Air Purifier Vs Humidifier – Explained For Homeowners

Josh Mitchell

Written By

Josh Mitchell

Expert Reviewed By

Holly Curell

Last Updated On

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Key Takeaways

  • Air Purifier and Humidifiers are both devices that aim to improve the air quality but they do so very differently.
  • Humidifiers raise the optimal humidity levels thus mitigating many dangers stemming from dry air to both your health and belongings. They do not clean the air.
  • Air purifiers have no impact on the humidity, however, they are designed to filter out dangerous allergens, pathogens and micro organisms that can cause diseases.
  • Many homeowners use both devices to improve the overall air quality in their homes.

Over the years, I’ve noticed that many people aren’t well-versed in the differences between air purifiers and humidifiers.

The two devices are not the same and have several key differences, including how they work, their effects on indoor air quality, and their suitability for different health problems.

Fortunately, it’s pretty easy for me to explain the main difference –  air purifier makes the air cleaner, and humidifiers make the air wetter.

However, I’ll go more in-depth about the differences between these two machines below.

By the time I’m done, you should have a clear understanding of the differences between air purifiers and humidifiers.

Comparing Air Purifiers Vs Humidifiers (Key Differences)

humidifiers vs air purifiers

The main difference between an air purifier and a humidifier is that one is designed to clean the air (air purifier), and the other is designed to add moisture to it (humidifier).

Deciding between them can be extremely challenging, so here’s a quick guide to air purifiers vs. humidifiers for a variety of different uses:

For Babies - Both Can Be Beneficial

Both humidifiers and air purifiers can be beneficial for babies, but for different reasons.

Air purifiers can help remove airborne pollutants and irritants like dust, pollen, pet dander, dust mites, and other allergens. 

This is great for babies with sensitive skin or respiratory issues like allergies or asthma.

Humidifiers can help add moisture to the air, which can benefit babies with dry skin or nasal congestion. Dry air can make it hard for babies to breathe and exacerbate skin issues like eczema.

Ultimately, whether to use an air purifier or a humidifier for your nursery will depend on their specific health needs and the air quality in your home.


You can use air purifier and humidifier together in the same room if you follow proper guidelines with regards to their placement.

For Allergies - Get an Air Purifier

do air purifiers help with allergies

Air purifiers are generally best for alleviating allergy symptoms. Airborne pollutants like dust, pollen, pet dander, and mold spores are filtered out of the air using an air purifier.

However, some allergies can also be caused by dryness of the nose, throat, and sinuses.

A humidifier can help alleviate these symptoms by adding moisture to the air and soothing irritated mucous membranes.

Always use air humidifiers properly to avoid the growth of mold and bacteria that can worsen allergy and asthma symptoms. You should always consult your doctor to determine how to manage your allergies.

For Asthma - Depends Upon Your Trigger

Humidifiers alleviate asthma symptoms

My son has asthma, so airborne pollutants and low moisture levels can trigger his symptoms. An air purifier can help with asthma if airborne pollutants are the trigger. 

If the trigger is low moisture levels, a humidifier can alleviate asthma symptoms by adding moisture to the air.

Both a humidifier and an air purifier are sometimes necessary for managing asthma. 

For Mold - Avoid Humidifiers At All Cost

can air purifier help with mold

To prevent mold growth, it’s important to avoid using humidifiers. 

This is because mold thrives in moist environments, and excessive moisture in the air can contribute to the development and spread of mold. 

Air purifiers can effectively remove airborne mold spores, which can be a common trigger for allergies and respiratory issues. 

So if you’re dealing with mold problems, using an air purifier and avoiding humidifiers is your best bet.

For Eczema - Humidifier Can Help

Humidifier can keep your skin moisturized

Low humidity can cause the skin to become dry, itchy, and flaky, exacerbating conditions like eczema. Using a humidifier can combat dryness in the air and improve eczema. 

You should look for a humidifier designed to improve skin hydration and prevent dryness.

Cool mist humidifiers, like ultrasonic humidifiers, are generally recommended for use with itchy skin. 

Ultrasonic humidifiers produce a fine mist that can be easily absorbed by the skin. 

For Cough - Depends On Your Triggers

A persistent cough and cold symptoms can be caused by several factors, including poor air quality and dry air.

Airborne pollutants like dust particles, mold, pollen, or pet dander can irritate the respiratory system and trigger coughing. 

In this case, using an air purifier can help improve your cough by eliminating these harmful particles and improving air quality.

However, dry indoor air can also irritate the throat, nose, and sinuses, leading to a persistent cough. 

In such cases, using a humidifier can help alleviate your cough. Adding water droplets to the air can soothe irritated mucous membranes and reduce coughing.

For Dust and Dust Mites - Get an Air Purifier

do air purifiers help with dust mites

While a humidifier is an excellent tool for adding water droplets to the air and improving indoor air quality, it is not designed to filter out airborne particles like dust.

Therefore, an air purifier is a better option for combatting dust in the home.

Air purifiers use filters to trap and remove these particles, making the air cleaner and healthier to breathe. 

TL;DR: Depending upon your environment and what triggers your health conditions, you may need an air purifier, a humidifier or both.

When To Use An Air Purifier VS. When To Use A Humidifier?

Knowing when to use a humidifier vs. an air purifier depends on the symptoms you’re dealing with. 

For example, if you’ve noticed that your skin tends to be drier during winter, humidifiers can come in handy.

What are the Optimal Humidity Levels

The humidifier will add moisture back into the air to help alleviate dry skin and other discomforts like dry nasal passages.

Unlike humidifiers, used mainly in the winter, air purifiers are used all year round.

That’s because indoor air pollutants don’t take any time off and can accumulate no matter the season. 

From dust and pet dander to mold spores and pollen, these particles can cause discomfort and even health problems for some people year round.

If you suffer from seasonal allergies, consider using an air purifier with an H13 HEPA filter during pollen season. 

As the wind carries pollen from trees and grasses into your home, an air purifier can help filter out those airborne allergens and reduce your symptoms.

TL;DR: Air purifier is often used all year long to remove impurities from the air. A humidifier is often used in dry seasons to add moisture to the air.

Price & Maintenance Of Air Purifiers VS. Humidifiers

When it comes to cost, there’s a big difference between humidifiers and air purifiers.

Humidifiers are generally pretty affordable and can cost less than $100, depending on the model you choose.

However, air purifiers can be expensive, and you could spend upwards of $500 for a top-of-the-line air purifier.

However, budget-friendly air purifier brands are available that can cost as little as $100.

The initial cost is not the only thing to consider when buying an air purifier, though.

For example, replacement filters for HEPA and activated carbon filters must be changed several times a year.


There are many different types of air purifiers ranging from mechanical air purifiers to ionizers and ozone generators.

The most recommended air purifiers in our opinion are the mechanical air purifiers with HEPA and activated carbon filters.

These costs can add up to over $100 annually. So, deciding between an air purifier or a humidifier is important to factor in the total cost of ownership over time.

TL;DR: Humidifiers are cheaper to procure and maintain. Air purifiers not only have a higher upfront cost, they also have higher running costs as they require frequent filter changes.

Air Purifier Basics and Working Principle Explained

how do air purifiers work

It’s all in the name – an air purifier is designed to purify the air that surrounds it.

It cleans the air by drawing in air molecules and passing them through multiple stages of filtration. There are a few filtration stages, each one targeting a different issue.

Most air purifiers start the filtration process with a prefilter where large airborne pollutants like pet hair and dander are removed.

Then comes the carbon filtration stage, which works to remove odors.

Finally, there’s HEPA filtration, which is responsible for removing those tiny particles that the previous stages missed.

There are a few more methods of filtration used in modern air purifiers, but these 3 – prefilter, carbon, and HEPA – are the most common.

When an air purifier uses the filtration method described above, it’s called passive purification.

do air purifiers give off radiation

There are also active purifiers, which work by releasing negatively charged ions into the air to remove airborne pollutants from the air. These, however, carry the change of releasing ozone.

When deciding between the two, passive purifiers are more efficient, effective, and safer.

TL;DR: Basic mechanical air purifiers draws in air and passes it through a series of filters to clean it. They can have further special features such as an ionizer, ozone generator, and UV light.

Do I Need An Air Purifier?

I believe everyone could benefit from investing in a home air purifier, even if it’s just a small portable air purifier.

An air purifier will rid your room of indoor air pollution, helping you breathe easier.

Are Air Purifiers a Waste of Money
But do you really need one? For some people, myself included, the answer is yes.

There are a few tell-tale signs to look out for to see if you should invest in an air purifier:

  • Your allergies are acting up – Allergy symptoms could be a response to pollen or mold spores in the air.
  • Your home has stuffy or stale air – Stuffy or stale air can be easily remedied by an air purifier.
  • Your home smells like varnish and disinfectants – If your house smells like varnish, disinfectants, or cleaning supplies, it could mean that volatile organic compounds (VOCs) are present in the air. There are many air purifiers on the market that can remove VOCs.
  • You suspect a dust mite problem Dust mites are a common trigger for allergies and asthma.
    Blueair says that “because dust mite particles often become airborne, using an air purifier with a high-efficiency particulate air (HEPA) filter can also help remove these and other allergens from the air.”
  • Members of the household are often sick – While this could mean many things, impurities and pollutants in the air can lead to on-again, off-again sickness.
  • You’re prone to snoring while sleeping – Poor air quality can irritate our airways, which can lead to snoring. If your snoring is triggered by allergies or pollution, an air purifier can definitely help.

TL;DR: If you live in a particularly dirty environment, if you often suffer from allergies, and if your home smells musty or of varnish then an air purifier can certainly help.

Basic Humidifier Working Principle Explained

A humidifier is a device that is designed to add moisture back into the air.

To use a humidifier, you’ll start by filling up the water tank. Once the machine is turned on, it will start working to turn the liquid into airborne moisture and then release that moisture into the surrounding air.

How do ultrasonic humidifiers work

The exact steps for how the internal components of a humidifier work depend on the type. The 2 most common types of humidifiers on the market today are:

  • Evaporative
    Evaporative humidifiers use the power of evaporation to turn water into vapor. It transforms the liquid water from the tank into its gas form (vapor), then disperses the vaporized water.
  • Ultrasonic
    Ultrasonic humidifiers use ultrasonic vibrations to deliver water vapor into the air. They’re very effective for increasing a room’s humidity – even more effective than the evaporative method.

No matter which one you go with, using a humidifier comes with a lot of benefits.

Medical News Today says that “humidifiers can benefit people with skin issues or respiratory problems who live in areas with low humidity.”

TL;DR: Humidifiers turn water into fine mist which is then released into the air raising the overall humidity levels.

Do I Need A Humidifier?

I live in a pretty wet climate, so I don’t need a humidifier.

If you’re not sure if you should invest in a humidifier, the easiest way to find out is to measure the moisture levels in your home.

The ideal humidity level is somewhere between 30 percent and 50 percent. If you can’t test your humidity, there are a few more signs that it’s time to start using a humidifier:

  • Dry Winter Skin, Hair, and Eyes
    Dry skin, hair, and/or eyes indicate that there is a lack of moisture in the air. This is extremely common in the winter season, and luckily, there’s an easy solution: use a humidifier!
  • Constant Colds, Sore Throats, Allergy Flare-Ups, or Asthma Attacks
    Dry air can be extremely irritating to the throat, airways, and lungs. It can lead to recurring health issues like colds, sore throats, allergies, and even asthma.
  • Excessive Sinus Congestion
    When the air you breathe is overly dry, mucus in the nose and sinuses cannot drain properly. This can lead to congestion and eventually sinusitis.
  • Excessive Snoring at Night
    Since dry air can lead to nose and throat irritation, it can also lead to excessive snoring.
  • Frequent Nosebleeds
    Low humidity is the most common cause of nosebleeds.
Can humidifiers help with snoring

TL;DR: If you live in a dry environment or if you are currently undergoing a dry season you may need a humidifier especially if dry weather is accompanied with dry skin and eyes, sinus issues, and excessive snoring.

Can You Use An Air Purifier And A Humidifier Together?

I always get asked if using a humidifier and air purifier in the same room is possible.

The good news is that you can use an air purifier and a humidifier together, and there are some benefits to using both together.

Air purifiers filter out harmful particles and humidifiers add moisture to the air to combat dryness and help soothe symptoms related to dry air. 

You can benefit from both functions by using an air purifier and a humidifier in the same room.


Be mindful of the placement when using an air purifier and a humidifier together. Keep the air purifier away from humidifier as high humidity can hinder air purifier's performance and can even damage it.

The air purifier can help remove harmful particles from the air while the humidifier can add moisture to it and help alleviate symptoms related to dryness.

However, using both devices in the same room requires careful monitoring.

The humidity level in the room should be kept within a comfortable and healthy range, typically between 30 and 50 percent. 

Using a humidifier for too long or at too high of a setting can lead to excess moisture in the air, creating an environment for mold and bacteria growth.

That could make it hard for your air purifier to keep up with the toxins in the air.

This is particularly important for individuals with allergies or respiratory issues, as excess moisture can worsen these conditions.

TL;DR: Yes, you can use both devices together and you can benefit from the improvements they bring.

People Also Ask (FAQs)

What is the Main Difference Between Air Purifiers And Humidifiers?

The main difference between an air purifier vs humidifier is that a purifier purifies the air, while a humidifier adds moisture to the atmosphere.

Is There An Air Purifier and Humidifier In One?

There are air purifier and humidifier all-in-one devices.

These devices, often called air purifier humidifiers or humidifier air purifiers, are designed to remove pollutants from the air while also adding moisture to it.

Can I Run An Air Purifier With A Window Open?

Yes, you can run an air purifier with a window open, but it may reduce its effectiveness. Opening a window brings in outdoor air, which may contain pollutants that the air purifier is not designed to filter.

Should I Sleep With A Humidifier Running?

You can sleep with a humidifier running. In fact, it’s one of the top recommendations for improved sleep quality.

Do Humidifiers Clean The Air?

No, humidifiers do not clean the air. While they have a lot of great functions – like combating dry skin and alleviating allergies, they do not clean the air.

Is There Such A Thing As A Whole-House Air Purifier?

Yes, whole-house air purifiers are designed to purify the air of an entire home. 

They’re a bit trickier to install due to the larger size, but once installed, you’ll get to enjoy fresh, clean air in every room of the house.

Final Worlds

With extensive knowledge of both machines, I can confidently say that air purifiers and humidifiers both play a pivotal role in enhancing the air quality of your home.

If you’re looking to raise humidity levels, a humidifier is the way to go.

If you need to eliminate airborne pollutants, an air purifier is your best choice. If you need to do both, get both machines and use them together.

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Josh Mitchell


Josh Mitchell
My name is Josh and I am obsessed with home appliances. From portable AC units to heaters and air purifiers, I enjoy testing, learning and using these devices to improve the air quality inside my family home.

My Favorite Home Appliance?

Midea U Shaped Window Air Conditioner

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