LGR vs Desiccant Dehumidifiers: Which Do You Need?

Quick answer: LGR dehumidifiers work best for water damage restoration above 60°F. Desiccant dehumidifiers outperform in cold environments below 60°F or when you need humidity below 30% RH. Most restoration contractors need LGR units; specialty applications like cold storage, ice rinks, and pharmaceutical manufacturing require desiccant.

How LGR Dehumidifiers Work

LGR stands for Low Grain Refrigerant. These units pull air across cold refrigerant coils, causing moisture to condense and drain away. The "low grain" part means they can keep extracting moisture even when humidity drops below 40% RH—something standard refrigerant dehumidifiers can't do.

LGR dehumidifiers typically remove 70-180 pints per day at AHAM conditions (80°F, 60% RH). Real-world performance on a water loss varies based on temperature and humidity, but expect 50-130 pints daily during active restoration.

Best LGR applications:

• Water damage restoration in heated buildings
• Flood cleanup in spring, summer, fall
• Crawl space drying (with adequate temperature)
• Structural drying to IICRC S500 standards
• Insurance restoration jobs with documentation requirements

How Desiccant Dehumidifiers Work

Desiccant dehumidifiers use a rotating wheel coated with silica gel or similar moisture-absorbing material. Air passes through the wheel, moisture sticks to the desiccant, then a separate heated air stream regenerates the wheel by driving off the captured moisture as exhaust.

Because desiccant units don't rely on refrigeration, they work at any temperature—including below freezing. They also achieve much lower humidity levels than refrigerant technology, reaching 20% RH or lower when needed.

Best desiccant applications:

• Cold storage facilities and warehouses below 60°F
• Ice rinks and hockey arenas
• Pharmaceutical manufacturing requiring ultra-low humidity
• Winter restoration in unheated buildings
• Food processing and packaging
• Museum and archive preservation
• Lithium battery manufacturing

Performance Comparison: The Numbers

When LGR Wins

For 90% of water damage restoration work, LGR is the right choice. Here's why:

Cost efficiency: LGR units cost 50-70% less than comparable-capacity desiccant models. A restoration contractor can buy two or three LGR dehumidifiers for the price of one desiccant unit.

Energy efficiency above 60°F: When temperatures stay above 60°F, LGR technology removes more moisture per kilowatt-hour than desiccant. Your operating costs stay lower on typical restoration jobs.

Simpler operation: LGR dehumidifiers are plug-and-play. Connect drainage, set the target humidity, and walk away. Desiccant units often require ductwork for exhaust air.

Industry standard: Insurance adjusters, restoration certifiers, and building consultants expect to see LGR equipment on standard water losses. Documentation and billing align with LGR-based drying calculations.

When Desiccant Wins

Desiccant technology becomes necessary—not optional—in specific situations:

Cold environments: Below 60°F, LGR efficiency drops sharply. Below 45°F, ice forms on the coils and the unit cycles into defrost mode constantly. Desiccant dehumidifiers maintain full performance at any temperature, including sub-freezing conditions in warehouses, ice arenas, and winter construction sites.

Ultra-low humidity requirements: Pharmaceutical cleanrooms, lithium battery plants, and certain food processing operations need humidity below 30% RH. LGR technology physically cannot achieve these levels. Desiccant units reach 10% RH or lower.

Hardwood floor drying: Some restoration professionals prefer desiccant for hardwood because the dry air pulls moisture from deep in the wood without the temperature swings that refrigerant units create. The gentler, consistent drying reduces cupping and crowning.

Specialty industrial applications: Bry-Air and other desiccant manufacturers build custom systems for processes where moisture control is critical to product quality—powder coating, 3D printing filament storage, seed storage, and electronics manufacturing.

When Does It Make Sense to Use Both LGR and Desiccant Dehumidifiers Together?

TL;DR: Pairing an LGR with a desiccant accelerates drying in cold or very low-humidity conditions where LGR efficiency drops. Restoration contractors serving climates below 40°F often run hybrid setups on large losses.

Many restoration companies own both technologies. They deploy LGR units on standard residential and commercial water losses, then bring in desiccant equipment for:

• Winter losses in unheated structures
• Cold storage and freezer facilities
• Final drying stages when LGR can't pull the last few percentage points
• High-value contents requiring controlled drying conditions

Starting with an LGR fleet makes sense for most contractors. Add desiccant capability as your business encounters jobs that require it.

How Do You Size Dehumidifiers Correctly for a Water Damage Job?

TL;DR: IICRC S500 recommends 1 LGR dehumidifier per 800 sq ft of affected area as a starting point. Adjust up for high humidity, concrete subfloors, or Category 3 water damage.

Whether you choose LGR or desiccant, proper sizing determines success. Use our Dehumidifier Sizing Calculator to estimate capacity requirements for your project.

For LGR units: Calculate based on AHAM-rated pints per day, then factor in real-world conditions. A 130-pint LGR unit might deliver 80-100 pints on an actual water loss. Plan for 100 pints of removal capacity per 1,000 square feet of affected area as a starting point, then adjust based on water category, affected materials, and ambient conditions.

For desiccant units: Sizing works differently because these machines are rated in CFM (cubic feet per minute) of processed air and pounds of moisture removed per hour. A 1,000 CFM desiccant unit processing air at 70°F and 50% RH removes roughly 10-12 pounds of water per hour. Consult manufacturer specifications for your specific temperature and humidity conditions.

Total Cost of Ownership

Purchase price tells only part of the story.

LGR operating costs: Expect $0.15-$0.25 per pint of water removed in electricity costs at typical utility rates. A unit pulling 100 pints daily costs roughly $15-$25 per day to run. Maintenance costs stay low—mainly filter replacements and occasional coil cleaning.

Desiccant operating costs: Energy consumption runs higher, roughly $0.30-$0.50 per pint equivalent. However, desiccant units often finish jobs faster in cold conditions, offsetting some of the energy premium. Desiccant wheel replacement every 5-10 years adds to long-term costs.

For a restoration contractor running equipment 200+ days per year, LGR's lower operating costs add up. For industrial facilities with 24/7 humidity control needs in challenging environments, desiccant's ability to actually achieve required conditions justifies the premium.

Which LGR and Desiccant Dehumidifier Brands Are Most Reliable for Restoration?

TL;DR: Ebac and Namco Manufacturing lead the LGR segment. Bry-Air builds the most widely used industrial desiccant systems in the US. All three offer AHAM-verified performance ratings.

Top LGR brands: Dri-Eaz, Phoenix, Xpower, and BlueDri offer reliable LGR dehumidifiers with good dealer support and parts availability. Look for units with built-in pumps for drainage flexibility and hour meters for maintenance tracking.

Top desiccant brands: Bry-Air leads the industrial desiccant market with equipment scaled from portable restoration units to facility-wide systems. Munters and Desert Aire also manufacture quality desiccant equipment for commercial and industrial applications.

Frequently Asked Questions

Can I use a desiccant dehumidifier for regular water damage restoration?

Yes, but it's usually overkill. Desiccant units cost more to buy and operate than LGR equipment for standard water losses above 60°F. Save desiccant for cold-weather jobs or specialty applications.

What happens if I use an LGR dehumidifier below 60°F?

Performance drops significantly. The unit spends more time in defrost mode than actually removing moisture. Below 45°F, most LGR dehumidifiers become ineffective. You'll extend drying time dramatically or fail to reach dry standard.

Do desiccant dehumidifiers need to vent outside?

Most desiccant units exhaust warm, moist regeneration air that should be ducted outside the drying area or outdoors. Some compact units recirculate this air, but performance suffers. Plan for exhaust ductwork when deploying desiccant equipment.

Which type is better for crawl space drying?

It depends on temperature. Heated crawl spaces or summer conditions favor LGR. Cold crawl spaces in winter require desiccant. Many contractors heat the crawl space with auxiliary heaters to keep LGR equipment effective.

How long do desiccant wheels last?

Quality desiccant wheels last 5-10 years with proper maintenance. Replacement costs $500-$2,000 depending on unit size. Keep filters clean to protect the wheel from contamination that shortens lifespan.

Related: Dehumidifiers With Pump · Commercial Dehumidifiers

Can I rent desiccant dehumidifiers instead of buying?

Yes. Rental houses in major markets stock desiccant equipment for contractors who encounter occasional cold-weather jobs. Renting makes sense until your desiccant utilization justifies purchase.

The Bottom Line

Most water damage restoration professionals should build their fleet around LGR dehumidifiers. The lower cost, simpler operation, and strong performance above 60°F make LGR the workhorse technology for standard losses.

Add desiccant capability when your market demands it—cold-climate restoration, industrial humidity control, or specialty applications where LGR can't achieve required conditions. The higher investment pays off when refrigerant technology simply won't work.

Need help choosing? Contact our equipment specialists to discuss your typical applications and get recommendations for the right mix of LGR and desiccant equipment.

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