Initial dehumidifier load by the cubic-feet ÷ factor method (IICRC S500), scaled by water class and dehumidifier type.
The cubic-feet ÷ factor method
IICRC S500 sizes the initial dehumidifier load by taking the room’s cubic footage and dividing by a factor set by the water class and the dehumidifier type. Higher classes and conventional refrigerant units use smaller factors, which means more capacity.
AHAM pints vs. real-world pints
Manufacturers rate dehumidifiers in AHAM pints at 80°F / 60% RH — near saturation. In the field, especially with LGR units running against drier air, you will pull fewer pints. Size for the initial load, then let daily psychrometric readings drive adjustments.
Frequently asked
How do I size a dehumidifier for water damage?
Take the affected room’s cubic footage (length × width × height) and divide by the IICRC S500 factor for the water class and dehumidifier type. That gives the initial pints-per-day load; divide by a unit’s AHAM rating to get the number of dehumidifiers.
What is an AHAM pint?
An AHAM pint is a dehumidifier’s water-removal rating measured at 80°F and 60% relative humidity by AHAM. It is a comparison standard — real-world removal is usually lower, particularly as the air dries out.
LGR vs conventional refrigerant dehumidifier?
LGR (low-grain refrigerant) dehumidifiers pull moisture from much drier air than conventional refrigerant units, so they finish a drying job and handle bound water better. Conventional units need more capacity for the same result.
More free tools
This knowledge, built into the software
RestoredOS runs the whole job on the same field knowledge behind these tools — drying logs, moisture mapping, scope, and billing.