Knowing The Best Filterless Humidifier: Reviews & Buying Guide 2021

For so many reasons, consumers prefer filterless humidifier over unit that uses filters in their operation. This is as a result of the low cost of maintaining filter-less humidifiers. That is no filter to clean or replace, saving your time and cost respectively.  However, on the market, humidifiers that uses filters has the highest numbers and that means, none-filter units are low in number.

You should also know that most humidifiers without filters are mostly ultrasonic and this type of humidifier is not powerful enough to cover a whole room humidity need. Nevertheless, you can count on filterless unit for whole room humidification. However, if your interest is getting a humidifier with no filter, I am here to help you as I have researched and compile my best filterless humidifier into a review form for your consideration.

Bionaire Ultrasonic

  • Up to 700 sq. ft
  • Digital timer
  • 48 hours operation
  • 1.5 gallon tank size
  • Releases cool mist
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MistAire XL Ultrasonic

  • 500 sq. feet coverage
  • Up to 20 hours runs time
  • One gal. water tank capacity
  • Delivered only cool moisture
  • 5 years warranty
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Rosewill Ultrasonic

  • 250 sq. feet.
  • 5 liter tank size
  • 360 degree nozzle
  • 10 hours of mist emission
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Honeywell Cool Mist

  • For space of 250 sq. feet.
  • 46 hours of mist delivery
  • 1 gal tank water holding
  • Equipped with rotating nozzle
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Honeywell HUL535B

  • 24 hour operation
  • 250 square rom coverage
  • Dual directional mist outlet
  • Quiet operation for night sleep
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Elechomes UC5501 Ultrasonic

  • 750. sq. ft.
  • 40 hrs. operation
  • 1.5 gallon tank
  • Essential oil cup
  • Dual mist (cool or warm mist)
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Everlasting Comfort With Oil Tray

  • 400. sq. ft.
  • 24 hrs. operation
  • 1.6 gallon tank
  • Essential oil cup
  • Cool mist only
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LEVOIT Humidifiers for Large Room

  • 750. sq. ft.
  • 36 hrs. operation
  • 1.5 gallon tank
  • Remote control
  • Essential oil cup
  • Dual mist (cool or warm mist)
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Vornado Ultra3 Whole Room

  • 600 sq. ft.
  • 1 gallon tank
  • 24 hours operation
  • Cool mist only
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OPOLAR Quietest Filter-Free

  • 500 sq. ft.
  • 0.8 gallon tank
  • 26 hours operation
  • Cool mist only
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10 Best Filterless Humidifier Comparison & Reviews

1. Best Tower Unit: Bionaire Ultrasonic Filter-Free Humidifier

Best Filterless Humidifier Reviews For Bedroom

To maintain a healthy state in dry month while eliminating problem of dry air such as bacteria with a filter-less humidifier, you can rely on the Bionaire Ultrasonic unit to restore relative humidity. The unit is a standalone unit that can be mount directly on the floor without any suspension table or desk.

The space saving designed filter free humidity provider is a perfect device for people living in rooms with limited space. Also with its black color, a little dusting will keep the unit surface clean and shinning.  The BUL7933CT model comes with other notable features that make it an attractive unit for the price which are stated below:

  • Great appearance perfect for any environment you can think of.
  • Programmable digital humidistat.
  • Installed with 1.5 water tank capacity that enable the unit to run for not less than 24 hours
  • The tank is designed with antimicrobial material that prevent growing of mold, bacteria etc. that can cause odors, stains or affect the unit performance.
  • Viewable LCD panel that lets you view settings such as current room humidity level, tank level, timer, and other features
  • It is ideal for large room/bedroom
  • Equipped with empty tank functioning
  • It’s pretty quiet while working

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2. Best Small Filterless Humidifier: MistAire XL Ultrasonic Cool Mist

MistAire XL Ultrasonic Cool Mist Humidifier for Large Rooms

The MistAir XL is another ultrasonic unit in this filterless humidifier reviews uses no filter which makes it one of the cheapest ultrasonic filter free unit discussed. The small and compact sized makes it fit for tabletop or office desk occupying lesser space. In addition, the size allows for easy mobility from one room to another making this large room ultrasonic preferable compared competitive bulky unit.  Safety is also engineered inro this cool mist humidifier while remarkable features outlined below:

  • Built for large space bedrooms (500 square feet)
  • One gallon tank last for up to 10 to 20 hours operation
  • Variable mist control knob
  • Optional night light (red, green and blue)
  • Has a dual mist outlet
  • Unit turns off when water level is empty or when tank is removed
  • 5 year warranty
  • Accessories includes AC power adapter, disk cleaning brush and user manual

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3. Rosewill Ultrasonic Cool Mist Humidifier for Bedroom

Rosewill Ultrasonic Cool Mist Humidifier for Bedroom

We recommend this Rosewill filter-less unit for small to medium sized rooms and also for those in needing a 360 degree nozzle for random mist distribution in their room. The transparent tank unit features a reservoir that hold a good amount of water  and last you through the night providing cool mist. Operating and maintaining the unit, is not a tasky as an ultrasonic model, no filters to clean or replace.  Check the specs below for more details:

  • 5liter tank capacity
  • Dual nozzle that rotates in 360 degree wise
  • Auto shut off when tank is empty
  • Different mist control
  • Built in low LED light
  • Runs quietly with
  • Associated with low maintenance
  • For spaces measuring up to 250 square feet
  • Tanks feature a tank for easy refilling

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4. Honeywell Cool Mist Filter Free Humidifier

Honeywell Cool Mist Filter Free Humidifier

You can as well choose this honeywell product in this best filter less humidifier. This humidifier with no filter, provides low cost of maintenance because no filters to wash or replace. although, not for bigger spaces, but perform effectively in personal spaces. Top of the pros, it comes cheap and yet run up to forty eight hours.  You may consider the rest of the feature if this unit may interest you:

  • Refilling is as easy as breeze
  • Equipped with 1 liter tank but will last you for up to 46 hrs of run time.
  • No filters needed
  • Automatic shut off
  • Removable safe parts dishwasher
  • Works more efficiently in small – medium size room /bedroom
  • Rotating mist nozzle

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5. Honeywell HUL535B Cool Mist Humidifier

Honeywell HUL535B Cool Mist Humidifier

This honeywell filterless system is one of the elegant machine with transparent water viewing tank.. This HUL535B model from Honeywell is designed to deliver cool mist. It is ideal for small bedroom use and also fit into little space or table.

The black color unit won’t prove difficult to maintain and also as an ultrasonic, no filter also means, no noise pollution. Small foot print unit but comes with outstanding features that makes operation an interesting one. Check for yourself if this unit meet your room moisture adding demand:

  • Variable mist setting
  • On low setting can run for up to twenty-four hour in one refill
  • Releases invisible cool mist that’s improves skin and ease congestion
  • Manufactured for medium room use
  • Ultra-quiet operation
  • The unit goes off when tank level is low
  • The need of washing filter or replacing is not required as a filterless humidity device.

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6. Elechomes UC5501: Best no filter humidifier

Elechomes UC5501 Ultrasonic Warm and Cool Mist Humidifier

This is one of the popular filterless humidifier among consumers that operate with low Db noise making it undeniable choice for night sleep. The low sound also makes it perfect for baby’s rooms. The ultrasonic has the capacity to spread mist to 750 square feet. With a reservoir capacity of 1.5 gallon, you’re guarantee of 40 hours run time. Elechomes UC5501 is designed to output either warm or cool mist which is one of the biggest pros to choose this unit because you’ll able to alternate from one mist form to another.

The smart humidity technology provides accurate levels, no excess moisture distribution. You’ll get as you have tailored the machine to provide. This also comes with a 360 degree nozzle that spreads moisture evenly as such proper home humidification can will be achieved. See highlight below:

  • Large water room storage
  • Automatic machine shut down
  • Classic design for urban environment
  • Customizable humidity settings
  • Spread mist all over room with a rotating nozzle
  • 750 sq. ft. rooms coverage and up to forty hours run time.
  • Low decibel nose improves sleeping with a humidifier

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7. Everlasting Comfort Ultrasonic Cool Mist Humidifier (6L) – Essential Oil Tray

Everlasting Comfort Ultrasonic Cool Mist Humidifier (6L) - Essential Oil Tray

If you’re looking for a filterless – humidifier for large room, you can consider Everlasting comfort. The Elechomes reviewed above also meet large room’s humidification. Nevertheless, Everlasting comfort is built to emit cool moisten air for reviving dry skin, chapped lips including sinus problems. In rooms of 400 sq. feet, the ultrasonic cool mist works effectively compared to higher coverage. As such do not use the everlasting unit above the said coverage area for efficiency.

From a six liter tank, you’ll enjoy mist for 24 hours. Top of the notch, mist will be circulated in an entire room, thanks a 360 degree nozzle.  While high humidity causes mold growths and her brother mildew, you don’t need to worry, set desire humidity and once the range is attain, unit turns off. As you humidifies, vaporize scent in your room atmosphere by adding essential oil to the tray designed for it. Check following highlight:

  • Night LED light
  • 400 sq. ft. coverage
  • 360 degree wise nozzle
  • 1.6 gallon tank size
  • Essential oil tray
  • Ultra quiet operation
  • Automatic shut off keeps unit safe

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8. LEVOIT Humidifiers for Large Room

LEVOIT Humidifiers for Large Room, 6L Warm/Cool Mist

Looking for a filterless humidifying system that comes with a reasonable warranty period? Levoit Humidifier featured here comes with 2 years warranty from the maker. This means mark of confidence from the manufacturer to consumers to enjoy assistance should anything goes wrong within warranty period.  Levoit delivered 2 mist form such as warm or cool mist just like Elechomes models seen earlier. For colder winter, most users switch to warm option while summer known for hotness, cool mist mode does the work better. The super high mist output best matches 750 coverage square ft and operates for up to 36 hours from a large tank of 1.5 gallon.

The remote system that comes with it let you control the device within room distance thereby allowing for convenient usage. You can maintain 30 to 50% humidity level, thanks to the auto humidity controlling technology. You’ll not also be left out of aromatherapy – vaporize favorite’s essential liquid. This device also feature safety functionality that protects unit from damaging. Glance specs quickly below:

  • Compatible with essential oil use
  • Built for maximum square feet of 750 limit
  • Conveniently operate the machine via remote
  • Switch between warm and cool mist option
  • 1.5 gallon tank powers unit for 36 hours in one refill
  • Ideal for living rooms, bedroom and office use
  • View actual humidity through the display for you to customize yours

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9. Vornado Ultra3 Whole Room Ultrasonic Humidifier

Vornado Ultra3 Whole Room Ultrasonic Humidifier

Another best filterless humidifier as highlighted by us, is the Vornado Ultra 3 model. This machine uses vornado vortex action in circulating mist air powerfully. For this reason, you can rely on the ultra 3 series to release cool humid air in spaces of 600 sq. feet. Choose from three mist control level such as high, medium and low.

To add to the features, an electronic humidistat for auto humidity control ensuring home is not over humidified. A filterless air humidifier of this kind also installed with easy to push buttons featuring LED nights for confirmation of settings. With 1 gallon water size, the unit function as long as twenty four hours. The surprising side, back up with highest industry warranty of five years. See highlights:

  • Bigger rooms coverage
  • Customize humidity display (low, medium or high)
  • Up to 24 hours runs time powered by 1 gallon capacity tank
  • 5 years industry warranty
  • It does not support essential oil use.

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10. OPOLAR Quietest Filter-Free

 OPOLAR Quietest Filter-Free Digital for Baby and Bedroom

Last but not the least machine in this reviews, comes Opolar digital humidifier. The filter-free unit grants you access to 3 speed humidification. This mean you can choose from 3 mist output level. The ultrasonic cool mist house humidifier also featured a timer settings that let you determine the duration you want Opolar to work before shutting down. The available timing option includes 9 hrs, 12 hrs to 26 hours.

The touch sensitive LED display, let you control humidity levels by viewing the current value and therefore tailor an ideal range. This 3 liter unit foster humidity faster in rooms measuring 300 to 500 ft2. There is also dual nozzle which you can rotates individually meeting different direction moisture releasing. It also comes featuring safety features and back up with warranty. Highlight specs below:

  • Speed settings includes sleep mode
  • LED display settings
  • Auto shut off
  • 300 – 500 sq. feet. coverage
  • Up to 26 hours timer settings
  • 0.8 gallon water tank size
  • One year warranty
  • Dual nozzle can be adjusted independently of each other. 

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Why do we recommend filterless whole house humidifier?

Humidifiers for whole house without filters are few on the market, you may be fortunate to run into one or may not even find one. However, with our in-depth researched, we were able to discover this unit as best deal for whole house.

What Are The Pros Of Filterless Humidifiers?

There are plenty of benefits to enjoy while using a filterless humidifier as your preferred choice of machine. This includes the following:

  • Low noise operation: Because this models of humidifiers don’t use filters in their operation, they however more quieter compared to unit with filter systems. If you want to have a quiet sleep at night, a filterless humidifier such as large room model from Leviot brand is a device to consider. With a humidifier machine that operates with reduced noise level, your family won’t be disturbed.
  • Reduced Maintaining Cost: I personally like filterless humidifiers because of the filters they lack, therefore no extra money to be spent on buying new filters.
  • Antibacterial Tank: Since these models have no filter in their operation, the manufacturer infused antibacterial material into the tank system to prevent mildew, mold, and other allergens causing agents from attacking the tank.

The end result is healthy breathable air devoid of bacteria and germs. The moisturized air also keeps your skin moist and glowing.

How To Choose the Best Filterless Humidifier

The competition among manufacturer is growing on daily basis. For this reason, filterless humidifiers are on the increase, because every brand want to sell more products. At the end those who purchase these products may be on the losing side if you don’t choose wisely. We care so much that’s why we went ahead putting this section together to further as assistant you. Find the detail below:

  • Types of Mist Option

Two mist models available for humidifiers without filters such as the cool mist and warm mist. Don’t get it wrong, both are designed to raise indoor humidity levels in homes but the functionality separate them into their various class. You may see cool mist humidifiers as units that disperses moisture without heating the water while warm mist humidifiers emit warmer air because of the preheating technology in them.

Your demand however may sets in when choosing among the two mist types. In most discussion context, warm mist models are seen better off compared to the cool mist as they heat water, bacteria are destroyed. In addition, no filter in them makes them less expensive to maintain.

  • Coverage Space

Each humidifier is designed to cover a limited area which is usually in square feet. Filterless whole house humidifier are nice for entire house, this exist in console form.

Smaller models are great for personal space or office desk use (their coverage is maximum 250 sq. feet.)  Units from 250 square feet and above are best filterless humidifier for large room’s usage.  

Note, the appropriate humidifier sizing for rooms/house is crucial because unit with higher power may disperse more moisture, thus encourages mold development and vice versa.

  • Digital Humidistat

Understating this feature will help you maintain the best home humidity levels throughout the year. A humidistat is digital technology in a humidifier that regulate moisture being release from the device to keep it at a desire level comfortable for living.

Wisely choosing a machine that comes with a humidistats, means you’ll get accurate humidity but if you already have a model, then a hygrometer – a humidity monitor will be the only option to keep tracks of moisture level.

  • Noise Level

When opting for filter-less humidifiers for bedrooms, you need to consider the sound level. A maximum decibel sound of not more than 42dBA is considered ideal for bedrooms sleeping. If you want a unit that won’t disturb your baby, here is our best quiet filter-free humidifier for the year.

  • Warranty

As for me I don’t purchase major appliances if there is not warranty backup due to previous experiences. Should in case there is malfunctioning of the unit or refusal to work within the stipulated warranty covered period, you can request for a repair or replaced depending on the warranty policy. In other words, this back up does not mean the device will last long but gives confidence as the manufacturer is able to place it on it.

  • Additional Specs

Feature such as automatic shut off enables you program the device to working duration you desire before turning off. In addition auto shut off shutdown the unit once water level is low beyond dispersion keeping your unit safe and saving energy than running continuously without water.

You may also check mist control settings, a machine with 3 speed fan settings such as low, medium and high, gives you control to tailored output accordingly.

One more features is a fragrance tray – where you can add essential oil – if this features is not available in the unit you’re aiming at, you won’t be able to flavor your air with liquidate.

Cons of Humidifier Without Filters

The following are the short coming associated with filterless units:

White dust: One of the biggest risk of without filter humidifiers is the white dust some models produce because there is not filter to trap them. White dust result from minerals compounds present in the water (especially hard water) being used for the machine.

When minerals are formed inside the unit, they’re supposed to be filtered out via filter system but seems no filter to hold them, therefore released into air. Over time, you start noticing white stains all over your house hanging on your properties and health risk may set in.

  • Purchasing Distilled Water: The good news, with the use of distilled water, you can avoid white dust being disperse into your home air but it’s expensive which may double humidifier operating cost.
  • Limited Coverage: If you want to power a larger space, you might be disappointed on filterless system because they are built to cover smaller areas. In this situation, you’ve to fall back to competitive models like the evaporative models.


  • Can I use ordinary tap water?

Yes, you can use ordinary water since it is more affordable and quick to get. But distilled or treated water is always the recommendation because your tap water creates mineral building up inside the unit and may be difficult to clean.

  • What causes white dust in humidifiers?

Ultrasonic humidifiers can disperse white dust when direct water from tap is used. However, white dusts are end products of minerals present in hard water. Often you start noticing whitish dust on home surfaces, chairs and others.

White dust can be a problem to allergy or asthma sufferer while to some, it’s something to overlook. The long run effect of white dust may lead to respiratory issues, that’s why distilled water is recommended by expert for cool mist filterless humidifiers.

  • How often should I clean my filterless humidifier?

Just like every other models, cleaning should be done on weekly basis. The tank should be giving proper washing using vinegar and mild soap ensuring all mineral built up are removed. Rinsed with clean water and allowed to dry out before the next use.

  • Should I run a humidifier all night?    

Yes, it is possible to run your machine all through the night but this depends on preference.

Our Verdict

I have come this far with you on the review of the selected filterless humidifier consider to be best in my own researched. By now so believed that you are well informed on the various products for effective decision on which unit that may interest you.  Wish you best of luck!

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