What does an air conditioning system primarily do in terms of humidity control?

An air conditioning system primarily functions to remove moisture from the air, which is crucial for maintaining comfort and enhancing indoor air quality. During the cooling process, the system circulates air over evaporator coils that are cooled by refrigerant. As warm, humid air passes over these coils, the temperature drops, causing the moisture in the air to condense into water droplets. This process effectively reduces the humidity level in the indoor environment, making it more comfortable for occupants.

Lower humidity levels are important not only for comfort but also for preventing mold growth and minimizing the likelihood of dust mites and other allergens proliferating. Therefore, controlling humidity is a key aspect of air conditioning systems, where the primary goal is to create a pleasant indoor climate by removing excess moisture.

The other choices do not align with the primary function of an air conditioning system in terms of humidity control. Adding moisture to the air conflicts with the objective of dehumidification, while increasing fresh air exchange and distributing hot air are functions related to ventilation and heating, respectively.