Graphic of air purifier vs humidifierA lot of people use air purifiers at home.

A good number also use humidifiers.

Some people even have both.

But do you know what qualities make these devices the same and what makes them different?

In this post, we’re going to explore the air purifier vs humidifier question so you get a clear understanding of how each of these powerful machines works.

Both an air purifier and a humidifier do great things to improve indoor air.

But, it can be difficult to understand which option is best for your particular needs.

For example, both products are great for people with sinus and respiratory issues; however, the way they offer relief is different.

An air purifier cycles your room’s air through a series of filters.

These filters remove allergens and contaminants to make the air quality better to breathe.

A humidifier adds moisture to your room’s air.

In turn, irritation to your sinuses or respiratory tract that’s caused by dry air can be relieved.

Air Purifier vs Humidifier Comparison Chart

This chart will give you a quick overview and comparison between air purifiers and humidifiers. If you want a more in-depth and comprehensive answer, read on.

Criteria Air Purifier Humidifier
Application Uses filters to trap and remove airborne contaminants Adds moisture to the air to soothe irritation caused by dry conditions
Benefits Beneficial for asthmatics and allergy sufferers, and people who want clean air Beneficial for asthmatics and people with irritated respiratory tracts due to dry air
Removes Allergens, Dust, Pet Dander, Mold Spores, Bacteria, and Smoke Dry Air
N/A 30% to 50%

Note: Our site includes a ton of free resources on air purifiers. If an air purifier sounds like something you want, take a look at our reviews on the best home air purifiers.

If you suffer from asthma, you may want to check out our guide on choosing the best air purifier for asthma relief.

Basic Air Purifier and Humidifier Functions

Although you may assume that air purifiers and humidifiers can be used interchangeably, this simply is not the case. Read on to find out why.

Air Purifier

An air purifier’s purpose is to remove a variety of airborne contaminants from your indoor air.

It traps and removes dust particles, bacteria, allergens, mold spores, pet dander, smoke odors, and other harmful particles.

When your air purifier runs, it sucks your home’s air into the machine and through a series of filters.

One of these filters is often called a HEPA filter, and it can capture tiny particles down to 0.3 microns.

The True HEPA version of this filter is 99.97% effective at removing airborne contaminants that irritate allergies, asthma, and other respiratory conditions.

Keep in mind that an air purifier doesn’t add any moisture back into the air. It only functions to clean and filter out the pollution.


A humidifier’s main function is to add moisture back into your home’s air.

It does this by pumping water vapor into a room that may or may not be visible.

To keep the humidifier running, you must continue to add water to a reservoir. It converts this water into a fine mist and expels it into the surrounding air.

Humidifiers are best used in dry areas because they add moisture back into the air.

Humidifiers can help relieve dry skin, throat irritation, sinus issues, nosebleeds, and breathing problems you may experience by being in an arid climate.

It’s important to know that a humidifier raises a room’s relative humidity level.

If you already have high humidity levels, this can encourage mold growth.

You want your indoor humidity levels to stay between 30% and 50%.

Below 30% is considered too dry and can cause the issues we mentioned in the last paragraph. Over 50% humidity can encourage mold growth, dust mite reproduction, and mildew.

Which is Better for Your Needs: An Air Purifier or Humidifier?

An air purifier might be best if:

  • You suffer from asthma, allergies, or a respiratory condition that’s irritated by polluted air
  • You want to decrease the amount of pet dander or allergens present in your home’s air
  • You want to reduce the amount of dust that accumulates indoors
  • You want to get rid of household odors due to cooking, pets, smoke, or mold

A humidifier might be best if:

  • You live in a dry or arid climate
  • You want to increase the moisture levels in your home’s air
  • You have frequent nosebleeds or sinuses issues, or your respiratory system is aggravated by dry air

Common Questions About Humidifiers and Air Purifiers

Air purifier vs humidifier for baby?

You could use both. An air purifier will give your baby cleaner air in their room and help promote better health.

If the air is dry, a humidifier will add moisture back to help your baby breathe and feel more comfortable.

Air purifier or humidifier for asthma?

Both devices work well but an air purifier is the best choice.

An air purifier removes common asthma triggers from the air so you don’t inhale them. A humidifier won’t remove the triggers but can make the air more pleasant to breathe.

Air purifier or a humidifier for allergies?

An air purifier is the best option for allergies. Air purifiers remove dust, pollen, pet dander, mold spores, and more from the air so they don’t end up in your eyes, throat, or lungs.

A humidifier doesn’t remove these items, and may actually increase them if the humidity level gets too high.

Can you use a humidifier and air purifier in the same room?

Yes, you can use an air purifier and a humidifier side-by-side in the same room.

The air purifier will clean the air of pollutants while the humidifier adds moisture back into the air to make it more comfortable to live and breathe.


By now, you should know which device will work better for your circumstances when you’re choosing between an air purifier vs humidifier.

We hope this guide gave you the tools and advice you need to make a well-informed decision.

As you learned, both a humidifier and air purifier can be beneficial for your health and home.

And in many instances, people choose to use both indoors to get the comfort and relief and they need.

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About David Morrison

David is an Air Quality & Comfort Technician. He has expert knowledge on the technology and design of air purification, air conditioning, and heating systems. His main role is to write content that helps people get the most value out of their air purifiers, air conditioners, and heating units. (See Full Bio)