Dehumidifier Sizing

Required pints per day by AHAM and field methods.

Run the calculator

Example

You enter

Room volume (ft³) 6000
Water class 2

You get

AHAM pints/day 240
Field pints/day 372
Recommendation 372

Details, formula, and sources

Required dehumidifier capacity (PPD = pints per day) sized from affected cubic feet, water class (1-4 per IICRC S500), and category (1-3 per IICRC S500). AHAM-rated capacity is the published rating at 80 °F / 60% RH; field-rating at 75 °F / 50% RH is typically 60-70% of AHAM.

IICRC S500-2021 §10 (Equipment); AHAM DH-1-2008 (Dehumidifier rating standard) by name.

AHAM standards licensed; rating principles free at AHAM (aham.org) outreach.

Estimate. AHJ and licensed professional govern.

Field names used by the API: room_cubic_feet, water_class, aham_pints_per_day, field_pints_per_day, recommendation

AHAM-to-field derate 0.65 (field-rated) unless user suppliesengineering practice