Utah Teens Invent Better Air Conditioner 755
Carl Youngblood writes "Two recent Utah high school graduates won the first-ever Ricoh Sustainable Development Award for inventing a better car air conditioner based on the Peltier effect. The peltier chips used in the device are more energy-efficient, last between 20 and 30 years, are solid-state, and don't harm the environment with ozone-depleting freon like today's car air conditioners."
Re:Peltiers (Score:2, Insightful)
Theoretically.
In today's society... (Score:4, Insightful)
Last longer?
Better for the environment?
It'll never catch on.
Re:Peltiers (Score:5, Insightful)
Ummmm, I believe the term you want to use is "coefficient of performance" - which is how many watts of heat are transferred per watt of electrical power used. Also called an energy efficiency ratio.
Having said that, your point about the relative efficiencies of mechanical refrigeration units vs Peltier effect devices is correct. I have a ~18 cu ft fridge in my garage that uses less energy than a 1 cu ft Peltier cooler. Another point, the main focus for the development of Gadolinium refrigeration was to replace Peltier effect devices for small scale refrigeration needs.
Re:/.ed (Score:2, Insightful)
They are mention the use of peltiers. Those are SOLID STATE heat pumps (for simplicity sake). that means no regrigerant (since Freon is a brand name) and no moving parts other than the fans on the hot and cold sides and the extra large alternator to power it.
not as efficient... (Score:3, Insightful)
This is just total bunk. The only way it saves energy is by not cooling as much.
Honestly, I think that the only threat to phase-change systems in small systems is sonic cooling. It could be more efficient, require less maintenance and have less environmental impact than a phrase-change system.
Evaporative systems are nice too, especially for large installations, but don't work for getting much below ambient.
Re:No more freon in cars (Score:4, Insightful)
Try again.
Re:freon? (Score:5, Insightful)
The peltier chips used in the device are more energy-efficient, last between 20 and 30 years,
I have a solid state ice chest. I don't believe the expected life rating when applied to a solution where condensation is present. It does not apply when they are used in high humidity. Corrosion from condensation kills these in a very short time. The module in my fridge died long ago from condensation caused corrosion. I would not want these in any application that runs below the dew point. Since my AC in my car is designed to run below the dew point to defog windows, there is no way I want a cooling solution that dies when it gets wet. Speaking of more energy-effecient; More effecient than what? Older modules, compressor driven? I have not seen any peltier chips ready to replace the compressor driven freezers and window AC compressors. They simply don't remove enough heat.
An advantage a working fluid AC has over a solid state solution is the hot side can be far removed from the cold side. The radiator for most car AC units is in front of the engine in cool air. A solid state AC would have the hot side behind the engine next to the passanger compartment. Just where were they planning on putting their waste heat? A typical car AC unit is over 20,000 BTU's. How many BTU is their system?
Re:No more freon in cars (Score:5, Insightful)
You mean compared to countries like Germany and France ? (Well known everywhere as bastions of conservative capitalism and mercifully free of the unionised workplace).
The Official R-12/R-134a/Freon Thread (Score:5, Insightful)
The noun "Freon" has a double meaning. Strictly speaking, it is the trademark name of refrigerant R-12, a single product of a specific formulation.
Due to its popularity it has become a sort of catch-all term used to describe an entire family of products. Much the same way that all couches can be called Chesterfields or all tissues can be called Kleenex, Freon can be used to describe a family of refrigerants.
As well all know, the actual Freon refrigerant, R-12, has been banned for a decade now. In this way, it is proper to say that no air conditioning unit in the US, Canada, etc., made since 1995 uses Freon.
The currently widespread refrigerant is R-134a, trademark name "Suva". It's chemically different from "Freon", but can be described as being part of the Freon family. This can make casual discussions a bit muddled as everyone argues whether or not Suva is Freon... Well, maybe I'm the only one having that type of casual discussion...
So, to make a short story long:
Freon is a Freon, Suva is a Freon, but Suva is not Freon. Got it?
Been there, done that (Score:3, Insightful)
There is nothing novel or innovative about this.
Re:Freon isn't used in new cars! (Score:3, Insightful)
Fatter alternator due to the giant amount of power consumed by a 40% efficient peltier. (Move 1 unit of heat with 2.5 units of power in)
VS
A/C compressor with a COP of 3 (move 3 units of heat for 1 unit of power in)
All that energy's got to come from somewhere. A typical car A/C is around 3-4kW. Or about 2kW of power to drive an A/C compressor. So, for a peltier equivalent, that's 10kW of electrical power from the alternator, driven from the engine, for the peltier array to get the same cooling effect.
I'll stick with compressor-driven A/C for now, thanks.
I keep toying with the idea of a twin ammonia-calcium chloride adsorption A/C, driven from the excess heat in the car exhaust. Heat one salt pack, release ammonia to condense in accumulator and tx valve , which then gets drawn to the other previously-heated-and-now cooling salt pack via an evaporator. When one pack is expended, direct hot exhaust gases to heat the other pack and continue. One of these days I'll get arond to it.
Re:Freon isn't used in new cars! (Score:1, Insightful)
Re:Freon isn't used in new cars! (Score:3, Insightful)
But your grammar-deficient tirade was fun anyway.
Re:Bad Link - better one (Score:1, Insightful)
Re:/.ed (Score:3, Insightful)
Re:/.ed (Score:5, Insightful)
The reason why the Peltier effect isn't used everywhere a heat pump is needed - and it's a really neat effect, mind you, as it has no moving parts, little to get corroded, is small and lightweight, etc - is that it's inefficient. We're talking god-awful inefficient until recently (~5%), and even now we're trying to stretch it to ~20% in the lab (no easy task).
As another poster mentioned, conventional refrigeration systems are quite efficient - at least, by themselves. Now, for a home refrigerator, it doesn't work out so nicely, because your power is being generated at 50% efficiency, transformed multiple times at a loss, suffers transmission losses on the way to your house, etc (that's why propane and even solar refrigeration systems are more efficient). But for a system like in a car, where the motor is directly running the compressor, it's going to be very efficient.
The Peltier chips - inefficient on their own - suffer from the inverse problem that the refrigerator suffers from! They need DC electrical power, but what the car engine produces is mechanical power! The car's alternator produces AC at a loss, which is rectified to DC, which then goes to the lossy Peltier chips. Assuming "ebay chips" are, say, 5% efficiency, we're looking at an overall system efficiency of 1-2%. Yeah, great way to save gas.
Re:/.ed (Score:3, Insightful)
Re:/.ed (Score:2, Insightful)
Gonna need some real Monster Cable(tm) to handle much of that! You know.. You should be worried when they start looking for cable in the kcmil range.
Re:Freon isn't used in new cars! (Score:3, Insightful)
Ammonia might not be a good idea for Joe Lugnut the backyard mechanic. One good whiff of ammonia can actually kill you. Granted, its properties are a dream for refrigeration cycles, but there's a reason why it isn't used in consumer products.
Theoretically, one could stick reverse Peltiers all over the catalytic converter too, and use the thermoelectric generated power to run the cooling Peltiers. It would be grossly inefficient and pretty damn expensive, but it would basically give you free cooling with no power loss, similar to your idea above. I suppose the cost could be brought down by using cheaper Seebeck junctions at a trade-off in output power.
troll (Score:3, Insightful)
Of course you can tell when it clicks on. However, in 99% of the cars out there, the A/C does not effect driveability a noticeable amount.
This was the grandparent's point. So the air conditioner takes up, say, 5% of your engine power while you're cruising at a low RPMs. Big deal. Maybe the car feels a tad sluggish when accelerating at part throttle. That's OK, because when you floor it, the air conditioner clutch disengages and you have full engine power at your command.
I drive a Mustang with that engine, and while I can tell when the A/C clicks on, driveability is in no way impaired. If a person is worried about having a slow, underpowered car, why doesn't he get a car with a V8 or turbocharger?
Re:In today's society... (Score:1, Insightful)
Re:scientific method? (Score:3, Insightful)
King Bedevere does a better job of establishing a woman's witch-hood than those guys do "explaining" everyday occurrences.
[Addendum] (Score:5, Insightful)
On a related note, remember when MTV involved music?
And the Republican party was conservative?
Re:No more freon in cars (Score:3, Insightful)
Italy for example is the worst example of antieconomic administration ever: entrenced 'corporative' unions that blindly protect privileges granted by unscrupulous policians for clientele sustainment; credit martket held hostage by individuals (yes, individuals... not even interest groups or boards) playing power games amongst themselves rather than just selling capital to investors.
Unions just represent part of the stakeholders, they're not bad per se. Of course in China, India or S America one can completely ignore them and eat the workers' cake but that doesn't mean being profitable, it's theft.
Eventually you have to admit that there's nothing bad in paying for labour as it produces the value add you sell and probably consumes it too! The point is going for the value add, there's nothing worse than stagnation with high salaries. Like sharks, economies have little if no buoyancy, if they stop swimming they sink.
Many, Many, Many things wrong with the article! (Score:4, Insightful)
- Peltiers are efficient-- NOT! They have an EER of way less than 1.0. A window air conditioner is above 10. End of discussion.
- There's no way to make them more efficient-- think-- they have their cold side right next to their hot side-- there's a lot of thermal conductivity there, effectively undoing a big percentage of the cooling.
- It's NOT more efficient to draw electrical power than to draw engine power. Somehow the kids think the alternator turns for free. Nope, it draws engine power just like the old AC, and as all defvices are less than 100% efficient, it has to be LESS efficient to use the power downstream from the alternator. { Minor caveat-- the alternator has the advantage of being able to put out more constant power-- direct drive from the engine to the compressor results in less AC (but not necessarily lower efficiency AC) available at slow engine speeds.)
- A typical auto AC puts out 30,000 to 50,000 BTUS/hr of cooling. A 1x1 inch peltier chip does about 150 BTU/hr at a cost of $9.95 on the surplus market. To duplicate a regular car AC would require 200 to 350 chips, $2000 to $3500. Plus a bunch more alternators, they'd need 1400 amps, about 20 alternators. Hard to fit them all under the hood.
- Peltiers do not last forever. They're prone to breakage due to cyclic stresses and degradation from humidity.
A REALLY bad aricle. The laws of thermodynamics rule.Re:/.ed (Score:3, Insightful)
1. equilibrium of the Halides in the upper atmosphere in destroying ozone, about 1:35 a BadThing(tm),
2. the tendency of the halides to concentrate over the poles, a GoodThing(tm),
3. the large number of balloons send up to study the "problem"
wouldn't it make more sense to just say, we don't know if it will help or not, but if your package doesn't have a chemical pack to sequester atmospheric halides in the upper atmosphere, we're not going to give you any grant money for your study period.
Re:"can't tell"? (Score:2, Insightful)
Re:"can't tell"? (Score:3, Insightful)
Um, dude, you're wrong. Ford claims that the air conditioning compressor alone will use 25 HP on a hot day.
Your headlights, OTOH might use 10 or 20 amps. At 13.5 volts, thats 270 watts max. Or about 1/3 of one horsepower.
Re:Freon isn't used in new cars! (Score:3, Insightful)
Re:/.ed (Score:2, Insightful)
Thinking about it more, the reason car a/c is belt-driven is probably because no-one makes an alternator that can handle the current to an electrically-driven compressor. Ideally you'd have TWO alternators, one running at 12V (or 14.4V, which is typical) and the other running at 400V to drive the a/c without using huge fat cables.
Insurance scales horizontally (Score:3, Insightful)
Specifically, the more healhty people you have in the system, the less the overall cost is per capita.
This is why the US system fails, because we only worry about insurance if you aren't healthy.
Re:New AC (Score:3, Insightful)