[roywiggins]

Air conditioners are often more than 100% efficient- they move more heat energy than they consume.

(Of course if you start with a fossil fuel, turn it into electricity, and then pipe that into an AC unit, the overall efficiency will be dropped by the efficiency of the power plant, but it's still somewhat made up for by the advantages of heat pumps)

[KMag]

As others have pointed out, the coefficient of performance is over 1.0. However, as I remember from my mechanical engineering classes, a single-stage piston compressor based refrigeration system found in most window-mount AC units, refrigerators, etc. typically operates at about half of the Carnot efficiency. Central AC units with scroll compressors do a bit better, and of course industrial chillers with multi-stage centrifugal compressors do quite a bit better.

[username505]

This is false

[URSpider94]

What is false?

[username505]

The total efficiency of an air conditioner will never be more than 100% based on design; you will never be able to remove more heat than what the system produces in net cooling effect based off of the energy consumption created from compression - this is what would lead you to the eventual path of the theory of the heat death of the universe. You may be able to remove heat from one place to another but never more than what the system produces. Heating systems are completely different regarding efficiency.

[tripletao]

The ratio of thermal power moved to electrical power input is more properly called "coefficient of performance" rather than "efficiency", but it's far greater than 100% in modern equipment.

> From 1990 to 2013, U.S. shipment-weighted efficiency for residential split-system A/Cs increased from 9.5 SEER (~2.2 COP) to 14.9 SEER (~3.8 COP).

https://www.energy.gov/sites/prod/files/2016/07/f33/The%20Fu...

[URSpider94]

I think you’re misunderstanding the terminology. In a heat engine, efficiency is the ratio of how much heat you can move per unit of energy you put in. An air conditioner can usually move substantially more than 1 joule of heat energy from one place to the other for each joule of energy put into the compressor.

Yes, the hot side will spit out all of the heat extracted from inside, plus the energy from the compressor operation, so indeed energy is conserved.