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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."
I wish they had built a better server.
Frigidaire got to them. Don't mess with the cooling conglomerates...
"Waste not one watt!" - CZ
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When all you have is a hammer, everybody looks like a Messiah.
Freon (R-12) hasn't been used in new cars for something like a decade now. R-12 is an ozone depleter. It hasn't been manufactured in the US since the mid 90's or so
:-(
Newer car air conditioners use refrigerant R-134a. This is *not* an ozone destroyer, but it is still a greenhouse gas.
Peltier coolers use electricity, which is generated by the horribly inefficient internal combustion engine which produces greenhouse gasses and other toxins by the boatload.
It's all bad.
not so sure 400% is possible, captain science....
...let's go back in the Slashdot wayback machine and laugh at the last air conditioning article.
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! :-)
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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?
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.
All cars with A/C still use freon. They don't use R-12!! (which is the stuff that supposidely depletes the ozone, and has been illegal since about model year 1995, NOT the late '90s)
Freon != R-12
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.
I built one of these back in 1999 with some peltiers I ordered direct from a manufacturer, some old heatsinks, case fans, and bent tin sheets.
It fit in the window, just like a regular ac unit, but it didn't stick out at all. Basically, it was just two layers of heatsinks with the peltiers sandwiched in between. The hot side faced out the window and fans forced air on them to cool them, and the cool side faced inwards, with fans along the lower edge, a sheet of tin across the middle to make the air flow more over the fins, and an opening on top where it blew into the room.
It worked well for a small room. I suppose if I had the money at the time, I could have purchased some massively power hungry units and been able to get some crazy cooling power out of it. I probably still have it in a box somewhere.
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Peltiers do not work very well and are not as efficient as a phase-change (freon-type) system. You can prove this to yourself by buying a Peltier-based portable cooler at Target (they've been available for 20 years, search for "coolerator") and a $99 phase-change based cube fridge. The Peltier can barely get a six-pack to 35 (F), the cube fridge can make ice in a 1+ cubic-foot space.
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.
http://lkml.org/lkml/2005/8/20/95
well that and the insane amounts they have to spend on workers salaries and benefits when compared to the rest of the world.
Other companies around the world do pay for pensions and health care as well. Not by setting up their own insurance funds, but by paying higher salaries (to compensate for the higher income taxes on those salaries) and by paying sometimes quite high employer fees. The difference is really that in state-run system everybody shares the cost, while for the US carmakers they are stuck with the bill for a lot of workers all by themselves.
Trust the Computer. The Computer is your friend.
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)
You're delusional. You really thing the average German worker in the automotive industry gets lower salaries and fewer benefits than his equivalent in the US?
Try again.
You know they call 'em fingers but I've never seen 'em fing. Oh, there they go.
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!
The students' research estimates their system would cut millions of pounds of hydrocarbons and nitrous oxides, and billions of pounds of carbon monoxide found in vehicle emissions. It also would increase gas mileage by four miles per gallon and hike horsepower by as much as 4 percent -- saving American drivers billions of dollars in annual gasoline costs.
.3 and a typical R134a vapor compression AC has a COP of about 4. In other words, the existing AC systems are an order of magnitude more efficient. Now how are they going to increase the mileage by 4 and add more horsepower?
;(
Since when do they hand out awards for bad research at best or out-and-out lying. A peltier effect heat pump has a COP of around
They would have to increase the size of the alternator several times to power this a peltier effect heat pump and you would have the unavoidable inefficiencies of converting mechanical energy into electrical to boot.
Why didn't they just mention that this thing runs off of cold fusion - and maybe they could get the University of Utah to endorse it
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.
The new standard calls for 42v not 48.
It looks like there is the Toyota Crown Royal which uses 42v and a "new SUV from GM" that will use 42v as well. Source.
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?
Free peltier with rebate.
*informative, stupid*
Errr... no. There are no cryo liquids in these coolers. They're used to make cryo liquids, although in much bigger form than you'd use in a car. A Stirling Engine is a reasonably simple device. You have two pistons, a regenerator, a hot surface, and a cold surface. Heat the hot surface, and you get energy as the heat is pumped to the cold side. Apply energy to drive the engine, and the cold side will pump all its heat to the hot side, making it that much colder. Damn efficient devices, they are.
I briefly discussed this topic recently when we were talking about keeping computers cool. The heat problem is becoming so critical that Intel is actually designing a Pulse Tube cooler for their microprocessors!
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The EPA also approves about twelve refrigerants for use in automobiles. You know how many the automotive industry approves? two. R-12 and R-134a. You will never find a shop anywhere in the world that will charge your A/C with anything but R-12 or R-134a. Just because the EPA approves something for automotive use doesn't mean the industry will. Afterall, the EPA most likely aren't experts in the field of automotive airconditioning.
What you reap is what you sow
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).
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?
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
- 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.These kids didn't really test their system - as in, make measurements of fuel economy with the old system and with the new system in real conditions and see what the difference was. They just assumed that "If we get rid of the load from the compressor, we will save 10 HP that will save X amount of fuel" (ignoring the load from the alternator).
Now, if they had wanted to REALLY do something that would cool the vehicle without costing more gas, they would have mated an adsorption cooler to the exhaust manifold, and recovered the energy to run the cooling system from the waste heat discarded to the atmosphere.
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