A home has a drying chamber that is 7,500 cubic feet, the loss is a...

The IICRC WRT body of knowledge provides initial LGR dehumidification recommendations based oncubic footage and class of water. ForClass 3 water intrusions, a commonly taught starting guideline is approximatelyone LGR dehumidifier (≈100–150 PPD) per 3,000 cubic feetof affected space.

In this scenario, the drying chamber volume is 7,500 cubic feet. Dividing 7,500 by 3,000 yields 2.5 units. Because dehumidifiers cannot be fractionally deployed and WRT guidance supports roundingupto ensure adequate moisture removal, the initial recommendation isthree LGR dehumidifiers.

The WRT manual emphasizes that this is an initial placement subject to adjustment after monitoring confirms drying progress. Insufficient dehumidification can increase ambient humidity, slow drying, and elevate secondary damage risk—particularly in Class 3 losses where evaporation rates are high.

Placing three units provides adequate capacity to manage evaporated moisture while allowing later downsizing as drying goals are achieved.