10 Best Filterless Humidifiers of 2021 Compared & Reviewed

Best Filterless Humidifier
Photo: Vicks

A filterless humidifier is a great appliance that promises to improve the air quality of your living or working space by countering air dryness, which can cause respiratory disturbances.

It works by converting water into either cool or warm mist, which is dispensed efficiently into the air you breathe.

If you experience cold-related symptoms such as throat irritation and stuffy airways, then a humidifier could help alleviate them.

In our filterless humidifier review, we explore some top models and their features while helping you choose one that’s ideal for your home.

Filtered Vs. Filterless Humidifiers

Filtered Vs. Filterless Humidifiers
Photo: Honeywell

Filterless Humidifiers

As the name suggests, these humidifiers don’t come with a filter. They eliminate the inconvenience of regular filter maintenance.

– Pros

  • Eliminates Filter Maintenance: Without a filter in the humidifiers, the appliance’s maintenance demands are lowered significantly.
  • No Filter Replacements: You won’t be buying any replacement filters for this humidifier. In the long term, you will save money.

– Cons

  • Demands Thorough Maintenance on Other Parts: Even in the absence of a filter, other components are doing the job of bacteria removal, for instance.
  • These will require regular maintenance, often weekly. Hard water may also increase the maintenance frequency for your humidifier.

Filtered Humidifiers

This humidifier dispenses moisture into the air after passing it through a filter that removes allergens and bacteria.

It is great for people who exhibit respiratory sensitivity.

– Pros

  • Effective Bacteria Removal: Unlike filterless humidifiers, filtered ones add a layer of protection by reducing the number of bacteria or allergens entering the air you breathe.
  • Water Boiling is Not Necessary: With water passing through a filter, it needs not to be boiled in most cases.
  • Because of the humidification simplicity, filtered humidifiers are generally affordable and will fit most budgets.

– Cons

  • Filter Replacement can be Costly: Even though filters tend to last long, typically for a couple of months, the fact that you will replace them for as long as your humidifier is running, can be costly.
  • Can Get Noisy: Can get noisier than filterless humidifiers because of the extra process involved in the filtration.

What To Know Before Buying Filterless Humidifiers?

How to Buy the Best Filterless Humidifiers
Photo: Honeywell

1. Types of Filterless Humidifier

  1. Warm Mist Filterless Humidifiers: They produce warm mist, which requires the water to be heated to some degree. They are effective in relieving common cold symptoms.
  2. Cool Mist Filterless Humidifiers: Produce mist that is the same temperature as the water being diffused. They include:
    • Impeller Filterless Humidifier: A rotating disk pushes water to a diffuser using immense force. The water is broken down into small droplets that are diffused outwards.
    • Ultrasonic Filterless Humidifiers: They use a vibrating diaphragm to produce an ultrasonic frequency, which converts water droplets into a mist.
    • Steam Filterless Humidifiers: They heat or boil water, which turns to mist at high temperatures, before being released into the environment.

2. Coverage Area

Coverage is a top priority when choosing a humidifier. You want a unit that will humidify the intended space efficiently.

Humidifiers have their coverage areas indicated on the packaging or specifications. You only need to confirm the size of your space, at home, or in the office, then grab one that matches it.

The area is typically represented in square feet, which you can easily measure. But if you have a really large space totaling 500 sq. ft., go for the Crane EE-5301W humidifier, which is rated for this space.

3. Water Tank Capacity

The tank capacity of your humidifier represents the amount of water it can hold, for mist production.

In attempts to keep these units compact while still maximizing utility, humidifier tank capacities are limited to about 1 gal. or slightly more.

With a high-capacity model such as PureGuardian H1175WCA, whose tank holds 1.5 gal., you will be refilling it less frequently compared to lower-capacity units.

4. Run Time

Humidifiers are designed to run for a given period on a full tank of water. You may get more convenience from your humidifier if it runs for long without requiring a refill.

And if convenience is a priority for you, consider getting a long-running unit such as PureGuardian H1175WCA, which runs for about 90 hours in its lowest setting.

But even 24 – 48-hr humidifiers are still great because they will get you through 1 or 2 night comfortably.

5. Noise Level

In the absence of a filter, humidifiers’ noise production is reduced significantly, but not completely.

The noise produced by your humidifier tends to reduce as misting strength lowers. Therefore, if your humidification demands are not high, you can keep the unit at its lowest power, for the least noise production.

Also, check the humidifier’s packaging for any indication of noise output, typically represented in dB(A).

6. Easy to Fill and Clean

For filterless humidifiers, the component needing the most maintenance is the water tank.

It requires regular cleaning especially if it is handling hard water, which could leave mineral deposits. Most tanks are easy to clean if you follow the prescribed steps in the manual.

Filling most tanks is easy because they will fit comfortably in most sinks. TrueMist HCM-29360107 especially boosts ease of cleaning and filling through its unique tank design.

7. Extra Features

Humidifiers are pretty straightforward appliances, but some will come with extra features that boost productivity and functionality.

The handiest additional feature you’ll find humidifiers is an essential oils’ tray. It is available in Guardian H940 and Honeywell HWM705B both have this feature.

Another convenience-boosting feature present in most models is auto shut-off, which turns off the humidifier when its tank runs out of water.

10 Best Filterless Humidifiers of 2021 Reviewed




Vicks V4600

1. Vicks V4600 (Best Overall)

  • High 100 – 400 sq. ft. coverage
  • Long 30 hr. run time
  • Includes 2 scent pad slots
  • Comfortable low-noise running
Rosewill RHHD-14002

2. Rosewill RHHD-14002 (Best Inexpensive)

  • Pocket-friendly & value-packed
  • 360° dual-nozzle outlet
  • Quiet for night operation
  • Convenient automatic shut-off
Guardian Technologies H940

3. Guardian H940 (Best Compact)

  • Compact space-saving design
  • Decent 350 sq. ft. coverage
  • Mold & mildew-free tank
  • Supports essential oil use
Crane EE-5301W

4. Crane EE-5301W (Best for Large Rooms)

  • Covers large 500 sq. ft. spaces
  • Whisper-quiet running
  • Efficient 360° mist lid
  • An easy-to-refill tank
Honeywell HUL535B

5. Honeywell HUL535B (Most Versatile)

  • Excels in home & office use
  • Directional & focused mist outlet
  • Easy to clean & maintain
  • Compact for desktop/nightstand
Honeywell HWM705B

6. Honeywell HWM705B (Best for Warm Moisture)

  • Warm-mist capacity
  • Simple 2-setting controls
  • Easy-grip tank handle
  • Handy essential oils cup
TrueMist HCM-29360107

7. TrueMist HCM-29360107 (Easy to Use)

  • Easy-to-clean tank
  • Simplified tank refilling
  • Long 48-hr run time
  • Multidirectional mist dispersal
PureGuardian H1175WCA

8. PureGuardian H1175WCA (With the Longest Run Time)

  • Extended 90-hr run time
  • Large 1.5-gal water tank
  • Reliable mildew/mold protection
  • User-friendly controls
Vicks V4500

9. Vicks V4500 (With a Scent Pad Heater)

  • Heated scented-pads support
  • Enhances symptoms relief
  • Easy-to-fill water tank
  • Flexible moisture adjustment
Honeywell HUT-300B

10. Honeywell HUT-300B (With a Stylish Design)

  • Stylish black & silver finish
  • Long 48-hr run time
  • Variable moisture adjustment
  • Convenient backlit water window

1. Best Overall: Vicks V4600

Vicks V4600

Photo: Vicks

  • Coverage Area: 100 – 400 sq. ft.
  • Water Tank Capacity: 1.2 gal.
  •  Run Time: Up to 30 hrs.

The large coverage, decent run time, roomy water tanks, and high run time combine to make Vicks V4600 our best overall filterless humidifier.

This cool-mist humidifier is optimized to maximize you and your family’s health by creating a humidity balance in medium rooms of between 100 and 400 sq. ft., a notably high coverage.

It features a roomy 1.2 gal. water tank, which extended the unit’s run time up to 30 hrs. You can run the humidifier during the day and at night without needing a refill.

Also included are 2 scent pad slots, where you can slot Vicks VapoPads to infuse soothing Vicks vapors into the air you breathe.

You will enjoy making this humidifier an essential part of you or your kids’ bedroom because of its impressively quiet running, which boosts the quality of sleep.

We did notice, however, that opening the Vicks V4600’s fill compartment is not an easy open. Its lid has a rubber gasket that increases friction.


  • Covers large spaces
  • Long run time
  • Also supports cent pods
  • Quiet for bedroom use


  • The fill compartment may prove hard to open

2. Best Inexpensive: Rosewill RHHD-14002

Rosewill RHHD-14002

Photo: Rosewill

  • Coverage Area: 250 sq. ft.
  • Water Tank Capacity: 1.32 gal.
  •  Run Time: Up to 10 hrs.

Rosewill RHHD-14002 is the best inexpensive filterless humidifier on our list. For less than $30, you get a low-noise unit with an advanced mist dispensing mechanism for optimal humidification.

It comes equipped with an advanced 360° adjustable dual nozzle mist outlet that is reliable in sending the cool mist wherever it’s needed.

There’s a 1.32-gal tank that holds a decent amount of water, minimizing the frequency of refills, and boosting operating convenience. And when the tank is finally empty, the unit automatically shuts off.

A built-in soft glow LED offers comfortable night lighting, while ultrasonic technology allows the unit to run quietly, preserving sleep quality.

The only significant downside of Rosewill RHHD-14002 is that its 10-hr run time is rather low compared to those of other rivals, many of which run for at least 24 hrs.


  • Great value for money
  • Omnidirectional mist outlet
  • Less frequent refills
  • Comfortable overnight operation


  • A rather low run time

3. Best Compact: Guardian H940

Guardian Technologies H940

Photo: Guardian

  • Coverage Area: 350 sq. ft.
  • Water Tank Capacity: 0.5 gal.
  •  Run Time: Up to 30 hrs.

Guardian H940 is designed to be a high-performance, but space-saving humidifier thanks to its compact build.

Measuring only 7.32 x 7.32 x 14.75 inches in size, the unit is not invasive of your space, and will even sit comfortably on a desktop. It makes for a great bedroom and office companion.

Even with its compactness, the humidifier still manages an impressive room coverage of 350 sq. ft. and will run continuously for up to 30 hrs.

The humidifier’s water tank features Silver Clean™ Technology, which actively fights mold and mildew growth on the tank surface so that the mist generated keeps you healthy.

There’s even an aromatherapy tray that helps create a relaxing environment by adding your favorite essential oils, while low and high cool mist settings create a soothing feeling.

Guardian H940’s tank capacity of 0.5 gal. is a bit limited and may require regular refills especially if run on highs settings.


  • Compact design
  • Decent room coverage
  • Hygienic mold and mildew-free tank
  • Supports essential oils


  • A low-capacity water tank

4. Best for Large Rooms: Crane EE-5301W

Crane EE-5301W

Photo: Crane

  • Coverage Area: 500 sq. ft.
  • Water Tank Capacity: 1 gal.
  •  Run Time: Up to 24 hrs.

If you’re you have a large room in your home that requires regular humidification, consider getting the Crane EE-5301W filterless humidifier, which offers a high coverage of 500 sq. ft. 

Because of its high coverage capacity, it is the ideal humidifier for medium-to-large rooms, and there’s a 1-gal tank to support continuous running for up to 24 hrs. The tank is also designed such that it fits under standard sinks, for easy refills.

It also runs with the quietness that will ensure a comfortable and peaceful night for light sleepers, such as babies and kids. Antimicrobial material has been included for mold and bacteria growth reduction of up to 99.96%.

You’ll be pleased with the humidifier’s variable speed setting, which offers operational flexibility. This feature combines seamlessly with a 360° mist lead for efficient mist dispersal. 

The LED light produced by the Crane EE-5301W may take some getting used to, especially at night, because of its brightness.


  • Large room coverage
  • Low noise output
  • Easy tank refilling
  • Efficient mist dispersal


  • LED light can’t be turned off

5. Most Versatile: Honeywell HUL535B

Honeywell HUL535B

Photo: Honeywell

  • Water Tank Capacity: 1 gal.
  •  Run Time: Up to 24 hrs.

The ease of use, directional mist dispersal, and medium-room coverage make Honeywell HUL535B a versatile filterless humidifier for both home and office use.

It’s directional mist outlet and variable speed settings allow you to direct humidification to the exact spot you want it, and with the intensity required. A 1-gal tank support’s the unit’s 24-hr run time, and there’s an auto shut-off feature to power down the unit when the tank is empty.

You’ll also enjoy the ease of cleaning the humidifier’s tank, thanks to its wide opening, which will accommodate your entire hand, when necessary.

Then there’s the compact build, which makes this humidifier ideal for use on smaller surfaces such as nightstands and desktops. And by balancing humidity levels in your space at 40 – 60%, everyone in your home or office can breathe comfortable healthy air.

When unscrewing the Honeywell HUL535B’s tank for refilling, some residual water may spill from the unit, hence the need for some extra caution.


  • Efficient directional misting
  • Long run time with auto shut-off
  • Easy to clean
  • Compact and space-saving


  • Possible spillage during refilling

6. Best for Warm Moisture: Honeywell HWM705B

Honeywell HWM705B

Photo: Honeywell

  • Coverage Area: 250 sq. ft.
  • Water Tank Capacity: 1 gal.
  •  Run Time: Up to 24 hrs.

Honeywell HWM705B is a unique filterless humidifier because it is the only one on our list that supports warm-mist humidification.

While most humidifiers are cool-mist models, this one will produce visible warm mist to boost comfort levels in your home by counteracting the discomfort resulting from the dry winter air.

You’ll find this unit easy to operate because it offers only 2 comfort settings, high and low. There’s a reset light that works reliably well to notify you when the tank needs refilling. And when it comes to the actual refilling, the tank simplifies this process using an easy-grip handle.

As a bonus, the humidifier comes with an essential oils cup, which is very handy when you want to use relief-boosting liquid inhalants.

You may, however, need to clean the Honeywell HWM705B regularly because its warm-mist capacity may accelerate mineral build-up especially when using hard water.


  • Effectively counteracts dry air
  • Easy to operate
  • Simplified tank handling
  • A bonus essential oils cup


  • May need frequent cleaning

7. Easy to Use: TrueMist HCM-29360107

TrueMist HCM-29360107

Photo: TrueMist

  • Coverage Area: 269 – 378 sq. ft.
  • Water Tank Capacity: 0.5 gal.
  •  Run Time: Up to 48 hrs.

The TrueMist HCM-29360107 filterless humidifier was built to simplify usage, refilling, and cleaning, while offering extended humidification for sizeable rooms.

It boasts of a patented detachable design, which includes a wider tank that opens fully to allow for easy cleaning. You can clean it as frequently as you want, to maintain high mist quality.

At the lowest setting, the tank will support continuous humidification for up 48 hrs. The efficiency of this process is further boosted by a multidirectional mist nozzle.

Ease of filling is another thing you’ll love about the HCM-29360107. Since the tank opens fully, you can fill it with any other container, or simply use the sink because the component fits under most faucets.

We did notice, however, that the TrueMist HCM-29360107’s tank lid isn’t the best sealed, and may cause occasional liquid buildup on nearby surfaces.


  • The tank is easy to clean
  • Long run time at low setting
  • Optimized mist dispersal
  • Easy and flexible refilling


  • The tank lid could be tighter

8. Longest Run Time: PureGuardian H1175WCA

PureGuardian H1175WCA

Photo: PureGuardian

  • Coverage Area: 390 sq. ft.
  • Water Tank Capacity: 1.5 gal.
  •  Run Time: Up to 90 hrs.

PureGuardian H1175WCA superior runtime of 90 hrs. allows the filterless humidifier to offer the ultimate operating convenience by freeing you from frequent refills and adjustments.

This extended runtime totaling at least 3 days, is enhanced by a large 1.5-gal water tank, both of which combine for a medium-room coverage of 390 sq. ft.

Because this tank will be holding water longer than that of the average humidifier, Silver Clean Protection has been added to fight mold and mildew growth on its surface.

When it comes to usability, the H1175WCA offers simplifies variable-speed mist control, a multi-directional mist controller, and auto shut-off at low water levels.

An issue you may encounter with the PureGuardian H1175WCA is its On/Off light, which is surprisingly bright, especially at night. The brightness may be a discomfort to some.


  • Superior run time
  • Large water tank
  • Mold and mildew tank protection
  • Convenient user control


  • On/Off light could be less bright

9. Best with a Scent Pad Heater: Vicks V4500

Vicks V4500

Photo: Vicks

  • Water Tank Capacity: 1 gal.
  •  Run Time: Up to 24 hrs.

The integrated scent pad heater of Vicks V4500 makes it a great filterless humidifier for supporting vapor therapy alongside eliminating the dryness from your air at home.

You can capitalize on the benefits of Vicks vapor therapy, which can relieve some common symptoms associated with dry air.

A 1-gal tank has been included to keep the unit running continuously for up to 24 hrs. You’ll find it easy to fill and clean the tank thanks to its large opening.

It offers you the flexibility of humidifying your air through an adjustable mist intensity support. And for ease of cleaning, the unit is also compatible with protec humidifier cleaning balls.

On the downside, however, Vicks V4500 is a very pricey humidifier, especially compared to its rivals offering similar or better features.


  • Supports scented pads
  • Boosts symptoms relief
  • The tank is easy to fill and clean
  • Flexible mist settings


  • Expensive compared to rival models

10. Stylish Design: Honeywell HUT-300B

Honeywell HUT-300B

Photo: Honeywell

  • Coverage Area: 250 sq. ft.
  • Water Tank Capacity: 0.8 gal.
  •  Run Time: Up to 48 hrs.

Honeywell HUT-300B delivers essential moisture to your room’s air, but with a touch of style, making it a great display appliance for the modern home.

The ultrasonic humidifier comes in a black finish with a silver-trimmed handle, mist nozzle, and intensity-adjustment knob.

On its lowest settings, the HUT-300B will run continuously for up to 48 hrs., while covering a space of up to 250 sq. ft. This long run time is supported by a 0.8-gal tank.

It makes mist dispensing efficient by adopting a directional outlet and variable moisture control, which offers you customization flexibility that will adapt to different comfort levels.

And for ease of water monitoring, the unit has a clear window, which is also backlit. You can easily keep track of the humidifier’s water utilization.

For a low coverage of just 250 sq. ft., the Honeywell HUT-300B’s price is a bit on the higher side.


  • Stylish black finish
  • High run time on low setting
  • Variable mist control
  • Easy to monitor water levels


  • Pricey for the value offered


According to our filterless humidifier review, these appliances are invaluable additions to your home, when it comes to boosting air quality.

If you want the best of them all, choose Vicks V4600, an inexpensive, high-performance, and long-running humidifier for medium-large spaces.

If you’re on a budget, Rosewill RHHD-14002 will deliver reliable humidification to your space, at a pocket-friendly price.

And if you need a large space, such as the living room, office, or bedroom humidified, Crane EE-5301W and its superior coverage will get the job done.