Drying methods and equipment

DisasterCare has a wealth of knowledge and expertise in the drying of building structures and of different building materials. The objectives on commencing any water damaged property project are to minimise secondary damage and indemnity spend, ensure the structural integrity of the building is maintained, and return the property to it’s pre-incident (dry) condition.

A wide range of drying technologies are employed depending on the individual circumstances of each individual water damage claim:-

Refrigerant Dehumidifier

Convectant Dehumidifier

Air Mover

Dessicant Dehumidifier

Drying methodology

Where ventilation is increased in a building, simply by opening windows, and adding supplementary air movement. For this to work the outside air must be warmer and drier than the inside air, so the temperature and humidity of internal and external environments needs to be regularly monitored.

All windows and doors are shut and dehumidification equipment is installed to remove and control evaporated moisture.

This uses an open drying system combined with the use of mechanical dehumidification equipment. This system can be used when environmental conditions outside fluctuate, but are periodically suitable for open drying.

Air exchange and heat drying systems work by raising the temperature of the air within a property, resulting in an increase in the rate of evaporation of moisture from wet materials. Heated air is circulated throughout affected areas and constantly exhausted to either the air outside, either directly or via a heat exchange system (this recovers heat which is then used to pre-heat incoming air). Many of these systems are large trailer-mounted units, which use propane as their main energy source.

Sometimes a wet wall in a single room is the only area that has been damaged.  If so, it may be preferable to just dry the air close to the affected wall. This is done by containing the affected area by using plastic sheeting or specially designed materials, which are attached to the wall or “targeted” areas.


Room air is pulled through the dehumidifier by an internal fan and cooled below its dew point as it passes through cold coils (the evaporator matrix), resulting in condensation. Condensate water is either collected in a container placed next to the dehumidifier or directed to a suitable drain or sink using an integrated pumping system.

Room air is pulled through the dehumidifier by an internal fan and passed through a desiccant material, which removes water by direct absorption and vapour pressure differences.  The machine has two outlets, one which blows very dry air back into the building and the second, which blows very wet air out of the building. Water is not collected in its liquid form but is extracted from the area being dried in in vapour form.

The temperature in the room is increased by re-circulating the air through the machine’s heating system, the rise in room temperature results in increased evaporation of moisture from wet materials. Once the room air has reached a pre-defined level or temperature or relative humidity, the machine switches to exhaust mode expelling wet air to the outside.

Increasing the air movement over the surface of a wet structural material encourages evaporation of the moisture within.  Air movement also encourages turbulence within the area being dried, which can make drying equipment and techniques more effective.

When the normal heating system in a building does not work or is insufficient, a secondary heat source may be needed. This is to achieve the required drying conditions and to accelerate the evaporation of moisture from the structure. Heating systems can also be used to target specific troublesome drying areas as heating the building material will encourage evaporation. Heating alone can result in uncontrolled evaporation and uneven drying, so it should only be used as part of a balanced drying system.

Moisture meters are used to measure the percentage of water in a material, which allows a technician to determine whether the material is wet or dry. Moisture meters are essential when making an initial assessment of the extent of water damage to a property, and in monitoring drying progress.

Thermo hygrometers measure both the humidity of the air and temperature of the air, they are used to monitor drying conditions (and also for some types of moisture measurement).