The best humidifiers for combating dry winter air

An unfortunate byproduct of heating your home in cold weather is that it dries out the air. Dry air can irritate nasal passages and increase your risk of getting a respiratory infection. The good news: Today’s humidifiers are better than ever at adding moisture to the air with designs that claim to address concerns about hard water and possible bacteria contamination. Here are some findings from Consumer Reports' humidifier tests:

Antimicrobial features. Humidifiers process a lot of water—the better room models have an output of 1.3 to more than 3 gallons a day—to cover 100 to 650 square feet. Yet some water tends to collect in the base and tank, where bacteria and other microbes can grow. Not all humidifier manufacturers suggest daily cleaning of their products, but you’ll need to replace the water at least once a day. Wondering how harmful that standing water might be? So are we, and we’re now running tests for bacteria in both the water that remains in the unit and the mist the humidifier adds to the air. The small-room HoMedics UHE-CM25, $60, and the medium-room Honeywell HUT-300, $70, are among models that claim to inhibit bacterial growth.

Hard-water resistance. Several models we tested, including the child-styled Crane Owl, an ultrasonic unit selling for $45, accept optional demineralization cartridges that manufacturers claim reduce or eliminate scaling. In homes with hard water, the buildup of minerals dissolved in the water can result in the dispersal of a white, powdery dust that coats surfaces in the room—and can be inhaled. Ultrasonic models, which use a vibrating nebulizer to emit mist, are most prone to mineral buildup and release. But using distilled water avoids the problem without the need to buy cartridges at an extra cost.

Energy savings. Humidifiers aren’t known as energy hogs, with some using as little as 25 watts. Vaporizers, however, are in a class by themselves. The single vaporizer that made our picks, the large-room Honeywell HWM-340, $55, is a warm-mist model rated for 400 watts. If you need a major-league tabletop model that can add lots of moisture to the air, though, you might want to swallow the extra energy cost. The Honeywell outputs 3.3 gallons a day for a claimed 600-square-foot space.

Choosing the right humidifier is a balance of mist output, convenient features, noise, and other criteria—all of which we test for in our humidifier Ratings of three dozen models. Before shopping, check our humidifier buying guide.

The best humidifiers from our tests

Looking for a humidifier? Keep in mind that you should size it to the room where you'll be using it. You'll probably need more than one. Here are the top picks from our tests.

For more choices see our full humidifier Ratings and recommendations.

—Ed Perratore (@EdPerratore on Twitter)

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