The short answer
A desiccant dehumidifier dries air with a moisture-holding material instead of a cold coil. Federal efficiency rules don’t cover it, so no public test gives its capacity or its energy use.
Ask the seller for both, with the conditions they were measured in. For a small or cold room, certified units come with figures you can compare.
- Not covered by federal efficiency rules, the DOE says.
- No capacity or energy figure from a public test.
- Capacity and power: ask the seller, with the test conditions.
On this page7 parts
What it is
Most dehumidifiers chill the air on a coil so that water condenses. A desiccant model uses a material that holds moisture instead, the way the silica gel packet in a shoebox does. There is no refrigerant circuit and no compressor.
That difference decides what you can know before you buy. Every public figure on this site comes from a test that only covers the refrigerant kind.
Outside the federal rules
Federal law defines a dehumidifier by its parts, and a refrigerating system is one of them. The Department of Energy rewrote its test in 2015 and settled the question in one line:
DOE agrees that desiccant-only products do not meet the EPCA definition and are therefore not considered a covered product.
So no DOE capacity test applies, no minimum efficiency, and no certification. None of the 482 models on the EPA list is a desiccant unit, and none of the DOE database entries we hold names one. A capacity printed on the box follows the maker’s own method, which may not match the DOE test at 65°F.
The hybrid kind
One mix is covered. The federal rules define a refrigerant-desiccant dehumidifier: a whole-house unit that adds a desiccant to a refrigeration system. The DOE tests it with its own setup, because part of the moisture leaves as vapor, vented outside, instead of dripping into a drain.
That kind is installed on ducts, like other whole-house units. It isn’t the small portable sold as “desiccant”.
Why people look at them
Mostly for cold spaces. A refrigerant unit struggles there, and ENERGY STAR® says why:
Frost can form on the condensing coils if the air temperature drops below 65 degrees, and may negatively affect the performance.
A desiccant unit has no coil to frost. Sellers state their own figures for the water it removes and the power it uses. Without a shared method, we can’t compare them with certified models, and we don’t rank them.
What to ask the seller
Four questions. The first matters most: a figure without its conditions can’t be compared.
0 of 4 asked
Certified alternatives
If the space is small, a certified unit comes with figures from the DOE test.
a year for a 20–25 pint certified portable, at the median: about $52 in the United States
EPAEPA list of Oct 15, 2026 · EIA prices
The small-room guide lists them. If the space is cold, see the low-temperature guide: it says what the data covers in cold rooms, and what to ask before you buy.
Sources
Every figure and quote on this page comes from these, each with the date we read it.
U.S. EPA, list of certified dehumidifiers (opens in a new tab)
Updated Oct 15, 2026U.S. Department of Energy, Compliance Certification Database (opens in a new tab)
Export of Oct 5, 2026Written by Julien Fourel
We don’t test dehumidifiers: this page puts official sources side by side and says where they stop. Updated Oct 16, 2026.