How to choose the right humidifier: Demystifying the winter mist must-have

"The [optimum humidity] for healthy skin and also nasal passages is about 40 per cent to 50 per cent," says Toronto dermatologist Dr. Sonya Cook. "In the wintertime in Canada, if you don't have a humidifier, it could get really low indoors, to 20 per cent or even less." At that level of relative humidity, says Dr. Cook, the air can have a drying effect, especially for anyone with an "impaired skin barrier" (for example, individuals with eczema and older adults), that can lead to dry, itchy skin.

"For anyone that's complaining of dry skin, or just for general health, it's good to have proper relative humidity," says Dr. Cook. "I find most people, even if they have a central humidifier, often it doesn't get up to that sort of perfect level, so it can be good to have an add-on humidifier in your bedroom." Just be sure that you keep it clean, as illness-causing mould and bacterial growth can develop over time if you're not cleaning out the mineral deposits and changing the water and filters out frequently, notes Dr. Cook.

She recommends looking for a humidifier with a built-in hygrometer, or buying a separate one at a hardware store, so that you can be sure to keep the indoor humidity level at home is in the optimal range. "In Canada, you're not supposed to have it so high that you'll get condensation on the window; we might have to keep it at a lower number just to prevent condensation," says Dr. Cook. "But hopefully you get away with 35 per cent humidity or higher."

How humidifiers work

To help you pick out the right room-humidifier for your home, we talked to George Oram, Lead Design Engineer at Dyson (he helped develop the company's humidifier) to find out the technical basics, the features to look for at all price points, and the newest innovations in the space.

According to Oram, generally speaking there are two different types of cool-mist humidifiers: "Evaporative, which takes water and evaporates it so it turns into water vapour — essentially humidifying drier air by passing it across a wet surface, such as a paper-based wick material or a plastic-covered plate — and ultrasonic, which projects water droplets out of the machine using a nebulizer (a fast-vibrating disc that atomizes the water) or centrifugal atomizer." Vaporizers that heat up water to create steam are a third option, but Oram notes that they can be dangerous for young children because of the heat and burn risk, and globally, heated humidifiers are not very popular outside of Canada and the United States.

Ultrasonic humidifiers offer a "cooling sensation when you're standing in front of them" because the water droplets "flash evaporate into vapour outside of the machine," says Oram, making them a popular choice for year-round use. Evaporative humidifiers need a lot of airflow to work well, and can be noisier, notes Oram. Plus, some models will require filter replacement over time. 

The key features to look out for

An important initial consideration, says Oram, is deciding whether you're looking for just a humidifier, or one that offers multi-functionality — pricier models can work as a fan, a heater or an air purifier, too. If you're looking to use essential oils with your machine, you'll want to find a model that's designed for that.

Beyond that, he notes that with ultrasonic humidifiers, you'll want to look for a machine with disinfection technology such as ultraviolet light (UV) or silver ion cubes built-in, because that water that's being projected into the room might otherwise contain things like bacteria or limescale, which can leave chalky white residue in your space. "That's really key because you are breathing in that room air, and so you don't really want to be projecting bacteria into a room," says Oram. And an easy-to-clean machine is also essential, because mineral or limescale build-up can be an issue with ultrasonic humidifiers. "I would also look for a water tank and machine that is easy to clean, whether you can physically remove the parts, or perhaps put your hand inside of the tank to clean it, or the machine has a specific cleaning cycle," advises Oram. For a strong machine with medium to high humidification output, Oram suggests looking for one with a 250–300 mL range, "That just ensures that it's not taking a really long time to humidify your room." Some of what Oram calls "machine intelligence" features, such an automatic mode that can monitor the room's humidity level and automatically switch on when required, can also be helpful, if they're in your budget.

With evaporative machines, which tend to have fewer bells and whistles, ease-of-cleaning should be a primary consideration. "Being able to easily either clean the water tank or the machine itself is important," says Oram. Machine intelligence and easy upkeep are other key features here as well.

The next-gen innovations to know

Combination purifier-humidifiers are becoming a big trend globally. "There's been a lot of awareness on air quality and how that affects your life," says Oram. "So it's adding that additional filter around the machine in some way, or passing the air in the room through a particulate filter to remove things like dust, pollen and smells."

There are also lots of new water disinfection and purification technologies starting to be used with humidifiers today. For example, "There are a couple of products now that have UV-C LEDs, so they have a smaller space package, use less energy, and can treat higher amounts of water," says Oram.

Ultrasonic Humidifiers

A shapely, no-frills option, Crane's drop humidifiers are available in a variety of colours and can humidify a space up to 250 square-feet. (The company's distinctive, animal-shaped humidifiers are a popular choice for children's rooms.) 

Crane Ultrasonic Cool Mist Humidifier Blue Drop, $84.99, Hudson's Bay

The priciest humidifier on the market, Dyson's sleek AM10 comes with features such as a sleep timer, UV-C anti-bacterial cleaning technology, automatic temperature and humidity reading, and a remote control. And, it can be used as a high-powered fan.

Humidifier AM10, $599, Dyson

Noma's modern looking, top-fill humidifiers are available in a variety of sizes (there's even an evaporative option, which costs a bit more). This one is recommended for spaces up to 400 square-feet and offers multiple fan settings, a pre-set timer, and built-in nightlight.

Noma Cool Mist Ultrasonic Humidifier 3.5-L, $119.99, Canadian Tire

Evaporative Humidifiers

This very reliable machine, recommended by review-site Wirecutter, is easy to clean and fill, and doesn't make too much noise — look for the model with ultraviolet sanitizing built in, which will cost a bit more than the one without. One drawback is that you'll have to buy replacement wicks a few times a year, and they're not cheap.

Honeywell Germ Free HCM-350 Humidifier, $122.04, Overstock.ca

Made in Germany, this boxy humidifier and air purifier combo doesn't require a replacement filter and comes with a 10-year warranty. It has an auto shut-off feature and is recommended for rooms up to 200 square feet.

Venta Airwasher LW15 2-In-1 Humidifier And Air Purifier, $279.99, Bed Bath & Beyond

Truc Nguyen is a Toronto-based writer, editor and stylist. Follow her at @trucnguyen.