Dehumidifiers are the backbone of the structural drying process after water damage. But not all dehumidifiers work the same way — and choosing the right type for a given situation can significantly impact drying time and cost. Here's what restoration professionals need to know about the two primary types: refrigerant and desiccant.
How Refrigerant Dehumidifiers Work
Refrigerant dehumidifiers (also called refrigerant or LGR units) remove moisture by drawing air across a cold evaporator coil. When humid air contacts the cold coil, moisture condenses and drips into a collection tank or drain line. The dried air is then reheated slightly by the condenser coil before being returned to the room.
LGR (Low Grain Refrigerant) units are the gold standard for residential water damage. They're efficient in the 70-90°F temperature range and can remove 70-150 pints per day depending on conditions. Allied Restoration's fleet includes Dri-Eaz LGR 6000Li units — some of the most powerful portable refrigerant dehumidifiers available.
How Desiccant Dehumidifiers Work
Desiccant dehumidifiers use a rotating wheel coated with silica gel to chemically absorb moisture from the air. The wet section of the wheel is continuously regenerated by a heated airstream, releasing the captured moisture to an exhaust duct outside the building.
Desiccant units excel in two scenarios: low temperature environments (below 60°F) where refrigerant units lose efficiency, and very low humidity targets where refrigerant units struggle to pull moisture from dry structural materials. They're also the preferred choice for large commercial drying projects.
Which Is Right for Your Job?
For most residential water damage jobs in San Francisco's mild climate, LGR refrigerant units provide the best balance of performance and efficiency. For commercial large-loss jobs, cold warehouses, or situations requiring very aggressive drying, desiccant units are the professional choice. Allied Restoration maintains both types in our fleet to match the right equipment to every job.