Choosing the Best Humidifier

When outdoor temperatures plummet, moisture and humidity inside your home can quickly drop from pleasant to parched. Replacing moisture via cool or warm mist humidifiers can relieve a host of physical discomforts, from chapped skin to allergy irritations to cold- and flu-related symptoms.

But excessive moisture isn’t good, either: Overhumidification can promote growth of mold, bacteria, and dust mites. You want to get the balance right. Follow this guide to find a humidifier that will have you breathing easier in no time.

How We Test Humidifiers

In Consumer Reports’ humidifier lab, we evaluate humidifiers for six criteria: moisture output, convenience, noise, efficiency, humidistat sensitivity, and hard water.

Using an environmental chamber to control test conditions, we measure the claimed moisture output—the number of gallons emitted daily per square foot. We also gauge how easy a model is to set up and operate, as well as how easy it is to clean. For our noise test, we measure the sound (in decibels) generated when the units are running on their highest speed to see how quietly they operate. That’s important because you’re likely to run a humidifier in the same room you’re in, such as your bedroom.

Because humidifiers run for long periods of time, we evaluate their efficiency by calculating how much energy it requires for the unit to emit a gallon of water into the air. You may want to avoid models that do poorly on this test because they’ll be more expensive to run. Our humidistat sensitivity test measures how accurate the target humidity setting is on the humidifier. This is important for comfort and efficiency.

Finally, we test each unit’s moisture output when operated with hard water. We conduct this test because hard water can have a noticeable impact on performance. (Keep in mind: Hard-water performance does not apply for every consumer, just in places where the water supply contains significant amounts of dissolved minerals.) All these test results are compiled into an Overall Score for each model in our ratings. 

Know the Types

Humidifiers come in two general types: warm mist and cool mist. The process they use differs, but both add moisture to the air. Choosing between them is largely a matter of personal preference. The prices for both types range from $45 to $170.

Make sure the model you choose is easy to clean. As we discovered in our clean-air tests, humidifiers can harbor bacteria if not cleaned regularly. Get the full story in “Why You Should Clean Your Humidifier.”

Note: There is a third type of whole-house humidifier. In-duct or furnace humidifiers are the ideal choice if you have a forced-air heating system and want to humidify the entire house. They are tapped into the air ducts and plumbed into your home’s water supply, so they usually require professional installation. (We do not test that type.)

A warm mist humidifier.

Warm Mist

Warm mist humidifiers heat water to a boil, then emit the resulting steam. Some warm mist humidifiers include mineral filters that trap water deposits. These filters are not pricey to replace, but they do need changing, so factor that maintenance cost into the equation. Because of the risk of burns, some pediatricians caution against using warm mist units near children. 

A cool mist humidifier.

Cool Mist

There are three kinds of cool mist humidifiers: evaporative, ultrasonic, and impeller. Evaporative models use a fan to blow air over a wet wick. The cost for a spare wick is around $10, depending on the model. Ultrasonic humidifiers use a vibrating nebulizer to emit water, and they usually operate quietly as a result. Impeller models produce mist using a rotating disk.

Choose by Room Size

Ideally, indoor humidity should be 30 to 50 percent. But without a humidifier, that level can drop to 10 percent in winter. Cold air holds less moisture and dries out even more when heated by furnaces or wood fires.

To determine the humidifier size you need, measure the square footage of the room. Based on the size you need, you can shop an array of humidifier styles. Making the right choice involves trade-offs in efficiency, noise, and convenience.

We organize our humidifier ratings by size, grouping them into five categories. You’ll find travel/personal humidifiers for spaces up to 25 square feet, small-room humidifiers for rooms from 25 to 299 square feet, medium-room humidifiers for rooms from 300 to 499 square feet, large-room humidifiers for rooms from 500 to 999 square feet, and console humidifiers for rooms from 1,000 square feet and beyond.

For small and medium rooms, tabletop and portable humidifiers are the least expensive, but their small tanks require frequent refills. Make sure your faucet height will accommodate the refill tank.

For large spaces, especially near sleeping areas, consider buying a quiet ultrasonic console model. Alternatively, buy an evaporative model but place it away from sleeping areas, because evaporative models are considerably louder than ultrasonic models. Evaporative and ultrasonic both will generate lots of moist air. Another advantage to console models is that their larger water tanks need fewer refills, but because of their size and weight when filled, they can be awkward to maneuver.

Interactive Video Guide

Watch our interactive video below for more details about humidifiers. You can skip to chapters on room size, maintenance tips, key features, and more.

Consider These Features

Humidifiers don’t have to look humdrum. There are lots of models designed with décor in mind. Just remember, form should follow function. When you’re shopping, stay focused on models that best suit your room dimensions and space requirements.

Ease of Cleaning
The key to maintaining a properly functioning humidifier is simple: Keep it clean. So you want one that’s easy to maintain. Drain, rinse, and dry it every day. Every week, remove any visible residue with vinegar, disinfect with a bleach solution following the manufacturer’s instructions, and rinse thoroughly. Do the same before and after storing your humidifier for the season. Regular, frequent cleaning is a must to ensure that the moisture the humidifier generates is safe to breathe.

Ease of Use
A tabletop or console humidifier should be easy to move and clean. The tank should fit easily beneath your bathroom faucet. With evaporative models, the wick should be easy—and economical—to replace. Look for user-friendly controls and clearly visible displays of humidity level and settings.

Some humidifiers have a humidistat that shuts the unit off when it reaches a preset humidity level. Models without a humidistat can raise the humidity so much that it causes condensation on windows. If your model doesn’t have one, consider purchasing a separate hygrometer to monitor humidity levels.

You can program some tabletop and console models to turn on at a set time so that your room is at the right humidity when you get home. But this convenience might pose a problem: Water that sits in the tank for hours can breed microbes if you don’t dry the humidifier thoroughly between uses.

A humidifier timer.
Humidistat and timer.

Humidifier Brands

Crane has brought an element of design to humidifiers. Offered in a rainbow of colors and playful shapes, they can be found at baby, home goods, and mass-market retailers. Prices range from $30 to $100.
Essick specializes in whole-house or console humidifiers. Most are made in the U.S. and are the evaporative type. Styles include credenza, pedestal, and more utilitarian-looking humidifiers. Prices for the consoles range from $100 to $200.
The Holmes brand is part of Jarden Consumer Solutions. Products are available at a wide variety of retailers, including Kmart, Target, and Walmart, and through Holmes’ website. Prices range from $25 to $120.
Honeywell is part of the Helen of Troy group. Humidifiers are available in a wide variety of mass-market and home-center stores. Honeywell offers whole-house and tabletop models. Prices range from $30 to $120.
Hunter is a brand often associated with fans. Hunter also offers a line of utilitarian humidifier models that are available nationwide at home centers and hardware retailers. Prices range from $30 to $80.
Vicks is part of the Helen of Troy group. Vicks offers a broad range of humidifiers, which can be found at mass-market retailers and drugstores. Prices range from $40 to $90.
Additional brands to look at include Air-O-Swiss, Aprilaire, Bionaire, Comfort Zone, HoMedics, Levoit, PureGuardian, Rowenta, Safety 1st, Sunbeam, Vornado, and Winix.
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