Did you know that the dry indoor air of winter might make it easier for airborne viruses to spread? Researchers have conducted experiments indicating that’s possible. One possible weapon: A humidifier.
Humidifiers add moisture to indoor air, weighing down virus particles and speeding their descent to the ground. Of course, humidifiers also provide relief for dry throats, noses, skin and lips.
However, buying a humidifier can be confusing. “Evaporative” humidifiers use a replaceable filter to wick water up from a tank while a fan blows the moist air through that filter out into the room. “Ultrasonic” humidifiers use high-frequency vibrations to convert water into a mist that a fan then distributes.
Ultrasonic humidifiers run the risk of over-humidifying and may create a “white dust” residue around the room if you fill the tank with unfiltered tap water.
Evaporative humidifiers require replacement filters, which adds to the cost. Another decision is whether you want a warm-mist option, which is available on some ultrasonic models.
Warning: Whatever humidifier you choose, clean it at least once a week and do not boost relative humidity in a room above 40% to 50%, or you could promote growth of mold and mildew.
We asked product reviewer Paige Szmodis to recommend some of the best humidifiers…
Best for a bedroom up to 400 square feet: Honeywell HCM-350 Cool Moisture Germ Free Humidifier is among the most reliable and easy-to-use evaporative humidifiers. Its 1.1-gallon tank has a handle for easy carrying and an opening wide enough for you to reach a hand inside for cleaning. It has parts that are dishwasher-safe…and it’s large enough that it can run for up to 24 hours between refills. But like most evaporative humidifiers, it requires filters that should be replaced every month or two. $61.99. Replacement filters $10.99 each.
Best for large spaces: Levoit LV600HH Hybrid Ultrasonic Humidifier can humidify up to 750 square feet for up to 36 hours with its 1.6-gallon tank. This ultrasonic humidifier has an “auto mode” that uses a built-in sensor to automatically adjust humidity levels and avoid over-humidification. It has both cool- and warm-mist settings and a remote control. $89.99.
Best value: TaoTronics 4L Ultrasonic Cool Mist Humidifier is bargain priced and includes a humidity sensor to avoid over-humidifying, unlike many other low-cost ultrasonic humidifiers. It can humidify up to 320 square feet for as long as 30 hours on a 1.1-gallon tank of water. It has a filter, but that filter is reusable—soak it in a vinegar-water mix every month. $49.99.
Best for quiet in small rooms: Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier is nearly silent—most other humidifiers create noticeable fan noise or humming. Its 0.4-gallon tank can humidify up to 175 square feet for up to 16 hours. Cleaning its tank is challenging, however—you have to reach inside with a special brush, which is included. $39.99.
Best when you have a cold: Vicks VWM845 Warm Mist Humidifier doesn’t just distribute warm, moist air. If you put Vicks VapoSteam cough-relief medicine in its “medicine cup,” this ultrasonic humidifier will distribute that as well, providing additional relief for sore throats and coughs without the messiness of the well-known Vicks VapoRub balm. Its one-gallon tank can run for up to 24 hours and is easy to clean. $62.