IICRC Applied Structural Drying Practice Exam

The process by which a conventional refrigerant dehumidifier removes water vapor relies on the principle of condensation. This method involves cooling the air that passes over coils containing a refrigerant, which has a significantly lower temperature than the air. When the warm, humid air comes into contact with these cooler coils, its temperature drops, leading to a reduction in the air's capacity to hold moisture.

As the air cools, it reaches its dew point—the temperature at which water vapor begins to condense into liquid water. This condensation process effectively transforms the vapor into liquid water, which is then collected in a reservoir or drained away, resulting in reduced humidity levels in the room. This mechanism is efficient for dehumidifying spaces and is the primary operational principle behind conventional refrigerant dehumidifiers.

In contrast, other methods such as absorption into desiccants involve different materials that chemically or physically attract water vapor, heating the air to drive moisture out requires significantly more energy and does not effectively capture humidity, and direct capture from surfaces pertains to different types of drying technologies rather than air dehumidification.