Best Humidifier for Whole House

The best humidifier to use in your home is a central unit built into the heating and air-conditioning system when the whole house is dry, and one room takes a portable sized to that room. For the whole house, the best home humidifier we'd get is the AprilAire fan-powered evaporative whole-house humidifier, rated at 21 gallons a day for a house up to 6,250 square feet.

Portables come in three kinds: evaporative, which blows air through a moistened wick and adds its moisture invisibly; ultrasonic, which makes a cool mist with sound vibrations; and impeller, which throws a mist with a high-speed rotating disk. Whichever kind you get, hold indoor humidity between 30 and 50 percent, because dry air irritates the nose and lungs and can aggravate a condition you already have.

Sizing a whole-house unit runs on the building rather than the floor area. A tight 8,000-cubic-foot building needs 3.3 gallons a day and a tight 56,000-cubic-foot building needs 23.4, while a loose one needs 10.0 and 70.2. Get your treated volume and a read on how tight the house is before you match a gallon rating to it, because those two numbers set what the unit has to put out.

Best Humidifier for Apartment

An apartment takes a small-room portable, and the pick is the filter-free Vicks EasyCare+ TopFill humidifier, 0.6 gallons that run up to 24 hours per filling on the low setting. The wide flip-top lid lets you refill at the tank or at the sink, so the water doesn't have to travel across the apartment.

Set it to 40 to 50 percent, and empty the tank, wipe every surface dry, and refill it daily to reduce the growth of microorganisms. Use water with low mineral content, distilled rather than tap, so you aren't releasing minerals into the air.

That covers a small room.

Best Large Humidifier

The best humidifier for living room use is one rated for the room's own square feet, and the Levoit smart hybrid ultrasonic humidifier is rated for 430 to 753 square feet. Past 753 square feet, the job goes back to a central unit.

It holds 1.58 gallons and switches between cool mist and warm mist, and in auto mode it turns the warm mist off to keep the noise down. Noise runs under 28 dB on low cool mist and under 40 dB on high warm mist, and on the low setting one fill lasts up to 50 hours.

Warm mist moves close to twice the moisture of cool mist, so it's the setting for a room that has dried out, and cool mist is the one that stays under 28 dB and runs two days on a fill.

A room of 300 square feet or less takes less machine, and the smart pick is built for it.

Best Smart Humidifier

The best smart humidifier is the Dreo smart humidifier, a 4-liter tank that runs up to 36 hours and covers 300 square feet. Its mist is rated ultrafine at 5 micrometers, and the unit runs at 28 dB.

The tank top-fills without coming off its base, so the daily refill happens where the humidifier sits.

That puts it in a bedroom, and a bedroom has its own rules about where the unit goes and how long it runs.

Best Evaporative Humidifier for Bedroom

For a bedroom, the evaporative pick is the Honeywell evaporative humidifier, which puts out 2 gallons a day through a wicking filter a fan pulls air through. Evaporative humidifiers put out fewer of the pollutants a standing-water tank can grow than ultrasonic and impeller units do, so keep one in the room where you sleep.

You soak and replace the wicking filter as part of cleaning.

For a child's room, get cool mist rather than warm mist, because a warm-mist humidifier can burn your child if they get too close. Keep your best humidifier for bedroom several feet from your bed, roughly 2 meters, and hold your room to that same range rather than leaving it on all night.

Sleeping with one is healthy if you keep your room in that same range and give the unit the same daily care; is it healthy to sleep with a humidifier has the rest. A humidifier also relieves a stuffy nose, loosens mucus so you can cough it up, and eases the discomfort of a cold. Dry air pushes you toward breathing through your mouth, and mouth breathing is what makes you snore and what raises the odds of waking with a cough, a nosebleed, or a dry mouth.