What is the basic principle of air conditioning?

The basic principle of air conditioning revolves around the process of cooling by removing heat from the air. This is achieved through a refrigeration cycle that employs a coolant to absorb heat from the indoor air and release it outside, effectively lowering the temperature indoors. The system utilizes components such as evaporators, condensers, and compressors to facilitate this heat exchange, making the living space more comfortable by controlling the air temperature.

While circulating cool air and maintaining humidity levels are important functions of an air conditioning system, they are secondary processes that occur as a result of the primary action—removing heat. Heating the air before distribution is also not a fundamental principle of air conditioning, as the primary goal is to provide cooling rather than heating. Thus, the correct choice highlights the essential mechanism behind air conditioning systems.