How to Set Up a Dehumidifier After Water Damage

A dehumidifier is your best defense against secondary water damage and mold, but only if used correctly. Here is how to set it up for maximum structural drying.

1. Choose the Right Capacity

A standard 50-pint consumer dehumidifier is sufficient for minor, localized spills in a single room. For extensive saturation, commercial LGR (Low Grain Refrigerant) dehumidifiers are required.

2. Optimal Placement

Place the unit in the center of the affected room. Ensure there is at least 12 inches of clearance around all sides of the machine so air can intake and exhaust freely.

3. Close the Envelope

Dehumidifiers only work in closed environments. Shut all windows and doors in the affected room to create a "drying chamber." Otherwise, you are trying to dehumidify the neighborhood.

4. Target Settings

Set the dehumidifier to its lowest possible humidity setting, or "continuous" mode. Your goal is to drive the relative humidity (RH) of the room below 40% to force moisture out of the wet materials.

5. Continuous Drainage

The internal bucket will fill quickly during a water damage event. Attach a standard garden hose to the drainage port and route it to a floor drain or sink (using a unit with a built-in pump) so it runs non-stop.

Limitations

Consumer units often freeze up in cooler temperatures or fail to pull enough moisture once the room humidity drops below 55%. If materials are still wet after 48 hours, call 1-800-755-8108 for commercial-grade drying equipment.