Picking the right humidifier
Humidifiers can help restore the balance of moisture in your home, particularly in dry climates and during the winter. They also can alleviate discomfort and symptoms associated with colds, asthma and other ailments by keeping the air moist.
The two main types of humidifiers are cool-mist humidifiers and warm-mist humidifiers
Ultrasonic humidifiers, which use high-frequency sound waves to vaporize water, are the most popular type of cool mist humidifier. They are also the quietest. Some ultrasonic humidifiers can also emit warm mist.
Evaporative humidifiers are exclusively cool mist humidifiers. These soak up water into a wick and use a fan to expel the moisture. These types of humidifiers can be inexpensive, but replacing their wicks or filters is an ongoing cost. In addition, evaporative humidifiers can be noisy.
Some cool-mist humidifiers use impellers to force (impel) water into the air as a fine mist; however, we found no positive reviews for those humidifiers, so we do not recommend any of those models.
Warm-mist humidifiers (sometimes called vaporizers) boil the water before expelling it as steam. This can eliminate bacteria that's present in the water if it's heated to a true boiling point of 212 degrees Fahrenheit, but it also means that minerals can build up in the tank and on the heating element over time, and vaporizers are not always easy to clean.
Some people prefer warm-mist humidifiers, saying the heated vapor is easier to breathe (especially if you're congested) and that it gently raises room temperature. But experts say the difference between cool mist and warm mist is minimal, and doctors, such as those at the Mayo Clinic caution that warm-mist humidifiers pose a safety hazard because they can be tipped over by young children, scalding them. They are also less energy efficient. Expert reviews are generally neutral to negative for this type of humidifier, and users aren't that much more pleased. In general, if you want a humidifier that can emit warm mist, we recommend an ultrasonic model that can produce both cool and warm moisture.
Finding the best humidifiers
In selecting the best humidifiers we weighed several factors, including performance (moisture output), ease of use, noise and the ownership experience, looking for both the best performers, and those that deliver the best bang for the book.
Both expert and user reviews s were evaluated. On the expert side, it's tough to find a better resource than ConsumerReports.org, which tests more humidifiers than anyone else. However, not all of the humidifiers listed on the site are current models (though many are) and the results of its hands-on tests can only be viewed by subscribers. TheSweetHome.com also consults ConsumerReports.org and other experts and reviewers, but then conducts its own testing to find the best choice. BabyGearLab.com conducts its own hands-on evaluations, and, while that review is aimed at someone looking for a humidifier for a nursery, anyone looking for a single-room humidifier will find the insights there useful.
While experts often -- but not always -- agree on which humidifiers are best, we found a sometimes startling divergence of opinion when it came to user reviews. This is likely because issues that don't always manifest during the short time experts have to evaluate a humidifier do show up after weeks or months of use. In some cases, issues apply to one user -- hard water, for example -- but don't apply to others. As a result, user ratings for humidifiers as a class are often mixed. Be that as it may, we consulted the user reviews at Amazon.com, HomeDepot.com, Lowes.com, Sears.com and others in compiling these recommendations.