Is there a way to generate cold from heat?

Question

Current air conditioner systems generates cold but also a lot of heat, I'm looking for a way to generate cold from heat (which is considered a kind of energy) so then in summer we could have a way to generate cold without wasting a lot of expensive energy and also without heating the planet at the same time.

Answer 1

no, impossible in the way your describe it.

However, you can get refrigerators that run by burning natural gas.

Answer 2

Cold is the absence of heat or energy. As "hip hop" says , you must transfer energy as it cannot be destroyed. To generate something means to produce something. One cannot generate a negative. One can transfer a positive to a negative or vise versa. Use a refrigerator as an example. The interior is cold but the exterior, the back of the refrigerator, is warm.  The thought should be 'where can we dissipate or send the heat so that it does not warm the earth?' The largest 'cold' area where the dissipation of heat would not affect the earth would be into outer space. The problem with this is the cost. A resolution to this problem would be to access the initial heat or energy from an abundant souce. This would be from the sun or the internal heat generated from the earth's core. If one could use the earth's internal heat to provide the energy to drive or sustain the motors required to cool something then the heat could be returned to the earth and the system would be "almost" self sustaining.

Answer 3

Of course there is. When you run the air conditioner in your car you are essentially doing that, extracting heat (not "generating cold") using energy generated from the heat obtained through fuel burning. Again, of course you need more energy to extract heat from a "cold source" and " throw" it to a hot one than the heat (=energy) extracted from the cold source. Otherwise, you would violate the second principle of thermodynamics. In other words, what you are dreaming of is a waste of time, and many years ago physics geniuses like Clausius and Lord Kelvin stated impossible. Regards.

Answer 4

The direct answer to your question is yes -- refrigerators and air conditioners do it all the time. But it appears you are looking for a way to do it that violates the second law of thermodynamics, and that is impossible. To extract heat from a body takes energy, and both the heat extracted and the energy required to do it end up as heat in some heat sink.

Answer 5

You have asked this question because you have a basic misunderstanding of what hot and cold is.  Infact, theres is really no such thing as "cold"!  All the term cold really describes, is a substance or object which has a temperature substantially less than that of our body.

What you need to grasp is the concept of internal energy.  Every object which has a non zero temperature (On the Kelvin scale) has molecules which are vibrating.  These vibrations are that internal energy.

Now what an AC unit does is transfer heat from the room you want to cool, to outside, and similarly heatpumps transfer the heat from the outside into the room when you want the room to be warmer.

How does this happen though?  Well did you know that you can make water boil at room temperature?  If you reduce its pressure significantly, you can lower its boiling point.  And what happens when a liquid changes state?  It "sucks up" surrounding heat.

AC units and heatpumps use refrigerants in a closed cycle to repeat this process over and over again using a compressor to compress the gas to high pressure, then a condensor to get rid of the heat and turn the refrigerant into a liquid (This is the hot bit) then this liquid goes into an evaporator connected to the suction line of the compressor where the pressure is low, and the liquid evaporates, absorbing heat.  This is the cold bit.

Hope that helps u understand things a bit better.  I recommend reading up on the laws of Thermodynamics on Wikipedia or another reputable source!

Answer 6

Of course.  Heat is used to produce electricity, which is used to run your AC and refrigerator.  Also the heat from burning gasoline is used to turn the engine in your car, which turns the compressor that cools the passenger compartment.

Answer 7

Interesting concept.  I have a refer in my RV that runs on electricity or propane and will freeze things rock hard.  It took awhile to understand the principles in a closed system.

Finding a way to utilize all the hot air produced from a heat pump/AC unit for further cooling would be a challenge that, if success is had, would revolutionize technology.  Not to mention, make someone very wealthy.

Answer 8

How does something cool down?

It has to transfer its heat to something else.  If you could somehow generate "cold" you'd win a Nobel Prize.