physorg.Com
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That's thinking. At first glance I thought the temperature models were refrigerator magnets. pretty funny.
Those with pacemakers have to be wary of microwave ovens. Will they have to be wary of the fridge too? :P
heh-- i think the pacemaker peeps may want to build a faraday fence around the fridge,
but its AWESOME! there are many ways to use magnetic fields that we are going to encounter... a similar but opposite one to the firdge is Troy Reed's heat wheel. you can heat a warehouse by attaching one of 'em to a bicycle!
there's lots of ways to get heat/cold or electricity using magnetic fields in new ways and it's like one of those paradigme shifting things. Wooo Hoo!
This isn't new. I remember hearing a CBC radio interview last year (2005) of a scientist from New Brunswick, Canada who had determined magnets increase refridgeration eff.
... and better magnets make for better electric motors, and here we go again... if we can sneak in better magnets into the energy economy via simple innocuous refrigerator magnets, that'd be a good subterfuge to get them past the national security act... in jest.
earthchange,
Heat wheels are easy to make. It's called "brake" -- if you put on the brakes in your car to bring it to a full-stop, all of the kinetic energy in your car becomes heat. A little bit more than that, if you have an automatic transmission.
If you want proof that brakes turn energy into head, ride brakes in your car (or bicycle) for 30-seconds or so, and then measure the temperature. (If it's a car, do NOT touch them!) After you're convinced that they get really hot, really fast, look at the design of the disc and the wheel - you'll see lots of ways for air to get in and out. This is because the heat generated has to go somewhere. Fortunately, you don't ride the brakes all of the time (do you?!?), so they only have to take heat-pulses from time to time -- say, at every stoplight. So, the brakes can heat up for a few seconds, and then cool down for a couple of minutes.
If you ride the brakes down the side of the mountian, the potential energy (from being on top of the mountain) will all turn into heat (provided you keep a constant speed -- your kinetic+potential energy will turn into heat if you stop at the bottom of the hill). So, the brakes will produce heat constantly, and many brakes will fail due to the brake fluid boiling or the drum expanding. There's no way to get around this, unless you provide a better place for heat to go.
"Heat wheels" have, indeed, been around for a long, long, long time. And they are one of the easiest energy-conversion devices in the universe!
Link: Read any Thermodynamics textbook for more information.
This may sound like a dumb question, but why is it that refrigerators have their exhaust heat coils to they are always inside of the house? Wouldn't it be useful to have them switch to external exhaust in the summer?
Actually, DavidE, it's probably for cost reasons.
Want a scoop? Some Swiss guys have already come out with a magnetic fridge. They built it with gadolinium material. The design grabbed an award from the Swiss Technology Awards, earlier this year. We covered it here. Cheers.
I want one :)
I was curious about the fridge heat exhaust too. You have one for your stove, why not the fridge?! I going to plan for that if I ever own a house.
I hope Camfridge Ltd comes out with this product soon. I wish them fast success. www.camfridge.com
hey DavidE and MGR: love that idea... or at the very least why not use that heat for something like a dehydrator...
but also, on that same tip, here's something itotally love thsi guy richard travers in vermont invented a way to take cold air from outside in wintertime (why should a walk-in fridge in a beer store or restaurant have to make cold air in the winter?).
I think that invention is called a 'window'. It also helps let in hot air in summer. (Just kidding.) I love these kinds of inventions. They don't require any electricity. And they use what is already there.
thanks anonymous. but brakes dont do a quasi short through a magnetic field. Which is what this does. Reed calls it HeatWheel as a proper noun not a common one. And i didn't read it on the net, or in a magazine, i travelled 2,000KM to see it. And my hand nearly burnt on it.
And brakes/thermodynamics don't heat up an entire room in less than 10 minutes (let alone a 2,000 sqft warehouse). Especially not brakes on a bicycle.
but with this machine (a 9" cube) you can use a bike and within 2 mnutes have enough heat to cook eggs & potatos. it's not what you are talking about. at all...
Hopefully the Stirling engine crowd will get their hands on this and run with it. The cold cycle in Stirling drives is always the hard part.
Houston, I think it used to be called a "root cellar". Where my mother grew up, they had a little room dug into the side of the hill near the house. It stayed a relatively stable cool temperature all year long, and was perfect for storing perishables.
I've been considering moving my loud, inefficient, and way too inviting refrigerator out to my garage, which is always 10 degrees cooler than my house, and putting another pantry in its place.
Why not just make this fridge that uses only 100 Watts a day?
http://mtbest.net/chest_fridge.html
Current fridge design (Homer Simpson method)- the compressor is under the food storage producing heat which rises into the space it is supposed to be cooling. Old fridges - and new efficient ones- have the compressor on top.
Also the winter cold air system is a no-brainer. Just think of all the grocery stores with their requirements- and all their Homerian open refrigeration units wasting energy 24/7
the element Praesodemium (spelling?) bahaves the same way when exposed to magnetic fields.
earthchange,
Heat is easy to create. It's called "stove" -- if you have a stove and turn the knob, heat will be released from the section called "burner". The burner gets very hot, so you should not touch it (do you?!?). If a metal pan is placed on the burner, the metal pan will absorb some of the heat and become hot. If you turn off the knob, the burner will stop releasing heat and the metal pan will cool! Gee whiz!
But first, you need some eggs & potatoes. Potatoes are planted in the ground by Irish people. Eggs are placed underneath chickens in the middle of the night by the Easter Bunny.
"Stoves" have, indeed, been around for a long, long, long, long, long, long time. Almost as long as "Heat wheels", but not as long as potatoes. And they are one of the easiest food-heating devices in the universe! Yes, the whole universe, not just the one I live in.
Link: Read any Cooking textbook for more information.
Anonymous,
You have proven that you are, indeed, holier-than-thou.
Uhm, despite the wacky "free energy" theories involved in anything like that 'heatwheel' i am going to stick with technologies based upon real science. "free energy" is about as intelligent as intelligent design.