Dehumidifier Size Calculator

How It Works

Dehumidifiers are sized in pints of moisture removed per day. Indoor humidity should stay between 30 and 50 percent for comfort and to prevent mold growth. Basements are the most common problem area because cool foundation walls cause condensation. A moderately damp 800 square foot basement typically needs a 30 to 40-pint unit. Very damp conditions (visible condensation, musty smell) may need a 50 to 70-pint unit. Look for Energy Star certified models, which use 15 percent less energy. Position the dehumidifier away from walls for good airflow, and drain it through a hose to a floor drain if possible rather than emptying a bucket. Running a dehumidifier in a basement also reduces the moisture load on your upper-floor AC system.