ENERGY STAR says whole-home dehumidifiers "are typically installed to use your home's air ducts to dehumidify one or more rooms and are often permanent." This guide uses "whole-house" and the federal term "whole-home" for the same equipment. It covers how the U.S. Department of Energy (DOE) defines these units, and the federal and ENERGY STAR efficiency levels. It also covers DOE's modeled cost and lifetime, advice on installation and sizing, and DOE climate regions for our five markets.
What a whole-house dehumidifier is
DOE's definition is in 10 CFR 430.2. It reads: "Whole-home dehumidifier means a dehumidifier that, in accordance with any manufacturer instructions available to a consumer, operates with ducting to deliver return process air to its inlet and to supply dehumidified process air from its outlet to one or more locations in the dehumidified space." We used the version in the Electronic Code of Federal Regulations (eCFR) as of October 1, 2026.
Pacific Northwest National Laboratory publishes DOE's Building America Solution Center (BASC). BASC has a whole-house dehumidification guide. It was last updated February 28, 2018, so it is more than five years old. It says, "Types of equipment for providing dehumidification to homes include stand-alone dehumidifiers, central fan-integrated dehumidifiers, and additional dehumidification controls for existing HVAC systems."
When a home may need whole-house dehumidification
The U.S. Environmental Protection Agency (EPA) has a mold guide. It says, "If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity." ENERGY STAR's dehumidifier page says the best level for a building "is generally considered to be between 30% and 50%." It adds that "anything above this range may promote mold growth." Our indoor humidity guide compares these targets with other federal sources.
ENERGY STAR says, "If you live in a humid climate and have central air conditioning, an ENERGY STAR certified whole-home dehumidifier may be the right choice for you." It says these systems "can be expensive, but they carry significant benefits..." ENERGY STAR says those benefits are "for relatively well sealed homes with central air systems that see humidity readings above 55% consistently throughout the house."
The 2018 BASC guide says, "In hot-humid climates, the air conditioner alone may not be able to remove enough latent heat to keep relative humidity below 60%." In those cases, BASC says the HVAC designer should consider two options. One is adding dehumidification controls, and the other is a separate dehumidifier. For an existing home, BASC says to add dehumidification "if indoor relative humidity levels exceed 60% and if moisture issues are apparent, such as mold, mildew, or occupant complaints of humidity..." It adds one more condition: that "no water leakage or water intrusion sources are found."
The BASC guide says oversizing a cooling system can cause short-cycling. It explains, "In homes with over-sized air conditioners, the thermostat quickly reaches the desired set point before moisture can condense on the coil and be removed from the home." It goes on, "In this situation, the temperature in the home drops but the relative humidity climbs." BASC tells designers to right-size the HVAC with Manual S. It also says, "Supplemental dehumidification is not intended to be used as a means for compensating for over-sized HVAC equipment or excessive building leakage rates."
Our guide to indoor humidity in Florida and whole-house dehumidifiers has Jacksonville weather data. It also shows how these sources apply to one hot-humid county.
Federal minimum efficiency and ENERGY STAR criteria
Federal rules and ENERGY STAR rate dehumidifier efficiency the same way. They use integrated energy factor (IEF), which is stated in liters per kilowatt-hour. For whole-home units, both set levels by the product's case volume in cubic feet. For portable units, the levels depend on the product's capacity in pints per day instead.
10 CFR 430.32(v) sets minimum IEF values for dehumidifiers "manufactured on or after June 13, 2019." For whole-home units, the minimum is 1.77 for a case volume of 8.0 cubic feet or less. It is 2.41 for more than 8.0 cubic feet. DOE set these levels in a final rule dated June 13, 2016. The rule applies to products "manufactured in, or imported into, the United States on and after June 13, 2019."
ENERGY STAR's current specification took effect October 1, 2025. Its key efficiency criteria call for at least 2.22 for a case volume of 8.0 cubic feet or less, and at least 3.81 above 8.0 cubic feet.
Minimum integrated energy factor for whole-home dehumidifiers: federal rule vs. ENERGY STAR
- Federal minimum, case volume 8.0 cubic feet or less1.77 L/kWh
- ENERGY STAR, case volume 8.0 cubic feet or less2.22 L/kWh
- Federal minimum, case volume over 8.0 cubic feet2.41 L/kWh
- ENERGY STAR, case volume over 8.0 cubic feet3.81 L/kWh
DOE's proposed changes to the dehumidifier standard
DOE published a proposed rule on November 6, 2023. It proposed whole-home minimums of 2.22 for a case volume of 8.0 cubic feet or less and 3.81 above 8.0 cubic feet. Those values match the numbers in ENERGY STAR's current criteria. We compared the two documents ourselves. DOE does not make that statement.
DOE published another proposed rule on May 16, 2025. Its title is "Rescinding in Part the Amended Energy Conservation Standards for Dehumidifiers." In it, DOE wrote, "The standard for whole-home dehumidifiers is required by 42 U.S.C. 6295(q)." The proposed rule text in that notice keeps the whole-home minimums at 1.77 and 2.41.
We searched the Federal Register for DOE documents on dehumidifiers. As of October 2026, we found no final rule after either proposal. The eCFR text as of October 1, 2026 still lists 1.77 and 2.41 for whole-home units.
| Date | What happened |
|---|---|
| June 13, 2016 | DOE publishes the final rule behind the standards now in 10 CFR 430.32(v) |
| June 13, 2019 | Those standards apply to dehumidifiers manufactured in, or imported into, the United States on and after this date |
| November 6, 2023 | DOE proposes whole-home minimums of 2.22 and 3.81 liters per kilowatt-hour (proposal) |
| May 16, 2025 | DOE proposes rescinding the dehumidifier standards in part, and its proposed text keeps whole-home minimums at 1.77 and 2.41 (proposal) |
| October 1, 2025 | ENERGY STAR's current specification, with whole-home criteria of 2.22 and 3.81, takes effect |
| October 2026 | Our Federal Register search finds no final rule after either proposal |
From DOE rules and proposals in the Federal Register, the eCFR and ENERGY STAR.
What DOE's model says about cost and lifetime
DOE's November 2023 proposed rule includes a life-cycle cost model. The model gives an average installed cost for a baseline whole-home dehumidifier. For a case volume of 8.0 cubic feet or less, at IEF 1.77, it was $2,733. For more than 8.0 cubic feet, at IEF 2.41, it was $2,734. Both figures are in 2022 dollars.
These are DOE model averages from a proposed rule, not 2026 prices. DOE says it used "data from RSMeans' 2022 Residential Cost Data to estimate installation costs for baseline and more efficient units." We found no government or utility source with a 2026 installed price.
DOE's lifetime estimates differ by document. Its 2016 final rule estimated an average lifetime of 19 years for whole-home dehumidifiers. Its 2023 proposed rule estimated 12 years. We report both and do not combine them.
| DOE figure | Value | Document |
|---|---|---|
| Average installed cost, baseline unit, case volume 8.0 cubic feet or less (IEF 1.77) | $2,733 in 2022 dollars | November 2023 proposed rule, Table V.8 |
| Average installed cost, baseline unit, case volume over 8.0 cubic feet (IEF 2.41) | $2,734 in 2022 dollars | November 2023 proposed rule, Table V.10 |
| Average lifetime, whole-home dehumidifiers | 19 years | June 2016 final rule |
| Average lifetime, whole-home dehumidifiers | 12 years | November 2023 proposed rule |
DOE model figures. They are not market prices or guaranteed lifetimes.
Installation types and drainage
The 2018 BASC guide describes two kinds of ducted dehumidifier. One kind is independent, and the other is integrated with the central system. It compares adding controls to the existing system with installing "a central or stand-alone dehumidifier."
| Approach | What BASC says |
|---|---|
| Dehumidification controls added to the existing HVAC system | "Generally less expensive than installing a central or stand-alone dehumidifier," and "best suited to climates with shorter shoulder seasons" |
| Independent ducted dehumidifier | "Ducted separately from the home's heating and cooling equipment"; can be installed in an attic, basement, crawl space, mechanical room or closet; "ideal for homes with ductless HVAC systems" |
| Integrated ducted dehumidifier | Sends dehumidified air "to either the supply side or return side of the central air handler"; warms the supply air slightly, so the air conditioner runs "a little bit longer" during cooling periods |
From DOE's Building America Solution Center, last updated February 28, 2018.
BASC says the controls option is best where shoulder seasons are shorter "because of the potential for comfort issues while running the air conditioner in cooler weather." BASC describes stand-alone dehumidifiers as portable appliances. It says a stand-alone unit "may be a more costly upfront investment." But BASC says stand-alone dehumidifiers "generally use less energy and thus cost less to operate" than central air handlers. It adds that they "also operate with less risk of comfort issues in the home." For integrated units, BASC says, "Because this system warms the supply air slightly, during cooling periods this will force the air conditioner to run a little bit longer, which will dehumidify the air even more."
ENERGY STAR says, "Most whole-home dehumidifiers are only equipped with a drain, which should be routed to a floor drain or condensate pump during installation by an HVAC professional." For air conditioners, EPA says to "keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly." We did not check plumbing or mechanical code rules for condensate disposal.
ENERGY STAR also says, "ENERGY STAR home sealing and duct sealing will improve the performance and decrease the energy use of your whole-home dehumidifier." BASC says to "avoid exhaust-only ventilation as it tends to depressurize a house," which it says "may increase infiltration of outdoor air and indoor humidity." Our guide to home ventilators explains how each type handles humidity.
How to size a whole-house dehumidifier
The BASC guide also gives a more detailed way to size a unit. It credits this method to an outside source. The method starts with a Manual J load calculation. It says, "After doing the Manual J, take latent load from the Manual J calculation (for example 3,868 Btu) and divide it by 1,054 Btu (which equals about 1 pint of water)." It adds, "This will give you pints per hour."
The method adds, "You want to size the dehumidifier so that when it reaches design conditions it will turn off rather than running constantly, so it must be sized for larger than 75-pint capacity." The 75-pint figure comes from the guide's worked example, not a general rule.
BASC also gives example control set points. In its example, enhanced dehumidification starts at 55% relative humidity. A supplemental dehumidifier starts at 60%. BASC marks both as examples ("e.g.").
Climate regions in our five markets
The BASC guide says its warm-humid region "includes all of climate zone 1, all of climate zone 2A, and portions of climate zone 3A." A DOE county guide from August 2015 lists a climate region and climate zone for each county. The county guide is more than ten years old and uses county assignments from that time. We did not check newer code editions.
| Market | County in the 2015 guide | Building America climate region | Climate zone |
|---|---|---|---|
| Austin | Travis County, TX | Hot-Humid | 2A |
| Jacksonville | Duval County, FL | Hot-Humid | 2A |
| Phoenix | Maricopa County, AZ | Hot-Dry | 2B |
| Seattle-Tacoma | King County and Pierce County, WA | Marine | 4C |
| Columbus | Franklin County, OH | Cold | 5A |
From DOE's Building America Guide to Determining Climate Regions by County (August 2015), a dated source.
Under the 2015 assignments, Travis and Duval counties are in zone 2A. BASC's warm-humid region includes all of zone 2A. Maricopa (2B), King and Pierce (4C) and Franklin (5A) counties are in zones that BASC does not list for that region. In the federal sources for this guide, we found no recommendation of whole-home dehumidification specific to Phoenix, Seattle-Tacoma or Columbus. We did not check dew-point normals for those cities.
Utility rebates for whole-house dehumidifiers
We searched rebate pages from utilities in our five markets for dehumidifier rebates. As of October 2026, we found none. We checked pages from Salt River Project (SRP), Seattle City Light, Puget Sound Energy and Tacoma Power. We also checked Austin Energy, JEA, AEP Ohio and Columbia Gas of Ohio. We did not check Arizona Public Service (APS). Its rebate pages returned errors when we tried to load them. Programs change, so confirm with your utility.
We also have guides to other HVAC rebates in these markets. See JEA rebates, Austin Energy rebates and AEP Ohio and Columbia Gas of Ohio rebates. For the Seattle-Tacoma area, see heat pump rebates from Puget Sound Energy, Seattle City Light and Tacoma Power.