Teens Invent Freon-Free Air Conditioner

Great use of waste heat. However, my recollectionis that the process is less than 20% efficient, which means that to match a 1000 BtU output Air Conditioner in a car you'd have to process 5,000 BtU's of waste heat. It takes quite a while for that amuch waste to be generated by gasoline engine so you'd have to swelter for a bit. Maybe better for stationary apps where you have waste heat from a combined heat and power unit.

What if one were to plaster some solar cells on the roof and have the system operating in some sort of "always on" temperature management mode when the car is off?

Either keep the interior always-cooler or bank the coolth in some shaded thermal mass.

"It takes quite a while for that amuch waste to be generated by gasoline engine "

Yes, it will take all of a few millaseconds for an engine to generate enough waste heat. Excess heat is a HUGE problem for cars - the more heat you can suck out of them the better they will run and last. Engines generate a HUGE amount of heat - at 20% effeciency it should be more than enough heat.

They're not using waste heat. They're using electricity generated by the engine.

It doesn't look like they did an enegry balance comparison. If they do, they'll find (like GM did in '64) that it's still more efficient to use mechanical pumps than Peltier chips.

da

This isn't an invention, nor is it especially useful. Waste heat production by the car is irrelevant, as you're mistaking what the peltier effect is and what the junctions do.

These junctions use electrical power to create a heat differential.

Read that again. USE electrical power to create a heat differential. So you run electricity through one of these and one side of the plate gets hot, and the other side of the plate gets cold. Just like those peltier based 12 volt car refrigerator/warmer iceboxes they sell at pep-boys. So in order to cool the cold side of the plate the junction is using electricity generating its own waste heat. No free lunch.

I'm quite sure that a normal air conditioner is better than 20% efficient, and that electrical power has to come from somewhere... wait... where was that? yes, the gasoline engine.

This isn't an invention, nor is it especially useful. Waste heat production by the car is irrelevant, as you're mistaking what the peltier effect is and what the junctions do.

These junctions use electrical power to create a heat differential.

Read that again. USE electrical power to create a heat differential. So you run electricity through one of these and one side of the plate gets hot, and the other side of the plate gets cold. Just like those peltier based 12 volt car refrigerator/warmer iceboxes they sell at pep-boys. So in order to cool the cold side of the plate the junction is using electricity generating its own waste heat. No free lunch.

I'm quite sure that a normal air conditioner is better than 20% efficient, and that electrical power has to come from somewhere... wait... where was that? yes, the gasoline engine.

I think the boys over at Slashdot and Fark have pretty much destroyed this story already, sometime last week. Peltier effect is one or two orders of magnitude less efficient than mechanical compressors, so you would be burning massively more gas to get effective cooling from a scaled up version of a Peltier cooler.

The people giving the award from Ricoh are idiots for thinking this is a good idea, and these kids are either ignorant or idiots for similar reasons. Possibly, they got this idea from overclocking their computers and using Peltier coolers for the CPUs, not thinking that the reason Peltiers would be used in that situation is because it's not reasonable to get a compressor into your computer case to do the job, and that Peltiers aren't efficient and do not scale well. It was also noted that car ACs don't use Freon anymore.

Here's the Slashdot discussion on this:
http://science.slashdot.org/article.pl?sid=05/07/21/0138216&tid=126&tid=14

I think you may be missing the point. Even if modern air conditioning systems do not use freon any longer. Mechanical pumps are still prone to failure and leakage. A peltier derived system could be far more "solid state" as it were and of course process efficiencies could improve the system further.

As other commenters have noted, /. already panned the idea and you can learn a lot about air conditioner efficiency in the exchange. There aren't very many more efficiencies to be squeezed out of Peltier, and the technology has a long way to go to achieve what you get out of a phase change process (a standard A/C), so the Peltier idea is a bust for the foreseeable future. Based on my experience using TE (Peltier) to cool cameras, you'd have to have something that takes up most of the trunk in a normal sized car to cool one in the Southwest US in the summer, and I don't think my alternator is up to the task. Finally, it isn't truly solid state if it relies on the engine to provide the electricity.

On the other hand, if you superlight the car by building it out of carbon fiber, insulate the heck out of it, and run the whole thing on a fuel cell, that would be a different story!

For cooling, especially in dry climates you might look into Coolerado coolers. Delphi recently became the world exclusive manufacturer of this technology.
It looks very promising. No freon, very efficient. I would think that if Delphi is involved a automobile application may be on the horizon.

http://coolerado.com/

Coolerado website reads a little fishy, and here
are some knowledge folks questioning it.

http://www.physicsforums.com/archive/t-68726_New_Efficient_AC.html

greeatt! I feel real let down. Myself along with two of my friends designed a similar cooler usig the TECs for a more personal application way back in April 2005. But I didn't get the recognition like u people did. Anyways congradulation for your contemporary work!

greeatt! I feel real let down. Myself along with two of my friends designed a similar cooler usig the TECs for a more personal application way back in April 2005. But I didn't get the recognition like u people did. Anyways congradulation for your contemporary work!

With this invention youre still using electricity, because you have to run the cooling fans, which adds load to the battery. my suggestion is why dont we use the waste heat from the engine by connecting a series of thermocouple to generate voltage.

It may not be perfect, but it's something.

It's encouraging to me to see other young folk, such as myself, "invent" something. If they can make something great, it leads me to believe that I can too. Over all, their hearts are in the right place; trying to better something for everyone else. I can't wait to research more about this Peltier effect.

I agree with others who have said it's great that these kids are using their brains to try and come up with a solution to our problems. But come on, when you go out and buy electric fans and TE cooler chips and claim you invented something you're really fooling yourself. Peltier invented it almost 100 years ago, so why not give the award to him. Infact most water coolers use this same thing. But if you don't agree with me, just the other day I used a pencil sharpener to sharpen my pencil, do I get an award? And all air conditioners now use R-134a, not freeon, that was banned in the early 90's. R-134a is a harmless gas as far as we know. In electric vehicles, or series hybrids, compressor systems are maybe not so feasible, so this method will likely be the only option for such vehicles.