Dehumidifier Sizing

Formula and source

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.

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