Energy Factor: What Is a Good Number?

What is the energy factor on a dehumidifier?

The energy factor is a rating that appears on dehumidifier listings and spec sheets. It tells you how much moisture the unit removes for each unit of electricity it uses. The unit of measure is liters per kilowatt-hour, written as L/kWh. A higher energy factor means the dehumidifier removes more water for the same amount of electricity, so it is a more efficient model.

The U.S. Department of Energy (DOE) sets the test procedure for this rating. Since June 2019, the official metric is the Integrated Energy Factor (IEF). Unlike the older Energy Factor (EF), the IEF also includes the electricity the dehumidifier uses when it cycles off, not just when the compressor is running. This gives a more complete picture of how the unit behaves in real use.

When you see a number like "1.8 L/kWh" on a listing, that is the IEF. The exact number depends on the test conditions, which the DOE sets at 65°F for portable units to reflect a typical basement. The number is a label, not a promise of how the unit will perform in your home.

For more on how the DOE defines and tests this rating, see the Department of Energy page on consumer dehumidifiers.

• Energy factor is measured in liters per kilowatt-hour (L/kWh).
• A higher number means more moisture removed per unit of electricity.
• The current metric is the Integrated Energy Factor (IEF), in use since 2019.

What is a good energy factor number?

There is no single "good" number that applies to every dehumidifier, because the energy factor varies with the unit's capacity and type. The DOE sets minimum efficiency standards for different capacity groups, but those standards are legal minimums, not shopping benchmarks. A unit that meets the standard is not necessarily a good choice for your situation.

Instead of looking for a specific number, compare the IEF values of the models you are considering. If two units have the same capacity, the one with the higher IEF will use less electricity to remove the same amount of moisture. This is a relative comparison, not an absolute promise.

The ENERGY STAR program certifies dehumidifiers that meet its efficiency criteria. The ENERGY STAR page explains that certified models use more efficient coils, compressors, and fans to remove the same amount of moisture as a conventional unit while using less energy. If a listing shows the ENERGY STAR mark, that is a separate signal of efficiency, but the mark is not the same as the IEF number.

For a deeper look at how the ENERGY STAR mark relates to the energy factor, see Energy Factor vs. Energy Star Rating.

• Compare IEF values only between units of similar capacity.
• A higher IEF within the same capacity group means better efficiency.
• The ENERGY STAR mark is a separate certification, not a number.

How to find the energy factor on a listing

The energy factor is not always printed in the title of a dehumidifier listing. Titles usually focus on capacity (pints per day), type (compressor, desiccant, LGR), and features like a pump or drain hose. The IEF value, when stated, appears in the bullet list, the spec table, or the maker's product page.

If the listing does not show an IEF value, that is a missing detail. You can check the maker's official page for the model, where the spec sheet should list the IEF in L/kWh. If the maker does not state it, you cannot assume a value.

When you find the number, write it down next to the capacity and the price tier. That way you can compare apples to apples. A unit with a higher IEF may cost more upfront, but the energy factor is only one part of the shopping decision.

For a checklist of what to look for in a listing, see How to Read a Dehumidifier Title.

• Look for the IEF in the spec table, not the title.
• Check the maker's page if the listing omits it.
• Record the IEF alongside capacity and features for comparison.

Energy factor vs. capacity: what's the difference?

Capacity and energy factor are two different numbers on a listing. Capacity is the amount of moisture the unit can remove in 24 hours, measured in pints per day. The energy factor is how efficiently it does that, measured in liters per kilowatt-hour. A unit can have a high capacity and a low energy factor, or the reverse.

When you compare two units, do not mix the two. A 70-pint unit with a higher IEF than a 50-pint unit is not necessarily more efficient overall, because it moves more air and uses more electricity. The IEF is only meaningful when compared within the same capacity group.

The DOE's test procedure sets the capacity at specific conditions, and the IEF is calculated from that test. The ENERGY STAR page on testing and capacity explains how the test conditions changed in 2020, which is why some older models show different capacity numbers.

For more on how capacity groups work, see Pints Per Day: What the Number Means.

• Capacity is pints per day; energy factor is L/kWh.
• Compare IEF only within the same capacity group.
• A higher capacity unit may use more electricity even with a good IEF.

Why this site does not give a benchmark number

This site reviews dehumidifiers based on the details stated in their listings, not on measured performance. The energy factor is a label that the maker or the DOE test provides, and this site does not have its own laboratory data. Giving a specific "good" number would imply a measurement this site cannot verify.

Instead, the reviews explain what the energy factor means and tell you to read the number on the listing or the maker's page. The site also points you to the ENERGY STAR and DOE pages, which are the authoritative sources for how the rating is defined and tested.

When you read a review on this site, you will see the IEF value if the listing states it. If the listing does not state it, the review will say "not stated by the seller." That is a signal to check the maker's page before you buy.

For more on how this site reviews units, see Best Dehumidifier Reviews.

• The site reviews stated details, not measured performance.
• The IEF value appears only if the listing states it.
• Check the maker's page for the number if the listing omits it.

What to pick for your situation

When you shop for a dehumidifier, use the energy factor as one of several comparison points. Start with the capacity you need for your space, then look at the IEF to choose between similar models. A higher IEF is generally better, but it is not the only factor.

For a basement, a unit with a pump and a good IEF may be worth the extra cost. For a small room, a lower-capacity unit with a decent IEF may be enough. The table below matches common situations to the guides on this site.

Remember that the energy factor is a label, not a promise of your electricity bill. The actual energy use depends on how often the unit runs, the temperature, and the humidity level in your space. The DOE and ENERGY STAR pages explain the test conditions, but your home will differ.

For more on how energy use is estimated, see Annual Energy Use: What the Listing Means.

What to pick for your situation

Questions

What does the energy factor number mean on a dehumidifier?

It measures how much moisture the unit removes per unit of electricity, in liters per kilowatt-hour (L/kWh). A higher number means more efficient operation.

Is a higher energy factor always better?

Within the same capacity group, yes. A higher IEF means the unit removes more moisture for the same electricity. But you should compare only units of similar capacity.

Where can I find the energy factor on a listing?

It is usually in the spec table or bullet list, not the title. If the listing omits it, check the maker's official product page.

Does the ENERGY STAR mark mean a good energy factor?

The ENERGY STAR mark is a separate certification that indicates the unit meets efficiency criteria set by the program. It is not the same as the IEF number, but certified models are generally more efficient.

Why do some listings show two different capacity numbers?

The DOE changed the test procedure in 2020, so older models may show a higher capacity under the old test. The IEF is calculated under the new test conditions.