Conceptual heat pump question

[sillyjoe]

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TBR Chemistry Section 8 states:

"Air conditioners and freezers have the same mechanics as a refrigerator. The difference between freezers, air conditioners, and refrigerators is the temperature of the internal coils. Because a phase change from liquid to gas is responsible for absorbing heat, the temperature of the cold coils depends on the boiling point of the refrigerant. A refrigerant is selected on the basis of its boiling point and the target temperature of the system. The temperature in a freezer is less than the temperature of a an air conditioner or refrigerator, so the boiling point of the refrigerant used in a freezer is lower than the refrigerant used in an air conditioner or a refrigerator. "


I get that a portion of the cycle involves the decompression of a liquid --> gas to cool the system down via the endothermic process. However, are they saying that the temperature at which that decompression will be is ~the boiling point for that liquid? Any clarification would be appreciated!

 

[DrknoSDN]

So in the cold refrigerator or freezer you want the phase change to occur from liquid -> gas (boiling), so that it absorbs heat endothermically from the interior of the refrigerator or freezer.
On the outside of the cooler it is then re-condensed back to liquid releasing heat to the exterior.

Having the liquid -> gas phase change occur near a temperature that you want the freezer to operate at would be critical in facilitating the endothermic/exothermic transfer of heat out of the container.