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Refrigerators To Cool With Sound (Cool!)
T-Kir writes "A very interesting report from the BBC where researchers at Penn State University are developing a prototype fridge that cools using metal plates and sound waves. If successful, this technology would help remove the dependance on gases that contribute to global warming. Talk about Cool!"
You can also make refrigerators using a Stirling-engine like gas compression cycle. The guys at Medis Technologies have designed this. See here for the brief description. I guess instead of trying to extract mechanical work from a Stirling engine, they are just removing heat from one area and piping it off elsewhere. They claim this uses no greenhouse depleting gases, and it sounds plausible to me.
What I find more interesting than the projected "energy" savings (which I would have to see the science and the experimental data before I'd bank on), is that there is no compressor to wear out, no refrigerants, etc. Conceivably a service call would be something on the order of "open the sound box, unclip the sound driver, put in a new one", right?
I wonder what the heat output on the hot side is -- enough to supply a home's hot water needs, perhaps?
...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
I'd worry about my ears more than Fido's. The article doesn't say the frequencies are ultrasonic, so it's possible human ears will need protection too. I can't imagine how much sound insulation you'd need to hold in 173dB. What happens if the chiller doesn't cut off when you open the fridge door? I'm picturing the last scene of Raiders of the Lost Ark where the Nazis get their faces melted off.
your high powered microwave oven can evaporate all teh tissue in your arm to steam in less than 30 seconds. dont see that happenning..its safe because its contained.
This is not a TROLL, those Piezo Electric fridges in use in some RVs work on the same principle.
It was shown 20 years ago on Tomorrows world. They had a demo, where he heated the outside with a burner and it cooled the inside.
They explained how the heat made the plates vibrate and how this effect drew the heat to the outside.
THIS IS NOT NEW.
First, for soundproofing the easiest method would be to place the sound source and the hot/cold plates in a "double, hollow walled box" evacuate most of the air between the hollow walls. This leaves no way for the sound waves to propogate outside the cooling unit. The cooling effect takes place outside of the hollow walled box because the fridge will still presumably circulate a fluid (which has absorbed heat in the refrigerator box through the cooling unit and back to the fridge/freezer. So there's wouldn't be a sound source even when the refridgerator is opened. Then put a sound sensor outside the box that shuts down the fridge if the vacumn fails and the sound rises above a certain level.
The second reason is that the current insulation in the refridgerator is still required --and the more the better-- to keep the heat from the rest of the world outside of the refrigerator or freezer box.
...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
Global Cooling has been developing more efficient (and safer) CFC-free refrigeration and cooling (even cryo-cooling) systems for quite awhile, now.
=Smidge=
and obviously, chip cooling. I always thought loud music was cool.
If your bitterest enemies are people who hack the heads off civilians, then I would say you're doing something right.
It was developed at Los Alamos.
"I assumed blithely that there were no elves out there in the darkness"
At ridiculous volumes and/or frequencies, sound has some amazingly powerful properties, but I'm skeptical as to how practical such a technology can be. Here's why:
A professor at my university was doing some personal research with a small team at his house on the properties of high-decibel sound. Based on incredibly complex differential equations, one could project two sound waves at ridiculously high frequencies and volumes to create a special kind of interference. This interference would in essence start a new sound (at a hearable frequency/volume) from where the two waves intersected, effectively making it seem like a controlled sound was being created out of thin air at any point in 3d-space.
I don't think I need to point out applications to this technology. BUT - he decided to discontinue the project before it was ever completed. He had several pets in his house (dog + cats) that he tried to keep away from the testing, but they were still being driven crazy by the sound. He also started developing nasty headaches and suspected that his high-range hearing was being destroyed.
Interestingly, one of the graduate students who worked with him on the project decided to continue the work on his own. From what I've heard, he had his work picked up and funded by the US military (DARPA, I think). When I heard this, it really didn't come as a surprise.
Experts agree: everything is fine.
Los Alamos national lab currently holds the record on using thermal acoustic engine. The thermal efficient of their engine is about 30 percent, compare that to automobile engine. which is about 25 percent. http://www.lanl.gov/projects/thermoacoustics/TASHE .html
refregerators are one thing, but I see this being a good application for roof mounted HVAC equipment. which is noisy anyways and are usually mounted in remote locations. This also applies to most commercial walk freezers/coolers. They all use a remotely mounted condencing (cooling) unit. My biggest questions are 1.) weight 2.) power consumption. I imagine this would remove the need for a compresser and radiator type vents making it lighter.
You know what I want? A fridge built into my countertop that pneumatically raises up at the touch of a button, leaving all the cold air still down in the refrigeration pit. It'd work just like your adjustable office chair. Yes, I know it would be a pain to clean when your cat knocks half a jug of juice down there, but isn't that a price worth paying?
Think about it... *whoooosh*... makes those 1950's techno-utopian dreams look almost attainable!
Wah!
"1. ...Of course it does raise the cost of opening the refrigerator door, in comparison to the cost ratio now. ..."
Now we get to one of my pet peeves. Why doesn't any of the major, or minor for that matter, fridge manufactures make a chest style fridge. There are many chest style deep freezes, but no fridges. With a chest style fridge you'd only loose very little of the cold air in it when you opened it, rather than dumping darn near every bit of cold air out onto the floor as with the cabinet style fridges.
Just my $0.02
"Oh drat these computers, they're so naughty and so complex, I could pinch them." --Marvin the Martian
I've often wondered why a two piece conventional freon refrigerator never caught on. You could place the compressor, condenser, and the support structure outside the house connected with two hoses (same as your whole house AC). This would eliminate most of the internal noise and be far more efficient as you are not releasing the hot air from inside the fridge + the electrical and mechanical losses into the house. In the fall through spring season cycle it would even be more an advantage as it is often much cooler outside then in the house and the compressor could even be bypassed. This would allow for smaller, quiter, and higher efficiency refrigerators and allow more flexibility as you could replace the inside and outside units seperately when and if needed. The inital conversion would be a little higher because you'd have to run lines and a concrete pad or wall hanging device outside but long term it would be much less. Installation in new construction would be simple. Anyone have some VC money they want to get rid of?
Bad boys rape our young girls but Violet gives willingly.
Global Cooling on the otherhand produce rival products to Medis El based on the Free piston Stirling Engine.
Despite being some impressive technology, Free Piston Stirling Engines haven't really been taken up to well. Its a shame because they do seem to be much more efficient.
If you are really interested then you might want to check this out At Ames Lab. Gschneidner's work on the giant magnetocaloric effect is REALLY impressive. Its all about the exchange of entropy between magnetic and kinetic forms. Damn cool.
- This and all my posts are public domain. I am a Physicist. I am not your Physicist. This is not Physically advice
It says compressed gas is needed to generate the sound. All that means is if someone breaks open the fridge it won't keep making 173dB noise. However sound conducts through many materials, solid, liquid and gas. While the chiller is running, you'll still have to soundproof 173dB of noise while taking into account things like heat exchanger tubes.
How's this for an experiment. Turn your stereo speakers up to the loudest (that's maybe 110dB if you have a killer stereo) and try to build a soundproof box around it that's smaller than your fridge.
Certainly expensive refrigeration wouldn't solve problems for the impoverished. Of course lots of people in the world STILL don't have refrigeration, which (as anyone who has played civilization 2 knows) lets you produce more food because you can store/transport more.
On the other hand for most of the world it makes sense to purchase initially expensive refrigeration hardware because it will save on costs in the long run. It regularly pisses me off that it is generally impossible to get a refrigerator with a basic set of features (IE, no ice maker/crusher, no water spigot, no computer in the door) without industrial-quality insulation.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Suddenly it seems a lot easier to soundproof.
There is also the issue of the density difference from the compressed gas media in the tube to atmospheric pressure (think about sound not transferring well from water to air or back), but I suspect that is a red herring given that you are going to a more dense material first before the atmosphere.
Incidentally, I think they have a compressed gas because you can't do 173dB in free air. You rip the air down to total vacuum in the low pressure parts before you get there.
Unrelated trivia note: Your hearing ends at 20Hz. If you put a mic on your body and pitch shift the 20Hz range up into audible frequencies you will find that your body is quite loud and distracting if you can hear it.
Chris
What I would really like to see is a house designed around a centralized heat reservoir. Dump the heat generated by your Fridge and your AC into a stack where your water heater, your over, and your Heater can pull from. Obviously you'd also want a heating element there, but the energy savings of recouping the heat from the other applicances would be significant.
Kind thoughts do not change the world
I can't remember the name of the program, but it was one of those "Look what's new in science" type programs on the Discovery Channel. On this one I remember, I saw them talking about a sonic fridge. This was 10 years ago. They had a prototype 10 years ago. What happened to that?
Look up impedance matching, particularly as it relates to sound transmission between differing media...
Christopher
Mozilla