What is the process used by refrigerant dehumidifiers to remove water from the air?

Refrigerant dehumidifiers remove moisture from the air through the process ofcondensation, as outlined in the IICRC WRT body of knowledge. In this process, warm, moist air is drawn across a cold evaporator coil inside the dehumidifier. When the air temperature is reduced below its dew point, water vapor changes phase from a gas to a liquid and condenses on the coil surface.

The collected liquid water then drains into a reservoir or is pumped out of the unit, while the dried air is reheated slightly and discharged back into the drying chamber. This mechanism is fundamental to both conventional refrigerant and low-grain refrigerant (LGR) dehumidifiers.

The WRT curriculum contrasts condensation withadsorption, which is used by desiccant dehumidifiers, andabsorption, which involves liquids—not air drying. Sublimation (solid to vapor) is not relevant to restoration drying.

Understanding condensation is essential because refrigerant dehumidifiers rely on sufficient temperature and humidity conditions to function efficiently. The WRT manual highlights operational limits and emphasizes monitoring to ensure that refrigerant systems are appropriate for the environmental conditions present on the job.