Can You Use a Humidifier Without a Filter?

Can You Use a Humidifier Without a Filter? The Surprising Truth

Can I use a humidifier without a filter?

Yes, you can use a humidifier without a filter. Filters in humidifiers primarily trap dust and airborne particles, but they are not essential for the basic function of emitting moisture. However, operating without a filter may require more frequent cleaning to maintain optimal performance and hygiene.


Navigating the world of humidifiers can often lead to a common query: Is it necessary to use a filter in a humidifier?

While many assume that a filter is an indispensable component, the reality is more nuanced.

In this article, we delve into the role of filters in humidifiers, explore different types of humidifiers and their requirements, and discuss how the choice of using a filter—or not—impacts the overall function and maintenance of your humidifier.

Whether you’re considering a new purchase or seeking to optimize your current humidifier, understanding these aspects is key to ensuring a healthy, humidified environment in your home.

filterless humidifierThe purpose of a filter on a humidifier is:

  • Trapping Particulates: The filter catches dust, pet dander, and other airborne particles from the air that is drawn into the humidifier. This helps to prevent these particulates from being dispersed into the room with the mist.
  • Preventing Microbial Growth: It can help to reduce the growth of mold, bacteria, and algae within the humidifier itself, which can otherwise proliferate in the moist environment of the humidifier’s reservoir.

It is not a type of water filter that will filter the minerals out of hard water. Water is not meant to pass through the filter whatsoever.

If that were the case, there would be no need for using distilled water in a humidifier.

If you have ever taken a filter out of a humidifier after it’s been used for a while, you will notice that it is more of a grimy dust. You’ll often see white dust forming around a humidifier; the air filter is responsible for reducing that as well.

The filter will help keep those particles from the air out of your humidifier, which will lengthen the life of the humidifier and keep you from inhaling those particles.2

Like I said, it is not ideal to run your humidifier without a filter, but if you have a humidifier that doesn’t have a filter, it’s not going to hurt anything to run it until you are able to get a filter or a humidifier that has a filter.

The humidifier will still do the job of humidifying without the filter.

Filterless Humidifiers

Not all humidifiers have filters.

If you have a humidifier that doesn’t have a filter, or one that you’re not familiar with, it would be worth the search to see if your humidifier actually calls for a filter.

For instance, ultrasonic humidifiers are one of the most popular types of humidifiers sold, and ultrasonic humidifiers do not use filters.

Comparison of Different Types of Humidifiers

Humidifier Type Filter Required Mist Type Noise Level Key Features
Ultrasonic Humidifier No Warm/Cool Mist Quiet Uses ultrasonic vibrations to produce mist, ideal for quiet environments.
Warm Mist Humidifier No Warm Mist Moderate Boils water to produce steam, good for reducing germs and bacteria.
Impeller Humidifier No Cool Mist Moderate Uses rotating disks to produce mist, effective in smaller areas.
Evaporative Humidifier Yes Cool Mist Louder Uses a wick filter to evaporate water, self-regulating moisture output.
Cool Mist Humidifier Yes (Some Types) Cool Mist Varies Either ultrasonic or evaporative, offers cool moisture, good for large areas.

Here’s a list of portable humidifiers that don’t use filters:

  • Ultrasonic Humidifiers: These use ultrasonic vibrations to produce mist. They are known for being quiet and can come in both warm and cool mist versions.
  • Warm Mist (Steam Vaporizers): These humidifiers boil water to produce steam, which is then cooled slightly before being released into the air. Because of the boiling process, they don’t generally need filters.
  • Impeller Humidifiers: These create mist using a rotating disk that flings water at a diffuser, breaking the water into fine droplets. They usually do not require a filter.

Here’s a list of humidifiers that do use filters:

  • Evaporative Humidifiers: These are the most common type that use a filter. They work by blowing air through a wet wick or filter to evaporate water into the air.
  • Cool Mist Humidifiers: Some cool mist humidifiers are evaporative and use a wick filter to absorb water from the tank and release it into the air as a cool mist.

Cleaning Maintenance

The filter on a humidifier is not meant to take the place of regular cleanings.

Humidifiers need to be cleaned often because of the risk of bacteria growing inside of the water. This is especially true when the humidifier has had standing water in it for any length of time.

The bacteria that grows on water and becomes airborne can be very hazardous to your health.1

Legionnaires’ disease and Pontiac fever are illnesses that are a direct result from inhaling airborne bacteria that has grown on water. Definitely not something you want to risk.

When to Replace Humidifier Filters Signs & Maintenance TipsOther Preventative Solutions Besides Filters:

Product Name Type Suitable for Humidifier Type Usage Frequency Key Benefits
Demineralization Cartridges Cartridge Ultrasonic Varies Reduces mineral buildup and white dust from hard water.
Humidifier Cleaner Solution Liquid Cleaner All Types As needed Cleanses and disinfects, preventing mold and bacteria growth.
Hard Water Filters for Faucets Water Filter Attachment All Types Continuous Filters minerals before they enter the humidifier, reducing buildup.
Distilled Water Water All Types Continuous Prevents mineral deposits and microbial growth in the humidifier.
Antimicrobial Silver Ion Balls Water Treatment Accessory All Types Varies Releases silver ions to prevent microbial growth in the water.
Vinegar (for Cleaning) Natural Cleaning Agent All Types As needed Natural and effective for descaling and cleaning humidifiers.

Use Distilled Water: Water with a heavy mineral content is not good for humidifiers. The minerals that these waters contain can be a source of food for mold and bacteria to start growing faster

Water Distiller: You can purchase distilled water by the gallon or can
consider other alternatives to constantly purchasing distilled water for your humidifier, one practical solution is investing in a water distiller.

Not only does this provide a steady supply for your humidifier, but it also has various household applications.

For instance, distilled water is ideal for use in CPAP machines, preventing mineral buildup in steam irons, and maintaining automotive cooling systems.

It’s also beneficial in preparing solutions for sensitive plants, ensuring purity in cosmetics and skincare, and even in cooking and baking for recipes where water quality impacts the result. Here’s a good one.

Hard water filters are also a fairly inexpensive item that you can attach to your faucet to help remove minerals from tap water.  Distilled water is still the better option.

Demineralization cartridges are a type of humidifier cleaner can be dropped right into the water of the humidifier. These can take the place of using distilled water, but you may have to replace them more often for especially hard water. The other downside of demineralization cartridges is that they are primarily for ultrasonic humidifiers.


Can you use a humidifier without a filter?

The removal filters that come in humidifiers are not necessary for the humidifier to moisturize the air.
They are primarily air filters to keep dust particles from mucking up your unit, and they are not water filters.
Water is not meant to run through the filters whatsoever.
There are plenty of humidifiers available that don’t use filters at all, such as ultrasonic, impeller, and vaporizers.

FAQs: Using Humidifiers Without Filters

  1. Can I use a humidifier without a filter?
    Yes, it’s possible to use a humidifier without a filter. The main function of a filter in a humidifier is to trap dust and airborne particles, not to emit moisture.
  2. What are the consequences of using a humidifier without a filter?
    Using a humidifier without a filter can increase the frequency of cleaning required, as dust and particles are more likely to enter the humidifier, potentially leading to quicker buildup of residues and microbial growth.
  3. Do all types of humidifiers come with filters?
    Not all humidifiers have filters. Types like ultrasonic, warm mist, and impeller humidifiers typically operate without filters.
  4. Is it safe to use tap water in a humidifier without a filter?
    While tap water can be used, it may lead to mineral buildup and the emission of white dust. Using distilled or demineralized water is recommended, especially in humidifiers without filters.
  5. How can I maintain a humidifier without a filter?
    Regular cleaning is crucial for a filterless humidifier. Ensure to empty, clean, and dry the water tank regularly, and follow the manufacturer’s guidelines for maintenance to prevent bacteria and mold growth.

Published by

Dennis Reed

Dennis Reed Owner and Author @