What size dehumidifier do I need? (sizing chart)
Short answer: For 500–2,000 sq ft rooms, aim roughly for 20–30 pints/day in slightly/moderately damp, 25–40 in very damp, and 30–50 in wet conditions (DOE 2019 test). That maps to today’s 22‑/35‑/50‑pint retail classes; on pre‑2019 AHAM labels those are roughly 30 / 60 / 70–90 pints per ENERGY STAR’s old→new correlation.
Sourced from ENERGY STAR capacity guidance and the DOE 2019/2020 test procedure (links below). For basements and crawl spaces, bias to the upper end or size up one class.
Dehumidifier sizing chart
| Square footage | Slightly–Moderately damp | Very damp | Wet |
|---|---|---|---|
| 500 sq ft | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) |
| 1,000 sq ft | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) |
| 1,500 sq ft | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) | 35‑pint ≈ 60 pints (AHAM pre‑2019; ENERGY STAR) |
| 2,000 sq ft | 22‑pint ≈ 30 pints (AHAM pre‑2019; ENERGY STAR) | 35‑pint ≈ 60 pints (AHAM pre‑2019; ENERGY STAR) | 35‑pint ≈ 60 pints (AHAM pre‑2019; ENERGY STAR) |
Cells show the current DOE 2019+ retail class first (tested at 65°F / 60% RH), then the rough old‑label AHAM 80°F equivalent for comparison.
Need room‑specific guidance? Open the hubs for detailed notes: 500 sq ft · 1,000 sq ft · 1,500 sq ft · 2,000 sq ft · Read AHAM vs DOE 2019 ratings.
Sources: ENERGY STAR Dehumidifiers — capacity guidance and testing & capacity changes; DOE dehumidifier test procedure (Appendix X1) final rule.
FAQ
Why do newer dehumidifiers have smaller pint ratings than older charts?
Since 2019, portable units are tested at 65°F (DOE 2019/2020), not 80°F (old AHAM). Cooler air holds less moisture, so the measured pints/day is lower. ENERGY STAR’s correlation shows an old 70‑pint ≈ 40–45 pints under the 2019 test, and old 90‑pint ≈ 55 pints. A current 50‑pint sits between those. See AHAM vs DOE 2019 ratings.
Should I size up for a basement or crawl space?
Often yes. Basements and crawls have persistent moisture through the envelope and often run cooler than 68°F. If borderline, step up one retail class (e.g., 35 → 50‑pint).
What if my home is over 2,000 sq ft?
Plan for multiple portable units or a ducted whole‑home dehumidifier sized to latent load or the manufacturer’s performance table at your design condition.