Air movers and dehumidifiers are the two primary pieces of equipment used by the water restoration supplier. What value does this water loss restoration equipment create? What do they do that is so important to you and your customer?

Air Movers
Given enough time, evaporated water disperses evenly into the air. However, at any given moment, air can be very wet several inches from a wet carpet or wall and relatively dry further away from the water leak. If the air at the boundary between the atmosphere and wet carpet is completely full, the relative humidity is 100%, and water will not pass from the carpet into the air, slowing down the drying process.

A high velocity air mover is designed to create a concentrated stream of air along the floor, carpet or wall. Also called "laminar" airflow, this air stream sweeps wet air away from the water source and replaces the wet air with drier air, which can accept more water. Other types of fans or blowers provide general air movement in a room that is somewhat helpful but they do not provide the "laminar" airflow required to sweep away the boundary layer of wet air.

Dehumidifiers
Eventually, the air sponge becomes full and requires wringing out. Dehumidifiers wring out the air sponge. Some dehumidifiers perform this function more successfully than others do. Let's look at some of the differences between the two types of dehumidifiers.

• A refrigerant dehumidifier draws the warm wet air over a set of cold coils. As the air passes the coils and cools, it can no longer hold as much water. The water condenses onto the coil, drips into a pan and is pumped out to a drain. A refrigerant can produce air which is 90° - 95° F and 35% relative humidity. Air in this condition will dry moderate to very porous materials well. Refrigerant dehumidifiers lose efficiency as the room temperature drops below 60°F and approaches freezing. As the air cools, the refrigerant dehumidifier spends increasingly more time melting the frost from the coils and increasingly less time removing water from the air.
• A desiccant dehumidifier must be used to dry efficiently when temperatures on the loss site are low or when finishing the drying of dense materials like wood and plaster.The desiccant dehumidifier draws the warm wet air over a wheel impregnated with a substance that, because of its immense surface area, can attract huge amounts of water to its surface. The dehumidifier then subjects the desiccant substance to high heat, creating steam, and pumps the steam away through an exhaust pipe.The desiccant is now ready to adsorb more water from the air. The processed air can be from 100° -115° F and an unbelievable 3% - 10% relative humidity. Air in this condition can dry all water losses very well but is particularly useful in drying wood and plaster which must reach a moisture content far below the 35% relative humidity air created by the refrigerant dehumidifier. Desiccant dehumidifiers maintain high water removal efficiency below freezing.

Since refrigerants are less expensive to own and operate, they are typically the workhorses used in situations where the supplier must dry out moderately or highly porous materials. However, though desiccant dehumidifiers cost more to own and operate, sometimes it is the only dehumidifier that will do the job.

Balancing Air Movement and Dehumidification
Finally, balancing air movement and dehumidification at a loss site is critical. When in balance, air movers sweep water-saturated air away from wet surfaces and convey it to dehumidifiers that remove the water from the air. This dry air is then conveyed back across wet surfaces efficiently drying contents and structural surfaces. However, two imbalances may occur; air movement without adequate dehumidification or dehumidification without adequate air movement.

In the first scenario, good air movement helps water evaporate into the air. But since dehumidification is inadequate, the water in the air begins absorbing into, warping or delaminating contents or structural elements that were not originally affected by the water loss. The cost of this secondary damage can be avoided by balancing air movement and dehumidification.

In the second scenario adequate dehumidification eventually reduces the relative humidity to 35%. But inadequate air movement allows water to stay in wet contents and structures. So, the dehumidifier spins idly, removing very little water even though drying is not yet complete. In either case, the water restoration service supplier must balance the equipment to achieve the maximum water removal efficiency.

The two main pieces of water loss restoration equipment, when used correctly create value in saved time and ultimately saved money Balancing the use of these two pieces of equipment is critical and equally as important as the technology itself.