air washer- water air purifier

Exploring Water Air Purifiers: The Efficiency of Air Washers and Revitalizers

It’s no secret that when you buy an air purifier,  you are unwittingly signing up for the filter of the month club.

Air purifiers, almost more than any other appliance, require upkeep.And when you’re talking about the upkeep as being replacing filters,
It can get very expensive.

But there is a style of air purifier that does not require any costly filter replacements and uses one of the most available resources you can find to work.


That’s right. Instead of the HEPA and carbon filter combo that most air purifiers require, this type of air purifier uses regular tap water as a filter.

Can You purify air with water?

“Water Air Purifiers” come in 2 different types:

    • Small tank Revitalizers
    • Air Washers

A Revitalizer is a small multi-purpose appliance that combines an air purifier,
A humidifier, and an aroma diffuser. 

An Air Washer is a water air purifier that covers a much larger room than a Revitalizer and reduces a higher amount of airborne pollutants.


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This unique air purifier draws air in and through a tank of water that is being swished around, and then blows the air out the other side after it has been washed by the water.

The effect is something like how the air feels after a nice heavy rain.

The unit also works as a humidifier because of the moist air that is being blown out of the water chamber.

These water based air cleaners also come with a bottler or two of essential oil to drop into the water turning the unit into a aromatherapy diffuser as well as a purifier.

These types of water air cleaners are a great idea as long as you understand that they are a jack-of-all-trades type of unit that will marginally work as a air purifier, humidifier, and diffuser but are not designed to do any of these things especially the best.

But they are inexpensive and usually run below the $50 to $75 range.

And the person who buys this is probably not looking for the best in any of these categories.

The durability is solid and there’s not too many parts besides the small motor that could go out. so the chances of buying a lemon are pretty slim.

Since they are a humidifier, they do require cleaning to ensure that mold and mildew do not build up in the machine.

But that only takes snapping a couple of parts off and putting them in the dishwasher or washing them off by hand.

One thing is, some of the advertising claims say that because these create a rain effect, they also manufacture negative ions.

purify air with water
Negative ions are not produced as much by rainfall in a storm but by lightning.

So unless you buy a model that has an additional negative ionizer, you’re not going to get negative ion production with these machines.

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Air washer

An air washer is also a hybrid appliance that combines an air purifier and a humidifier and like the revitalizers, many of them also give you the option of adding a drop of scented oil as a means of adding a fragrance or masking an odor.

The difference is that:

Air washers are designed to cover a larger square footage and are equipped to handle a much heavier level of bad indoor air quality.

These are a 2 in 1 Humidifier and  water-based air purifiers that take as much as 1.5 to 3 gallons of water to fill.

purify water with air

How do Air Washers Work?

Air is drawn into the machine and goes through a 2- 4-Part filtering process called disc stacks that essentially scrub the air with water and deposit the air pollutants into a separate basin.  The air is then blown, out of the other side of the machine “cleaned”.

The amount of air that is being washed and moved through the machine also makes it much more efficient at adding humidity into the air in the form of a humidifier.

But unlike the revitalizer that acts as a humidifier only in that it creates moisture in the air cleaning process,

Air washers can control the amount of humidity being created and come with hygrometer and hydrostat gauges to measure and set the humidity to your liking.

The price difference for these is substantially higher. Ranging from $250 to $450.

Air washers also require regular cleaning because of the chance of mold and mildew growing in the machine. But it is a very easy process that can be performed in a very short time.

Water air purifiers are good at removing larger particulate air pollution.

Namely pollen and dust, and pet dander

But although they are not as efficient at removing other types of pollutants like mold spores as a HEPA air purifier would be, they do help reduce these type of pollutants also.

As for odors, the fact that many of these come supplied with extra essential oils to add fragrance in the air tells you how good they are at actually removing odors.

water air purifierAdding Aromatherapy with Essential Oils

But that is part of the charm and there is a big audience of people who like to treat their air with essential oils.

As a humidifier, an air washer is the absolute best type of humidifier you can buy.

But as an air purifier, there are definitely better, more efficient ways to clean air.

Air washers do well at removing particulates from the air as small as 1.5 microns. HEPA filters on the other hand are manufactured to capture particular to smallest .03 microns. And almost all HEPA air purifiers are coupled with carbon air filters that are capable of removing even much smaller airborne offenses. Carbon filters are also well known for their capacity of absorbing odors, something an air washer does not do well.

Another aspect of using water air filtration that doesn’t quite add up is that there are many times throughout the year, especially this summer months where adding more humidity to the air would be unbearable.

In fact the opposite is true, placing a dehumidifier in the house at that point would actually be better for the air quality and would reduce dust mites which thrive in humidity. Dehumidifiers also take the strain off of overworked HVAC units and air conditioners when the humidity is high.

There is also the point that putting essential oil into the humidifier it’s not something a lot of people suggest because humidifiers come with nebulizers that are meant to create a fine mist of moisture. Oil can leave residues that clog up the tubes that are required for them to work.

At this point, you’ve got to be wondering if buying a 2 in 1 humidifier and air purifier is worth it.

Pros and Cons


  • Function: Combination of air purifier, humidifier, and aroma diffuser.
  • Price Range: Generally below $50 to $75.
  • Working Mechanism: Air passes through a water tank, getting “washed,” and then released, simulating a rain-like effect.
  • Maintenance: Requires cleaning to prevent mold and mildew.
  • Limitations: Not as effective as dedicated air purifiers, humidifiers, or diffusers. Often require specific essential oils sold by the manufacturer.
  • Misconceptions: Advertisements may claim they produce negative ions like those in a storm, which is not accurate without an additional ionizer.

Air Washers

  • Function: Hybrid of air purifier and humidifier; larger and more robust than revitalizers.
  • Capacity: Designed for larger spaces with more severe air quality issues. Can hold 1.5 to 3 gallons of water.
  • Price Range: Typically $250 to $450.
  • Working Mechanism: Air is scrubbed by water through disc stacks and pollutants are collected in a separate basin. They can also control humidity levels.
  • Maintenance: Requires regular cleaning to prevent mold and mildew.
  • Effectiveness: Better at removing larger particulates like pollen, dust, and pet dander, but less effective with smaller particles compared to HEPA filters.

General Points

  • Advantages of Water Air Purifiers: No need for filter replacement, can provide air cleaning, humidity, and aromatherapy.
  • Drawbacks: Not as effective in air purification as other methods, potential issues with added humidity in certain climates, maintenance to prevent mold, and potential clogging due to essential oils.
Category Revitalizers Air Washers
Function Combination of air purifier, humidifier, and aroma diffuser Hybrid of air purifier and humidifier; more robust than revitalizers
Price Range Generally below $50 to $75 Typically $250 to $450
Working Mechanism Air passes through a water tank, simulating a rain-like effect Air scrubbed by water through disc stacks; controls humidity levels
Maintenance Requires cleaning to prevent mold and mildew Requires regular cleaning to prevent mold and mildew
Limitations/Effectiveness Less effective than dedicated units; requires specific essential oils Better at removing larger particulates; less effective for smaller particles
Misconceptions/Additional Info May claim to produce negative ions; not accurate without an ionizer Can hold 1.5 to 3 gallons of water; designed for larger spaces

General Points

  • Advantages of Water Air Purifiers: No need for filter replacement, can provide air cleaning, humidity, and aromatherapy.
  • Drawbacks: Not as effective in air purification as other methods, potential issues with added humidity in certain climates, maintenance to prevent mold, and potential clogging due to essential oils.

Common Questions

Can you put any essential oil in the water air purifier or does it take a special kind, just for the air purifier?

It is recommended to use oils specifically formulated for water air purifiers as per the manufacturer’s guidance. While using essential oils in humidifiers isn’t new and some even have a designated compartment for oils, avoid using them in nebulizer-type humidifiers to prevent damage.

What’s the difference between an air purifier and humidifier?

An air purifier cleans the air, while a humidifier adds moisture. Water air purifiers or air washers clean the air using water and also add moisture.

What is the difference between a humidifier and a diffuser?

A humidifier adds moisture to the air, whereas a diffuser spreads aromatherapy scents or essential oil scents.

What is the difference between a revitalizer and an air washer?

The main difference lies in the size and volume of air they can clean. Revitalizers are smaller, three-in-one units combining an air purifier, a humidifier, and a diffuser. Air washers are typically two-in-one units, functioning as both air purifier and humidifier, and some models allow the addition of essential oils.

Additional FAQs on Water Air Purifiers and Air Washers

Water Change Frequency

Q: How often should the water be changed in a water air purifier for optimal performance and hygiene?
A: The water should be changed every 1-2 days to maintain optimal performance and hygiene, preventing mold and bacteria growth in the water tank.

Effectiveness Against Microorganisms

Q: Are water air purifiers effective against viruses and bacteria?
A: While effective at trapping larger particles like dust and pollen, their effectiveness against microorganisms such as viruses and bacteria is limited compared to HEPA filters.

Using Hard Water

Q: What are the effects of using hard water in air washers, and how does it impact maintenance?
A: Hard water can lead to mineral buildup, requiring more frequent cleaning and maintenance. Distilled or demineralized water is a better option to avoid these issues.

Child and Pet Safety

Q: What safety guidelines should be followed when using water air purifiers in households with children and pets?
A: Ensure the device is stable and regularly check the water tank for cleanliness. Be cautious with essential oils around children and pets.

Noise Levels

Q: How do the noise levels of water air purifiers compare to traditional models?
A: Water air purifiers generally operate quietly, similar to ultrasonic humidifiers, and are typically quieter than traditional models with HEPA filters.

Handling Smoke and Odors

Q: How effective are water air purifiers in neutralizing smoke and strong odors?
A: They can help reduce smoke and odors but are less effective than purifiers with activated carbon filters designed for this purpose.

Maintenance Best Practices

Q: What are the best practices for maintaining water air purifiers?
A: Regularly change the water and clean the tank to prevent mold and bacteria. Check for mineral deposits if using hard water and follow the manufacturer’s maintenance guidelines.

Impact on Indoor Humidity

Q: How do water air purifiers affect indoor humidity levels, and what should be considered based on the local climate?
A: They can increase indoor humidity, beneficial in dry climates but not in already humid conditions. Monitoring indoor humidity levels is essential for maintaining a comfortable range.


Published by

Dennis Reed

Dennis Reed Owner and Author @