Dry sinuses, bloody noses and cracked lips — humidifiers can help soothe these familiar problems caused by dry indoor air. Humidifiers can also help ease symptoms of a cold or another respiratory condition.
But be cautious: Although useful, humidifiers can actually make you sick if they aren’t maintained properly or if humidity levels stay too high. If you use humidifiers, be sure to monitor humidity levels and keep your humidifier clean. Dirty humidifiers can breed mold or bacteria. If you have allergies or asthma, talk to your doctor before using a humidifier.
What are humidifiers?
Humidifiers are devices that emit water vapor or steam to increase moisture levels in the air (humidity). There are several types:
Central humidifiers are built into home heating and air conditioning systems and are designed to humidify the whole house.
Ultrasonic humidifiers produce a cool mist with ultrasonic vibration.
Impeller humidifiers produce a cool mist with a rotating disk.
Evaporators use a fan to blow air through a wet wick, filter or belt.
Steam vaporizers use electricity to create steam that cools before leaving the machine. Avoid this type of humidifier if you have children; hot water inside this type of humidifier may cause burns if spilled.
Ideal humidity levels
Humidity is the amount of water vapor in the air. The amount of humidity varies depending on the season, weather and where you live.
Generally, humidity levels are higher in the summer and lower during winter months. Ideally, humidity in your home should be between 30 and 50 percent. Humidity that’s too low or too high can cause problems.
Low humidity can cause dry skin, irritate your nasal passages and throat, and make your eyes itchy.
High humidity can make your home feel stuffy and can cause condensation on walls, floors and other surfaces that triggers the growth of harmful bacteria, dust mites and molds. These allergens can cause respiratory problems and trigger allergy and asthma flare-ups.
How to measure humidity
The best way to test humidity levels in your house is with a hygrometer. Anyone who has breathing issues and is concerned about air quality in their home should own one of these inexpensive gadgets.
This device, which looks like a thermometer, measures the amount of moisture in the air. Hygrometers can be purchased online, at hardware stores and department stores.
Humidifiers, asthma and allergies
In addition to helping with COPD and asthma, The National Institutes of Health recommends the use of humidifiers to help relieve congestion from the common cold, flu and sinus infections, as well as symptoms of dry eyes, eczema, itchy skin, dry nasal passages, cracked lips and nosebleeds due to dry air, allergies or asthma.
However, if you or your child has asthma or allergies, talk to your doctor before using a humidifier. Increased humidity may ease breathing in children and adults who have asthma or allergies, especially during a respiratory infection such as a cold. But dirty mist or increased growth of allergens caused by high humidity can trigger or worsen asthma and allergy symptoms.
When the air’s too damp:
Dehumidifiers and air conditioners
Just as air that’s dry can be a problem, so can air that’s too moist. When humidity gets too high — common during summer months — it’s a good idea to take steps to reduce indoor moisture.
There are two ways to reduce humidity:
Use an air conditioner. Central or window-mounted air conditioning units dry the air, keeping indoor humidity at a comfortable and healthy level.
Use a dehumidifier. These devices collect excess moisture from the air, lowering humidity levels. Dehumidifiers work like air conditioners, without the “cooling” effect. They’re often used to help dry out damp basements.
Keep it clean: Dirty humidifiers and health problems
Dirty reservoirs and filters in humidifiers can quickly breed bacteria and mold.
Dirty humidifiers can be especially problematic for people with asthma and allergies, but even in healthy people humidifiers have the potential to trigger flu-like symptoms or even lung infections when the contaminated mist or steam is released into the air.
Steam vaporizers or evaporators may be less likely to release airborne allergens than may cool-mist humidifiers.
Tips for keeping your humidifier clean
To keep humidifiers free of harmful mold, fungi and bacteria, follow the guidelines recommended by the manufacturer. These tips for portable humidifiers also can help:
Use distilled or demineralized water. Tap water contains minerals that can create deposits inside your humidifier that promote bacterial growth. And, when released into the air, these minerals often appear as white dust on your furniture. You may also breathe in some minerals that are dispersed into the air. Distilled or demineralized water has a much lower mineral content compared with tap water. In addition, use demineralization cartridges or filters if recommended by the manufacturer.
Change humidifier water often. Don’t allow film or deposits to develop inside your humidifiers. Empty the tanks, dry the inside surfaces and refill with clean water every day if possible, especially if using cool mist or ultrasonic humidifiers. Unplug the unit first.
Clean humidifiers every three days. Unplug the humidifier before you clean it. Remove any mineral deposits or film from the tank or other parts of the humidifier with a 3 percent hydrogen peroxide solution, which is available at pharmacies. Some manufacturers recommend using chlorine bleach or other disinfectants.
Always rinse the tank after cleaning to keep harmful chemicals from becoming airborne — and then inhaled.
Change humidifier filters regularly. If the humidifier has a filter, change it at least as often as the manufacturer recommends — and more often if it’s dirty. Also regularly change the filter in your central air conditioning and heating system.
Keep the area around humidifiers dry. If the area around a humidifier becomes damp or wet — including windows, carpeting, drapes or tablecloths — turn the humidifier down or reduce how frequently you use it.
Prepare humidifiers for storage. Drain and clean humidifiers before storing them. And then clean them again when you take them out of storage for use. Throw away all used cartridges, cassettes or filters.
Follow instructions for central humidifiers. If you have a humidifier built into your central heating and cooling system, read the instruction manual or ask your heating and cooling specialist about proper maintenance.
Consider replacing old humidifiers. Over time, humidifiers can build up deposits that are difficult or impossible to remove and encourage growth of bacteria.
Today’s Best Humidifiers Reviewed
Best Ultrasonic Humidifier
The SPT SU-4010 is an ultrasonic tabletop humidifier that can produce either warm or cool mist — enough to humidify 500 square feet of space. The moisture output can be adjusted with a manual dial, but there is no built-in humidistat. It does well in expert tests, and users say that this humidifier produces plenty of good, fine mist, and it runs quietly.
Produces cool or warm mist
Some durability problems
The SPT SU-4010 is an excellent option for those looking for a top performing ultrasonic humidifier at an easy to swallow price. It’s compact, effective and can emit either cool or warm mist. There aren’t too many bells or whistles on this model, but provided you pay close attention while filling its tank, it should satisfy most users’ needs.
Ease of use
Minimal features, but simple and effective. The SPT (formerly Sunpentown) SU-4010 humidifier is an excellent pick for those users who are looking for a straightforward machine with both cool- and warm-mist options. The large control knobs are easy to use, and users praise the SPT’s dual nozzles, which rotate 360 degrees to pinpoint where you want the mist to go. Some experts say that cleaning is a chore, but others note that ease of cleaning is above average compared to most ultrasonic humidifiers.
Fine mist, few issues with dust. This ultrasonic model can produce either warm or cool mist, enough to humidify 500 square feet of space.The moisture output can be adjusted with a manual dial, but there is no built-in humidistat.
Users say that this humidifier produces plenty of fine mist. Its demineralization cartridge (called the Ion Exchange Filter) seems relatively effective as we saw fewer complaints of dust residue than with other ultrasonic humidifiers, though the SPT SU-4010 is not completely immune from that issue.
A low humming, but otherwise quiet. Most reviewers agree that the SPT SU-4010 is incredibly quiet. It generates a low humming noise when on, but most owners and reviewers say that it is only nominally noticeable.
Some durability concerns. User feedback for the SPT SU-4010 is mixed, but very much in line with most ultrasonic humidifiers, including those that cost twice as much. While most owners are generally happy with the SPT SU-4010 humidifier, questions about durability, and reports of units that failed prematurely, are easy to spot. We also found some owners that noted problems with leaking.
Others say this can be easily fixed by simply paying closer attention to the washer when screwing the cap back on (it sometimes can become knocked out of place). The value of the SU-4010 compared to other options comes in for kudos.
Best Humidifier for a Large Room
Ultra-large Capacity: 3.0L water tank can support 33 hours continuous use at the “Weak” level and 12 hours continuous use at “Strong” level.
Ultrasonic: Humidifying immediately right after starting, producing no heat, so suitable for both young and old.
Sensor Control: Built-in sensor can sense the indoor humidity, then enables the humidifier to auto control.
Auto Swing: Swing 45° the left or right for wide-range humidification.
Aroma Diffuser – you can use medicated liquids in the pullout tray on the back that has a small pad. These would be 100% pure essential oils (not included) to drop onto the pad. Be careful when you pull the tray out—it does not have stops and can fall to the floor.
Do not put oils into the water tank because it will corrode the parts—only put on the small pad.
7 Colors Night Light: 7 available colorful lights together with the white light so it works like a night light at bedtime and creates romantic atmosphere.
Best Cool Mist Humidifier
The Honeywell HCM-350 cool mist humidifier is an evaporative tabletop humidifier with sufficient output to handle medium sized rooms — 400 to 500 square feet, depending on who you ask.
This humidifier is a little bit louder than some ultrasonic humidifiers, and can only output cool mist, but it is effective, easy to clean, and there’s no white dust residue from minerals in hard water to worry about.
Easy to clean
No white dust residue
Cool mist only
The Honeywell HCM-350 cool mist humidifier earns very positive reviews thanks to its effectiveness, ease of use, and ease of cleaning.
There are few features, including no humidistat to monitor and maintain room humidity, but operation is simple and straightforward.
It’s a great choice for those with hard water: This is an evaporative humidifier so there are no issues with white dust settling on your furniture (the byproduct of minerals in the water) — a drawback with competing ultrasonic humidifiers.
Ease of Use
Basic, but it works well. While the Honeywell HCM-350 may not have as many features as other top-reviewed models, reviewers say that it’s simple to use — just a single dial to set fan speed — and efficient. The water tank has a wide mouth and is easy to fill — and a sturdy built-in handle makes carrying the tank a snap.
One feature it does have is a UV lamp to kill germs, but experts say that its effectiveness is dubious, making this more hype than help — just as well as the bulb tends to burn out quickly and replacements are hard to find.
There’s a filter that needs to be periodically replaced, but it’s inexpensive. One expert reviewer dings the HCM-350 saying that it is difficult to put back together once the filter is saturated because it won’t hold its shape.
One of the big pluses experts largely agree on is that the Honeywell HCM-350 is designed to make ongoing maintenance easier than with most competing humidifiers. “The Honeywell didn’t have any of the difficult-to-reach areas and small spaces that some of the ultrasonic humidifiers had, and we could easily fit our entire hand into the water tank to clean it,” BabyGearLab.com reports. As an added plus, the tank and the base are dishwasher safe.
Plenty of moisture for medium sized rooms. This humidifier is rated to humidify a space of around 500 square feet, though TheSweetHome.com says it’s best with rooms of 400 square feet or less — which covers all but the largest rooms.
The tank, to some reviewer’s concern, holds only a gallon of water; because of this, the machine can go through two full tanks a day at maximum output. However, the positive side of this is that larger tanks are heavier to carry, harder to fill as they many not fit under some sink spigots, and more difficult to clean, notes John Holecek at TheSweetHome.com
In the ear of the beholder. I saw split opinions regarding noise. As an evaporative unit, noise levels will certainly be higher than with an ultrasonic model.
TheSweetHome.com tests sound levels from one meter away and says that while the HCM-350 is loud enough to be noticed, it’s not loud enough to be objectionable at top speed, and drops down to barely noticeable levels at medium speed.
Holecek adds that the pitch of the sound helps minimize any issues. “It’s a pleasant white noise that sounds like a box fan on a medium to low setting,” he says.
BabyGearLab.com downgrades the HCM-350 quite a bit more over its noise, while conceding that, “During in-home testing, we actually found the Honeywell’s fan noise at the lowest setting to be soothing and felt that some parents may appreciate the added “white noise” benefit.”
A third expert weighs in on noise level and rates it at “very good” at its highest fan speed, but offers little additional insight.
So there are certainly a variety of opinions when it comes to noise level. The consensus appears that it is similar to a fan at lower settings, and not particularly irritating.
Well-made to reduce leaks. TheSweetHome.com likes that the tank on the Honeywell HCM-350 is made from a single piece of plastic, without the seams that seem to develop leaks over time with other humidifiers — and something that will help make sure the HCM-350 survives to the end of its generous three-year warranty, Holecek says.
Because this is an evaporative humidifier, there are no issues with a fine white dust settling on furniture; a byproduct of minerals in water, especially hard water, that’s unavoidable with ultrasonic models (even those with good filtration), and the source of lots of user complaints with such models.
The HCM-350 is large compared to some ultrasonic models — so large that it might be a tight fit on some nightstands.
User feedback, while not universally positive, is better than we generally see with most humidifiers, including a 4-star rating at Amazon.com based on more than 1,500 reviews.
Best Cool Mist Humidifier for a Small Room
Compact and cute, the Safety 1st Ultrasonic 360 humidifier is another excellent choice.
With a small, three-quarter-gallon water tank, you won’t see as much moisture output as larger machines. Still, reviewers say that thanks to its quiet operation, variable mist settings and easy-to-use design, this is a nice option.
There are 1,850 consumer reviews on Amazon, where it has earned a 3.5 star rating, as well as 149 answered questions.
Here are two particularly helpful reviews from verified purchasers:
Very quiet, very nice cool mist humidifier
I’ve used a few different types of humidifiers over the past couple years, and my favorite so far has been a warm mist/vapor humidifier, like the simple boiling water kind you get from Vicks. Those humidifiers put out a lot of humidity, they’re easy to refill, and they don’t make everything in a room get a white powdery coating.
Ultrasonic/cool mist humidifiers often make a white powder coating appear on some surfaces if you have hard water (like I do), but they are quieter (no boiling or fans), they don’t raise the ambient temperature, and the mist can be directed via the vent at the top. They also don’t use filters, so there is no maintenance or extras you have to purchase other than a simple weekly (at least) cleaning.
This humidifier has simple controls (on/off switch on the back, mist level knob on the front), and a neat little port on the top that you can direct in two different spots. I usually just keep both vents pointed in the same direction.
Refilling is easy; just grab the translucent top part, turn it upside-down, unscrew the drain plug, and fill in a standard-size sink.
If I set the level to low/medium, I can use the humidifier up to a full day or so before a refill. If set on high, it only seems to last about 8-10 hours. Also, the humidifier shuts itself off if it senses no more water.
RECOMMENDATION: If you need a simple cool mist humidifier, like one for a baby’s room, this is a great option–especially if you only need to have it on for a small part of the day (otherwise you’ll be refilling it a lot).
TIP FOR LONGEVITY: Make sure you follow the included cleaning instructions, especially with regard to cleaning mineral buildup every week. If you don’t this humidifier will probably only last a year or less (especially if you have hard water at your home, and don’t use distilled water to humidify the air). If you clean it weekly, expect years of use.
My top choice, though not perfect
Pros: I love that I can turn it on high and get a room humidified fast. (When needed, I can leave it on high for an our or two to get one kid’s room humidified for bed time and then move it to another kid’s room). I love that I can turn it on low and leave it for two days running without touching it. And that there are settings in between high and low. I love that it doesn’t have a filter to deal with and to purchase regularly! I have used a filtered ultrasonic humidifier in the past, and besides having the filter to deal with, I disliked that it was so slow to humidify a room. After a day it was fine, but when a child is sick at night, you want the humidifier to work immediately.
Cons: The plastic tank is very thin. Others have complained about it leaking after a while. I had mine for half of a season and then it was knocked over from a high shelf and broke. That is understandable from how hard it fell, but I worry about how long my new one will last. The tank is also a little awkward to fill. It would be nice if it had a flat top or a better handle. But it’s not bad.
I didn’t clean my first one as often as I should have, and then I did have a hard time keeping it clean. The second time around, I rinse it all every time I change the water (or sometimes sooner if I have it on low), and rinse with vinegar once a week as it explains in the instructions, and have had no problems keeping it clean.
The switch is easy to move from low to high, and I have had the problem of a child turning it up to high at night without me knowing, and things being a little too humid the next morning.
I spent a lot of time looking at humidifiers, and I am very happy with this purchase for the reasons mentioned and with the relatively low price. (It was about $30 when I bought it.)
Best Whole House Humidifier
The Essick MA1201 is an evaporative humidifier that can put out up to 12 gallons of moisture per day, enough to humidify 3,600 square feet of space. Its humidistat allows you to adjust the humidity in 5-percent increments, and its double-fill tank system reduces the number of trips you must make to the sink.
Professional tests indicate that the AirCare MA1201 produces very good moisture output, although it is much louder than most humidifiers. Users say this machine is easy to fill, and that its value is terrific.
Covers up to 3,600 square feet
Easy to refill
Humidistat might not be accurate
The Essick MA1201 is a good bet for a budget-friendly whole house humidifier. The 3.6-gallon water tank means infrequent refilling. The moisture output is excellent. Plus, bonus features like the automatic shut-off, check-filter message and electronic display are welcome additions. Consumers do lament the flimsy, cheap construction; cost of replacement filters; and say that despite an “ultra-quiet mode,” this machine is very loud — yet this humidifier still gets excellent feedback overall.
Ease of use
Simple design and easy-to-use controls: The Essick AirCare MA1201 whole house humidifier is an excellent pick for those looking to humidify a large space. The simple digital controls and built-in humidistat allow users to easily control the moisture level in their homes. Owners appreciate the automatic shut-off, check-filter message and the water refill light. A few reviewers claim that the humidistat is calibrated poorly, meaning that you might need to experiment with the settings to get the best results.
Large, easy-to-clean tank: The Essick AirCare MA1201 is rated for up to 3,600 square feet — nearly five times the space of a traditional tabletop model and enough to provide humidity for even a large home. We found excellent user feedback on the room coverage offered by this model. The 3.6-gallon tank allows for up to 12 gallons of moisture output per day.
It’s loud. Perhaps the most common complaint about the Essick MA1201 is that this evaporative humidifier is very loud. Many reviewers claim that this machine can be heard from another room. The humidifier does feature an “ultra-quiet mode,” but users say that even in that mode the machine is quite noisy.
Good value, but iffy build quality: Many reviewers say the plastic housing is flimsy, but also say that in spite of the poor build quality, this humidifier does perform quite well.
Some reviewers who said that the unit lasts only through a few seasons with continual use, but others seem quite pleased with the durability of this product. We also saw some accounts that the LCD control panel stopped working after just months of use. Some did note that the humidifier tank does require regular cleaning, but it does a relatively good job at bacterial and mold growth regulation.
Best Warm Mist Humidifier
1-gallon capacity; operates up to 12 hours on a single filling
Quiet operation. Soft glowing nightlight.
2 Comfort settings
Medicine cup allows the use of Vicks Vaposteam or Kaz Inhalent to produce a medicated vapor that soothes
Here is the Vicks Humidifier review which Amazon readers consider most helpful:
An Honest Review
I love Amazon because of the reviews. For the most part, the reviews are honest, detailed and very helpful, especially when a true defect or some other “quirk” is described. However, many of the reviews for this item are really…bizarre! I have to wonder what some of these reviewers were actually thinking. Also, are they are realistic in their expectations? It is what it is – an inexpensive humidifier. It WILL make some noise, It will NOT humidify your entire house, it WILL require cleaning and care, it will NOT last forever, etc.
1) This item is being shipped from a warehouse to your home. If it arrives broken, cracked, leaking or damaged in any way, contact Amazon- they offer one of the best return policies around. This is an issue with whoever shipped it, not a reason to leave a one-star rating.
2) This is a HUMIDIFIER and uses tap water and electricity to create a heated mist. Should you be horrified to find mold or mildew? NO. Does it require regular maintenance and cleaning? YES. There is no way around it. If you allow water to sit, mold will grow. If you use tap water, there is a good chance you will have mineral deposits. Inspect the humidifier each time you fill it.
When you re-fill the tank, give it a good rinsing out. It if smells, add a teaspoon of bleach, swish it around and dump it out.
If it has deposits around the heating element, pour vinegar into the bottom, let it sit for a few hours, take a small toothbrush to it and rinse it out.
If it has deposits on the plastic pieces, remove them from the unit and soak them in vinegar, same as above. It is not difficult to disassemble at all.
It is a fact of life, humidifiers need to be cleaned and maintained.
3) This is a very INEXPENSIVE humidifier. Is it helpful to compare it to a humidifier that costs 5x as much? NO. That is like comparing a Toyota Corolla (MSRP 25K) to a Bentley Continental (MSRP 175K).
4) This is an electrical device. Like anything that uses electricity, it has the potential to start a fire. Even though it has an automatic shut-off, I wouldn’t bet my house on it. Pay a little attention to it and treat it like any other electrical device.
5) Seriously, having to carry it by it’s handle with the plug on top is a big issue? Would you carry a bottle of water (or any liquid with a screw cap, for that matter) upside down? As for the leaking, screwing the cap on tightly and carrying it by it’s handle would probably help.
6) Will it last for a lifetime? NO. Does any inexpensive product last beyond a few years? NO. Will the gaskets dry out if it is stored for long periods of time? It’s entirely possible. Again, this is an INEXPENSIVE humidifier.
BOTTOM LINE: It is very reasonable priced, does a good job and lasts a couple of years if you take care of it. I am about to make my 4th purchase of this exact humidifier. I read the reviews to see if anything changed or if a better, similarly priced unit was introduced into the market. The answer is NO. This is the best deal for the money.
****UPDATE**** 11/19/2011 Almost one year later, last week I pulled out the humidifiers and gave ’em a nice, thorough cleaning, set ’em up and they are working perfectly. I am going on at least my 5th New England winter with the first one I bought, and it still works like new – whisper quiet, zero leaking, couldn’t be happier for the price! From the looks of it, Amazon’s price hasn’t changed much either (although it does fluctuate day-to-day). It’s still the BEST YOU”LL FIND in this price range!
Although experts generally say cool-mist humidifiers are better for most purposes, the Vicks Warm Mist Humidifier is an option if you want to make a room feel warmer during the winter.
The Vicks humidifier has two vapor settings and, while some noise complaints are seen, others seem not to be bothered.
The Vicks Warm Mist Humidifier has an automatic safety shut-off (though some say this feature can be unreliable) and a nightlight.
One caution: I read several reports of leaks with this model and some users find this humidifier difficult to clean.
Regardless of the model you choose, you must clean it regularly. Otherwise, you run the risk of spreading bacteria and mold, which can exacerbate allergies and asthma symptoms.
Choosing one of the newer models that come with built-in antibacterial technology will help keep the water clean so you don’t have to wash the unit as frequently, but even the newer models will still require occasional cleaning.
Also pay close attention to the moisture level of the room. Some humidifiers automatically adjust their output based on the moisture level, others let you set the level. It should always be between 30 percent and 50 percent or, again, you run the risk of increasing mold and bacteria growth.