Dehumidifier Energy Factor: What It Means

What is the integrated energy factor?

The integrated energy factor, or IEF, is a number that describes how efficiently a dehumidifier removes moisture. According to the ENERGY STAR program, it is measured in liters of water removed per kilowatt-hour (kWh) of energy consumed, written as L/kWh. In general, a higher integrated energy factor means a more efficient dehumidifier.

This rating is set by the U.S. Department of Energy (DOE). The DOE defines the test procedure that determines a dehumidifier's capacity and its energy efficiency metric. The IEF replaced an older metric called the Energy Factor (EF). Unlike EF, the IEF includes the energy the dehumidifier uses when it has cycled off, so it gives a fuller picture of annual energy use.

When you see an IEF figure on a listing or a maker's page, it is a label from the manufacturer based on the DOE test. It is not a promise about how much your energy bill will change or how quickly the unit will dry a space. It is a comparison tool for shopping. For more on how to compare models, see the best dehumidifier guide.

How the IEF helps you compare models

When you compare two dehumidifiers with the same stated capacity, the one with the higher IEF uses less energy to remove the same amount of water. That makes it a more efficient choice in general terms. The IEF is especially useful when you are deciding between two models that otherwise look similar.

The ENERGY STAR program uses the IEF as part of its certification. A dehumidifier that earns the ENERGY STAR label uses more efficient refrigeration coils, compressors, and fans to remove the same amount of moisture as a similarly sized conventional unit but uses 20% less energy. That percentage is a program statement, not a guarantee for your home.

You can check whether a model is ENERGY STAR certified by looking for the mark on the listing or by searching the ENERGY STAR product finder. The product finder lists certified models and their stated details, including the IEF. For a list of certified picks, see the best Energy Star dehumidifier guide.

Reading the IEF on a listing

Not every listing prints the IEF. Some titles and bullet lists focus on capacity, drain options, and features. If the IEF is not stated, you can look for it on the maker's page for that model. The DOE test procedure is public, and makers often publish the IEF in the specification sheet.

When a listing does state the IEF, it appears as a number with the unit L/kWh. For example, a listing might say "IEF: 1.85 L/kWh." That number is the result of the DOE test at specific conditions, not a measurement from this site.

The IEF is separate from the capacity rating, which is the pints per day figure. Capacity tells you how much water the unit can remove in 24 hours under the test conditions. The IEF tells you how efficiently it does that. Both numbers come from the same DOE test procedure, but they answer different shopping questions. To understand capacity, read the capacity versus square footage article.

What the IEF does not tell you

The IEF does not tell you how fast a dehumidifier will dry a room, what humidity level it will reach, or how much it will cost to run. Those outcomes depend on the space, the conditions, and how the unit is used. This site does not have measured data for those things, so the guides compare listings on stated details only.

The IEF also does not tell you about noise, durability, or build quality. A more efficient unit is not automatically quieter or longer lasting. Those are separate questions you would need to check on the maker's page or in the manual. For noise considerations, see the noise levels explained article.

If you are comparing two models, use the IEF as one factor among several. Capacity, drain options, and features like a pump or continuous drain may matter more for your situation. The IEF helps you choose between models that are otherwise similar.

Energy Star and the IEF

The ENERGY STAR program is a voluntary certification run by the U.S. Environmental Protection Agency. A dehumidifier that earns the ENERGY STAR label meets the program's efficiency criteria, which are based on the IEF. The program states that certified models use 20% less energy than conventional models of the same size.

If a listing says "ENERGY STAR," it means the model has been certified under the program. You can verify this on the ENERGY STAR product finder. If a listing does not say ENERGY STAR, the model may still be efficient, but it has not been certified.

The ENERGY STAR page for dehumidifiers also explains that certified models are available for both portable and whole-home units. Portable units are meant for a single room or space, while whole-home units are installed and often use the home's air ducts. The IEF applies to both categories, but the DOE sets separate minimum efficiencies for each. For whole-home options, see the best whole house dehumidifier guide.

What to pick for your situation

When you shop, start with the capacity you need, then look at the IEF to compare efficiency. If two models have the same stated capacity and similar features, the one with the higher IEF is the more efficient choice. If a listing does not state the IEF, check the maker's page or the ENERGY STAR product finder.

For a basement or large space, capacity and drain options often matter more than a small difference in IEF. For a bedroom or small room, a smaller unit with a good IEF may be enough. The guides on this site compare models on stated details, including capacity, drain, and features, so you can see which units fit your space. For basement sizing, see the basement sizing article.

Remember that the IEF is a label, not a promise. It describes efficiency under the DOE test conditions. Your actual energy use will depend on how often the unit runs and the conditions in your home.

What to pick for your situation

Questions

What does IEF stand for?

IEF stands for integrated energy factor. It is the energy efficiency metric for dehumidifiers, measured in liters of water removed per kilowatt-hour of energy consumed (L/kWh).

Is a higher IEF always better?

In general, a higher IEF means a more efficient dehumidifier. But it is only one factor. Capacity, drain options, and features may matter more for your specific space.

Where can I find the IEF for a dehumidifier?

The IEF may be printed on the listing or on the maker's specification page. You can also check the ENERGY STAR product finder for certified models.

Does the IEF tell me how much my energy bill will change?

No. The IEF describes efficiency under test conditions. Actual energy use depends on how often the unit runs and the conditions in your home.

What is the difference between IEF and capacity?

Capacity is the pints per day rating, which tells you how much water the unit can remove in 24 hours under test conditions. IEF tells you how efficiently it does that, in liters per kilowatt-hour.