The best humidifiers are designed to banish dry air from your home and increase the humidity of a room, without loud background noises or breaking the bank. Dry air in your home can dramatically reduce the quality of your day-to-day life, particularly if you suffer from allergies, asthma or respiratory conditions, while lack of moisture can lead to inflamed mucous membranes in the throat and nasal passages, skin rashes and dry skin.
“Humidifiers add moisture to indoor air and are often used in homes to relieve the physical discomforts of dry nose, throat, lips, and skin caused by drier indoor air. However, it’s important to note, excess moisture can also encourage the growth of biological organisms, including mold in the home.” - Tim Carroll, Environmental Protection Agency
“Humidifiers are commonly used in homes to relieve the physical discomforts from dry air such as dry nose, throat, lips, and skin,” says Taylor Gillespie, from the Environment Protection Agency (EPA). However, too much humidity can create the perfect environment for the harmful microbes to flourish, causing irritation in individuals with chronic conditions. “Excess moisture in the air can encourage the growth of biological organisms such as dust mites and mold, and cause additional problems such as allergy and asthma symptoms.”
But Gillespie adds that humidifiers are different to the best air purifiers. “Humidifiers are not air cleaners,” she points out. “In fact, some humidifiers have the potential to release microorganisms and minerals from their water tanks into the air”.
For example, ultrasonic humidifiers (known as 'cool mist') increase moisture levels by vibrating and sending water droplets into the air. However, they may cause more condensation in a cold room, as the water droplets are more likely to condense on surfaces instead of dispersing into the air. This can encourage mold growth, which can lower indoor air quality further by releasing spores into the air.
“Ultrasonic humidifiers generally appear to produce the greatest release of both microorganisms and minerals”, agrees Gillespie. At the same time, evaporative humidifiers heat the water and release water vapor for the same result, which may be less harmful to air quality.
Knowing how to clean your humidifier and keep it in working condition will also make a great difference, no matter which humidifier you decide to go for. Luckily, we've tried and tested the best devices on the market, so you can find a humidifier that suits your requirements. Read on for our full round-up.
We spoke with members of the Environmental Protection Agency to confirm the latest research and findings on humidifiers, as well as advice on how to maintain a humidifier so that it performs smoothly.
Best humidifiers we've tested
The Dyson AM10 is a sleek model that features a stylish loop design and a clear water tank.
Amazon reviews give the Dyson AM10 an average score of 4.2 out of 5, however 70% of them are five star reviews. Positive reviews commented on how well the ultraviolet light worked to kill bacteria in the water, as well as how easy it was to use. Negative reviews cited that the machine is quite complicated to set up and clean, and others commented on how small the water tank was, which means that you have to fill it up more often than other humidifiers.
It acts as both a humidifier and a fan, featuring 10 levels, and will look good in any office or living area space. With some great functions, it enables you to set it for sleeping, while an auto mode gives you a choice of your preferred humidity level. However, it’s one of the most expensive models on the market and its water tank is relatively small - only holding 3.75 quarts.
One of the best things about this Dyson Humidifier is that before the water gets vaporized it purifies the water - getting rid of bacteria and minerals with its ultraviolet light. This is one of its best qualities, especially for those who are worried about the air quality in their house. It’s easy to refill the water and our tester found that it ran continuously for 12 hours before it needed to be refilled. This model is better for smaller rooms up to 172 square feet.
Unlike other humidifiers we’ve tested, the Dyson AM10 Humidifier doesn’t have multiple mist settings. Instead, it asks you to target a humidity level. The humidifier will run until your set humidity is reached and regulate the humidity from there. Humidity levels can be set to between 30 and 70 per cent. However, this humidifier also aims to regulate your desired temperature and will change according to the temperature in the room. Our tester also noted that the noise on any level was never louder than her air conditioner.
This Dyson humidifier is a great investment piece, especially as it doubles as a fan, which means that in the summer months it won’t sit dormant.
- Read our full Dyson AM10 humidifier review
This humidifier is great for big rooms due to its large water tank, which holds up to three gallons of water.
Reviews for the Honeywell Top Fill Cool Moisture humidifier on Amazon rate the model 4.5 out of 5, with the majority giving 4 or 5 star reviews. Happy customers comment on how quickly and effectively it humidifies a room. Others like that it is an evaporative humidifier, so no visible mist comes out. Negative reviews write about how expensive replacement filters can be.
However, it’s a loud and bulky model, so it’s not ideal for an office or sleeping environment. This humidifier features a fairly basic design, with fewer features than its competitors at this price range.
This model is easy to set up and it comes with two flat paddles, which are easy to install and two water tanks. As an evaporative humidifier, the model sucks in dry air from the room via a wet filter and then pumps out warmer air in order to change the humidity of the room. If you’re looking for a high tech humidifier, then you might want to look elsewhere, as this model only has two buttons to control its humidity and fan speed. The fan speed can be either fast, medium or low, which is also its quiet setting. With no LED screens, being able to actually set the humidity level you’re after can be confusing.
This humidifier performs well. In our at-home testing, it reached up to 63% humidity on its highest level, while on the lowest level it reached up to 53%. As its two water tanks are so large, it can also run continuously for 24 hours on its lowest setting before needing to be filled up again.
- Read our full Honeywell Top Full Cool Moisture review
The Levoit LV600HH humidifier has some interesting features, including three mist settings, an essential oil diffuser for aromatherapy and a dual nozzle that twists 360 degrees.
Customers on Amazon gave the Levoit LV600HH humidifier an average score of 4.5 out of 5 and mentioned its humidity levels and remote control the most. Positive reviews cite its high output of mist and how easy it is to clean, while negative reviews mention that the warm mist can get quite hot and how the auto setting isn’t accurate.
As a smaller model, it’s ultra-quiet but is capable of holding a large amount of water, which means that it can run for up to 36 hours.
This humidifier is great for larger rooms that measure between 430 to 753 square feet. The built-in water tank is see-through, which means that you always know how much water you have left in your tank. Able to sit on your worktop or tuck under a table, it’s a little tricky to fill up. However, this humidifier is ready to use as soon as you get it out of the box, with nothing to set up aside from filling the water.
With a small LCD display on the front, it also has various buttons that enable you to control the mist level, humidity and how long the humidifier will run for. The mist function has three settings going from low to high, while the humidity button enables you to change the percentage of humidity in the air. During testing, we found that even on the highest mist level, the humidifier didn’t need a refill until the next day, running for more than 17 hours. Meanwhile, the nifty remote control means that you can control the humidifier from up to 16 feet away.
Usefully, this humidifier is both easy to operate and extremely quiet.
- Read our full Levoit LV600HH humidifier review
This is a small and attractive model that features touch screen buttons and a large display that shows the temperature and humidity levels.
The Elechomes HTJ-2119 Ultrasonic Humidifier fares well on Amazon, featuring a 4.5 out of 5 rating. Many like how sleek the humidifier was, along with its very low noise. Other positive reviews loved how it could be controlled via remote control and how easy it was to set a specific humidity level. Negative reviews concentrated on how small the handle of the model was, and others said that the lights on the model distracted them at night.
The humidifier pumps out a cool mist, while the built in humidity sensor enables you to set your preferred humidity level. Other functions include a child lock, sleep mode and the option to add essential oils.
This model is sleek, but tall, so you’ll need around a foot of height if you want to tuck this into a corner or under furniture. Filling the tank is fairly easy and it performs best in a medium sized room or house – or anything that equates to 322 to 528 square feet. The buttons on the display are easy to use and very self explanatory, while the remote control can also control the humidifier as well.
The highest mist setting can raise the humidity levels in a medium sized room up to 69% in just under an hour, while the humidity target can be adjusted so you never feel uncomfortable with the humidity levels in the room. However, be careful that the water doesn’t leak on the highest setting - our reviewer had a pool of water escape when it was tested. The aroma pad is also a nice extra, enabling you to add essential oils to the pad that the humidifier then emits with the mist, giving an extra scent to the air.
- Read our full Elechomes HTJ-2119 Ultrasonic Humidifier review
The only smart humidifier on our list, the Levoit Classic 300S humidifier connects to the VeSync app, which enables you to control the mist levels and notifies you when it needs cleaning.
The Amazon reviews for the Levoit Classic 300S humidifier scores an impressive 4.6 out of 5 with many happy customers commenting on how quiet it is and how easy it is to clean, because of its wide opening at the top of the humidifier. Negative reviews focused on how the humidifier was too sensitive and that the auto mode didn’t work as well as other models.
A medium sized sleek model, the clear water tank sits on the top, giving you a clear indication of how much water is left.
Perfect for small or medium sized rooms, the humidifier will need some assembling, but it's not a complicated affair. With a large LED display, it clearly indicates the humidity level, while the buttons for mist levels, night mode and humidity levels sit around this. The connecting app is easy to download and connects via WiFi. Once downloaded, the app enables you to switch between the manual, auto and sleep modes. You can also set a timer and change the humidity levels via the app.
This humidifier is easy to clean and its humidity levels perform well on both the high and middle mist setting, climbing to a 68% level within two hours on the highest setting. Another quiet model, it will last for 19 hours on a high setting, but 60 on a lower setting. However, the built-in humidity sensor is quite sensitive and the model does need to be cleaned regularly to avoid bacteria getting into the water.
We also like the aromatherapy option on this humidifier. We added six drops of strongly-scented tea tree oil to the aroma pad and enjoyed the lightly-scented air in our room an hour later. Note that six drops is more than the recommended 2-3 drops.
- Read our full Levoit Classic 300S humidifier review
How do we test humidifiers on Live Science?
Every humidifier in this guide has been tested to the exact same standards, using the same processes.
We start by noting the humidity level of a closed room. We fill each humidifier’s tank to the maximum and let it run on the highest setting (also noting how long it takes to empty the tank). While the machine is running, we measure the noise level of the machine in decibels. After an hour, we measure and take note of the humidity level in the room. This is repeated at the two hour mark, or when the tank is empty. This process is repeated for each mode the unit has, such as lower mode and night mode.
Our testing also takes into account the size of the unit, whether it emits cool or warm mist, the cost, ease of use, availability of additional parts, ease of cleaning and the energy use on the lowest and highest settings. Finally, we check online user reviews to see what people think, and we test for any persistent problems or defects that we read about.
As per our testing policy, we fully disclose all our findings in our reviews.
How to maintain your humidifier for optimum performance
The best humidifiers are great at ensuring the air quality is maintained in your home, but there are some best practise guidelines you should follow to ensure they are running at their best. Tim Carroll, a representative from the Environmental Protection Agency, explained to Live Science the best ways to keep your humidifier maintained to ensure it runs smoothly:
• You should empty the tank of the humidifier, wipe all of the surfaces dry and refill the water in portable humidifiers daily. This will help to reduce the growth of microorganisms.
• Try to use water with a low mineral content in order to prevent the build-up of unwanted minerals in the tank. This will also reduce the potential dispersal of minerals into the air.
• You should aim to clean portable humidifiers every third day.
• Clean and dry the humidifier thoroughly when storing the product or when it is being used infrequently.
• Do not humidify to indoor relative humidity levels exceeding 50 percent.
• Do not allow the area around the humidifier to become damp or wet.
• Follow any specific manufacturing instructions regarding use, cleaning, and maintenance.