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The 2nd law of thermodynamics as explained by University Physics states that

"It is impossible for any process to have its sole result the transfer of heat from a colder to a hotter body."

Now my question is simple, in reverse refrigeration or inverter Air Conditioner, heat flows from a colder (outside) to a hotter (inside) body. Work done is often 1/3rd of what is transferred depending on coefficient of performance. So let's suppose a 2kW (electrical energy) inverter is delivering 6kW of heat inside. The net transfer is 4kW of heat from a colder to a hotter body. How is that not violating the 2nd law of thermodynamics?

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The process you describe doesn't have heat transfer as its sole result. The machine did work, which means electrical energy was consumed as part of the result.

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In both the coils of a heat pump, heat flows from a hotter to a colder environment, per second law of thermodynamics. It is the Freon compressor that compresses the Freon to a hot liquid in one coil, then bleeding off to a cold gas in the other coil.

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  • $\begingroup$ Adrian Howard, I think you have things a bit "backwards". The compressor produces high pressure and high temperature Freon vapor, that Freon condenses in the condenser, and pressure drop through an expansion valve causes the hot liquid to boil and become a mixture of cold liquid (approximately 90%) and cold vapor (approximately 10%). $\endgroup$ – David White Dec 17 '19 at 16:03
  • $\begingroup$ @DavidWhite You are describing an overcharged, extremely inefficient cycle that would soon ruin the compressor. My answer (that was only meant to show no violation of second law) may be a bit terse and idealistic, but is not backwards. $\endgroup$ – Adrian Howard Dec 17 '19 at 16:17
  • $\begingroup$ I made an edit, in case any one else thought I meant it condensed in the evaporator, and evaporated in the condenser $\endgroup$ – Adrian Howard Dec 17 '19 at 16:25
  • $\begingroup$ Adrian Howard, see physics.stackexchange.com/questions/287757/… $\endgroup$ – David White Dec 17 '19 at 19:15

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