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Utah Teens Invent Better Air Conditioner
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."
Frigidaire got to them. Don't mess with the cooling conglomerates...
"Waste not one watt!" - CZ
If you're having trouble seeing the article, try this: Google Cache
When all you have is a hammer, everybody looks like a Messiah.
not so sure 400% is possible, captain science....
An aircon using vapour change effects is a heat pump. Therefore, it can move more heat, than the amount of energy consumed to move the heat.
Oh well, what the hell...
I *still* think that Cryocoolers are the way to go. You can't tell me that a Stirling or Pulse Tube cryocooler would cost that much more to mass produce than a regular AC unit. Not to mention that the engine load would drop to an unnoticable amount in comparison to today's AC units. Even the EPA's own documents mention Stirling coolers as an acceptable solution! :-)
Javascript + Nintendo DSi = DSiCade
Vapour phase airconditioning uses direct power from the engine, which often has an output of 100+ Kilowatts. More in a recent design.
:(
:)
No one notices a few Kilowatts disappearing. Except ricers.
Peltier devices come from the Altenator with an output capacity of around 1Kw or less, And most of that is used by Lights, Engine management etc... And for charging the battery
There's not a lot of electricity spare to run a Peltier based cooling device.
I've built something similar myself for a car once, but it only provides piped air - and didn't have to cool the whole cabin.
A 12 amp peltier device consumes a LOT of power... About 150 watts Not all cars can spare that much. And it doesn't cool much either.
I'm sorry I can't get the article up though. I really wanted to read it
Good on them though for experimenting
GrpA.
Enjoy science fiction? "Turing Evolved" - AI, Mecha, Androids and rail-gun battles. What more could you want?
Peltier coolers use electricity, which is generated by the horribly inefficient internal combustion engine which produces greenhouse gasses and other toxins by the boatload.
Not to nitpick, but the compression cycle of regular car AC is also powered by the motor...
Plus, if your alternator can handle it, the peltier is probably much lighter, and certainly much smaller, further improving your engine efficiency.
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this is not a sig
For the naysayers, it does say that it saves some 4 MPG over current ACs. IOW, it is more efficient.
I prefer the "u" in honour as it seems to be missing these days.
The current refrigerant, hfc134a contains no chlorine (the ozone damaging part of R12) and has an ozone depletion potential of zero.
The idea of using Peltier devices is interesting, because there'd be no mechanical parts to wear out, or refrigerants to leak out, so the system should be much more reliable, but I thought Peltiers would require a huge amount of current to do as much cooling as a car A/C system delivers.
Putting moderation advice in your
Last longer?
Better for the environment?
It'll never catch on.
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.
A Shadeless room is a brighter room.
This should actually have been modded as "misinformed" (don't we wish...)
R134a A/C systems have evolved over the years. Granted, the early systems left a lot to be desired, but the output of the recent systems rival that of old R12 systems. R134a systems are very pressure-dependent, far more than R12, and must be precisely charged for maximum effectiveness.
It's hot here in Texas, at or above 100F in the summer, and both of my Chevy trucks (an '02 and an '03) blow frigid air.
To refer to posts above, the peltier coolers have a severe disadvantage.
#13120684: Normal peltiers have an efficiencies of less than 30% Modern air conditioners have an efficiencies approaching 400%.
#13120746: Modern aircon works by using matter phase change and using pump to move the fluids. It transfers more heat than the energy consumed in moving the fluids.
So while I don't have one of these, I'm really really sceptical that the CO2 and other greenhouse emissions per unit of cooling by a peltier can get anywhere near a modern air conditioner.
Ahh, I "read the fucking article" and now I understand. The main article makes you think a couple of chips save the day, and makes A/C's last longer. They do, in a way, but the article on ./ here should have quoted the real article, instead of trying to paraphrase.
"Today, the young inventors say, U.S. drivers use about 7.9 billion gallons of fuel each year to run their air-conditioners, which draw power from the engine. By adopting their contraption - which taps into the electrical system, using fans to blow hot air through five Peltier chips and then releasing cold air - they say the country stands to save 3.9 billion gallons of fuel annually, or about $10 billion based on current gas prices."
It doesn't say 20 to 30 years longer, it just says that the peltier chips "last between 20 and 30 years". I have no idea why you just randomly inserted a word, but that's exactly what you've done.
OK, allow me to put some things into perspective. In addition to being a MCSE, A+, etc. certified geek, I also hold EPA certification to handle refrigerants and to service and install refrigeration systems in commercial, residential, and automotive applications.
:)
The parent poster is absolutely correct, R134a is a greenhouse gas. However, that statement should be qualified: it is only a greenhouse gas when it is released into the atmosphere. Modern technicians use recovery equipment to remove refrigerants from cooling systems (everything from your freezer to your central A/C). The refrigerant is either recycled, or disposed of properly.
As long as we are all conscious about our environment (and we all should be, lest anyone turn us in to the EPA, causing us to have to fill out the reams of paperwork!) there is no problem. Oh, and there is always that pesky thing about preserving the planet for generations to come
I, for one, am quite sick of people blowing things out of proportion when there is no real problem. Having said that, kudos to the two teens for their inventive spirit. Maybe with some refining, the invention will prove more efficient and ultimately prove commercially useful!
bash: rtfm: command not found
2. unit can be in passenger area and not in engine compartment
3. you could have several small units instead of one big one
4. flip the peltiers and you have a heater
5. no pulley being spun even when not in use
6. should be much lighter (although alternator would get bigger)
In the new Prius, the AC is no longer belt driven. This eliminates the shaft seal, a common wear and slow leak source. The new AC is electric using a sealed compressor much like a home AC unit.
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?
The truth shall set you free!
I'm sorry, but you're completely full of shit. Every time my A/C compressor clicks on while I'm driving, I can tell; I drive a manual, and if I'm paying enough attention, I can tell especially if revs are low (ie 2k).
Vapour phase airconditioning uses direct power from the engine, which often has an output of 100+ Kilowatts.
You are making the assumption that the engine produces its power evenly across the band, which is outright garbage. Most engines make much more horsepower at high engine speed; better engines tend to keep making that power the closer they approach redline (at high engine speeds, resistance in exhaust and intake paths kills horsepower because volumetric efficiency drops).
The engine will not make NEARLY as much power down at ranges people typically use; ie 2000 to 3000 RPMs. Example- the current Ford Mustang engine (no, I don't drive one- just the first chart I could find) makes 250HP at 5,000RPM+. At 2,500 RPM, it makes 100HP. The chart started at 2,500; numbers probably drop to 50HP at 2000. Suddenly, an AC compressor that uses several HP becomes a two-digit percentage of total engine output. While humans suck at absolute measurements, we can be -really- good at picking up on the finest relative differences.
Also, maximum claimed horsepower is often under ideal circumstances; ie cool air temps, engine cold/warm not at full operating temp, lightweight oil, and at sea level. It's also always on a perfectly functioning engine; ie fresh air cleaner, ignition bits are all new, perfect compression in all cylinders, etc.
Please help metamoderate.
You mean compared to countries like Germany and France ? (Well known everywhere as bastions of conservative capitalism and mercifully free of the unionised workplace).
Let's set the record straight, here.
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?
Syntax error.
Yeah, of course this contraption ain't gonna be anywhere close to the efficiency of a decent/good refrigeration system.. I'm no AC guru, but I understand that refrigeration systems can be very very efficient. 80% on the low end and 90+% on the high end. That's pretty astonishing in the mechanical world, where typical engines are less than half that efficient.
/desktop "silent refrigerators" using peltier chips at Cost-Co for $100.. They're not at all efficient, but if the need scratches... Itch it.
"Invent" is a pretty strong word when you can go and find those mini in-car
If one determines that it takes 5kw to cool a space then that's what it takes. At that point, it dosen't matter except for efficiency and other factors (i.e. environmental concerns) what you use to move the heat, but that's the power you'll need to provide... Unless you're using magic or mutant powers or something.
In this car, we obey the laws of thermodynamics!
Constitutional rights may be respected, repealed, or modified; but they must never be ignored.
Yeah, this article sounds like "really, really bad misunderstanding of science".
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.
Point of interest. Offering to shoot us might not work so well as an incentive as you might imagine.
The seemingly trivial change of having a light colour roof can substantially reduce air conditioning requirements (although it can also increase heating requirements).
That depends on what was done when changing the roofing materials. For a couple summers when I was in college, I had a job as commercial roofer. We would rip off the layers of tar and rocks that had built up over the years. In its place, polyurethane foam insulation would be sprayed down and then coated with a thick rubbery paint. We would normally see a big difference in how much the A/C units were running before we were even 1/2 way done. The cost savings due to using less energy all year round usually paid for the roofing in a couple years.the good ground has been paved over by suicidal maniacs
Domestic fridges are the most reliable applicances in the home because they are built as a completely sealed unit.
Remember when the Discovery Channel was all about actual learning and knowledge?
On a related note, remember when MTV involved music?
And the Republican party was conservative?
± 29 dB
I have been proven wrong by slashdot once again.
When Argumentum ad Hominem falls short, try Argumentum ad Matrem
Those numbers are skewed. Today's cars use more gas at highway speeds if only one window is down compared to the air conditioning. Hell the econobox I bought to beat gas prices loses only 1mpg when the AC is on (based on using a tankfull of gas. Comparing a month of commuting in cooler weather with only fan and vents open compared to the tankfull used when the AC was on full blast non stop.)
Older cars had horribly inefficent AC systems, and larger vehicles that have the equilivant of a house sized AC system also have horribly inefficent AC systems.
One of the most efficent AC setups in current production vehicles is in the Honda Insight and Toyota Prius. using less than 72 watts of electricity to run the electric compressor and a synthetic compressor oil + newer coolant technology.
you can not get near the efficency of a phase change cooling system with peltiers.
Do not look at laser with remaining good eye.
Those numbers are skewed. Today's cars use more gas at highway speeds if only one window is down compared to the air conditioning.
Completely false. This statement is a common urban legend, and nothing more.
Using your AC taps mechanical power from the engine. This requires you to use more gas to maintain the same speed. Opening your windows adds some wind resistance, but doesn't add the same amount of loss as engaging the AC compressor. (you should watch mythbusters sometime, its a great show!)
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I take no responsibility for any spelling mistakes in the above post.