What is an LGR dehumidifier?
An LGR (low grain refrigerant) dehumidifier is a refrigerant-based moisture removal unit designed to extract water vapor from air at lower humidity levels than conventional refrigerant dehumidifiers, making it effective for drying structural materials after flooding or water intrusion.
Low grain refrigerant (LGR) dehumidifiers work by passing humid air across cold evaporator coils that condense moisture into liquid. The key advantage over standard refrigerant units is their ability to continue removing water even when relative humidity drops below 40 percent, a range where conventional refrigerant dehumidifiers become inefficient and frost-up.
Restoration crews rely on LGR models for structural drying work because they pull substantially more moisture from concrete, wood framing, insulation, and drywall than refrigerant or desiccant units alone. They also produce warm, dry air as output, which prevents cold spots and condensation that can trigger secondary damage. In Ontario water damage jobs, this efficiency translates to faster drying times and reduced risk of mold growth in walls and substructures.
LGR dehumidifiers are portable, draw moderate electrical power, and work continuously at low humidity, making them standard equipment for mitigation crews tackling wet basements, burst pipes, and roof leaks. They typically run 24 hours during the critical first days of damage response and are often paired with air movers to circulate dried air throughout affected areas.