How we calculate
The rule, the cost, the limits
- The size comes from the EPA’s tableENERGY STAR gives a range of pints a day for three levels of dampness and two room sizes, under or over 2,000 sq ft. We show that range, unchanged.20–30 pints, damp, under 2,000 sq ftENERGY STAR · read Oct 5, 2026
- The cost uses the models you can buyWe take the portable models on the EPA list in your range and their median yearly energy. Then we apply the average home electricity price of the state you pick, or the U.S. average until you pick one.285 kWh × 18.31¢ a kWh = $52EPA · EIA
- A rule of thumb, not a diagnosisFix leaks and flooding first: a dehumidifier dries air, not a wet floor. A very large or open space may need a whole-house unit.21 whole-house units certified
The EPA’s sizing table
pints a day| Dampness | Under 2,000 sq ft | Over 2,000 sq ft |
|---|---|---|
| Damp50–75% relative humidity | 20–30 | 30+ |
| Very damp75–90% | 25–40 | 40+ |
| Wet90–100%, or laundry drying | 30–50 | 50+ |
Running cost
What each size costs to run in the United States
Median and range of the EPA yearly energy estimate, at the average home electricity price there.
Up to 25 pints
$52 a year
From $19 to $57 · median 282 kWh
215 models26 to 40 pints
$68 a year
From $52 to $71 · median 374 kWh
87 models41 to 52 pints
$95 a year
From $79 to $97 · median 519 kWh
159 modelsOver 52 pints, whole-house
Compare by IEF
The EPA yearly figures of whole-house units don’t line up: compare efficiency instead
21 models
Questions
Sizing questions
Short answers, with where they come from.
Is a bigger dehumidifier better?
The EPA says it’s better to oversize than undersize. A bigger unit does cost more to run. In the 30–50 pint range, the median certified portable uses 507 kWh a year. In the 20–30 range, it’s 285 kWh. Our 35 vs 50 pint comparison puts the two sizes side by side.
ENERGY STAR buying guidance, read Oct 5, 2026 · EPA list, Oct 15, 2026Why do older guides give bigger numbers?
Since 2019, the Department of Energy rates dehumidifiers at 65°F instead of 80°F, where they pull out less water. The EPA’s own example: a unit sold as 70 pints under the old test rates about 40–45 pints today. A chart written for older ratings overstates the pints you need.
ENERGY STAR, Dehumidifier testing and capacity, read Oct 5, 2026What humidity should the space reach?
The EPA recommends 30 to 50% indoor humidity, and below 60%. Set the unit’s target there and let it cycle.
U.S. EPA, A Brief Guide to Mold, Moisture, and Your HomeI have no floor drain. What then?
Empty the bucket by hand, or pick a model with a built-in pump. The pump pushes the water up to a sink or out a window. The pump lift isn’t always published, so check it before you buy.
How we compare