Dehumidifier Calc, With the Formula Left on the Table

Field notes

The calculator combines floor area with five relative-humidity bands and four fixed moisture additions, including sump water, open-air ventilation, bare earth, and a utility sink. Its worked example keeps the area fixed at 1,500 square feet while changing the recommendation from 30-pint to 70-pint class equipment as conditions worsen. The page also advises measuring humidity for a week and addressing gutters, grading, drainage, and vapor barriers before relying on mechanical drying.