Thermoacoustic Cooler Means Green-Friendly Icecream

MuddyRiverDoc writes "National Public Radio aired a story describing ice cream manufacturer Ben & Jerry's sponsored development of a thermoacoustic refrigeration technology, which uses helium gas subjected to ultra-loud 173 db sound to chill an ice cream cooler. The NPR interview and pictures of the Penn State researchers who did the development is available. There is also a brief description of the technique at the Penn State Live site and at the BBC, and an over-cute Ben & Jerry's broadband presentation, Sounds Cool!, that does however provide a useful diagram. Thermoacoustic refrigeration has been a focus of research for more than a decade at Purdue and elsewhere, and has reportedly flown on the Space Shuttle, but this prototype is reportedly the first that demonstrates the size, efficiency, and quiet operation that promises successful commercial introduction. Cool Sound Industries, Inc. is reportedly exclusively licensed for this thermoacoustic technology."

Comments

Parties

[Mikkeles]

So does this mean that noisy, drunken parties will be cooler than quiet, staid cocktail parties?

Re:Parties

[tzanger]

Noisy, drunken parties are always cooler than hoity-toity affairs.

Re:Parties

[dasmegabyte]

He didn't say hoity-toity, he said staid. Staid parties be the bomb yo. Hanging out all night on the veranda, chatting about minor investments and german cars, solemly flexing your priggish style to the thrill of genteel ladies...and let's not forget apple martinis!

Re:Parties

[gstoddart]

Any additional cooling generated by the noise would be offset by the increased kinetic energy of the guests by a large factor anyway, so no.

Re:Parties

[AndroidonPPC]

Apparently if you pump a bunch of helium into the party venue. Of course, then you run into the problem of one side being cool, and one side being hot.
Strategic placement of the keg of um... root beer.... would be neccessary.

Re:Parties

[ryanoo]

You had until the part about apple martinis. There is absolutely no reason to desecrate a martini with anything besides vermouth. Go back to drinker's kindergarten and learn the basics. A martini is gin and vermouth, period. Some may say simply introducing the bottle of vermouth to the martini glass is enough, or that the light that shines first through a stained glass window, then through a vermouth bottle, and finally onto a martini glass is enough vermouth to make the martini divine.
If you're a bit of fop or really can't stand the taste of juniper berries use vodka.
Oh, and James Bond was an idiot. Martinis should be stirred, not shaken, to preserve their crystal clear properties in a fine glass.

Re:Parties

[dasmegabyte]

Hey, you're preaching to a guy who's almost solely a gin and tonic drunk. I've got about 3 liters of Bombay Sapphire in my freezer at any given time (buy a case at the duty free every year). Apple martinis were mentioned because it's the kind of girl-drink cocktail partiers thrive on.

Incidentally, when I do have martinis, I prefer them stirred with 1 part sweet vermouth to 3 parts gin (the tangier the better) and with a slice of lemon instead of the olive detritus. Is this okay?

Re:Parties

[ryanoo]

Hey, you're preaching to a guy who's almost solely a gin and tonic drunk... Apple martinis were mentioned because it's the kind of girl-drink cocktail partiers thrive on.

Point taken. The martini gods will forgive you for the previous blasphemous murmurs then.
The only bad thing about gin is the hangover... ugh. It's not pretty.

I prefer them stirred with 1 part sweet vermouth to 3 parts gin (the tangier the better) and with a slice of lemon instead of the olive detritus. Is this okay?

Sure. In fact that sounds pretty good, I think I'll give that a try next time. That actually sounds like a recipe some of those amateurs drinkers could cut their teeth on.

Carry on.

Re:Parties

[theonetruekeebler]

No, but you'll be able to tell if somebody's sneaking into the refrigerator to steal your beer. 190dB in there---sheesh!

Re:Parties

[dasmegabyte]

I would gladly take a Gin hangover over a Beam hangover any day of the week. For some reason, an evening spent sipping Beam leaves me feeling like I'm glancing idly through the foggy window of my own life and finding it to be pretty boring. I'll take a nice whopping headache over that any day.

Re:Parties

[Anonymous Coward]

From BC Liquor Stores:

Ever since "Bond, James Bond" ordered a martini "shaken, not stirred", bartenders and liquor retailers have been asked the eternal question "what's the difference?" Well, the biggest difference is in the temperature of the final martini. A shaken martini will be much colder and slightly diluted as the agitation caused by the shaking will melt some of the ice. Gently stirring the drink with ice cubes will result in a warmer, slightly stronger drink. Devotees of both camps do not expect a resolution any time soon. Shaken versus stirred is but one of the three main debates raging about martinis. The other two are: gin versus vodka and an olive versus a twist. Both camps, however, are definitely enjoying the debate.

No matter what you say, I like my Martinis one way, and thats Gin, Shaken, and Twist.

Re:Parties

[Anonymous Coward]

I prefer parties hosted by rich people too, but that "be the bomb yo" shit isn't going to convince anyone.

noisy

[hugzz]

wouldn't the sound polution kinda reverse the positive environmental effects? and dont tell me to RTFA.. there were too many links, I didn't know where to click :|

Re:noisy

[br0ck]

Well, here's yet another link that says..

But from the outside, it's no noisier than your typical icebox. The noise generated by the Penn State fridge can only be reached when the gas is under tremendous amounts of pressure -- 10 atmospheres worth. If the gas escapes, the pressure dissipates and the sound dies down.

Re:noisy

[Stile 65]

I think Joe L. User would have it right on this one - CLICK EVERYWHERE! :)

Re:noisy

[Guignol]

No, outside it's all quiet,
but I'm worried about the dwarf who lives inside and is supposed to shut the lights off...

Re:noisy

[Deadstick]

tremendous amounts of pressure -- 10 atmospheres worth.

Wow, 10 atmospheres...that's almost one-fifth as much as that old lady in front of you in the supermarket line has in her roll-around oxygen tank.

rj

This stuff works

[toast0]

Ever see people driving down the street with their radio so loud their car buzzes. They're pretty cool right?

Re:This stuff works

[Brento]

Ever see people driving down the street with their radio so loud their car buzzes. They're pretty cool right?

It also explains why I yell at those morons to "Chill out!", they just turn the volume up even louder.

What is the ultra-loud 173 dB sound?

[gleepskip]

The sound that would send the necessary amount of "green-friendly" chills down the spine of any helium-cooled refrigeration unit is Howard Dean's famous scream.

Re:What is the ultra-loud 173 dB sound?

[baldeep]

Funny... I thought it would be playing Vanilla Ice. "Yo VIP, let's kick it!"

Re:What is the ultra-loud 173 dB sound?

[Anonymous Coward]

The sound that would send the necessary amount of "green-friendly" chills down the spine of any helium-cooled refrigeration unit is Howard Dean's famous scream.

Of course, that would be nothing compared to the chills available from the sound of thousands of bombs exploding in a pointless war.

Hmm..

[Anonymous Coward]

subjected to ultra-loud 173 db sound

When I see Motorhead live I don't get cold. Why is that?

Re:Hmm..

[REBloomfield]

All the sweaty b*stards who are packed around you.

Microwave Fridge

[tindur]

I really miss a microwave fridge in my kitchen

Re:Microwave Fridge

[kaos.geo]

Some 8 years ago, I suggested a "microwave fridge"
to a friend, he dismissed it as impossible... but his mother who happened to be there (and also happens to be a major Physics major) liked the idea and after some years of occassional debate between her and her college professor-type friends, they phoned me to tell me that sound waves would do the trick... :P
At least now I know I wasnt so crazy after all! :P

Re:Microwave Fridge

[MadBiologist]

Too bad you didn't patent the idea then.... you could be just like SCO.

Re:Microwave Fridge

[mangu]

The difference between heating and cooling is that one can send energy, in the form of electromagnetic waves, into the food, where it's converted to thermal energy. The frequency used in microwave ovens is 2.45 GHz, which is absorbed by water and converted to heat.

OTOH, one can't convert thermal energy back into microwaves, so the heat must get out of the food by thermal conduction, which isn't very quick in the usual food substances.

Re:Microwave Fridge

[Anonymous Coward]

>OTOH, one can't convert thermal energy back into microwaves, so the heat must get out of the food by thermal conduction, which isn't very quick in the usual food substances. ... then how do you explain this article? You know, "Thermoacoustic Cooling"?

Re:Microwave Fridge

[Anonymous Coward]

First of all this most definitely would be a valid patent. I don't know how anybody could argue against that. Second of all SCO is suing over Copyrights. Get your trolling straight.

Re:Microwave Fridge

[Detritus]

OTOH, one can't convert thermal energy back into microwaves, so the heat must get out of the food by thermal conduction, which isn't very quick in the usual food substances.

Everything with a temperature above absolute zero emits black body radiation, which includes microwaves. See Planck's law of black body radiation.

Re:Microwave Fridge

[mangu]

Thermoacoustic cooling does not convert heat into any other form of energy. It works as a heat pump, where the gas absorbs heat at one end and carries it to the other end. Sound waves are used to move the gas from one end to the other.

Unfortunately, there's absolutely no way to move heat from anywhere to a warmer place. When one wants to cool something to a temperature that's lower than the ambient we are in, one must first raise the temperature of the medium we want to cool. In both "classical" refirgerators, where a compressor is used, and in these new thermoacoustic chillers, the means used to raise the temperature is by compressing a gas. The compressed gas becomes warmer than the ambient and radiates heat away, through a heat exchanger. When the gas is expanded its temperature drops. Since we let it radiate heat when it was compressed, this expansion will make it drop its temperature to a point that's lower than the ambient temperature.

Re:Microwave Fridge

[SalsaDot]

If the microwave cavity could have *such a low* "impedence" that it absorbed/dampened EM energy within, would it cool whatever was inside?

Maybe with superconductors...

Re:Microwave Fridge

[BorgCopyeditor]

I think all you have to do is to take your ordinary microwave and reverse the polarity of the power source. Always worked on Star Trek.

Re:Microwave Fridge

[StarsAreAlsoFire]

In order to cool something using 'waves' (e.g. radio energy) you would have to have two beams interfering and creating a 'trough' of the almost perfect size to hinder molecular movement: the molecule falls into the trough, and in order to escape has to expend energy. If you use microwaves, the problem would be that any 'stray' beams would impart EXTRA energy into the mix. Beyond that, I couldn't tell ya much :~) Oh! Except that said method is essentially how the latest record for closest temp to absolute zero was made -- lasers interferring with individual atoms. Sweet stuff.

Re:Microwave Fridge

[Anonymous Coward]

Unfortunately, there's absolutely no way to move heat from anywhere to a warmer place. When one wants to cool something to a temperature that's lower than the ambient we are in, one must first raise the temperature of the medium we want to cool.

Um... no. This is simply not true. I think what you're trying to get at is the second law of thermodynamics

http://en.wikipedia.org/wiki/Thermodynamics

. It's impossible to get work out of the process you described. It is certainly possible to do it, it's just that you have to put work into the system to get a cooling effect on one side.

Re:Microwave Fridge

[brokenwndw]

Oh no. Now you've done it. The zero-point energy oil-company conspiracy tinfoil hat trolls are going to come out with their one-way mirror blackbody-radiation SECOND-LAW OF THERMODYNAMICS IS A FRAUD!!1!!!111! rants and we'll be modding them down until the end of time.

Shoot me now!

(Please??)

Re:Microwave Fridge

[Dog135]

Unfortunately, there's absolutely no way to move heat from anywhere to a warmer place.

Using the Peltier effect you can. By connecting a high conducting material and a low conducting material to a battery, the high conducting material becomes cold, without even getting hot. The heat transfers to the low conducting material regardless of the ambiant temprature.

http://www.its.caltech.edu/~jsnyder/thermoelectric s/history_page.htm
http://www.quasarelectronics.com/3066.htm

Re:Microwave Fridge

[Neward Rylet]

Don't worry, Penn State dorms come with Mircofridges.

Re:Microwave Fridge

[Anonymous Coward]

Unfortunately, there's absolutely no way to move heat from anywhere to a warmer place.

The Second law of thermodynamics.
Heat cannot of itself pass from one body to a hotter body
Heat won't pass from a cooler to a hotter You can try it if you like but you'd far better not-a
'Cos the cold in the cooler will get hotter as a rule-a

Flanders and Swann

Re:Microwave Fridge

[kaos.geo]

Well, you see.. that was exactly my point! ;)

Great

[osullish]

Now I can buy that new kick-ass sound system without worrying about that new fridge my wife has been hounding me about and not feel guilty!

Re:Great

[kd4evr]

Better yet,

I have an excuse not to buy a new fridge until this technology is proven, spread and reasonably priced. While this sound-helium thing is being beta-tested, wives-of-the-world should give us a break.

Helium

[dialate]

Alright! So if I climb in this thing and shut the door.....

Re:Helium

[daggins]

...you'd come out as a smurf: blue and with a high-pitched voice.

Same Energy as Freon Systems

[N8F8]

I heard this interview on the radio. Apparently the process doesn't save any energy. It doesn't use ozone depleting chemicals though. Unless it ends up being much less expensive to manufacture I doubt it will go anywhere.

Re:Same Energy as Freon Systems

[kfg]

Nowadays "Green Friendly" means something that you can print on a flyer to drive sales, not something that has anything to do with the enviroment. We've already done away with freon.

I like watching the recent phenomenon of both wood and plastic products being promoted as "Green Friendly," One, because it's, like, natural, organic, renewable and shit, and the other because, like, it's a recycled resource and doesn't require cutting down any huggable trees and shit ( and I can only surmise the latter have never been to the Newark area. Well known for cracking plants. Very few trees.)

Every product is "Green Friendly," if you know how to write the brochure to make it that way.

KFG

Re:Same Energy as Freon Systems

[Fian]

There is another disadvantage - Helium is a finite resource (excluding fusion). A lot of our current supply of helium is collected almost as a by-product of natural gas mining. When the supply runs out, which is anticipated to happen with a few decades, there won't be any liquid helium for super cooling or *gasp* for your party balloons - let alone to chill your groceries

Re:Same Energy as Freon Systems

[proj_2501]

solution: mine helium from the sun until cold fusion is perfected.

Re:Same Energy as Freon Systems

[Null_Packet]

Ben & Jerry's has been pretty active on the environmental front, and I think they will probably be willing to eat the costs of initial deployment by signing a contract with the manufacturer. While not a GreenPeace person, I am happy to see alternative technologies that can do a 1:1 replacement for less environment-friendly technologies. To me, this falls in line with socketed flourescent bulbs, hybrid cars, and low-water clothes washers.

Re:Same Energy as Freon Systems

[Anonymous Coward]

and "all" you need is Helium, which of course is cheap and readily available and doesn't require tons of energy to produce making lots of harmful byproducts (COUGH).

Re:Same Energy as Freon Systems

[deacon]

Yes. And what's worse, a system that would have improved efficiency and been a drop-in replacement for R-12 (Freon) was blocked from approval.

The drop-in substitution would have saved hundreds of tons of equipment that was otherwise scrapped.

I am talking about refrigerants that are a mixture of Propane and Butane. The thermodynamic properties of these mixtures are better than that of Freon. The gases are very inexpensive and relatively harmless to ingest, and can be disposed of by using them to cook food.

Someone will doubtless joke that the fridge will go boom, but of course sealed systems are normal, the amount of gas inside is small, and designing spaces which don't go boom if there is a leak is a well known art.

There is more risk of harm when you carry a butane lighter in your pocket.

Re:Same Energy as Freon Systems

[WindBourne]

Nah. You just run a gas chromatograph on the atmosphere. It will be expensive, but easy enough to do. It is how we currently obtain a large number of our gases/liquids today.

Re:Same Energy as Freon Systems

[JustDisGuy]

The clip with the technology developers mentioned that they sometimes use argon instead of helium. There are probably characteristic differences in the efficiencies of the process depending on which noble gas is used, but at least we're not going to run out of Argon, which it seems is simply distilled from liquid air.

Re:Same Energy as Freon Systems

[WindBourne]

Actually, we have not done away with freon, yet. We no longer manufacture freon based equipment here in the USA, but it is sold elsewhere (like DTD). In addition you can still obtain freon from other countries for quite some time. But IIRC most countries have banned it, so that in the near future, all the equipment will get expensive.

Re:Same Energy as Freon Systems

[MindStalker]

Low water clothes washers? I thought water was the ultimate renewable resource. Water cycle and all.

Re:Same Energy as Freon Systems

[nharmon]

It was blocked from approval because it had the very real potential of being used as a weapon.

Re:Same Energy as Freon Systems

[DerekLyons]

Nowadays "Green Friendly" means something that you can print on a flyer to drive sales, not something that has anything to do with the enviroment. We've already done away with freon.

I was thinking much the same thing. All too often "Green Friendly" seems to mean "pollution hasn't been reduced, but it has been moved out of sight and mind", (cf. electric and hydrogen cars).

Re:Same Energy as Freon Systems

[Tackhead]

> solution: mine helium from the sun until cold fusion is perfected.

And without thermoacoustic helium refrigerators, just how are you gonna cool your sun-skimming probes, huh?

I say we skim some helium from Jupiter. It's pretty cold out there to begin with, so we can use that helium to run the fridge that keeps the ship cool until it reaches the sun!

What, why's everyone laughing at me? I talked to the guy who designed the Shuttle and the ISS, and he said it was the best idea he'd heard in 30 years!

Re:Same Energy as Freon Systems

[the0ther]

Just so long as my supply of nitrous oxide doesn't deplete, the impending helium shortage is copacetic.

Re:Same Energy as Freon Systems

[HPNpilot]

We most certainly have NOT done away with Freon. We have changed the formulation of refrigerants (Freon is a brand name) to eliminate chlorine because in the upper atmosphere the chlorine splits off and catalytically destroys ozone. The refrigerants were reformulated to use flourine instead. However, these gases are still harmful as "greenhouse gases" in that they tend to make the atmosphere and earth absorb more heat than is lost through radiation, unbalancing the thermal ecosystem.

Present refrigeration systems rely on phase change, meaning the heat transfer is aided by a phase change of the refrigerant (gas to liquid, liquid to gas). This new system does not require that phase change so it may use an inert gas which is not formulated to have a phase change point near the target cold side temperature. Helium and argon were mentioned as possible gases.

This is new technology and it may end up being possible to create higher efficiency systems than the present phase change systems. I haven't done an analysis of the thermodynamics to see what the limits are but it is certainly interesting to see what comes of this.

Re:Same Energy as Freon Systems

[trentblase]

Yeah, but if you want to do those whites you have to heat the water. That uses energy. Then, you have to spin a greater mass... and in many places sewage gets treated. So tack on a little something here and a little something there. Multiply by the number of washers out there. That's a nice little energy savings.

Re:Same Energy as Freon Systems

[Threni]

> I heard this interview on the radio. Apparently the process doesn't save any
> energy. It doesn't use ozone depleting chemicals though. Unless it ends up being
> much less expensive to manufacture I doubt it will go anywhere.

A `Green Tax` should shift things in favour of sustainable, responsible energy usage.

Re:Same Energy as Freon Systems

[Cecil]

Fire also has the very real potential of being used as a weapon. What a bunch of dipshits we are for loosing (no, that is not a mispelling) that into the world. X-rays do too. Lasers, definitely. Nuclear reactions, don't even get me started. (sarcasm)All of these things clearly shouldn't be allowed because they may become a weapon in the hands of terrorists, completely disregard any other benefits they may provide to our society.(/sarcasm)

This trend to use "omg think of teh childrens!!!!11!!1one!" to suffocate invention and innovation is abhorrent. I cannot even begin to describe how short-sighted and painfully ignorant it is. I am tired of all this pansying. Danger is part of life, get over it.

Re:Same Energy as Freon Systems

[dnoyeb]

Electric plants are far more efficient than automotive engines. Thus, while the pollution has been shifted from the car to the electric plant, overall, the amount of pollution will decrease.

Not only that, gas engines have an optimal efficiency at a certain speed. That is why hybrid cars can be even more efficient that gas cars. because the hybrid can run its engine at a set speed.

Re:Same Energy as Freon Systems

[kfg]

Thank you for that elucidation, although I'll note that it was specifically the ozone depleting properties of Freon(tm) that I was refering to (from the OP), and not any other properties the newly formulated gas might have.

Present refrigeration systems rely on phase change, meaning the heat transfer is aided by a phase change of the refrigerant. . .

As does the low tech, water evaporation refrigerator that was discussed here on Slashdot not too long ago, although in that case the phase change from gas to liquid (and the energy to drive and recirculate it) is somewhat obscured.

KFG

Re:Same Energy as Freon Systems

[ArsonSmith]

there is a hybrid design like what you suggest but the current crop of hybrid cars utilize waste energy from breaking and slowing down by storing it in batteries and releasing it during acceleration. My Civic Hybrid gets better gas millage (about 47-50mpg) in city and rush hour, stop ang go traffic. When on the highway doing 65-85mph average it usually drops to something more like 40-45mpg. Climbing through mountains will drop it to 35mpg. Still better than most 4door small sedan style cars.

I bought the car for the cool technology, but the novelty of it has worn off. I still love the car for the performance (not great but as would be expected from decent a 4cylender car) and the great economy at the same time.

Re:Same Energy as Freon Systems

[MindStalker]

Of course assuming the washer washes as good with less water. If its like the low water toilets where you have to flush it multiple times and use the more water in the process, no thanks.

Re:Same Energy as Freon Systems

[fireweaver]

I live out in the boonies where most people use propane for fuel. When my R-22 air conditioner spring a leak, I was able to patch up the leak but the local refrigeration shop wouldn't sell me any R-22 because I don't have a certification. So after a day or two, I hit on the idea of recharging the system with propane which I already had on hand. And it works great. The only downside is [1] propane is inflammable, and [2] I've been told it's illegal. Probably because of [1].

Funny thing is, propane is already used in large industrial chillers, typically in refineries and chemical plants, but elsewhere as well.

Re:Same Energy as Freon Systems

[rsadelle]

Canvas is the real Green Friendly grocery bagging option. Reusable and as long as your groceries don't spill, they don't need to be washed very often.

Re:Same Energy as Freon Systems

[Anonymous Coward]

We no longer manufacture freon based equipment here in the USA, but it is sold elsewhere (like DTD).

Oh, we still manufacture document type declarations in the US.

Re:Same Energy as Freon Systems

[fireweaver]

You are confusing chromatography with either fractional distillation or molecular sieve technology.

Chromatography relies on the fact that substances of different molecular weights take different amounts of time to work thier way through a long skinny column which is often coated with various materials to enhance the separation effect. It is almost purely an analytical technique, although there are instances of it being used to separate out very small amounts of material as a purification technique.

Oxygen, nitrogen, argom (and I think) krypton are made from the air. The air is compressed and liquefied, then led to a fractional distillation tower like that found in oil refineries. At various levels, liquid nitrogen, oxygen, etc are drawn off and stored. Sometime, the process is repeated on the products of the first distillation in order to further enhance the purity of the finished product.

Molecular sieve technology is most useful when you want to (say) enrich the oxygen content of the air passing through it; and finds use in the medical field. This is also the process used in reverse osmosis to purify drinking water.

Re:Same Energy as Freon Systems

[kfg]

I use either a Mexican/Guatamalan string bag, or my bike messenger bag. I'm afraid the bike messenger bag is nylon, but it's over ten years old now and really hasn't begun to show any signs of aging yet, and I use it very, very hard at times.

KFG

Re:Same Energy as Freon Systems

[York the Mysterious]

Your messing up how gas-electrics work. They just work at a certain speed. I mean they can, but they work all the time. If you're at a low speed then they will shut off the gas engine and run completely. Also to the guy who bought the Civic hybrid. Bad buy. Those are crappy hybrids. Should have bought the Prius. Much better technology.

Re:Same Energy as Freon Systems

[Anonymous Coward]

Oh, we still manufacture document type declarations in the US.
s/DTD/DDT/g

Re:Same Energy as Freon Systems

[IceAgeComing]

Every product is "Green Friendly," if you know how to write the brochure to make it that way.

I know what you mean; the most extreme examples for me are the oil companies and their "We Love the Earth" commercials.

Adbusters had a parody of a Chevron magazine ad, showing a lynx drinking from a pool of crude oil. The caption: "Do animals get rich from oil? No. People Do."

Re:Same Energy as Freon Systems

[nharmon]

You don't realize the explosive capabilities of protane/butane. The stuff they wanted to use for refrigerants is not the same stuff you light up a cigar, or BBQ on a grill with. Both of those include significant amounts of moisture to prevent a large explosion.

Butane/propane-based refrigerants if used in a conventional single family refrigerator appliance would have enough explosive gas to not only take out your house, but both of your neighbors as well.

Painfully ignorant? No sir, it is you who did not check your facts.

Re:Same Energy as Freon Systems

[Trepalium]

And this would be different from natural gas heating in what way? And not everyone agrees on the dangers of using propane/butane in cooling systems. Some (those who have a stake in selling propane/butance retrofit kits) claim that the danger is extremely minor because there's not a lot of propane used in the systems, and that it's no more dangerous than typical CFCs. The other side (usually those who make and sell conventional refrigerants) say the opposite, that propane is so extremely explosive that it should not ever be used. I don't know which is the truth, but I imagine it lies somewhere between these two extremes.

Re:Same Energy as Freon Systems

[Cecil]

Actually, I work as a lead programmer for an international petroleum engineering/consulting company. So when it comes to petroleum products I do actually have a pretty good idea of what I'm talking about, at least relative to most Slashdotters. I know a lot of numbers for Propane off the top of my head, so I'll stick to that primarily. Butane is very similar in properties to Propane though, so it shouldn't make much difference.

The stuff they wanted to use for refrigerants is not the same stuff you light up a cigar, or BBQ on a grill with.

I guarantee it is the same stuff, although it's kept in compressed or liquid form, by the sound of it.

Both of those include significant amounts of moisture to prevent a large explosion.

I've never heard of this. The only additive in commercially-available propane and butane is the mercaptans used to make it smell. The only thing that I can imagine adding moisture would do is reduce the effectiveness of the mercaptans, which are actually quite notorious for being suppressed by moisture.

Butane/propane-based refrigerants if used in a conventional single family refrigerator appliance would have enough explosive gas to not only take out your house, but both of your neighbors as well.

If you happened to get this propane into a healthy mix with oxygen and then light it, yes, it can be very explosive, but realistically that isn't quite as easy as it sounds. If it was, you would hear much more often about trailerparks and campgrounds completely obliterating themselves, considering each resident usually has at least 1 propane tank and usually several. Propane has a fairly narrow flammability range. With a mix of anything less than about 2.5% propane to air, there isn't enough fuel and any attempt at ignition starves. Any more than 10% propane, though, and it will quickly suffocate itself of air, preventing further ignition. This is the same reason real cars don't explode when they burn, unlike Hollywood's take on the concept.

Basically, the only way for a large-scale explosion to occur is for the propane gas to leak into the house, slowly propagating and mixing with the air, then being ignited by a spark while the concentration is in its flammable range. Keep in mind this has to be done without anyone noticing the stink of mercaptans, which are quite noticable at concentrations of around 0.5% and higher. So, basically, the only way for the gas to reach the 2.5% lower limit without someone noticing, is if no one is home. This is basically identical to the process that leads to the relatively few natural gas explosions (which are often fed by a shattered pipeline after the explosion, for added fun and destruction)

We have already been managing risks just like this sucessfully for a long time now, with few problems. That's what really irks me about this. Most of the fear-mongering that goes on doesn't seem to notice that almost everything around us is, or can be, extremely dangerous. But we're crafty, adaptive little creatures and we have many very smart people carefully ensuring that any danger is sufficiently mitigated. And given the amount of stuff that *just works*, compared to the small percentage that have turned out to be dangerous above and beyond what we anticipated, I think that our creativity has earned some trust.

Re:Same Energy as Freon Systems

[rtb61]

Reminds me of the demonstrations of cars with lpg refigerant systems, that were shown to blow up. Only a couple of little fudges they used five times as much gas as is usually in an aircon system and rather than a leak they rigged it for a full all at once discharge. Looked good and had the desired marketing affect, of course nothing last for ever and the bull is dying out. So give it up, the expensive patented in-efficient refigerant gases are on their way out.

Beware the chunky monkey....

[Anonymous Coward]

I have it on good authority that the ultra-loud sound is at 82 Cents Above the lowest E flat. I wouldn't want to anywhere near that thing when the fire it up.

Peltier cooler?

[beldraen]

Out of curiosity, is there a reason why peltier coolers haven't been more main stream? I even have a small cooler that uses one, but it seems the idea of making it into larger appliances is something not which of thought.

Re:Peltier cooler?

[Geiger581]

Peltier coolers are very inefficient in terms of heat shift. Right now, the best known materials aren't much more than ~10% of Carnot (thermodynamically limited) efficiency. This means that they produce a lot of heat to move just a little. This is why your Peltier block will get pretty chilly on one side but scalding hot on the other and why CPU Peltier rigs virtually require a water block to operate. Standard phase-change coolers are much better, and these new devices (haven't read the article yet) may be even better.

Re:Peltier cooler?

[WindBourne]

They opperate at 5% efficiency, while top end refrigeration is at 45%. Instead, these guy should be looking at cool chips, which opperate at 55% efficiency.

Re:Peltier cooler?

[ultrasonik]

Peltier effect devices aren't very efficient unfortunately. Compressors are still better for larger applications.

Re:Peltier cooler?

[Geiger581]

These cool chips still sound a little wishful and/or far off. It's illegal in the US to even use Tritium gas for glow in the dark products, and these things supposedly will require Cesium gas. Will be great if they work and are available for commercial use.

Re:Peltier cooler?

[mangu]

Besides the low efficiency mentioned above, there are two other problems with Peltier chips. One is cost. The second problem is that, being made of lead telluride, they aren't very environment-friendly. Lead compounds are rather toxic and do not degrade in nature.

Re:Peltier cooler?

[sckeener]

Instead, these guy should be looking at cool chips, which opperate at 55% efficiency.

The system, currently under development, contains no moving parts or motors and can be miniaturized for use in micro-electronic applications.

It sounds great, but I'm still waiting on Duke Nukem. Let me know when they're closer to a commercial release.

Re:Peltier cooler?

[Anonymous Coward]

These cool chips still sound a little wishful and/or far off.

They have working prototypes and a small production facility. Thats not exactly "wishful thinking"

Re:Peltier cooler?

[WindBourne]

My understanding is that they are doing an ultra thin coating rather than doing a gas. But you do have a point.

Of course, I do find it funny that we allow our homes to be built on radon sites, but would prevent Tritium from being used on watch dials. But that was a total knee jerk reaction.

From what I have heard, Boeing is getting ready to use them as is the military. In many ways they make a lot more sense as no mechanical parts. Pretty much means no future repairs or re-filling.

Re:Peltier cooler?

[Detritus]

Tritium isn't illegal to use, it's just regulated. There are many commercial products that use tritium. I've owned a few.

Re:Peltier cooler?

[deacon]

while top end refrigeration is at 45%

I think you mean that refrigration is 1300 %..

That's what the EER means on an air conditioner..

The machine with an EER of 13 moves 13 times as much heat as it uses in electricity.

Re:Peltier cooler?

[nherc]

Actually, from their literature, it appears this is just A BETTER peltier.

Basically, they put a gap (of air or other gas) which acts as an insulator between the hot and cold side of the peltier which they somehow get the electrons to tunnel over. This keeps the hot and cold sides completely seperated, which is the real efficiency issue with current peltiers.

Re:Peltier cooler?

[ChrisMaple]

Natural cesium (At. Wt. ~133) is not radioactive - what's the problem? It's probably being used because it emits electrons easily. It has been used in vacuum tubes as a getter for decades.

Re:Peltier cooler?

[Anonymous Coward]

>>Join Slashdot.
>>Visit faraway lands.
>>Meet new people.
>>Offend them :-)

>No it doesn't. Get your facts straight

WOW. You really know how to take a sig to heart.

Re:Peltier cooler?

[Anonymous Coward]

What about the tritium sites on my HK USP, and my MILITARY ISSUE compass?

I call bullshit.

It's not like tritum is that bad anyhow.

Re:Peltier cooler?

[trentblase]

I'll second that. Tritium products are the bomb, no pun inten... ok actually I did intend it. I like how they have notices in the airports about how radioactive material is illegal except "small amounts for personal use"

Re:Peltier cooler?

[Anonymous Coward]

I'm tired of idiots with a bad grasp of science spouting garbage. Is that wrong?

Re:Peltier cooler?

[po8]

As other posters have mentioned, it's not cesium gas but cesium metal, and it's not radioactive AFAIK.

I actually have done some consulting for the owner of Cool Chips (on an unrelated project), and have chatted with him about the tech. As I understand it, they are in an early prototype stage: they've built chips that work, but they are in the process of negotiating their first volume contracts and ramping up production. In other words, they are definitely for real, but you may not see them in anything you own for a year or two.

Re:Peltier cooler?

[Rambo]

Lead? Ahhhh no. Most coolers are made using bismuth telluride, and it's the relatively rare peltier power generators that use lead because it can handle the higher (250C+) temperatures required.

Re:Peltier cooler?

[York the Mysterious]

If you want a very efficient conventional refrigerator check out these guys. http://www.sunfrost.com/index.html

Re:Peltier cooler?

[Anonymous Coward]

Isn't there some sort of Stirling Engine refrigeration mechanism with a couple of Stirling thermally tied together? Since a Stirling Engine has nearly 100% Carnot efficiency, wouldn't it make the basis for an efficient heat pump refrigeration unit?

Re:Peltier cooler?

[F34nor]

Someone at IBM has gotten the Peltier onto a modern fab process and has the efficency approching 30%. I think I heard about this on NPR in the last year but cannot find any reference to it on the so called "internet."

I'm amazed B&J's still operates semi-autonomou

[Kuad]

When Unilever bought them out, most of us (shareholders, that is) assumed B&J's would get folded into the corporate machine and lose some of its identity. It's good to see that they've sort of remained a seperate entity that just happens to be owned by a corporate giant.

Dangerous

[SlayerofGods]

173 db? That's like liquefy your ear drums loud.... I think most people will stick with frezers that don't kill them.

Re:Dangerous

[Anonymous Coward]

If you suck the freon out of your conventional freezer it will kill you too. If you'd RTFA you'd know the sound waves are contained in the cooling chamber ond only a dull hum (comparable to a normal fridge) is heard.

Re:Dangerous

[SlayerofGods]

Freon
Because Freon is non-toxic, it eliminated the danger posed by refrigerator leaks.
First result when googleing for freon.
Things can brake you know and the sound can get out.

Re:Dangerous

[SlayerofGods]

It says that the noise can only be generated inside the chamber. But I bet it will still make a pretty loud bang when it cracks.

Re:Dangerous

[AndyRobinson]

Why not try reading one the many fine articles that are linked to above? For example, the BBC says:

"Were the fridge ever to crack open, the vast sounds generated within would not escape because the intense noise can only be generated in the pressurised gas locked inside the cooling system.

Re:Dangerous

[tzanger]

Non-toxic doesn't mean it can't kill you. I was ripping apart a freezer back in my youth and cut one of the tubes on the low-side of the compressor. 15 years later I still do not have feeling in the tip of my left ring finger.

So I am quite positive that if you inhaled enough freon you'd either die of shock or asphyxiation. Or both. :-)

Re:Dangerous

[SlayerofGods]

That's from a news site, who have a tendency to fudge the facts.
I believe they were alluding to the fact that if your fridge broke open you wouldn't here a constant loud noise.
But the prude article points out that its 20 atmospheres of pressure in there, that's 100s of psi. You don't think that is going to make some noise if it brakes open?

Re:Dangerous

[Anonymous Coward]

You don't think that is going to make some noise if it brakes open?

Er... The sound of it screeching to a stop?

Re:Dangerous

[Reverberant]

It says that the noise can only be generated inside the chamber. But I bet it will still make a pretty loud bang when it cracks.

Probably not. The 173 dB is a measure of the sound pressure. Pressure is force divided by area - in this case, it's a force generated by a transducer over the limited area inside the device. If the enclosure breaks, the area goes to infinity, the sound pressure is significantly reduced.

not 173db

[paradesign]

190! Read the article.

Re:not 173db

[HiQ]

wow, an icecream machine with an amplifier that goes up to eleven

Re:not 173db

[ChrisMaple]

The articles I read said 173. Apparently they don't all agree.

Summary please!

[moxruby]

I'm too lazy to RTFA and the writeup was full of links but short on information.
Can someone tell me what this is all about? Is there a chance I can get indignant and rant about something I have neither the time nor patience to understand?

Apparent Contraditions

[PurplePhase]

and quiet operation

If 173 dB is quiet for you, I'd hate to be around when you throw a rock concert! Liquified bones are not my idea of a good time!

And did anyone read that as
the Penn State researchers who died in the development
? I must need a couple more hours sleep...

8-PP

Re:Apparent Contraditions

[phaze3000]

Were the fridge ever to crack open, the vast sounds generated within would not escape because the intense noise can only be generated in the pressurised gas locked inside the cooling system.

RTFA

Re:Apparent Contraditions

[roseblood]

RTFA? Which one?
http://www.npr.org/ ?
http://www.benjerry.com/ ?
http://www.npr.org/features/feature.php?wfId=18 614 34 ?
http://live.psu.edu/story/6482 ?
http://news.bbc.co.uk/1/hi/technology/2543085.s tm ?
http://www.benjerry.com/our_company/sounds_cool / ?
http://www.purdue.edu/UNS/html4ever/9706.Mongea u.r efrig.html ?
http://www.auditory.org/asamtgs/asa93dnv/2aPAa/ 2aP Aa7.html ?
http://www.coolsound.us/ ?

-- all of these are linked to from the summary/blurb.

Re:I'm amazed B&J's still operates semi-autono

[REBloomfield]

Thankfully they realised that Ben & Jerry's identity is a big part of the brand marketing. I'd still buy it if it was rebranded, just for the great flavours, but I'm not sure everyone would.

Computer

[indros]

Now I want something like this so I can drop my computer in!

Re:Computer

[scifience]

No you don't. Your processor will shatter, your motherboard will crack in two, and your hard drives will explode from the noise.

What if Master P really was the Ice Cream Man?

[ProppaT]

"Yo B, turn that sh*t down..."

"Naw man, it's cool...just makin' ice cream"

"Word"

Pop Sci

[ryanmfw]

Pop Sci had a small bit of coverage on this about half a year ago. Not very informative, but, it can't hurt. Anyway, I'm wondering how feasible putting this in a house is, since the padding required to block the noise would be so bulky (IANAAE) that to make it fit in a standard refrigerator cabinet, you'd have 3 ft^3 of space. :-) Of course, they could just make a small compartment for freezing the foods quickly, and then move them into normal storage. Well, I'll go off to read the article so I have a clue now. :-)

Re:Pop Sci

[CodeMonkey4Hire]

IANAAE = I am nonetheless ambiguous and equivocal?

googling on 'ianaae':

IANAAE (AE == "Aeronautical Engineer")
I am not an acronym expert
I am not an aeronautical engineer
I Am Not An Acoustics Engineer
I Am Not An Aeronitics Engineer
I am not an ASUS engineer
I am not an alpha expert

Re: Political Hot Air

[Alien54]

Sounds like we may have either a power source here, or a cure for the condition.

Of course, you may happen to like politicians. Your milage may vary.

Oh no

[Woogiemonger]

So they've taken "We all scream for ice cream!" literally?

Not at all...

[cnelzie]

...the system works with the 'woofer' producing the single note within a sealed container. From what I heard on NPR, the sound is no more loud then walking into a large server room and hearing the fans run. It's just a bit deeper of a sound.

Inside the canister there's 198 Decibels going on... That would shatter your ear drums and make your eyes bleed (possibly) pretty quick I understand...

Outside the container all your hear is a regular humming noise at one frequency...

Re:Not at all...

[AKnightCowboy]

...the system works with the 'woofer' producing the single note within a sealed container. From what I heard on NPR, the sound is no more loud then walking into a large server room and hearing the fans run. It's just a bit deeper of a sound.

Err, I guess I won't be getting one of these for my house anytime soon. My "large" server room really needs hearing protection if you're going to stay in there for a few minutes. Farking loud Cisco stuff.

Re:Not at all...

[kd4evr]

Well, there's a chance of success with
geeks, but only if the sound pitch matches that Enterprise next generation humming background noise.

Re:Not at all...

[Anonymous Coward]

Actually, the sound outside the cannister is about the same as a normal refrigerator...says so in the article.

Inside the cannister, 198Db, would do more than just shatter your eardrums, it's enough to set you on fire! Really, according to Dr. Garret, who metioned this in a talk at Penn State many years ago when they were making one of these Thermoacoustic Refrigerators for a Navy warship to cool the high power radar unit. No demonstration of 'acoustic ignition' tho... :-(

Re:Not at all...

[trentblase]

Ironically (or not), most of the noise in server rooms I frequent comes from the giant AC units needed to keep everything from spontaneously combusting.

Re:Not at all...

[NuclearDog]

IIRC, it's like 150-160 DB will stop your heart, so I don't think you'd be around long enough to experience your eyes bleeding.

Just my opinion, though.

Re:Not at all...

[digitalunity]

Where do people get this shit? It won't make your heart stop. Maybe under a long enough duration, but a brief exposure won't kill you. Look here to see what DB's are all about. The most frequent side effect of high-amplitude sound exposure is a perf'd drum or permanent hearing loss.

Re:Not at all...

[NuclearDog]

I guess I didn't remember it correctly. I thought I saw it on the Discovery channel.

Anyway, thanks for that link. Interesting.

I knew this !!!

[Anonymous Coward]

Shit, I knew this technology worked from a long time ago: Each time my wife screams at me, I freeze...

Well, I'll leave it at that and not go into icecream-producing issues using the same "technology"..

Rocky Road _is_ Noise Pollution

[Anonymous Coward]

Runs on AC/DC.

Re:Rocky Road _is_ Noise Pollution

[Anonymous Coward]

Actually if they used Barbra Streisand at any volume it could chill anything. The down side of that is their ice cream sales would fall to zero.

Reportedly?

[Anonymous Coward]

Buy a thesaurus and learn to write.

CPU usage

[troon]

So, if that swanky new case with 8 screaming fans wasn't loud enough for you, you can now get a screaming case!

Until high volume is reached...

[cnelzie]

...this new refridgeration device will be much more expensive then the 'traditional' designs. Once production ramps up, if ever, the cost of producing this device will equal that of the current cooling technology.

It's also possible that in the drive towards production, the system could be made more efficient. As I understand it, the goal so far has been to get it working. That goal has nothing to do with energy efficiency.

The next goal is or should be ramping up production after long-term testing... After that the goal of energy efficiency can be worked on.

Re:The saying is true!

[whovian]

WTF, redundant? I searched the comments before posting and it hadn't been mentioned.

Re:Bad News . . .

[Tuxedo Jack]

So how about deploying this around stadiums/arenas for A/C supplements?

Or even better, put it on the set of Jerry Springer. That way, the audience can call people "frigid bitches" and be serious for once.

Quiet operation!?!

[Openstandards.net]

"173 db sound"!

Some I have been in...

[cnelzie]

...weren't all that loud. Of course, my experience is rather limited in that aspect. I have only been in a room with a series of Sun Rackmounted units for a brief amount of time.

Anyway, I understand that the sound refridgeration unit isn't much louder then the average refridgeration unit of today. That's not very loud DB-wise.

Question

[(ana!)a]

Hi, I live in Canada and I've always wondered why we didn't have a fridge that would take advantage of the outside temperature ? I mean, when it gets down to -20s celcius and you spend a lot of energy heating your house to +20 celcius, then you spend some more energy to cool down the fridge inside the house (although it actually participates in heating up your house), it sounds kind of ridiculous, don't you think ? Is there a particular reason for this ? Maybe it wouldn't be of much use for anyone but canadians, russians, norvegian and the like, but still... I've always known there was a link between noise and temperature... After all, my fridge sure is noisy !

Re:Question

[subtropolis]

During the ice storm blackout a few years ago i put everything on the balcony. It *was* about -20c then. It's not a great solution (think cucumbers, or anything else with a lot of water in it)

Re:Question

[Johnny Mnemonic]

I've lived in Iowa, and wondered that too. You could, I suppose, attach your fridge directly to the wall, and then simply connect a duct to the outside temperature. Here's some thoughts why that wouldn't work:

• It would break in the summer, and it might be cheaper to cool in the winter using the traditional method than cool in the summer with the inefficiency of the duct;
• it could get too cold--you don't want to keep you milk stored at -20F, you want it at +40F--so you would actually have to heat it up. But why not do this for a freezer?
• The temperature change typical throughout the day might not guarantee that the food stays cold, which could lead to inconsistency and lawsuits over food poisoning.
• Every time you open the door, heat would escape from the room to the outside--and it might be more efficient to keep food cold using the traditional method than to warm up the room again.

It does seem like each of these issues are surmountable with clever tech. Of course, there isn't anything stopping you from keeping your freezer on the porch and turning it off during the winter.

Re:Question

[timothv]

You're assuming none of those challenges can be solved. Basically, just make it so that there's some tube to the outside but can be closed by some fridge CPU. If it's too cold, close it; if it's summer, close it; if the temperature changes, close it or use some algorithm to keep it consistent with help from the fridge cooler as well; if the door opens, close it.

Re:Question

[2nd Post!]

Due to the fact that fridges are, at most I've read, 45% efficient, your fridge is *warming* your house. If it's spending 45 watts to cool your food, it's also spending 55 watts to warm your house (or something like that).

Which means your house would take even *more* energy to heat in the winter if you didn't use the fridge!

Re:Question

[dnoyeb]

We do, its called a Heat Pump. But nobody wants to increase the cost of their fridge by having to add piping to outside of their house.

Re:Question

[Theaetetus]

Speaking of kitchen efficiencies, Spider Robinson once had an essay about the incredible heating-cooling inefficiencies in any modern kitchen...

• Stoves that have doors that must be opened to see inside, and doors that open downwards letting heat escape. Could be better designed with larger, clearer windows and lighting inside, and doors that either open upwards (hinged at top) or have some shutter-type arrangement that would allow heat to stay inside the oven with less escape.
• Refridgerators that have freezers on top, doors that open horizontally, and create waste heat in the rest of the room. More efficient would be freezers that open upwards (like ice chests) or freezers on the bottom (let the heat rise up and keep the 'fridge' compartment warmer than the freezer), windows that let you see food so that you don't have to let the cold out while you look at the contents, and a way of harnessing the waste heat for use in the oven or dishwasher located right next to the fridge.
• Sinks without thermocouples, necessitating playing with the faucet to get the proper temperatures... A dial would be much faster and easier.

Etc.

-T

Re:Question

[(ana!)a]

I had mentioned this in my original post, but the fridge is not the most efficient way to warm the house ! I know there's plenty of drawbacks to the idea (cost, wouldn't work in summer, etc.) but still it would be nice for the winter. BTW, just so you know, don't put beer outside when it's below -5 celcius, it will freeze !

Re:Question

[sbeitzel]

My dad lived in Palouse, WA when he was a kid. He tells me that on the north wall of their kitchen there was a pantry which had no insulation from the exterior; there was just a board or something. The temperature inside the pantry was a close approximation of the temperature outside, and since that wall was always shaded it never got too hot. In the winter, it was like a second fridge.

Re:Question

[Anonymous Coward]

You don't see this because somebody in Halifax owns the patent

(Posted by a true Haligonian).

Re:Question

[TheLink]

Even if a fridge isn't the most efficient way to warm the house, it very efficient.

A fridge isn't that efficient in cooling, but it is very efficient in generating heat. Basic physics/thermodynamics.

Like many other devices most of the energy ends up as heat, very little escapes the room/house as light or other forms of energy. In fact a fridge pumps the heat from stuff inside it.

A heatpump can actually be more efficient at heating than a pure 100% heater. This is achieved by pumping the heat from somewhere so you get additional heat on top of the energy you put in.

A fridge is problematic if you don't want the room warmer. e.g. you are airconditioning the room and your fridge is inside the room.

Of you want the fridge to cool more effectively whilst inside an already warm room.

Re:Question

[misterpies]

I get the feeling you don't spend much time in the kitchen. Oven or fridge doors hinged at the top? Firstly you'd need to move the oven/fridge to head height for it not to get in the way, so you have to lift up the food to put it in. Second, oven doors opening down give you a convenient place to rest dishes when turning/basting etc. (Also what is the logic that argues it's more energy efficient to have both oven and fridge doors opening upwards? if hot air rises and cold air falls, shouldn't the fridge door open downwards?

Also it makes more sense to have the freezer on top, so you can concentrate the cooling on the freezer and let the natural airflow cool the fridge. (Just like when heating, you put the source on the bottom, when cooling, you put the refrigeration element on the top).

Re:Question

[Anonymous Coward]

Actually just putting the radiator of the fridge outside would do. No need for any extra logic.

Re:Question

[Theaetetus]

I get the feeling you don't spend much time in the kitchen. Oven or fridge doors hinged at the top? Firstly you'd need to move the oven/fridge to head height for it not to get in the way, so you have to lift up the food to put it in. Second, oven doors opening down give you a convenient place to rest dishes when turning/basting etc

Nope, spend a lot of time in the kitchen.
Anyways, yes, have the oven at head height (chest height, rather). You don't have to have the range on top of the oven - look at a lot of newer kitchens with the oven wall-mounted and the range on an island. Makes much more sense. Then you don't need to have the door to rest things on, just reach in at normal height (or have a slide-out rack).

... if hot air rises and cold air falls, shouldn't the fridge door open downwards?

You misread... From my post: "Refridgerators that have freezers on top, doors that open horizontally"

Also it makes more sense to have the freezer on top, so you can concentrate the cooling on the freezer and let the natural airflow cool the fridge. (Just like when heating, you put the source on the bottom, when cooling, you put the refrigeration element on the top).

Nope, more inefficient. The freezer needs to stay real cold, right? So, why not save energy and let the natural flow of the cold air help? Ambient temperatures are also colder nearer the floor, so you'd save there too. Finally, the freezer (other than ice-cube makers) are accessed less often than the fridge - hence should be down lower.

-T

Re:Question

[2nd Post!]

For summer, I agree.

But for winter, the fridge works great *especially* in Canada.

You heat the house and cool your food at the same time.

In the summer though what you would want is a more efficient system; perhaps run a heat exchanger against the coils in the back to heat up your hot water tank or your radiant floor heating in the bathroom?

Re:Question

[jaakkeli]

Hi, I live in Canada and I've always wondered why we didn't have a fridge that would take advantage of the outside temperature ?

You don't? Well, we certainly do over here in Finland! I just cooled down a pizza outside. Unfortunately (yeah right, mwahaha!) it's not cold enough to properly cool down beer right now, but when it is, we do that, too.

I mean, when it gets down to -20s celcius and you spend a lot of energy heating your house to +20 celcius, then you spend some more energy to cool down the fridge inside the house (although it actually participates in heating up your house), it sounds kind of ridiculous, don't you think ?

No, it doesn't. Your fridge (or anything else) cannot destroy energy, so every bit of energy taken from the electrical socket must end up in the house - and the only thing that a fridge really produces is heat (it doesn't radiate away any energy as light, for example). You have to remember that when you put energy in an object to heat it, you take energy out from it to cool it. If you were to use the outside air to cool things, you'd actually be throwing away some heat that you've paid for - what you suggest would be a waste of energy, not the other way around.

(Of course, it might make sense for you personally to cool things outside, depending on how you're heating your house. My apartment is heated by some waste heat from some factory or power plant or something like that, so I'm not actually directly paying for the amount of heat; it's included in the rent. Cooling things outside would be economical for *me*, but it's always unecological. Not that it matters much either way, but...)

Maybe it wouldn't be of much use for anyone but canadians, russians, norvegian and the like, but still...

Not for most Norwegians. I think most of them live on the coast and there they have the Gulf current heating up the place, so they don't have proper freezing weather. Besides, the Norwegians don't have to worry about some tiny energy savings - they have oil to burn. (Way too much oil! Damn we hate those Norwegians.)

Re:Question

[CrimsonAvenger]

Nope, spend a lot of time in the kitchen. Anyways, yes, have the oven at head height (chest height, rather). You don't have to have the range on top of the oven - look at a lot of newer kitchens with the oven wall-mounted and the range on an island. Makes much more sense. Then you don't need to have the door to rest things on, just reach in at normal height (or have a slide-out rack).

Have you ever considered a 20 pound (9 kilo for the metric types among us) turkey, plus dressing, within that context? Have you asked your wife about it?

For that matter, have you considered "reaching in" to that nice, hot oven with the turkey inside? It had better be one huge oven, or you're going to have some lovely burns on your arms/hands as you attempt to baste the the thing while inside the oven.

Please note that I do NOT spend a lot of time in the kitchen, but my wife had a few things to say about oven doors swinging up, and ovens at chest height. And while she concedes the latter is done quite a bit these days, she also points out that more often than not, the lady of the house asks her husband to put the turkey in/remove it from such ovens....

Note further that "lady of the house" is my phrasing, not her's. She'd kill me if she knew I used it to describe her.

MY own opinions - a door swinging upward would not prevent heat from escaping the oven, since the entire front of the oven would still be open. Freezer doors that open horizontally (like an ice chest) have been done forever, on large floor deep freezes, such as my mother has in her pantry - works quite well. However, you couldn't practically put a fridge on top of it, or it on top of a fridge, so it would double the floor space required for the combined functionality. At least. Which is not a big deal if you have a big freezer, but for the usual freezer compartment-sized box, it would be impractical.

Large, clear windows in either oven or fridge would tend to be points where heat escapes, either inward or outward. They would reduce the efficiency of the unit somewhat. Whether this would be overcome by the lessened need to open the door is debatable. And besides, how long do you actually spend with the door open when you reach in for a beer/steak/whatever? Would it be appreciably shortened if you could see it in advance? Don't know about the rest of you, but I know where pretty much anything I'll be wanting normally is inside my fridge, and seldom have to actually root around in there looking for things.

And finally, please note that even eskimos use fridges these days - keeps stuff much warmer than outdoors, thus allowing you to thaw things faster. A fridge/freezer is all about controlled temperature, not low temperature per se. Sure, low compared to the inside of the house, but not necessarily low compared to the outdoors.

Re:Question

[c4ffeine]

COLTON is really gay

Re:Question

[pluvia]

Could be better designed with larger, clearer windows

Hmmm... do larger, clearer windows insulate as well? There might be a trade-off there.

More efficient would be freezers that open upwards (like ice chests)

Yeah, they are a good idea, but bookshelf-style access is usually more convenient than vertical stacking.

or freezers on the bottom (let the heat rise up and keep the 'fridge' compartment warmer than the freezer)

It's late, but I don't think that putting the freezer on the bottom would increase efficiency at all. The AC has to remove every joule of heat to accomplish its target temp, regardless of the ultimate location of the air inside, and I think insulation works pretty well to maintain that distinct temp in each of the fridge and freezer.

Would the cold air still be formed at the top?
or use a fan to push it up to the fridge and to aid homogeneity?
Could you walk me through a scenario that shows a better efficiency due to this arrangement?

windows that let you see food so that you don't have to let the cold out while you look at the contents

Good idea unless you don't want everyone to see the inside of your fridge all the time... though maybe it could use some of that glass that only turns transparent when a little electricity is applied... though that would make it a bit less efficient. Plus, I think most of the energy might be lost in the actual openning and closing of the door and somewhat less keeping it open.

Somewhat similarly, I once heard of an air current to cover a fridge rather than a normal physical door. Apparently, it was more efficient, since less cold air was lost. It had the same "transparent" problem, plus if the power went out, you're fscked.

Maybe this "air door" idea could be extended to work alongside actual doors (which might also help with ovens)? Though this is significantly more complex and might not even be much more efficient.

and a way of harnessing the waste heat for use in the oven or dishwasher located right next to the fridge.

If placed and timed properly, I think it could help a very little bit in the initial temperature rise for either of those (the dishwasher, by extension any "hot water")... or are you going to recompress it to raise the temp? In any case, I'm not sure it's more efficient.

NB: I'm not an expert in any of this. :)

Re:Question

[Anonymous Coward]

COLTON is really gay

Who the fark are you, who the fark is Colton, and why do I give a fark?

and that explains..

[cabazorro]

Barry White.. cool
Cindy Lauper.. not cool.

"Quiet operation"?

[adrianbaugh]

173dB is quiet? Was your previous job in the PR department of a CPU fan manufacturer?

Re:"Quiet operation"?

[gstoddart]

WHAT??

Re:I'm amazed B&J's still operates semi-autono

[StateOfTheUnion]

There was a contract that allowed them to remain somewhat autonomous . . . the ex-hippies (Ben and Jerry) would sell unless the buyer was contractually obligated to continue some the socially concious initiatives that they started.

And its probably good marketing . . . keeps the "socially concious" brand reputation.

Penn Staters

[rayde]

It's nice to see PSU doing research with Ben & Jerry's, considering Ben and Jerry are among Penn State's more famous alums.

Re:Penn Staters

[biobogonics]

Penn State is famous for its dairy plant on campus and its short course on making ice cream

http://conferences.cas.psu.edu/IceCream/icsc.htm l

which Ben & Jerry attended.

I agree

[2names]

that it is pretty cool to have a $10k stereo in a $200 car, but if you are going to do this, at least put some silly putty between the license plate and the trunk lid.

"...bzzzzzz.....bzz bzz.....bzzzzzz.....bzz bzz....."

In a karma-losin mood, are ya?

[Anonymous Coward]

1. 'we all scream for ice cream' is redundant just cause its obvious.

2. If you can scream at 190db, the department of defense would be interested in giving you a job.

Whohooo...!

[Tore S B]

This may be the first technology where yelling at a piece of broken equipment really loud makes it work?

Efficiency?

[irrelative83]

Anyone know how efficient this is relative to normal refrigeration techniques? Seems like that would better measure the practicality of this device.

Why use acoustics? Why not a mechanical diaphram?

[Anonymous Coward]

Looking at the flash explanation from the Ben and Jerry site, it sounds like pressure waves are used to move a diaphram which compresses and de-compressess a sealed chamber which creates heat transfer on opposite ends of heat transfer fins attached to said chamber.

Heat build up is concentrated on the tips of the fins during compression, while the opposite ends of the fins get cooled by the opposite effect of the decompressing air.

My question is why use acoustics to move that diaphram? Why not a simple mechanical device instead?

Argggh... Flash required.. .

[nurb432]

F-ing flash pages.. i was really interested in seeing the details on how this beast works..

Depending on efficiency, it could be used for home and car A/C and regular freezers..

It would appear easier to repair and maintain, at least from the one still shot i get to view..

I think they are

[Anonymous Coward]

I believe the 12v operation mode in RV fridges use a bank of peltiers? I've seen a large bank of peltiers on ebay before and they looked just like the visible part of the cooling heat unsink in a 1978 fridge...

"quiet operation"?

[roseblood]

"thermoacoustic refrigeration technology, which uses helium gas subjected to ultra-loud 173 db sound."

I know...RTFA, but...I did read the FA. Problem is I must have read the wrong one (so many links here.)

Whatever they use to keep the 173db sound locked inside the box, I want. I'll use it to line my appartment walls, as I'm tired of hearing the latest crap..err...latest top 40 hit being blasted by my neighbor's juvenile deliq..err...teenager.

I heard that

[N8F8]

A class I was taking last semester was being taught by a retired NASA program manager who mentioned the helium scarcity. Most of the world's helium is "mined" in Texas, so if this were handled correctly it could lead to quite the litte technology monopoly. OTOH, if helium were to become more scarce on earth I pretty sure someone would find an alternative source.

Re:I heard that

[Thavius]

Maybe the shortage of helium will drive the fusion research market, pushing fusion technology to the forefront to drive the alternative source for helium market. But what will Big Helium think of that? Will Big Helium try to stop the development of alternative sources? Or do I just need more coffee to stop talking nonsense?

Re:I heard that

[Noren]

Like a lot of other natural products, it's currently produced where it's cheapest to do so (and where they've installed the apparatus to seperate it from the natural gas). If the Texans were to start to act monopolistically, or if the price were to rise for other reasons such as increased demand, many other places where it would be slightly more expensive to produce would retool to do so. Helium just isn't that rare.

Re:I heard that

[eclectro]

Yes and no.

I found this interesting thread having some interesting helium facts.

Helium is a finite non-renewable resource, as it does eventually escape the upper atmosphere.

But keep in mind that Texas is not the only place natural gas is found. There are significant reserves in the middle east as well (and the source of much argument as to how much we should import, the prices are rising for it in the US).

The helium that came from when the earth was formed has gone, and the helium we have today comes entirely form radioactive alpha decay in rocks. Thus the amount of helium in natural gas in any given area is variable.

Also, natural gas is not the only potential source for helium, as it exists in other places. It could conceivably be fractionally distilled from the atmosphere (and it was initially, read the link above), though this would be costly. Also, helium could be produced in nuclear reactors.

In the end, helium is a commodity, like many other things. As such, it follows fundamental market forces and the laws of economy. Demand for helium thus determines the price for helium (mostly, there is some government influence that comes into play through regulation, but that is beyond the scope of this post).

So, if for some reason they could not produce helium in Texas (unlikely) or for some reason there was shortages for helium due to demand, the price would go up. This would lead to higher prices, and people would start to look for other sources. Foreign producers would be motivated to produce helium. If it was expensive enough, conservation would take place, and where it was possible, other substances/methods would be would be used (like in welding, they would use argon instead of helium. In fact many do already as it is cheaper). Interestingly, a large part of the cost of helium is the shipping of it around in the big heavy metal tanks. That's why they may use argon in this acoustic fridge rather than helium.

Instead of using helium in party ballons, hydrogen (possibly mixed with air to reduce flammability) could be used. While some may see this as dangerous, it would be a lot less dangerous than the flammable silly string used in many a party. But I digress. You get the idea.

But I do think that this calls for a sense of perspective. We live in a world with limited resources. From gold to oil to water to food even (it could be argued) clean air.

So, as you can see, the chance of a Texas monopoly on helium is slim. Your second statement, that alternate sources would be found (and don't forget substitutions made) is more correct.

Helium scarcity is a physical reality, but it also obeys the laws of economics.

Re:I heard that

[G00F]

Umm, lets see . .
"Instead of using helium in party ballons, hydrogen (possibly mixed with air to reduce flammability) could be used. While some may see this as dangerous, it would be a lot less dangerous than the flammable silly string used in many a party. But I digress. You get the idea."

You do know that hydrogen + oxygen make water right?

Also Hydrogen is also prone to escaping the atmosphere, since it is lighter than He. Yes there is a lot of it trapped in water and so forth. But:
1. It takes energy to make
2. It is very hard to store. Not because of the fire hazard, but because those things are so small, they lend their electron to the container and slip right through, then take an electron back on the other side.
3. Water is a valuable and very important resource.

Honestly, if we get to the point where we are using these gasses, we mine the gas giants. Infact they should keep that in mind for terraforming Mars. We got plenty of other planets with lots of atmosphere.

Green Friendly?

[thelizman]

The electricity that powers this best still comes from the same pollution belching power plant as other refridgerators. Guys, face it, nothing is green friendly until we get a hydrogen and nuclear based economy going.

Re:Green Friendly?

[Anonymous Coward]

That's a canard. Hydrogen plus nuclear is not the "only green solution".

Power plants don't have to be so pollution belching.... some reasons:
1. Plants don't have to haul around their equipment (like cars do) so they can have lots of heavy anti-pollution equipment

2. Carbohydrate economy (eg biodiesel) www.biodiesel.org

3. Diversity of sources in general is a Good Thing: some places have lots of moving water, others wind, others sun; some have lots of agricultural waste, others plenty of grease and offal. Every 10% counts, especially with returning-electricity-to-grid.

Nothing against hydrogen. But nuclear? Has got some reasons against it.

Re:Green Friendly?

[WindBourne]

green friendly means that it is better than current technology. If they do not use any of the normal refrigerants it is "green friendly". But not by much. As to getting a hydrogen and/or nuclear based economy going, well, that is not the only approachs. In fact, we would do better to putting research dollars into electricity storage via Super Conductors or via heat/sterling engine, and then use it to help balance power generation/useage.

Re:Green Friendly?

[Anonymous Coward]

That's a canard. Hydrogen plus nuclear is not the "only green solution".

Power plants don't have to be so pollution belching.... some reasons:
1. Plants don't have to haul around their equipment (like cars do) so they can have lots of heavy anti-pollution equipment

Yes, but that would cost money and make American Industry uncompetitive.

2. Carbohydrate economy (eg biodiesel) www.biodiesel.org

I'll bet farmers will be glad to plant this. For an enormous subsidy, of course.

3. Diversity of sources in general is a Good Thing: some places have lots of moving water, others wind, others sun; some have lots of agricultural waste, others plenty of grease and offal.

But they'll burn oil anyhow.

Every 10% counts, especially with returning-electricity-to-grid.

Nothing against hydrogen. But nuclear? Has got some reasons against it.

Of course. It costs money. See above. The future of energy in America is... *drumrole* O-I-L. So you'd better start getting used to it.

+5, Insightful

Re:Green Friendly?

[acidrain69]

The only "green" with Nuclear tech is the glowing. Nevada doesn't seem to happy to be the chosen site of the nuclear disposal site. Now solar, wind power, geothermal and wave powered? Those are green techs. But I suppose you could also take MANUFACTURING into the equation, which has a lot of byproducts and isn't really green, but I suppose using some filthy-tech to make green tech is acceptable for now.

Re:Green Friendly?

[pclminion]

The electricity that powers this best still comes from the same pollution belching power plant as other refridgerators.

Pollution belching? Coal and oil fired plants haven't released nasty black smoke full of sulfur gases for years. Pretty much the only "bad stuff" coming out of modern petrochemical plants is CO2. Bad for the environment, yes, but I hardly think it qualifies as "pollution belching."

Do you really think people still tolerate smokestacks blasting thick, black, pungent smoke into the atmosphere? Have you ever seen a coal-fired plant?

The other major environmental impact is heat. Coal plants use river water to transfer the heat energy in their turbines. They then reject the heated water back into the river again, wreaking havoc on local ecosystems. Nuclear plants have this same problem. The only thing that sets nuclear above coal is the fact that it releases no CO2.

Having said that, I agree with you that nuclear is what we should be heading toward, at least in the interim until we figure out what the hell the real solution is.

Refrigeration efficiencies compared

[Geiger581]

Reported maximums (research-only included) in terms of Carnot efficiency:
Stirling-cycle (phase-change): ~50%
Peltier junction (solid state): ~10%
Thermoacoustics (standing wave in gas): ~40%

Using a 'speaker fridge' now would be quite wasteful in terms of efficiency, although researchers believe that they can surpass the old CFC-type compressors soon.

The question that comes to my mind, though, is why the focus on the cooling itself. For a non-emissive object like ice cream, better energy conservation may be more easily achieved through better insulation. How about investing in cheaper silica aerogel, hippies? This stuff is virtually as light as air, essentially made of sand, almost as insulative as pure vacuum, and fairly strong. Having a cooling engine without any ozone-depleting chemicals is great, but it's kind of silly if your freezers still have interior styrofoam lining.

What's the problem GreenFreeze?

[danharan]

There already is a climate-friendly alternative, GreenFreeze. And the Europeans that have adopted this technology (despite the fact it was heavily pushed by GreenPeace) have a lot of experience making very energy-efficient appliances.

Unless they expect this to be cheaper/ more efficient, I can't understand why they would finance such research- except as publicity.

Mod parent down

[Anonymous Coward]

Normally, I ignore people like you, but I have to ask. How many laguages do you speak?

Has it dawned on you (and others), that there are many people here that have english as a 2'nd (or 3rd, or 4th, and even 5th) language? Why do you spend your time trying to correct everybody else? Do you think that you are superior to others here? Do you find that growing up with a language gives you the right to correct everybody?

Re:Mod parent down

[B'Trey]

Why do you assume that I spend my time trying to correct everybody? You can look up my posts if you like. You'll find that I don't correct people who use English as a second language, nor do I normally bother to correct people who use improper English. However, it's pretty apparent to me that the post to which I replied is a native English speaker who contorted his sentence in an effort to avoid ending a sentence with a preposition. To quote Winston Churchhill, "That is something up with which I will not put." It wasn't an incorrect usage that caused my comment - it was the act of going to such extremes to try to be correct that you comletely distort the sentence. That's simply silly.

Heard this on NPR yesterday

[Lebo]

First off, the 190db figure is the sound level INSIDE the unit. Acording to the reporter, the sound level outside the unit was no louder then a standard cooling unit.
From the description of given, the tech sounds interesting. They use a powerfull speaker to create areas of high and low preassure in the chamber. In the areas of low preassure they place tubes which run to the cold case. In the areas of high pressure they place tubes which run to an external heat exchanger to vent the waste heat.
I can definately see this technology comeing into widespread use in the future, as stricter enviromental controls continue to restrict conventional refirgerants. I also wonder how well it would work in an automotive setting, where the high level of vibration makes coolant loss more of an issue.

thermal energy back into microwaves in 6 steps

[oliverthered]

Where do you think the energy for making the microwaves comes from in the first place?

1: invade Iraq.
2: Steal the Oil
3: Burn it to produce CO2 other greenhouse gases and high-pressure steam (that's the heat bit).
4: run it througn some turbines attached to alternators.
5: send the electricity down wires, loosing some of it as you go.
6: out of the transformer, down the local loop and into your microwave.

Re:thermal energy back into microwaves in 6 steps

[nelsonal]

I'm curious does anyone know how much electric generation is accomplished by burning oil? Is it above 10%, seems like sort of a waste, but I don't understand why we don't all have ground source or geothermal heat pumps.

Re:thermal energy back into microwaves in 6 steps

[zero_offset]

For one thing, geothermal is too impractical in many areas -- perhaps most areas. I live in Florida. The only thing you'll find underground around here is cold mud and cold water. As a child I lived in Iceland for awhile, and their geothermal projects are expansive and fascinating. But by comparison, their heat sources are plentiful and very easy to tap.

I'm not sure what you mean by "ground source".

As for oil -- are you asking about the efficiency of burning oil for energy, or are you asking how widespread is the use of oil? I think coal is still the primary source of electrical power generation in the world. Surprisingly, only France has it right, generating almost all of their power from nuclear fission.

Re:thermal energy back into microwaves in 6 steps

[oliverthered]

France and Japan.
Japan has no-oil, no-coal but lots of nuclear power plants (and quite stringent efficiency controles)

Japan has also got a active volcano so they should realy try and produce more geothermal power.

Re:thermal energy back into microwaves in 6 steps

[jgalun]

I know you're making a valid point about the science of this here, but could we lay off the "invading Iraq to steal oil" meme?

1: invade Iraq.
2: Steal the Oil

The US did not invade Iraq to steal oil, for a number of very obvious reasons:

1. Invading Iraq caused oil production from Iraq to dip below pre-war levels, as everyone predicted it would
   
2. Invading Iraq has already cost $200 billion - the equivalent of purchasing 6 billion barrels of oil. Since Iraq produces 2.5 million barrels per day, we'd have to steal about 6 years worth of production to break even. Of course, the US would actually have to steal more than 6 years to break even, because to continue stealing the oil it would have to keep paying to keep its army in Iraq.
   
3. If the US wanted cheaper oil generally and access to Iraqi oil for US companies specifically, the easiest way to do it would have been to drop sanctions in return for Saddam Hussein selling a lot more oil and giving contracts to American companies. Hussein wanted to sell more oil and get rid of sanctions anyway, and would have been happy to throw some contracts to the Americans to get that.
   

Please...It's getting ridiculous that so many people still believe that this is a war for oil when the numbers didn't add up before the war and still don't add up after the war...

Re:thermal energy back into microwaves in 6 steps

[Anonymous Coward]

the availability of oil in the future is less than what it is now. this is not about cheaper gas today, it's about reasonably affordable gas tomorrow.

Re:thermal energy back into microwaves in 6 steps

[MooseByte]

Apologies for the offtopic reply to the offtopic post, folks. ;-)

"Please...It's getting ridiculous that so many people still believe that this is a war for oil when the numbers didn't add up before the war and still don't add up after the war..."

You're looking at it wrong, using hindsight instead of what the Bush administration promised and predicted for how Iraq would "transform". Here's how it was supposed to go, according to the Neocons:

• 0) Invade Iraq and topple Saddam.
• 1) Be greeted by grateful Iraqis, who shower US with flowers and sweets.
• 2) Grab full control of Iraqi oil production and distribution.
• 3) Profit!!!

According to the Neocons, this was going to be a cheap and easy war. According to their plan, the US would have control of Iraqi oil for a pittance.

It's all painfully well documented, even by the Bush adminstration's own quotes and documents (and no-bid contracts). And as many of us knew beforehand, they were painfully, tragically far off the mark.

Re:thermal energy back into microwaves in 6 steps

[nelsonal]

It's a heat pump (air conditioner that can be reversed to function as a heater that buries its external heat exchanger (the ground is a relativly stable 55-60F mass) which allows both processes to be tuned to pour heat into or take it from that temperature. The technolgy is pretty neat, well I think it is anyway, your cold mud would have to be a bit more solid to work well.

Re:thermal energy back into microwaves in 6 steps

[zero_offset]

Interesting, I haven't heard of those. (Found some links on Google.)

Re:thermal energy back into microwaves in 6 steps

[Anonymous Coward]

Ya know, all those rich oil men who are still in business aren't in the business of oil anymore. They're in the business of selling equipment to those in the oil business. (Kinda like during the gold rush -- the ones who got rich were the store owners.)

So it was a war for oil. Just not for stealing the oil. But rather to make Bush's backers a boatload of money selling oil mining equipment.

Re:thermal energy back into microwaves in 6 steps

[bcboy]

According to the Neocons, this was going to be a cheap and easy war.

Not merely cheap. They claimed Iraqi oil was going to pay for it. They put forward this claim by overstating Iraqi oil infrastructure to the point of absurdity. Everyone (outside of American neocons) knew these predictions were nuts before we went into Iraq.

Re:thermal energy back into microwaves in 6 steps

[hmbJeff]

And I am sick of the claim that any particular military intervention is not done for economic reasons because it costs more than that one situation might pay (i.e. Panama, Haiti, Grenada, etc.)

In fact, these "police actions" are just that--in order to keep the overall system in line, you make a conspicuous example of anyone who refuses to play along with the dictates of our global corporate empire. Anyone else who was thinking about breaking "the law" (i.e. that we get to access your raw materials, your labor and your markets on terms we dictate) gets a clear message of what will happen to them if they do.

In much the same way that McDonalds spends the money to buy out, at a loss, any US franchise that appears poised to have a union get in (see the book Fast Food Nation for details), the U.S. must take these losses in order to keep the overall world trade and investment system working the way they want it to.

In the case of Iraq, there is an additional motive. We are approaching the end of plentiful oil in the coming decades. The US government and the corporations who own it are well aware that controlling who does and doesn't get access to oil will be the preeminant lever of geopolitical power. And depletion trends show that the importance of the Middle East oil relative to overall world supply will grow significantly.

Iraq's oil itself is tremendously valuable, but that is only one aspect. Having political control and substantial permanent military bases in a country that is at the center of the middle east geographically and also a major player in OPEC, gives them an unprecidented ability to exert control over the region and the oil industry.

They want to be in a position to control the spigot and decide who gets oil and who doesn't. For that, they would gladly pay many times the current $200 Billion / 715 soldier price.

Besides, the other aspect always glossed over in this kind of discussion is this: The billions being spent are not the dollars of the companies and politicians that will reap the benefits from the policy. It is our (the US taxpayer's) money. They are more than happy to spend our money and our lives to make themselves richer.

Re:thermal energy back into microwaves in 6 steps

[oliverthered]

It's my plan to invade Iraq so I can make microwaves. Where the hell did you get even the glipmse of the idea that the USA invaded Iraq for oil.
Some people.....

Re:thermal energy back into microwaves in 6 steps

[Anonymous Coward]

Project for a New American Century Read it. Check out the authors. Draw your own conclusions. For the lazy /.ers, here is a key sentence:

'The United States has for decades sought to play a more permanent role in Gulf regional security. While the unresolved conflict with Iraq provides the immediate justification, the need for a substantial American force presence in the Gulf transcends the issue of the regime of Saddam Hussein.'

Re:thermal energy back into microwaves in 6 steps

[javcrapa]

So , why the US did it? wmd? i don't think so, the us has been for decades invading countries for its own profit 1-Invade country 2- ??????? 3- Profit!

Re:thermal energy back into microwaves in 6 steps

[Bearpaw]

The problem with your "obvious reasons" is that you miss an obvious fact: the people who are paying most for the war are not the same people who will profit from it. If Halliburton et al have offered stock options to the families of dead soldiers, I haven't heard about it. Hell, many corporations profiting off of the war play accounting games to avoid even paying taxes on the money they make. So, why isn't it worth it to them ...?

A large part of the "success" of many corporations comes from "externalizing costs", aka getting someone else to pick up as much of the tab as possible. This is just a particularly vicious example of that.

Three Observations

[MooseByte]

- How eco-friendly is the helium extraction process? Off the top of my head I believe it's fine, but are there any hidden eco-hostile effects in its production? Probably still far better than the method it replaces.

- Have they experimented with different sound sources for the 173dB? Playing Barry White could produce seriousness smoothness...

- Will they equip the Refrigerator Gnome that controls the internal light with OSHA-approved protective headphones, or will a generation of the little critters be doomed to deafness? (Don't laugh, I saw one of them in my 'fridge once after a Dead concert.)

Re:Three Observations

[(ana!)a]

Helium is extracted from natural gas, and it's a rare and non renewable resource. You can find it in the atmosphere, too, but it would be way to expensive to exploit. Right now the trend it too reduce the amount of helium used in the industry where possible, or else we'll eventually run out of the resource. You can have a look at : http://www4.nationalacademies.org/news.nsf/isbn/03 09070384

Re:Three Observations

[Anonymous Coward]

How eco-friendly is the helium extraction process? Off the top of my head I believe it's fine, but are there any hidden eco-hostile effects in its production?

Yes, it turns out the local squirrels' voices become very high pitched, the lady squirrels laugh at them, and they get the crap beat out of them by the bad-ass males further from the mine.

Squeee

The Hilsch Vortex Tube

[ch-chuck]

I always liked these - not too hard to make, but also not as effecient as other methodes. Apply compressed air, tube gets hot on one end and cold on the other.

Re:The Hilsch Vortex Tube

[Anonymous Coward]

Interesting. I've always known compressed air had the potential to release a lot of heat cos I burned myself with an air pump once. The vortex tube seems a bit impractical for domestic technology as I imagine it makes a lot of noise.

Re:The Hilsch Vortex Tube

[The_REAL_DZA]

THANK YOU!! I hadn't seen that diagram since way back in high school when I built a variant of the vortex tube for a science fair (essentially, I tapered the tube along the horizontal axis, so the "cold" end was at the point-end of a cone shape...at least I think it was the cold end; that was twenty years, two careers, and several (root)beers ago...)

Here's a link to one company that's apparently making some money from the idea (and a couple of other clever air-based devices -- check out the "air conveyor" and "air amplifier")

Re:The Hilsch Vortex Tube

[Anonymous Coward]

This is nothing new....Auto mechanics have used such devices to test choke valves on carburators. Snap-On still sells them AFAIK.

So you're saying....

[AstroSurf]

The news is expected to have a chilling effect on listeners, particularly when the volume is turned up.

I thought it was the ice cream

[hottoh]

But its creators say their system works, and it uses cheap components to do work currently done by exotic -- and often dangerous -- chemicals.



And all this time I thought it was the loads of cholesterol and sucrose in the ice cream that was dangerous. It took Ben and Jerry's work to show us where the real dangers are lurking.

Ice cream plants are already enviromentally safe

[chrisatslashdot]

This technology may be great for retail coolers and the like but virtually all ice cream plants already use an environmentally safe refrigerant. Anhydrous ammonia is the refrigerant of choice for industrial applications.

• It causes no ozone depletion
• It does not contribute to global warming
• It has heat transfer characteristics 1.6 to 4 times that of HFCs and CFCs
• It requires 1.22 HP per ton of refrigeration (versus 1.27 for R134a and 1.25 for R22 this can be important when you have 10,000 HP engine rooms)
• It cost $0.25/lb (versus $3.40 to $25.00 for HFCs and CFCs) Important when you have hundreds of thousands of pounds of charge.
• It is lighter than air (unlike HFCs and CFCs) so releases typically float away
• It has a narrow window of explosive concentration that is difficult to achive LEL:16% UEL:25%(its is hard to make it go boom)
• It is a naturally occuring chemical. Your body make ammonia.
• Its pungent odor is 'self-alarming'. You will leave an atmosphere of ammonia long before concentration levels reach dangerous limits.

The reason you don't have ammonia in your car and home is that exposure to the chemical in concentrations above 300ppm poses health risk. 30 minutes of exposure above 1720ppm can cause death and 5,000ppm is rapidly fatal. It should never be used in a run-to-failure, zero maintenance system like your kitchen fridge or AC unit.

Re:I'm amazed B&J's still operates semi-autono

[Anonymous Coward]

The social concious thing may still be somethign they're doing, but the dedication to putting out the most "healthy" (in terms of lack of artificial additives and ingredients) ice cream around has definitely dropped off. Every single B&J pint used to have All Natural printed on it, and it was true. Now, some of the flavors include partially hydrogenated vegetable oils and high fructose corn syrup (i'm thinking of "Makin' Whoopie Pie" in particular, though other examples exist) and have lost the All Natural label.

Somewhat ironic, given Ben and Jerry's removal of paper bleeched with Dioxins(one of the most dangerous-to-your-health chemicals currently produced, if you believe the hype) from from their products, that they would chose to include chemicals that have been strongly linked to health problems.

Also somewhat ironic: Bryers ice cream, which is also owned by Unilever but not known for it's humanitarian efforts, produces (as far as i have seen) only all natural ice cream.

Don't put too much stock into the socially conscious stuff, it's still about making money.

Thermoacoustic cooling for airconditioning?

[bheer]

Question to the engineers on /.: A lot of places around the world (in 3rd world countries) can't afford airconditioning largely because of the prohibitive electricity cost: the electricity bill for even a small AC would be backbreaking for many third-worlders. Could thermoacoustic cooling be used to develop airconditioners? Even if they were small, they could be useful (if they were energy efficient) for small rooms, or even for airconditioned tents etc.

Re:Thermoacoustic cooling for airconditioning?

[Reverberant]

Even if they were small, they could be useful (if they were energy efficient)

The Ben & Jerry's Flash presentation notes that the thermoacoustic cooling process they developed was "efficient." I'm not real familiar with their process (other than what's presented in the linked articles), but I do know that loudspeakers are generally very inefficient - a very "efficient" loudspeaker may translate 1% of an electric watt into an acoustic watt. The rest of the energy goes to heating the voice coil.

Now it could be that normal refrigeration methods are even more inefficient, or that the thermoacoustic cooling process benefits from the use of the inert gas as a propagation medium. But it's probably not a panacea yet.

Re:Thermoacoustic cooling for airconditioning?

[Lebo]

Could a thermoaccoustic AC unit be created? Sure, but it won't fix the problem of 3rd world AC. The electricity costs of a Thermoaccoustic AC unit would actualy be HIGHER then the costs for a conventional unit.

The issue here is not energy-efficency, it's abandoning ozone-depleateing refrigerants.

Finally!

[Shoten]

"...thermoacoustic refrigeration technology, which uses helium gas subjected to ultra-loud 173 db sound to chill an ice cream cooler..."

A use for '80s hair metal bands, at last.

Re:Why use acoustics? Why not a mechanical diaphra

[Reverberant]

My question is why use acoustics to move that diaphram? Why not a simple mechanical device instead?

A loudspeaker is a simple mechanical (well, electro-mechanical) device!

.

Re:Why use acoustics? Why not a mechanical diaphra

[JustDisGuy]

My question is why use acoustics to move that diaphram? Why not a simple mechanical device instead?

Answer in two parts: "Frequency" and "moving parts". If you could get a significant enough compression wave from such an insignificant mechanical disturbance, or perhaps by setting up the right resonance wave maybe you could use a piezoelectric diaphragm...

what happens if the container cracks?

[voss]

178 db is not something you want to be exposed to

Re:what happens if the container cracks?

[Reverberant]

what happens if the container cracks?

Answered here.

Re:what happens if the container cracks?

[Lebo]

Well, I would imagine the sudden loss of PSI (remember, the enclosure is pressurized to 10 atmospheres with He.) Should be easy to pick up, and you shut down the speaker. Remember that the 190db figure is inside what ammounts to a highly efficent echo-chamber which is under pressure. Change the conditions, even slightly and the sound pressure will drop a lot.

Uh no.

[WindBourne]

The EER is a relative term that is consumer friendly. What I am speaking of is the maximum (Carnot) theoretical efficiency. IOW, what is the absolute max that you can do. Today's top end phase change (normal refrigerator/air considtion) operate at 45-46% of the max, while a peltier operates at less than 10%. This operates at 55%. It will use less energy to run, I think less energy to build, and zero energy for maintenance.

Re:Ice cream plants are already enviromentally saf

[jafiwam]

Themoacoustic coolers can probably be produced with a much higher mean time between failure as well. Fewer moving parts. I assume they could make a long-life speaker cone and make it replacable with a "slide out, slide in, recharge gas" type fix.

The end result is fewer fridges go to landfills beause they broke.

Even if the average lifetime of the fridge can be raised by a few percent, that's significant reduction in appliance-garbage.

OLD HIPPIES

[flyneye]

A mentor from my teens was an old hippie who once dug out an aged copy of the whole earth catalog and showed me the kit for the "wood burning refrigerator."
Not New Technology!just old hippie crap regurgitated by old hippies and try to tell us its new.
Never Trust a Hippie.they try to sell you icecream for far more than its worth.

Re:OLD HIPPIES

[Anonymous Coward]

When did you first lose your self-esteem?

Re:OLD HIPPIES

[flyneye]

when I realized,hippies were an infection there was no vaccine for.kinda like anonymous cowards.

Penn frig comes from work at NPS in Monterey, CA

[Anonymous Coward]

The Naval Postgraduate School (NPS) in Monterey California has been doing this stuff for nearly 20 years with the work of Tom Hofler.

STAR (Space Thermoacoustic Refrigerator) flew on the Space Shuttle (STS-42) in January 1992 and was an experiment of NPS.

Professor Garrett at Penn is actually from NPS where hid did this research with Hofler in the late 80s and early 90s.

crazy

[Anonymous Coward]

considering the fact that microwaves != sound waves (electromagnetic radiation != air pressure differentials), maybe you were crazy after all.

Won't work..

[beldraen]

Doesn't quite work that way. The reason why you have problems with noise is that speakers are intentionally designed to propogate sound. When sound waves hit your walls the walls resonate and pass along the sound. The refrigerater is quiet to the external world because the compression chamber is designed exactly so that the sound waves reflect and cancel in exacting positions inside the chamber. There is no excess accustic energy left to leave the chamber. This can only be done because the sound waves generated are exactly the wave length that matches the distance inside the chamber necessary to cancel. In other words, if you could "build a wall of it," it would only stop one exact frequency. What you really want is accustic foam that is designed to stop a wide frequency range of sound. This is commonly used in studios to prevent echos off the walls that give the "recorded in a box" sound effect.

Re:Won't work..

[Anonymous Coward]

Plus there's loads of pressure going on, which does something. I think. Someone posted that w/o the pressure and stuff, it's really quiet.

Helium is derived from natural gas

[stecoop]

Helium is extracted from natural gas. Most of our supply comes from natural gas wells in Texas and Oklahoma. Oklahoma actually has a larger untapped reserve than Texas due to more natural gas wells in Oklahoma as opposed to the majoriy are oil wells in Texas - can't find a link and don't know if it meant per capita, per square mile or per volume.

Re:Helium is derived from natural gas

[York the Mysterious]

If Helium is a byproduct of natural gas then most of our Helium should be comming from Canada. According to the last Senate Subcommitee meeting on the natural gas shortage I read our largest supplier is Canada.

I Scream For....

[jeephistorian]

I scream for icecream!!!!!

_____________

Re:Ice cream plants are already enviromentally saf

[Analogy Man]

Consider your two statements:

Anhydrous ammonia...enviromentally safe

AND

...and 5,000ppm is rapidly fatal

So a thermonuclear device or a metric ton of sarin gas released in New York city subway system would REALLY environmentally safe? Consider they evacuate large areas when a tanker car of Anhydrous derails it does need to be used with care.

Helium and Argon

[dpilot]

The key difference between helium and argon is density. Helium is (obviously) lighter than air, and when released, floats to the top of the atmosphere. Presumably some evaporates into interplanetary space, given the energetic environment, there. Argon is denser than air, so it will tend to stay in the lower atmosphere.

Both are fossils of creation, but helium is also generated by alpha decay of radioactives inside the Earth. (Alpha decay particle steals two electrons from an unsuspecting nearby atom and presto, helium.)

If there were enough desire for helium, it might be possible to scoop it from the upper atmosphere. There has been talk of space planes running an oxygen liqufaction cycle for an 'air-breathing rocket'. If we can actually do that, we're halfway to mining helium. Helium would be part of the stuff that *didn't* liquify on the first part of the cycle.

Re:Helium and Argon

[WalksOnDirt]

Argon primarily comes from the radioactive decay of potassium-40. Alpha decay being more common, a lot more helium is generated then argon.

The atmosphere is basically homogeneous up to about 100 km, and contains about 5 ppm helium.

Helium doesn't doesn't become a large part of the atmosphere until well above the altitude of the international space station, where I think the prospects for helium mining is limited.

Re:Helium and Argon

[dpilot]

Heck, at the altitude of the ISS, I wouldn't be surprised to see the helium doubly-ionized, so you're back to alpha particles, again.

(OT) don't know about burning oil but

[oliverthered]

Burning Coal and Gas can be upto 55% efficient.

freon huffing

[rebelcool]

apparently you can get a high from huffing freon. a couple of years ago some kids sucked all the freon out of my A/C. So while i'm sure its not *good* for you, it won't kill you.

I seem to remember some old 1940s era promotional movies showing the inventor of freon inhaling it to show its non-toxicity also.

Meta-Moders

[Anonymous Coward]

Please check this carefully. The statement is correct. This appears to be vindictiveness instead of a good mod.

Just Let the Penguins explain it to you.

[Anonymous Coward]

It has two chambers, separated by metal screen stacks. The speaker expands and contracts a gas which creates separate hot and cold parts of the screen stack. The cold parts cool liquid pumped through the refrigerator. The hot parts are exhausted to the room.

Watch The F*ing Animation
http://www.benjerry.com/assets/flash/ou r_company/s ounds_cool/soundsCool.cfm

Properties of Helium?

[Slowleggs]

I'm far from an expert in chemistry, but this sounds fishy to me (my bolding):

"The Penn State thermoacoustic chiller uses helium gas instead of chemical refrigerants. Helium, which is used to keep birthday party balloons aloft, doesn't burn, explode or combine with other chemicals. If released into the atmosphere, helium drifts harmlessly into outer space. "

Is this true?

Re:Properties of Helium?

[Anonymous Coward]

Yes, it's true, Helium is the lightest noble gas. It's almost impossible to get noble gases to react with anything since they have filled outer electron shells, and being so light, it does tend to escape into space; that's why it's not virtually absent in our normal mix of atmosphere (maybe 0.0005%, IIRC), despite being abundant in the universe.

A fan substitute?

[fnc]

Someone know if this could be used to cool a CPU?

Hasn't this been done before?

[Anonymous Coward]

I know I'm short on details but I remember hearing about this technology ~15 years ago. If I recall correctly it was on a science show that used to air on Nickelodeon about future tech. At the time they claimed a scientist had developed an acoustic compressor that would revolutionize the industry.

The only other details I can remember are: They stressed the shape of the unit was the key, some sort of odd funnel tuned to the wave. They also said it would last forever because it had no moving parts, consumed less power, and would be cheep to produce.

I know it sounds like vaporware but it's got me wondering if some great tech has been lost and reinvented.

refrigerant gases

[ajs318]

The whole point about CFCs in fridges is that they are sealed in a closed loop {compressor - condenser - evaporator}, therefore, not able to damage the ozone layer until the fridge is disposed of {or you have an accident while defrosting with a chisel .....} The usual way of getting rid of CFCs is to wait until nobody is looking, then discharge them into the atmosphere. Practically speaking, there's not a lot else you can do with them anyway. So if you have a CFC-based fridge and it's still working reasonably well, you should hang onto it -- as long as it's not being abused, it won't be using significantly more energy than a more modern one would, and manufacturing a refrigerator uses up a lot of energy {which also is conveniently forgotten}. If it cost x kWh to make in the first place, and saves y kWh per year compared to the old fridge, it needs to last for x/y years before you have actually made any saving -- if it packs up before that time limit, you actually lose out on the deal {assuming the old one would have survived that long; but older kit was built to last forever, whereas newer stuff is built to pack up after awhile}.

My new fridge {purchased in a hurry after a defrosting accident last year involving a chisel, the evaporator and a faceful of evil-smelling chemicals} uses iso-butane -- cigarette lighter and camping stove fuel -- as its refrigerant. It's sealed in the pipes, so there is no danger of an explosion. Even if the pipes do start leaking, the thermostat won't be satisfied -- no matter how long the motor runs {trying to cool down the sensor} it won't get anywhere because there is no pressure, so no cooling ..... so the contacts will stay closed and not spark. If anything does set off an explosion, it won't be the fridge itself.

Re:Ice cream plants are already enviromentally saf

[chrisatslashdot]

...Consider they evacuate large areas when a tanker car of Anhydrous derails it does need to be used with care.

But once the ammonia dissaptes into the atmosphere there is no lasting, negative effect. This cannot be said of HFCs and CFCs. Heck, this probably can't be said for most of the chemicals under your sink or in your auto. Farmers plow thousands of pounds of ammonia into the ground every year. Thats what I meant about environmentally safe.

With respect to the rail car, with ammonia you will think you are going to die from the pungent odor long before you suffer any ill health effects. i.e. ammonia causes lawsuits long before it causes any health problems. OSHA's Permissible Exposure Level is 50ppm. That means the average Joe could work 8 hours/day 40 hours/week for a lifetime with no ill health effects at 50ppm. To give you some referece, chopping a strong smelling onion is similar to exposure to about 10-15ppm of ammonia.

With respect to your serin gas analogy, consider water. Water is also fatal in certain quantities but I am certain that it is still environmentally safe.

Space shuttle

[mrogers]

Thermoacoustic refrigeration has been a focus of research for more than a decade at Purdue and elsewhere, and has reportedly flown on the Space Shuttle...

Apparently thermoacoustic refrigeration works better in orbit because in space, no-one can hear ice cream.

Re:Space shuttle

[jared42]

Why can't there be a moderation for PAINFUL!?

Cool Sounds NOT !

[anothermulekickin]

As one of the inventors of this technology, I want make certain that readers understand that COOLSOUNDS and Kieth Franklin are NOT licenced, are UNRELATED, and are NOT IN ANY WAY ASSOCIATED WITH THE PSU TEAM !

Re:I'm amazed B&J's still operates semi-autono

[Deagol]

I'd still buy it if it was rebranded, just for the great flavours, but I'm not sure everyone would.

No doubt! B&J's Cookie Dough is the best cookie dough icecream brand, bar none. When I ran into a 5-quart bucket of the stuff at Costco a few years ago, I thought I would die of joy. However, I only got to buy one -- Costco just stopped carrying it for some reason.

Greener Freezers for Ben & Jerry's

[rpiquepa]

Some comments mention that these coolers are eco-friendly. This is true, because they don't use any environment-damaging chemical refrigerants linked to global warming. However, they can be hard on your ears. The sound waves generated by these freezers will really 'scream for ice cream': they will be attached to amplifiers generating 183 decibels, a sound level thousands of times beyond rock concert levels. This post on my blog contains additional details and a diagram showing how the chiller works.

Life at home

[know_gnus]

So when my wife comes home after we receive the new fridge, she says, "Honey, the fridge is running too loud. We should take it back" Smoothtalking, I say, "It's all good, baby... it's supposed to sound like that." And she says, "What? Can't hear you!"

Re:Ice cream plants are already enviromentally saf

[customjake]

Environmentally friendly and fatal to humans

Sound in space

[Anonymous Coward]

So, they figured out how to make a loud boom in space? I guess when ice cream is involved, people are willing to break laws of physics.

Help, my refridgerator is floating away!

[Anonymous Coward]

I knew I shouldn't have taken out that last beer.

More Anti-Nuclear Paranoia

[thelizman]

Nuclear technologies present today actually produce less overall and less harmful by products than traditional fossil fuel methods. This fear of anything "nuke" is driven by dirty technologies that are 5 generations old, almost as hold as the waste they're burying a mile under a mountain in nevada that is miles away from anyone else. Lets have a little science, and a little less fiction when we look at our energy needs, and hey...bring on the quantum nucleonic reactor powered cars.

Does someone know how it works?

[Zoinks]

Tired of chasing non-informative links...

So what actually happens in that chamber? Anyone know? Here's my guess: they set up a high power standing wave at the fundamental frequency in the chamber. The low-pressure node gets cold; the high pressure node gets hot. Then they pump heat into the low pressure node and somehow it flows through the helium to the high pressure node and is conducted out of the system.

it's dB, not db

[Anonymous Coward]

dB stands for decibel, i.e. 1/10 Bel

More technical info for geeks

[PaulBu]

Now that jokes about 190 dB have died out, it's time for us geeks to learn how the damn thing works. The thing that has reportedly flown on the Space Shuttle (and many other space missions) is properly called "pulse tube cryocooler", good background is here.

And where I work the joke was "Hey, Ben and Jerry switch to pulse tubes, NOW they'll become cheaper! ;-) "

Paul B.

Re:Ice cream plants are already enviromentally saf

[chrisatslashdot]

Nucience exposures are not fatal. Most are not harmful.
<p>
With ammonia you get a chance to run. With HFCs and CFCs you can't smell them. One breath in an air displaced environment (remember all HFCs and CFCs are heavier than air) and you hit the floor.

Oh no!!

[kavau]

I, for one, already get annoyed by those loud refrigerators you find at Starbucks & Co., whose noise fills the entire room...

Now imagine one of those 176dB thingies at your favorite coffee shop!

Re:Ice cream plants are already enviromentally saf

[Carnildo]

Thermoacoustic cooling using helium or argon:

* No ozone depletion
* No contribution to global warming
* Natural part of the atmosphere
* Not explosive at any concentration
* Non-toxic

Re:Ice cream plants are already enviromentally saf

[chrisatslashdot]

If this technology can be scaled to an industrial size and meet current system efficiencys it could revolutionize industrial refrigeration. Currently all large ammonia systems (>10,000 lbs) are required to meet OSHA Process Safety Management standards and EPA Risk Management Planning requirements. These are very resource intense programs and they are ongoing. An inert gas replacement could be adopted quickly.

There is a large difference in scale in these thermoacoustic coolers and an industrial refrigeration system. A typical ice cream cooler may be 600 Watts, and thats compressor plus condensor fan. Thats 0.8HP. A typical industrial ammonia refrigeration compressor will be 200 to 800 HP and the typical engine room will have from 4 to scores of these compressors. Suppose a 5000 HP system, thats smallish for a freezing operation. Thats over six thousand times larger than an retail icecream cooler. Clearly there is some engineering to be done before we can buy thermoacoustically frozen B & J ice cream.

Perhaps we now know what to do with that massive speaker McFry used at the beggining of Back to the Future.

Re:Refrigeration efficiencies compared - Aerogel

[Anonymous Coward]

There are companies that make aerogel, looks
like you need to be very careful with use and
disposal, since the material is so small..if
inhaled it work better than Abestoes in causing
health problems. So you probably do not want
Aerogels today near customers/consumers.

Re:Why use acoustics? Why not a mechanical diaphra

[Anonymous Coward]

I have not seen the flash animation, so I assume that it is either flawed or does a poor job of properly displaying the process. Suffice it to say that your ideas on impovement are right on the money because that is exaclty what is done with the real devices. The diaphragm is a speaker which *is* a simple mechanically moved device. This produces compression and de-compression of the gas in the chamber which is commonly reffered to as 'sound'. Now, the actual sound produced is in a standing wave pattern which would be difficult to show in a flash animation, so they probably drew it as a traveling wave to make their job easier, but at the same time misrepresented what was actually happening.

Re:Acoustic cooling for airconditioning? -Speakers

[Anonymous Coward]

Speakers are inefficient when designed for consumers since consumer designs are oriented towards cost of production not operating costs.

Professional speaker systems are much more efficient.

A new class of speaker drivers call Class D have finally be reduced to integerated circuits and are being mass produced. There are much more efficient then previous generations. Interestingly, it was the cell phone, and portable mp3 markets that drove their development...since battery power is small compared to wired house power.

wait wait

[Zebra_X]

Thermoacoustic refrigeration has been a focus of research for more than a decade at Purdue and elsewhere, and has reportedly flown on the Space Shuttle

Why on earth would you put something like this on the space shuttle? I mean, you are in SPACE after all, a place known for very low temperatures. Seems like it might be a bit of a waste of the shuttles $100,000/kg lift costs.

Thermoacoustic cooling

[DaChesserCat]

Guys, it's a thermoacoustic Stirling. Stirling engines can do a variety of things. You can supply heat, and they will supply motion (usually a reciprocating motion, which works nicely when connected with a linear alternator). Or, you can supply motion (reciprocating), and they will move heat (i.e. usually cooling something). Sunpower has been making cryocoolers based on them for years. And yes, they even played with a module which would attach to a CPU and supercool it.

Hit Google and look for information on Stirling engines. Then, reduce the number of moving parts. Instead of a power piston and a displacer, they use sound waves as the displacer and the speaker as the power piston.

There are already companies at work trying to commercialize this technology. The guys at Purdue are re-inventing the wheel. Check the first link about thermoacousting Stirling engines, and you'll see they've been working on this for some time.

Wait – what is the measured Efficiency?

[xtronics]

There is usually a reason they fail to mention efficiency - (and cost). Why is it called green friendly if it wastes energy?

Sterling Cycle?

[cr0sh]

Ok, I admit this is a pretty damn nice way to cool things - relatively simple, few moving parts, no CFCs or HFCs.

But did anyone notice what was missing? Did you see in the flash animation on the chart of refrigerants that the one refrigerant that isn't EPA approved is also (supposedly) the safest - ie, HC's? Now, I know the presentation wasn't about HC's - but why did they list them, but not talk about them - and why don't they have EPA approval if they are *better* than CFCs and HFCs?

There are other cooling technologies out there that are "environmentally friendly" - one such technology is used almost exclusively for cryo-cooling (you know, cooling to cryo temperatures - much colder than freezing), and could be used for regular cooling: the Stirling Cycle.

We have all heard of Sterling Cycle engines (or at least, I hope we have!), which are "external combustion" engines that utilize thermal energy transfer from hot to cold to create mechanical motion (all it needs is hot and cold - some small demo models can run on an ice cube and/or hot coffee - or the heat from a monitor!), which then can be used to do work.

Well, if you reverse that, and instead put mechanical motion in, the hot side get *very* hot, and the cold side gets *very* cold (in an efficient Stirling Cycle engine).

There is a company out there that makes such Stirling Cycle heat pumps (which can also be used as an engine - they sell kits to experimentors) that use a solenoid-type electromagnetic driver system (run in reverse, the solenoid generates electricity!) - unfortunately I can't find the link to them, but they make cryo-coolers using the Stirling Cycle and electromagnetic drivers.

More information and kits for Stirling Cycle engines can be found here.

Also note that google can help you find a lot of links on the subject, too.

Stirling Cycle engines aren't the only environmentally friendly way to cool things - there are methods that use the power of the sun! One could run a refrigerator off of solar panels (not very efficient). A better method uses something called something like "ammonia sodium absorption" - which basically uses heat to expand ammonia in a closed system (similar to a propane refrigerator). Now, ammonia is a nasty substance (poisonous) if it gets out of the system, but it isn't the only method.

One could take two Stirling Engines, hook the shafts together, have one be driven by a solar concentrator, the other would act as the heat pump - this is likely to be more efficient than a solar electric version.

I have also heard of an innovative way of using wind power to cool something down (and heat something up - why "waste" the hot side?) - run an AC compressor directly from the blades (instead of a generator) and store the cold and heat in separate insulated water storage tanks, for use later to cool/heat the house or such.

Another method, while "solar" doesn't directly use the sun, but is similar to how the earth heats and cools - negative radiant energy. In fact, you can use a solar oven to make ice using this method - but I will describe a simpler manner: Get an old large freezer (doesn't need to work - we need an insulated box) - put a ton of extra insulation around it. Paint the inside black. Put about a half inch of water in the bottom. When the sun has set, open the lid wide open to the sky. Before the sun has risen the next morning, close the lid. Do this several times, and eventually the water in the bottom will freeze (note, this will likely not work during the summer months in hot climates, unless you can insulate the box extremely well during the day). By openning the box to the night sky (adding reflectors will help, just like on a solar cooker, to allow it to "see" more sky), the heat is let out, cooling the inside. Closing it in the morning "traps" the coolness inside, waiting for the next cycl

Ice cream truck

[wanab12]

Could you imagin what the ice cream truck song would sound like at 175db?

CFCs didn't hurt the ozone layer, so why this?

[RagingDaigo]

nt

Re:Ice cream plants are already enviromentally saf

[customjake]

well, while the new refriderants like 404 and 134a are more environmentally friends, the old refridgerants, R12, R22, R502 and such which were cfcs, were not harmful to humans, except in quantities approaching 100% (suffication).

"WITH AMMONIA YOU GET A CHANCE TO RUN" I say BS. With ammonia, the first breath you take burns the lining of your lungs, and if your eyes are open, them too. So with one breath of ammonia, you are most likely unable to run, barely able to breath, blind and probably on the floor.

I think ammonia is a good idea, as in it has good cooling properties, but if we're talking about environmentally friendly, a substance that harms and kills most of the mammals on earth probably wouldn't be much of a upgrade.

And tell me, what do you tell the technicians who have to repair and maintain that equipment who may have to breathe in small amounts of ammonia all day, every day. I think not.

Re:I'm amazed B&J's still operates semi-autono

[Bilestoad]

It's a damn shame they had to discontinue "The Full Vermonty" (maple syrup flavor) ice cream due to a dispute over the name with Universal Studios.

And worse that corn syrup has crept into the mix. I don't blame them for selling out, I probably would have, but I hate corn syrup in everything.

Re:Ice cream plants are already enviromentally saf

[chrisatslashdot]

What you tell the technicians is how to protect themselves. You tell them what protective equipment is required for each job that releases ammonia. You train them in the proper procedures required to work on an ammonia system. Then you verify that they understand what you told them, you audit to make sure they follow the procedures and wear the PPE, you ask them if they want more training, you involve them in the certification/modifications of the procedures and you repeat this constantly. You provide them with ammonia level monitoring equipment and train them in how to use it. You provide them with data on the health effects of ammonia, including the fact that there are no cummulative effects of ammonia exposure below the PEL(50ppm by OSHA, 20ppm NIOSH). You provide them with full access to and participation in your program for maintaining a safe ammonia system.

All of this is not just a good idea, its the law. Non-compliance is costly.

Because..

[Herz]

The astronauts want icecream too

Re:I'm amazed B&J's still operates semi-autono

[Colazar]

That's the way Costco works. They want you to know that there inventory is a crap-shoot, so that if you see something there you want, you better buy it right then, cause next time you're there, they may not have it.

There goal is to drive up impulse purposes, and it works pretty well.

Ice cream has always been green-friendly..

[Xilo]

..except for stuff like Rum Raisin, ick. Oh, and practically the entire Little Debbie line of snacks, burgers, chips, a lot of standard Mexican foods, oh - Chinese, for sure.. uhm, brownies. Everyone likes brownies.

Re:Ice cream plants are already enviromentally saf

[Bela_Phi]

1. "[Anhydrous ammonia] is lighter than air (unlike HFCs and CFCs) so releases typically float away"

I'd heard this before about HFC's and CFC's.

IANAP[hysicist], so can someone help me understand how a subtance that is heavier than air (and therefore can't "float away"), when released at or near ground level, can be responsible for damage to the ozone layer 10 to 50 km above the earth's surface?

I'm really interested in understanding the science, since we were taught for years that our old aerosol hair spray was damaging the ozone layer. How is it getting up there?

Re:Slashdot's Leftist Bias

[Anonymous Coward]

Amen, Hippies suck, liberals suck and lefties suck. Oh and anyone who thinks their level of education gives them more knowledge about the real world than living in the real world, suck too.

Refinement of Einstein and Szilard's design?

[Mark of THE CITY]

The story reminded me that Einstein and Szilard obtained patents on various thermoacoustic refrigerators.Is this a refinement of that?

Re:Ice cream plants are already enviromentally saf

[vuo]

Answer: diffusion.

How can smoke then go to the atmosphere, when it's not even gaseous but dead SOLID? Similarly you could claim you can't mix mud and water because mud is heavier than water.

The thing about fluoridated hydrocarbons is that under ultraviolet light they decompose and start to destroy random molecules, one of them ozone. They're a very efficient catalyst for ozone decomposition. It's been estimated that one mole of CFC can catalyze 100000 moles of ozone decomposition reactions until it settles down.

In this respect, it is different from, say, methane and CO2: one mole of methane corresponds exactly to one mole of methane pollution effects. One mole of CFC corresponds to 100000 moles of destruction. That's why even small amounts, like leaking from fridges, can be significant.

Ammonia, on the other hand, is a plant nutrient.

Re:Ice cream plants are already enviromentally saf

[Niko.]

It's been a while since chem class, but IIRC anhydrous ammonia is a very different critter from regular cleaning fluid.

Anhydrous means it's absolutely dry and is thus /violently/ reactive with anything containing water such as skin or mucous membranes. Get a big whiff and you're dead, or wish you were.

I'm also not sure about its being lighter than air. Any chemists around? Anyone?

Re:Ice cream plants are already enviromentally saf

[chrisatslashdot]

Density of saturated vapor ammonia at 14.7 psia is 0.0555 lb/ft^3[IIAR Ammonia Data Book]
Density of air at standard conditions 0.074 lb/ft^3 [Wikipedia]

And these numbers are conservative since ammonia will quickly absorb heat (sat temp is -28F), become supreheated, and expand. And water is rarely dry. Sometimes ammonia does not rise immediately because it condenses and freezes the moisture in the air creating a dense white cloud of ice, air, and ammonia vapor.

You are correct in that ammonia is hygroscopic (water loving). It will cause tissue damage via chemical or temperature burns due to its alkalinity and typical low temperatures. It is attracted to water but it does not react violently with it. In fact a common practice in ammonia refrigeration is to vent ammonia into a barrel of water when evacuating an oil serparator for instance.

Ammonia's hrgroscopic nature 'attracts' it to moist areas such as armpits, crotches, eyeballs, and mucous membranes. It is vitally important to irrigate exposed skin with water ASAP after exposure.

An interesting aside is that the Salt Lake City Winter Olympic bob sled/luge is a direct ammonia system. NH3 flows throughout the track. Interestingly the track was designed and installed with complete disreguard for good safety practices and mandatory OSHA/EPA safety programs. There was no way to install the needed safeguards before the games. So, during the Olympic events there were literally dozens of people standing guard with wrenches to manually shutdown parts of the system in the event of an accident. Others were guarding critically exposed piping that any vandal could have compromised.

Interview with Dr. Garrett

[fdesibert]

Interview available with the inventor of the fridge, as recorded on KSPB 91.9 FM, a few weeks after the NPR interview. URL when I compress it 10MB (20 min interview) Freddie