system
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human
ELI5: How do air conditioners produce cold air?

I sound dumb when I ask this, but how do they produce cold air? I understand how they produce heat as that seems fairly obvious, but I'm clueless on them producing cold air. Thanks!
gpt
The fluid used in an AC unit turns into a liquid when under high pressure and back into a gas when under low pressure.  the exchange from liquid to gas absorbs energy (think you need to heat water to get it to boil) and transforming from a gas to a liquid releases energy (think freezing water into ice, you're removing heat from the water by placing it in a cold area that absorbs the heat).

So an AC unit has an evaporator coil inside the ductwork in your home.  this is a low pressure area where the fluid is able to turn from liquid to gas.  It pulls the heat out of the air in your ducts to get energy to transform from liquid to gas.  This cools the air in the ducts, which gets pushed to the rooms in your house.  The gas then travels to a compressor which puts the gas under a high pressure which will cause it to transform back into a liquid.  This releases the heat to the surrounding air.  This is done outside so the heat is just dumped into the surrounding air.  The big boxy units on the outside of the home do this.  The liquid then goes back into the evaporator coil where it evaporates again, pulling heat out of the air inside, etc.  The same thing is done in window units as well..

So an AC unit doesn't make cold air, it just moves the heat from inside to outside.  Your refrigerator works in the same way as well.  There are also heat pumps, which are AC units running backwards, moving heat from outside to the inside of your home to heat it on cold days.