A big problem for people in dry climates that require home humidification the amount of noise some of these devices can make. If you are a light sleeper, it can be extremely frustrating to get good night’s rest in a room with a fan whirling at high speeds. Enter the ultrasonic filterless humidifier. These modern-technology devices have become a popular option due to their whisper-quiet operation, and the fact that you don’t have to shell out money for a new filter ever few months. They come in a wide range of sizes, aesthetics, and have various features included to make operation efficient and enjoyable.

What Types of Filters are there?

As far as filterless humidifiers go, they do a fine job of helping restore moisture to your home, but in the end, they cannot provide 100% clean air. Warm mist humidifiers will heat up the water to a boil, killing any bacteria, but as there is no filter, the unit will still release grey dust into the atmosphere. Cool mist humidifiers will release anything that is in the water into the atmosphere. Some models have an ionic filter that can help slow the mold and mildew growth rate, but that’s about the best they can do.

Evaporative humidifiers use a wick filter that acts as a barrier between the water in the tank, and the mist that is distributed throughout the home. Basically, any bacteria and impurities in the water to cling to the wick so that only clean air is being released. These filters are high maintenance, are required to be soaked in a vinegar solution weekly, and replaced every few months due to the amount of mineral deposits that build-up on them.

The other type of filter would be an air purifier. These add no moisture to you room, but they do filter out allergens and hazardous airborne particles quite effectively. They suck in the bad air, pass it through a filter, and release the clean air. As with any device that employs filtration, the purifier needs to be cleaned regularly to maintain proper operation, with a full filter replacement to be done after a few months of use.

How does a Filterless Humidifier Work?

Filterless humidifiers use ultrasonic technology to add moisture to a room. The water from the tank is converted into vapor as a result of vibrating a metal diaphragm via a high-pitched (ultrasonic) frequency. A fan then disperses the mist into the room.

Most manufacturers will recommend using only distilled water. This helps to accomplish two things:

  • Distilled water, unlike tap water, has already had bacteria and impurities filtered out of it
  • Distilled water, unlike tap water, won’t release any grey/white dust into the atmosphere, which can get on your floors, furniture, and into your lungs

While filterless humidifiers will never be able to fully purify tap water, there are some 2-in-1 models that come with a built-in air purifier.

Things to Consider Before Buying One

Before you plunk down your hard earned cash on a filterless humidifier, you should take into account the following considerations.

Capacity

Humidifiers come in a variety of sizes. Some are portable and can be taken anywhere you go, while others can hold multiple gallons of water if you need to eliminate dry air in a large living space. The majority of humidifiers are made for medium-large rooms, as these are usually the size of bedrooms, nurseries or offices. 1 gallon (almost 4 liters) is a very common tank size, and can usually output 24 consecutive hours of moisture on a low setting. Adjustable humidification knobs allow you to regulate how much mist is released, and you can even find some models that include how many milliliters per hour the tank will put out.

Maintenance / Cleaning

Cleaning filterless humidifiers is something that has to be done on a regular basis. While distilled water is always recommended for use with a filterless humidifier, the tank can still accumulate mold and mildew after only a few uses, and warm mist humidifiers are also susceptible to mineral deposits forming on the bottom of the tank. Cleaning the unit once a week will help keep the air bacteria-free. Soap and water, or vinegar and water, are both effective ways to clean your humidifier. Your owner’s manual will most likely come with a step-by-step how-to guide for reference.

Noise

The noise output of filterless ultrasonic humidifiers is next to nothing, making you sometimes forget that’s its even on!

Coverage

Most humidifiers now come with an adjustable nozzle that you can use to direct your mist in either 180 degrees, or a full 360. This comes in handy if you place the unit in a corner and you want to make sure the mist sprays into the room and not all over the walls. Some humidifiers can also shoot moisture a few metres into the air, giving you wide coverage in a short amount of time, and the bigger the tank size, the more square footage it will cover.

Cost

The popularity of filterless humidifiers has made them extremely affordable. Starting as low as $30 for a basic model, a solid, middle of the road option will be around $60, with larger, more elaborate models costing over $100.

Best 7 Filterless Humidifiers

Vicks Filter-Free 1.2 Gallon Cool Mist Humidifier Review

This easy-to-fill 1.2 gallon humidifier from Vicks is designed for medium-sized rooms and will help those congested nights become a distant memory. Giving you up to 30 hours of cool mist, the translucent tank allows you to monitor water levels while emitting zero noise during operation. Controlling the amount of moisture is simple using the adjustable knob on the front of the unit, and when the tank runs out of water you can rest assured that the automatic shut off feature will keep you and your family safe from a potential fire hazard. A slot on the side of the humidifier allows for use of up to two Vicks Vapopads, providing 8 to 16 hours of soothing vapors to help you sleep.

Capacity

This model holds 1.2 gallons (4.5 liters) of water and can run continuously for up to 30 hours.

Noise

The ultrasonic technology renders this humidifier noiseless.

Pros

  • Great value
  • Long lasting for medium-sized rooms
  • Adjustable mist output
  • Auto shut off feature
  • Can add Vicks Vapopads to unit

Cons

  • Can’t purify water
  • Distilled water recommended
  • Regular maintenance to reduce mold and mildew

Honeywell HUL535B Cool Mist Humidifier

Producing a fine stream of mist, this Honeywell option comes in black or white. Designed for medium sized rooms, you won’t have any noise from the unit, and the tank is transparent giving you a real-time visual on how much water is left in the tank. This humidifier can mist for 24 hours straight on the 1 gallon tank, however this depends on how much moisture you are outputting, which is controllable using the regulator knob on the front. You can also direct where you want the mist to go using the 180 degree nozzle, and the unit will shut off on its own when it is out of water. At 13.5 x 8.5 inches, it is an extremely portable option that can be easily added to desks, tables, or the corner of any living space.

Capacity

This humidifier hold 1 gallon of water, giving you up to 24 uninterrupted hours of mist.

Noise

This unit makes no noise.

Pros

  • Excellent price
  • Great option for medium-sized rooms
  • 180 degree output nozzle
  • Adjustable humidity levels
  • Auto shut off feature
  • No filter to clean or replace
  • Multiple color options

Cons

  • Will not filter out impurities
  • Distilled water recommended
  • No aromatherapy box

TaoTronics Cool Mist Humidifiers for Babies Review

Sleek and compact, Taotronics designed this vertical humidifier to save you space while efficiently adding moisture to any room in your home. Available in white or black, it has a straightforward operation, with adjustable knobs to give you full control over how much humidity is released. Cleaning the unit is pretty simple (they even include a brush for you) but needs to be done regularly as bacteria and mold can accumulate over time. This humidifier is noiseless and works well for anyone that needs a silent sleeping environment, and also includes an automatic shut off feature in case the tank gets drained during the night. FCC certified and BPA-free, the 1.8 litre tank can give you anywhere between 8 and 20 hours of use, with the mist nozzle rotating a full 360 degrees for directional control.

Capacity

This model puts out 50 to 210 ml of mist per hour, giving you between 8 and 20 hours of use from the 1.8 litre (0.48 gallon) tank.

Noise

This ultrasonic humidifier is very quiet, making it perfect for offices, bedrooms, and nurseries.

Pros

  • Great option for small rooms
  • Quiet
  • Vertically-designed to save space
  • FCC certified safe
  • BPA free
  • Safety shut off feature included

Cons

  • No filter to get eliminate bacteria in water
  • Distilled water recommended
  • Cannot use with oils / formulas

Crane Ultrasonic Cool Mist Humidifier

Also known as the “Crane Drop” (due to its resemblance to a drop of water), this ultrasonic humidifier is competitively priced and comes in a wide array of colors to match the decor of any room you want to use it in. The 1 gallon tank removes from the base and is upside-down filled, which may or may not pose a challenge depending on your level of dexterity. With a full day’s worth of misting capability, the 360 degree lid makes it easy to fill any area of your room, and the ultrasonic characteristics make this one noiseless machine. Running up to 24 hours isn’t a problem, and if the unit does run out of water it will automatically turn off. Crane also coated the base in an anti-microbial material to deter mold and mildew from forming easily. Weekly cleaning of the tank is recommended with a simple water and vinegar solution to keep it operating with maximum effectiveness.

Capacity

Outputting continuous mist for 24 hours, this tank can accommodate 1 gallon (3.78 liters) of water.

Noise

This humidifier makes virtually no noise.

Pros

  • Good price point
  • Quiet operation
  • Mist regulator knob
  • Automatic shut off function
  • Transparent tank
  • Anti-microbial coated base
  • Small size to fit into any space

Cons

  • Cannot add aromatherapy oils
  • Does not filter water
  • Distilled water recommend for use
  • Weekly cleaning

Rosewill Ultrasonic Cool Mist Humidifier for Bedroom

With a 5 liter tank, you can be sure there will be no water shortages if you decided to pick up this humidifier from Rosewill. The large capacity makes it an ideal choice for medium or large sized rooms, and it operates at a quiet 32 decibels. Customizable features include two fully rotatable nozzles to direct where you want your mist stream (or streams) to go, as well as a volume output knob on front so you can regulate how much moisture is being dispersed. Designed with night time use in mind, a night light illuminates the tank, and if it is running on empty, the unit will turn off by itself. All in all, a solid choice that will help you breathe better any time of the year.

Capacity

This tank holds 1.3 gallons (5 liters) of water and can give you anywhere from 12-24 hours of uninterrupted use depending on the output level.

Noise

At 32 decibels, this unit is virtually noiseless.

Pros

  • Good value
  • Silent operation
  • Adjustable volume output
  • Two 360 degree nozzles
  • Night light included
  • Automatic shut off

Cons

  • Cannot add oils / formulas
  • Distilled water recommend for use

Safety 1st Filter Free Review

Catering to the new parent market with color choices of pink and blue, this bare-bones humidifier from Safety 1st could still be used in any room to alleviate respiratory illness brought on by dry air. The tank is a decent size at 1 gallon, and you should have no problems filling small to medium-sized rooms over the course of a night without interruption. Outfitted with a rotating nozzle for directional control and wider coverage, the unit also has a dial to adjust your mist output, and the automatic shut off feature will ease your mind if you are asleep or out of the room when the humidifier runs out of water. The flat top design makes it easy to rest the tank in the sink while refilling or cleaning, and at this price point, its hard to find a better budget humidifier.

Capacity

This one gallon tank can provide soothing mist for up to 36 hours.

Noise

This humidifier uses ultrasonic technology for quiet operation.

Pros

  • Low Price
  • Basic but does the job well
  • Multiple color options
  • Rotating nozzle for wide coverage
  • Automatic shut off safety feature

Cons

  • Not to be used with aromatherapy oils
  • Distilled water recommended

OPOLAR Quietest Filter-Free Digital Humidifier

Looking like something you would see in a film about the not-too-distant future, Opolar’s ultrasonic digital humidifier gives you an assortment of features in a tiny, noiseless unit. Going completely dark when put in sleep mode, the unit can hold 3 liters of water for a 12 to 26 hour return of moisture. The digital display on the front allows you to customize the controls – everything from the amount of humidity in the room to the amount of mist expelled. You can also program anywhere between 1 and 9 hours of use using the timer function. A water shortage protection feature safely turns off the unit and tells you it’s time to refill the tank. Standing 10 inches wide x 10 inches tall, it seamlessly blends into any style of home decor, and while it may be small, it packs a mighty punch.

Capacity

This ultrasonic humidifier holds 3 liters (almost 1 gallon) of water, outputting 300 ml/hour of mist volume, over a span of 12 to 26 hours.

Noise

Very quiet operation, although it does beep when it needs to be refilled.

Pros

  • Aesthetically pleasing
  • Noiseless
  • Fully customizable
  • Auto shut-off sensor
  • Humidity level can be set between 45% and 85%

Cons

  • Cannot use aromatherapy oils
  • Distilled water recommended
  • Unit repeatedly beeps when out of water

Conclusion

Filterless humidifiers allow you to alleviate allergy symptoms and sickness caused by dry air, in a healthy and affordable way. While their filterless design makes them ideal for quiet operation as well as rapid balancing of moisture levels in a room, their Achilles’ heel remains the problem of potentially releasing waterborne bacteria and grey dust into the atmosphere. The way to solve this issue is to always use distilled water with these humidifiers and clean them regularly. If you can manage that, you will greatly improve your chances of rarely falling ill, and a good night’s rest will no longer be a pipe dream.