Why Commercial Dehumidifiers are Crucial for Water Damage

Xavier

IICRC Certified Master Restorer

Fact Checked100% Verified Accuracy

• Commercial LGR dehumidifiers achieve near-zero humidity for effective drying.
• Air movers and dehumidifiers must be used together to prevent secondary mold.
• LGR dehumidifiers are ideal for standard residential drying.
• Desiccant dehumidifiers are used for dense materials or extremely cold environments.

Many homeowners attempt to dry out water damage using box fans and a small dehumidifier from the hardware store. Unfortunately, this almost always leads to massive mold outbreaks. Here's why professional equipment is required.

The Concept of Grain Depression

To pull moisture out of dense materials like drywall and framing studs, the air must be incredibly dry. Commercial Low Grain Refrigerant (LGR) dehumidifiers can reduce the humidity in a room to near zero, creating a "thirsty" environment that forcefully evaporates trapped water. Standard residential units simply cannot achieve this level of grain depression, leaving moisture trapped inside the walls.

Air Movers vs. Dehumidifiers

Drying a structure requires a delicate balance of two forces:

• Air Movers: High-velocity fans that strip the boundary layer of moisture off wet surfaces, pushing water vapor into the air.
• Dehumidifiers: Machines that capture that airborne moisture and pump it out of the house.

If you use air movers without powerful dehumidifiers, you are simply blowing wet air around your house, which will cause secondary mold growth on previously dry walls and ceilings. Conversely, using dehumidifiers without air movers will dry the air, but won't pull the water out of the materials.

Desiccant vs. LGR Technology

Professional restoration companies utilize different types of dehumidifiers based on the specific psychrometric conditions of the loss:

• LGR (Low Grain Refrigerant): Uses specialized cooling coils to condense water out of the air. Perfect for standard residential drying and warm environments.
• Desiccant: Uses silica gel to chemically absorb moisture. We deploy Desiccants for incredibly dense materials like hardwood floors or concrete, or in extremely cold environments where traditional refrigeration coils would freeze over.

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