Refrigerant Dehumidifiers for Water Loss Restoration

A refrigerant dehumidifier removes moisture from air by passing it over a refrigerated evaporator coil that is below the dew point of the incoming air. Moisture in the air condenses on the coil and is collected in a reservoir or discharged via a drain hose. The dried, slightly reheated air is then discharged back into the room to continue absorbing moisture from wet building materials.

In a structural drying context, the dehumidifier does not dry building materials directly — it maintains the psychrometric conditions in the room (low relative humidity, adequate temperature) that cause moisture to evaporate from materials into the air, which the dehumidifier then removes. This distinction is critical: the dehumidifier manages the drying environment; air movers drive evaporation from material surfaces. Both are required for efficient structural drying.

Refrigerant dehumidifiers used in restoration are rated by their moisture removal capacity, typically expressed in litres per day (L/day) at a reference condition (usually 26.7 degrees Celsius, 60 percent relative humidity). Real-world performance differs from rated performance depending on actual temperature and humidity conditions on site. Understanding how conditions affect performance allows you to predict drying timelines and identify when conditions are limiting your equipment's output.

The two main categories used in restoration are conventional refrigerant dehumidifiers (effective above approximately 15 degrees Celsius) and low grain refrigerant (LGR) dehumidifiers (effective at lower temperatures and lower humidity levels). Selecting the right category for site conditions is the first equipment decision on any job.

Reference: IICRC S500 | Equipment manufacturer technical specifications