When disaster strikes a large commercial property, whether it’s a high-rise office building, a manufacturing plant, or a warehouse, the sheer volume of water damage can feel overwhelming. Time is the enemy, as prolonged moisture exposure rapidly leads to secondary damage like structural degradation and devastating mold growth. For these “large loss” projects, the standard approach to drying often falls short. This is where desiccant dehumidification proves to be the superior method, offering drying power that conventional refrigeration (LGR) dehumidifiers simply can’t match.
The Conventional Hurdle: LGR Dehumidifiers
Conventional dehumidifiers, primarily the Low Grain Refrigerant (LGR) units, operate by cooling air below its dew point, causing moisture to condense and be collected as water. This method is highly effective for smaller, residential, or contained drying environments, but they face significant limitations on a large commercial loss:
- Temperature Dependency – LGR units lose efficiency dramatically as the ambient air temperature drops or as the required moisture content (grain depression) becomes very low. In other words, as the building dries out, dehumidification slows down.
- Scale – To dry a massive structure, an impractical number of LGR units would be needed, creating logistical nightmares with power and placement.
- Humidity Floor – LGRs struggle to achieve the very low relative humidity (RH) levels often required for complete structural drying, especially for materials like concrete and lumber, which hold moisture deep within their structure.
The Desiccant Advantage: Unmatched Drying Power
Desiccant dehumidifiers operate on a fundamentally different principle: adsorption. Instead of cooling, they pass air through a rotor coated with a highly absorbent material, typically silica gel or lithium chloride, which pulls the moisture directly from the air and traps the water vapor. This moisture is then removed by a separate, heated “reactivation” air stream that is typically exhausted outside, allowing the rotor to continuously remove moisture out of the damaged structure.
Here’s the top 4 game-changing advantages of using desiccant dehumidifiers for large-scale projects:
- Superior Low-Humidity Performance (Grain Depression)
Desiccant dehumidifiers excel at achieving the extremely low dew points and grain levels required to force moisture out of dense materials like drywall, concrete, and sub-flooring. They can consistently achieve specific humidity levels far below what LGR units can handle, pushing the drying process faster and deeper. This capability is non-negotiable for large buildings with thick structural elements.
- Temperature Independence
Unlike LGRs, desiccants are not dependent on temperature for their moisture removal process. In fact, many desiccant systems utilize heat (from the air reactivation) to boost the overall drying process. This allows for consistent, aggressive drying even in cooler environments or seasons, ensuring the drying timetable remains predictable.
- Centralized and Scalable
A single, large desiccant unit can handle a massive volume of air, often through ducted systems connected to multiple floors or sections of a building. This centralized approach reduces the footprint, simplifies power management, and provides uniform drying conditions across a large facility, leading to faster stabilization of the environment.
- Accelerating the Time-to-Recovery
Ultimately, the goal is to get the commercial space back to operational status as quickly as possible. By achieving faster, deeper moisture removal, desiccant technology significantly reduces the overall drying cycle. Shaving days or even weeks off a large loss project directly translates to reduced business interruption costs for the property owner—a key metric for a successful restoration.
Conclusion: Choosing the Right Tool for the Job
While conventional LGR units remain essential for many restoration tasks, desiccant dehumidification is the definitive choice for rapid moisture removal on Large Loss projects. It offers the speed, power, and logistical efficiency needed to mitigate secondary damage, meet aggressive deadlines, and safeguard the significant investment of commercial properties.
Work Cited
U.S. Environmental Protection Agency (EPA). Mold Remediation in Schools and Commercial Buildings. (2008). Section 3.4. Available at: https://www.epa.gov/sites/default/files/2014-08/documents/moldremediation.pdf
Institute of Inspection, Cleaning and Restoration Certification. ANSI/IICRC S500-2021: Standard for Professional Water Damage Restoration. ANSI/IICRC, 2021.
Carlson, Larry and Steffes Mike. What You Need to Know About Desiccant Drying. Restoration & Remediation Magazine. 10 May 2017, https://www.randrmagonline.com/articles/85738-what-you-need-to-know-about-desiccant-drying, Accessed 7 Oct 2025