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/sci/ - Science & Math

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1419155 No.1419155 [Reply] [Original]

why can't we make a cooler(reversed heater) that uses heat to create electricity, thus gaining an air-cooler that charges batteries?

>> No.1419159
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1419159

because entropy

>> No.1419165

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

>> No.1419170

>>1419155
>The Seebeck effect is the conversion of temperature differences directly into electricity.
>temperature differences
>differences

>> No.1419175

It's called a Thermocouple. The reason we don't use them widely is because they're at best 7% efficient.

>> No.1419182

invent highly efficient thermocouple

become trillionaire

>> No.1419185

>>1419170

The only way to get energy out of heat is with differences in temperature. It's very shitty, and is barely useful.

>> No.1419191

>>1419182

>while bankrupting the Fireplace service industry because they'll have nothing to replace.

>> No.1419204

>>1419191
Best part of becoming a trillionair? All the people and businesses you crushed along the way.

>> No.1419211

>>1419204

>Trillionair

>TRILLION AIR; FOR ALL YOUR OBSCENELY RICH FLYING NEEDS

>> No.1419218

>>1419159
THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER

>> No.1419219

>>1419170
If you have no differences, you have no electricity. It seemed safe enough to assume, but I guess... I guess people are retarded.

>> No.1419226

>>1419219

Our differences make us stronger.

>> No.1419234

>>1419211
i lol'd crazy hard

>> No.1419239

but could you use electricity to just cool something down? without heating something else up in the process, like a heat pump...

>> No.1419251

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

>> No.1419254

>>1419239

Sadly, no. Think about it. Heat cannot be destroyed. In order to cool something you remove the heat from it. Now you have heat that has to go somewhere. You cannot get around it.

>> No.1419270

hay guise can you have change w/o difrances???

>> No.1419291

>>1419254
thats the idea. the heat could be converted into electricity. ergo first law intact.

>> No.1419314

>>1419291
It takes energy to move that heat somewhere else. Overall, you've increased entropy by cooling something with, say, a refrigerator. You've converted energy into a useless form. Statistically, you will never be able to recover it.

>> No.1419322

>>1419314
I should read my posts before I send them. That was supposed to be two separate points.
> Refrigerators increase entropy even though they cool shit down.
> Reclaiming heat energy as usable energy is statistically impossible. You can't undo friction/unfry an egg/reverse entropy.

>> No.1419323

>>1419314 Statistically, you will never be able to recover it.

... some kind of pejorative use of statistics.

>> No.1419329

>>1419323
What do you mean?

>> No.1419346

>>1419239

Heat doesn't just disappear. It has to go somewhere.

>> No.1419348

"but could you use electricity to just cool something down? without heating something else up in the process, like a heat pump..."

No, never.

Think of it like this. Electricity is energy. Heat is also energy. There is no such thing as negative energy.

If I add electricity to a system, I add energy to a system, because electricity is energy. And since heat is energy, too, it means that I added heat to the system.

No amount of electricity will ever be equal to negative energy, so I cannot remove heat from a system by adding electricity to it.

>> No.1419356

>>1419348

>There is no such thing as negative energy.

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

>> No.1419365

>>1419356
I like how you almost posted relevant information.

>> No.1419411

>>1419356
>Negative energy plane, an aspect of the Dungeons & Dragons game
Which is why thermoelectric generators are not used; they create zombies.

>> No.1419414

>>1419155
http://www.popularmechanics.com/science/environment/green-energy/4243793
We can't make a "cooler" but we can convert heat energy into electricity.

>> No.1419465

>>1419414
I say we use a radioactive decay source of heat, and for safety keep it very deep underground. Luckily, such a source is already available to us.

>> No.1419503
File: 268 KB, 240x240, heat.jpg [View same] [iqdb] [saucenao] [google]
1419503

I'm totally uneducated on the topic, but I always think of it as analogous to motion. It takes force to change momentum, no matter what that momentum may be, and change in position is the result of that momentum. If a hot pan is cooling slowly in a normal room, it would take energy to heat it up (introducing fire) or to cool it down (introducing cold water) faster than the rate it already is.

Experts... am I close?

>> No.1419509

fucking energy, how do they work?

>> No.1419525

>>1419503
the hot pan is increasing the temperature of the cold room.

entropy, do you even know what it is?

>> No.1419550

"Cool" is just a term to refer to a relative lack of heat. The only way to make something cool is to remove heat. In other words, you have to remove energy from the system. If you are adding anything at all to the system, you are adding heat to the system.

>> No.1419582

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

/thread

>> No.1419600

Most kinds of energy can transform into heat. I'm pretty sure it's possible to turn that heat back into some other kind of form of energy.

>> No.1419614

You will lose most of the energy during conversion. The energy it takes to convert has to come from somewhere. The product energy is insufficient for this purpose due to the loss. If you added energy such as additional electrical you could make it work but it would still not be as efficient as a device running entirely off of outside electricity that already exists such as a standard heat pump.

>> No.1419630
File: 72 KB, 618x600, BetaStirling.jpg [View same] [iqdb] [saucenao] [google]
1419630

>>1419582

interesting article you posted. im not sure why but i find this diagram strangly facinating.

>> No.1419650

>http://en.wikipedia.org/wiki/Heat_engine#Efficiency
this