How the Dehumidifier Sizing Calculator works
Last data update: 2026-08-24.
Data
Sizing grid (pints/day under the 2019 DOE rating, by floor area × dampness) reproduced from an AHAM DH-1-2022-style chart via a third-party source, cross-checked against ENERGY STAR's published bands (moderately damp < 2,000 sq ft: 20–30; very damp: 25–40; wet: 30–50). Three of the four dampness descriptions are ENERGY STAR's (moderately damp, very damp, wet); "slightly damp" follows the AHAM chart.
area slightly moderately very wet
500 10 14 18 26
1000 14 20 26 36
1500 18 26 34 46
2000 22 30 42 52
2500 26 34 46 56
Formula
Bilinear interpolation on area between grid rows; below 500 sq ft the 500 row is scaled by area/500 with a floor of 10; above 2,500 sq ft, +4 pints per additional 500 sq ft (cap 70) with a two-unit suggestion. Retail mapping: ≤ 22 → 20/22 pint; ≤ 35 → 30/35; otherwise 50; pump suggested for basements/pump drain.
2019 rating change
DOE Appendix X1 (65 °F / 60 % RH) replaced Appendix X (80 °F / 60 % RH) for compliance from June 13, 2019 (background in 88 FR 48035). ENERGY STAR's conversion table: 30→20, 40→25, 50→30, 55→30–35, 60→35, 70→40–45, 90→55 (portable units).
Change log
- 2026-08-24 — first release.
Cite this page
GridComfort, "Dehumidifier Sizing Calculator — methodology," https://gridcomfort.com/tools/dehumidifier-sizing-calculator/methodology/, data updated 2026-08-24.