Informational Guide

Comparing Air Purifiers Vs Humidifiers

This guide showcases the key differences between purifiers and humidifiers and will help you decide which is the right choice for you.

by Josh M

Air purifiers and humidifiers have the potential to impact the air quality of your home. Both can help with common health issues and ailments, like allergies, asthma, and dry skin. But there are some major differences between the two and deciding between them can be challenging.

This guide on the key differences between purifiers and humidifiers will help you decide whether an air purifier or humidifier is the right choice for you.

The name “air purifier” says it all; this machine is designed to improve air quality by purifying the air that surrounds it. It cleans the air by drawing in air molecules and passing them through multiple stages of filtration. There are usually a few filtration stages, each one targeting a different issue.

Air Purifier Basics

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. There are also active purifiers, which work by releasing negatively charged ions into the air, so those airborne pollutants will stick to surfaces. When deciding between the two, passive purifiers are more efficient and effective.

Do I Need an Air Purifier?

In all honesty, everyone could benefit from investing in a home air purifier. But do you really need one? For some people, the answer is yes, and there are a few tell-tale signs that it’s time to invest in an air purifier:

  • Your allergies are acting up – Allergy symptoms could be a response to pollen, pet dander, or even 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.

Humidifier Basics

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.

Humidifier Basics

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 to 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 droplets 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.”

Do I Need a Humidifier?

If you’re wondering whether or not it’s necessary to invest in a humidifier, the easiest way to find out is to measure the moisture levels in your home.

When it comes to the ideal indoor humidity level, Bob Vila says that “while you can’t change the outdoor humidity, there are a number of steps you can take to control humidity levels in your house, which should ideally be between 30 percent and 50 percent.”

Here 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.

Comparing Air Purifiers Vs. Humidifiers

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 into it (humidifier).

Comparing Air Purifiers vs Humidifiers

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

Infants can benefit from either a humidifier or air purifier for the nursery. If your home’s air quality is poor, go with an air purifier. If your home’s air is dry, go with a baby-friendly humidifier.

For Allergies

In most cases, allergies are caused by airborne pollutants, so air purifiers for allergies are a great investment. However, some allergy symptoms are triggered by dryness of the nose, throat, and sinuses, so it’s also possible to benefit from a humidifier for allergies.

For Asthma

The same rule for allergies applies to asthma. Asthma symptoms can be triggered by both airborne pollutants and low moisture levels, so depending on the cause, you can benefit from either an air purifier or a humidifier for asthma.

For Mold

For mold, you’ll want to steer clear of humidifiers. Mold is often caused by too much moisture in the air, so adding a humidifier will just further the problem. Air purifiers for mold, on the other, are great for removing airborne mold spores.

For Eczema

Dry skin and skin conditions like eczema are often triggered by low humidity, so in this case, it’s best to browse around for humidifiers for dry skin.

For Cough

There are a few possible explanations for a cough (especially a stubborn one that won’t seem to go away). One reason might be poor air quality and airborne pollutants like dust, mold, pollen, or pet dander. An air purifier can help.

Another explanation, though, is that dry air is irritating the throat, nose, and sinuses, in which case it’s better to go with a humidifier for sinus problems.

For Dust

A humidifier won’t do much for combatting dust in the home, so this is best solved with the help of an air purifier.

People Also Ask (FAQ)

What is the main difference between air purifiers and humidifiers?

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

Can you use an air purifier and humidifier together?

Many homeowners wonder if it’s possible to use a humidifier and air purifier in the same room.

The Molekule company says that “because both an air purifier and a humidifier perform completely different functions (removing pollutants from the air as opposed to adding moisture to the air), they can be used together, even in the same room.”

Is there an air purifier and humidifier in one?

Yes, there are a few great options on the market if you’re looking for a 2 in 1 air purifier and humidifier.

Should I sleep with a humidifier running?

It’s perfectly OK to 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 have a lot of great functions – like combating dry skin and alleviating allergies. But 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.


Whether you’re looking for an air purifier or humidifier for asthma or you’re interested in comparing an air purifier vs. humidifier for eczema, the main thing to remember is that both of these devices can improve your home’s air quality.

Choosing between the two comes down to what your main priorities are; are you hoping to increase your home’s humidity levels, or is it more vital to remove common airborne impurities? If the answer is “both,” it’s perfectly fine to use an air purifier and humidifier simultaneously.

Last Updated on June 29, 2022

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.