Efficiency
How to Read ENERGY STAR and IEF Ratings for Dehumidifiers
ENERGY STAR status and IEF are efficiency signals. Compare them within the same category and test basis, alongside capacity—not instead of it.
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Two different efficiency signals
ENERGY STAR certification means a dehumidifier meets the applicable program requirements. It is not itself a pint rating, an IEF value, or a predicted electricity bill.
Integrated Energy Factor measures efficiency as liters of moisture removed per kilowatt-hour. It accounts for energy used during dehumidification and applicable standby or off modes over representative operating periods. A higher IEF indicates more moisture removal for each unit of energy under that method.
What each figure answers
| Signal | What it tells you | What it does not tell you |
|---|---|---|
| ENERGY STAR status | The model meets the program’s efficiency criteria | How many pints it will collect in your room |
| IEF (L/kWh) | Moisture removed relative to energy use under the rating method | Whether capacity is enough for the moisture load |
| Capacity (pints/day) | Rated moisture removal under specified test conditions | Which unit uses less electricity in every installation |
Compare IEF only inside the right band
Portable and whole-home dehumidifiers have separate efficiency requirements. Do not compare their IEF figures as if they shared one scale.
For ENERGY STAR-certified portable units, the applicable minimum IEF under the stated test conditions is 1.70 L/kWh for units rated at 25.00 pints per day or less, 2.01 L/kWh from 25.01 to 50 pints per day, and 3.30 L/kWh for units rated at least 50 pints per day.
Whole-home units use product case volume instead of the portable pint band. Case volume is the rectangular volume of the product case, excluding duct collars and other external parts. The applicable minimum is 2.22 L/kWh at 8.0 cubic feet or less and 3.81 L/kWh above 8.0 cubic feet. ENERGY STAR Version 6.0 requirements took effect October 1, 2025.
Read IEF next to capacity, not instead of it
An efficient unit that cannot keep up with the moisture load is still the wrong machine. Capacity—water removed in 24 hours under specified conditions—belongs in DOE pint ratings explained. Pint-class choices such as 35 versus 50 live in the capacity-class guides.
DOE began using IEF for new dehumidifier ratings in June 2019, replacing EF. IEF includes energy used while the unit is cycled off, so an older EF number and a newer IEF number are not a like-for-like comparison. If a listing still shows EF, do not rank it against IEF.
When two current listings both show IEF, confirm category, band, and test conditions, then use IEF to compare efficiency. Installation, drainage, and whether the capacity fits the job still decide the purchase.
Sources
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Related guides
Dehumidifier Capacity Classes
Read pint classes against moisture load, on the same rating basis.
DOE Pint Ratings Explained
What a pint rating measures, and when two numbers are not on the same scale.
How to Choose a Dehumidifier
Match capacity, drain path, and upkeep to the job — not a square-footage claim.