Are Air Purifier and Humidifier Combos Good?

A HEPA filter removes at least 99.97 percent of particles 0.3 microns in size, and indoor humidity should stay below 60 percent, ideally between 30 and 50.

An air purifier answers a particle problem, and it leaves one job behind: a dry room stays dry until a humidifier goes in it. That's the downside you'd notice in dry air, and the fix is a second machine. The best home humidifier for you depends on how much of the house you're covering: a central unit for a whole home, a portable unit for one room.

Air Purifier and Humidifier Combo for Home

For a whole home, the best humidifier for whole house is a central humidifier installed in your heating and air-conditioning system. AprilAire's fan-powered evaporative whole-house humidifier is rated at 21 gallons per day and pulls heat directly from the furnace plenum.

Size it by the building's treated volume in cubic feet and by its tightness, not by floor area. A tight 8,000-cubic-foot building calls for 3.3 gallons a day and a tight 56,000-cubic-foot one for 23.4, while a loose building's number runs from 10.0 to 70.2.

Are Air Purifier and Humidifier Combos Good for Baby?

A humidifier is good for a baby's room, as long as it's a cool-mist unit rather than a warm-mist one: warm mist can burn you if you get too close. Place it several feet from the bed, roughly 2 meters, and run it up to the 40 to 50 percent setting and stop.

An evaporative humidifier is the safer type for that room, since it disperses less of the pollutants a standing-water tank can grow than ultrasonic and impeller units do. Your baby is more susceptible to airborne pollutants a humidifier disperses.

The Honeywell evaporative humidifier is the pick for a nursery: it adds 2 gallons of moisture a day out of a wick instead of a mist. Cleaning splits in two. The water tank and water tray are top-rack dishwasher safe, and the tank cap, the filter, and the main housing get washed by hand. Soak the wicking filter and replace it as part of cleaning.

The UV bulb sits in the water path, so it works on the water the unit holds.

Air Purifier and Humidifier 2-In-1

Run the 2-in-1 as two units, an air purifier and a humidifier in the same room, and hold that room between 30 and 50 percent humidity. Set that number with the humidistat rather than by feel.

That same ceiling keeps the pair safe, because condensation is how mold gets a start. Excess moisture encourages biological growth in a house, dust mites and molds included.

Then the chore, which is daily: empty the tank, wipe all surfaces dry, and refill it so standing water has no time to grow microorganisms. Every third day, scrub off the scale, deposits, or film and wipe the unit dry, and rinse the tank thoroughly after any cleaning or disinfecting agent so the chemicals don't go into the air.

That's also why distilled water beats tap. Tap minerals land as white dust on your surfaces and as crusty scale inside the tank, and scale can become a breeding ground.

Air Purifier and Humidifier for Bedroom

Sleeping with a humidifier is worth it when the air in your room is dry. The Levoit smart hybrid ultrasonic humidifier runs under 28 dB on low cool mist.

Dry air makes mouth breathing more likely, and mouth breathing makes you snore and raises your odds of waking with a cough, a nosebleed, or a dry mouth. Dry air irritates the nose and lungs, and moisture thins mucus, so coughing and blowing your nose clear more.

Set a portable unit to 40 to 50 percent and leave it there. Surfaces that stay damp to the touch mean mold and mildew can grow, so that number is the one to hold.

The tank is 1.58 gallons, and it runs up to 50 hours on the low mist setting, so a fill before bed covers a couple of nights. Its effective range of 430 to 753 square feet takes in a bedroom with room to spare.

Noise is what decides a bedroom humidifier. The two mist settings you'd run overnight read like this:

In auto mode it switches between warm and cool mist and shuts the warm mist off to keep the noise down. For a bedroom, we'd leave it in auto.

Air Purifier and Humidifier Combo for Small Room

In a small room, the humidifier is the machine that has to fit, and the Vicks top-fill cool-mist humidifier is built for that size. Its 0.6-gallon filter-free tank runs up to 24 hours per filling on the low setting, so a single fill covers a day and there's no wick to soak or replace.

The fill is the other half of living with it. The wide flip-top lid lets you refill at the tank or take the tank to the sink. For one room, we'd take the easy fill.