Every dehumidifier gets a score from 0 to 100% built from six factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Dehumidifiers are ranked within their size: small (under 25 pints a day), medium (25 to 40), large (40 and up) and whole-home.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per pint of daily capacity | 30% |
| Efficiency | water removed per kWh | 25% |
| Quiet | rated sound level | 15% |
| Drainage | built-in pump or drain hose | 15% |
| Warranty | warranty length | 10% |
| Smart | app control | 5% |
Where the numbers come from
Capacity and efficiency are the ratings each maker certifies to the Department of Energy, taken from the DOE certification database or the ENERGY STAR certified dehumidifier list. Where the two disagree, the DOE figure is used and the product page notes it. Noise, drainage, warranty and features come from the maker’s spec sheet, manual or warranty terms.
2019 pints and 2012 pints
In 2019 the DOE moved its portable test from 80 °F to 65 °F air, closer to a real basement. Cooler air holds less water, so the same machine now rates about 30% lower: a unit once sold as “70 pint” is a 50-pint unit today. Some listings still quote the old figure, or a “saturation” figure at 90 °F and 90% humidity that’s higher still. Every capacity here is the current 2019 rating, and the older marketing figure is shown on the product page where the maker gives one.
Whole-home test conditions
Whole-home units are normally certified at 73 °F, warmer than the portable test, which gives a higher figure for the same machine. A few crawlspace units here are certified as portable units at 65 °F instead. Their capacity and efficiency look lower than they would under the whole-home test, so the comparison within the whole-home size slightly favors the units rated at 73 °F. Each product page says which test applies.
The factors
Value is the price divided by the 2019 pint rating: dollars per pint of water removed a day. Smaller units always cost more per pint, so each size has its own scale:
| Size | Scores 0 | Full marks |
|---|---|---|
| Small | $20 per pint | $6 per pint |
| Medium | $10 per pint | $4 per pint |
| Large | $8 per pint | $3.50 per pint |
| Whole-home | $40 per pint | $12 per pint |
Whole-home prices are for the unit alone; installation isn’t included.
Efficiency is the integrated energy factor (IEF), liters of water removed per kWh, including standby power. The DOE minimum for each size scores zero:
| Size | Scores 0 | Full marks |
|---|---|---|
| Small | 1.30 L/kWh | 2.00 L/kWh |
| Medium and large | 1.60 L/kWh | 2.40 L/kWh |
| Whole-home | 1.77 L/kWh | 3.50 L/kWh |
A dehumidifier that runs all summer can use several hundred kWh, so a more efficient one saves real money over its life.
Quiet is the maker’s rated sound level: 56 dB(A) scores zero and 42 dB(A) full marks. Makers measure at different distances and fan speeds, so it’s a guide rather than a true comparison.
Drainage: a built-in pump scores full marks, because it pushes water up to a sink or out a window and the bucket never needs emptying. A hose outlet that drains downhill to a floor drain scores half. Bucket only scores zero.
Warranty: 1 year scores zero and 3 years or more full marks. Longer sealed-system cover is shown on the product page.
Smart: Wi-Fi and an app, for alerts when the bucket is full and to check humidity remotely, score full marks. It carries a small weight.
What isn’t scored
Coverage claims in square feet aren’t scored: there is no standard test behind them. Weight, tank size, wheels, minimum operating temperature and auto-defrost are listed on each product page. Independent tests are listed where they exist, but there are too few to score.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated.
Ties and discontinued models
Products are ranked by score within each size. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.