How does a dehumidifier remove moisture from room air?

A dehumidifier removes moisture from room air primarily through the principle of condensation, which is also fundamental to air-conditioning.

In this process, a blower pulls room air across evaporator coils that contain a cold refrigerant. As the air is cooled, it reaches its saturation point and can no longer hold its moisture. Consequently, the water vapor condenses into liquid form on the fins covering the coils. This water then drips off the fins and is collected in a drain or reservoir, while the now-dehumidified air is returned to the room.1

Alternatively, some systems achieve dehumidification through absorption or adsorption. This can involve passing air through materials like silica gel, which absorbs moisture, or using liquid absorbents to cause dehydration of the air stream.1