Think of the air as a sponge. As we increase the air flow across the wet materials, using a high velocity air mover, the moisture will begin to evaporate. When the air becomes so full it cannot hold any more moisture, evaporation stops and secondary damage can begin. We need to get the moisture out of the air so we can continue with the evaporation process. This is accomplished with the use of dehumidifiers. Dehumidifiers remove excess moisture from the air.

The Vital Role of Airmovers

Airmovers are the initiators of the drying process. Without their evaporative airflow, drying efforts will be stuck in neutral. Airmovers provide high-velocity airflow for water damage restoration. The role airmovers play:

  1. Airmovers direct high-velocity airflow across wet materials.
  2. The airflow evaporates the top layer of moisture into the air as water vapor.
  3. Dehumidifiers remove the water vapor from the room
  4. Trapped water wicks to the surface of the material to be evaporated.
  5. This cycle repeats until all the abnormal moisture has been removed from the structure.


Dehumidifiers are used to promote faster drying, prevent humidity damage, and help indoor air quality problems. Dehumidifiers do this by removing water vapor from ambient air at a rate equal to or greater than the rate it is being evaporated from wet materials. Without dehumidifiers, the airmovers on a job would merely circulate moist air and the evaporation (drying) rate would be very slow. there are two basic types of dehumidifiers used in the restoration industry: refrigerant and desiccant. In saturated environments it is often helpful to use desiccant together with refrigerant units to speed the drying process.

Refrigerant Dehumidifiers (Standard)

Refrigerants are the most effective dehumidifiers in warm and humid conditions. Refrigerant dehumidifiers operate by refrigerating ambient air below its dew-point temperature and condensing out the moisture (condenses water vapor into a liquid). Refrigerants are most effective when both humidity and temperature are high. They are much less effective in conditions under 40% relative humidity and 50° F.

LGR Dehumidifiers (Low Grain Refrigerant)

LGR dehumidifiers employ new technologies that enable them to remove hgiher levels of water at lower humidity than typical refrigerants. LGR’s obtain lower specific humidity to incredibly low levels that standard refrigerant dehumidifiers cannot reach. The resulting conditions actually pull bound moisture out of difficult-to-dry materials like drywall, frame material, and subflooring.

Desiccant Dehumidifiers

A desiccant dehumidifier can create extremely low humidity conditions,and operates efficiently in very low temperatures. These two benefits of the desiccant are not possible with refrigerant dehumidifiers. Desiccant dehumidifiers pull ambient air over a desiccant material, which draws the moisture out. A desiccant dramatically reduces humidity to very low levels – even down to 1% Rh or below. This allows faster and more thorough drying of dense materials like hardwood flooring and structural woods.

Specialty Equipment

DriForce Interair Drying System (InjectiDry)

Positive or negative pressure for drying. High-pressure air will dry hard-to-reach spaces with minimal intrusion. It is great for wall cavities, cabinets, under stairwells, etc. one unit can dry up to 90 lf.

Airwolf/WolfPack (Hardwood Floor Drying System)

Forces water out of hardwood floors – fast. The AirWolf provides incredible airflow with high static pressure – the wolfpack attachment channels it through the flutes beneath the hardwoods to drive water out by force. Doubles as an intermediate wall-drying system and is very effective.

Vortex Axial Fan and Vortex Ducting

Ventilator and dryer in one. Powerful airflow from the Vortex – with up to 125 ft. of ducting to ventilate, create negative air pressures, and aid in the drying process.

Rescue Mats

Mats are used to dry out water-damaged hardwoods from above the surface. The Rescue Mat System uses the power of a high-pressure blower like the DriForce to vacuum water vapor right through the surface of the floor. Also effective on other types of hard flooring surfaces.

LayFlat Ducting

Strong, 4-mil poly ducting used to direct processed air. LayFlat Ducting can be used with all types of dehumidifiers.

Mini-Vents and Turbo Vents

These attach to the snouts of high velocity air movers to direct airflow. THese are useful in small areas of wall and cavity drying situations.

Water Damage Category – IICRC Definitions:

Category 1 Water: Water originating form a source that does not pose substantial harm to humans. Also referred to as “clean water.”

Category 2 Water: Water containing a significant dgree of chemical, biological and/or physical contamination and having the potential to cause discomfort or sickness if consumed by or exposed to humans. Also referred to as “gray water.”

Category 3 Water: Grossly unsanitary water, containing pathogenic agents, arising from sewage or other contaminated water sources and having the likelihood of causing discomfort or sickness if consumed or exposed to humans. This category includes all forms of seawater, ground surface water and rising water from rivers or streams. Also referred to as “black water.”