Humidifier vs. Air Purifier: A Comparison

It is essential to ensure that the air in your home or office is clean and breathable. Clean air helps keep you and the people around you healthy. There are different aspects of air quality to consider and different actions to take if you want to improve any of these aspects. Humidifiers influence the amount of humidity in the air while air purifiers seek to reduce the number or concentration of indoor air pollutants.

This article explains the different aspects of air quality that humidifiers and air purifiers influence. We talk about how maintaining humidity levels affects the human body. The section focusing on air purifiers has definitions and examples of indoor air pollutants, their sources or causes and how to minimize your exposure to them.


The primary function of a humidifier is to increase the humidity levels of indoor air. This is done by adding water vapor or water droplets to the environment. By increasing the humidity, the harmful effects of dry air can be avoided.

One of the ways the human body loses moisture are through respiration, ore breathing, when you exhale. There is nothing to do about this one, it is just part of being a human.

Another way moisture leaves the human body is through the mucous membranes, specifically in your nose and throat. These membranes keep the tissues hydrated and help protect them from invading bacteria and viruses. Without this protective layer, your nasal passages and airways becomes dry and painful.

Your body will take water and other components to continuously produce mucous to keep your nose and throat protected. However, if the air you breathe is too dry your body cannot produce mucous fast enough. When this happens the membrane protecting the tissues in your airways becomes drier than normal.

This dry condition leads to a whole host of problems including increased colds, sinus infections and even nosebleeds. A less serious but no less annoying problem is louder and more frequent snoring.

By increasing the humidity levels of the environment, all of these issues can be avoided. In terms of health, it can reduce cough and dry skin. It can also provide relief to asthma patients by decreasing the intensity of attacks. People who suffer from eczema often use humidifiers to help manage their symptoms as well.

Do You Need a Humidifier?

A humidifier is exactly what you need if you or an occupant of your home suffers from one or more of the conditions listed below. Of course, if you are having real trouble seeking medical attention is always the safest route. Many people that suffer from eczema use humidifiers to supplement the advice and directions their doctor gives them. The same thing goes for sore throats. No amount of humidity will cure you of strep throat. Properly humidified air can only make your throat feel better.

What can humidifiers help with?

    • Sinus pressure or stuffy nose from a cold
    • Frequent nosebleeds that are caused by dry or cracked nasal passages
    • Dry skin, eyes or hair
    • Excessive snoring
    • Persistent asthma attacks
    • Sore throats
    • Allergy flare ups

Other Humidifier Issues

The next sections of this article deal with special considerations when using a humidifier. If you want to skip ahead to the air purifier section then click here! Otherwise, keep reading to learn more about controlling the humidity levels in your home.

Wooden Fixtures

In addition to these health issues, dry air can also cause wood to crack. Wooden fixtures and furniture need moisture in them as well. The only way they can maintain moisture levels is by being in an environment that is properly humidified.

As moisture leaves wooden fixtures they will shrink and oftentimes crack. An easy way to visualize this is letting your kitchen sponge dry out. It gets smaller and curls. (This does not happen with a synthetic sponge.)

While wood is not as receptive to water as a kitchen sponge is, your fixtures will need to be exposed to reasonably humidified air to keep them from cracking and releasing formaldehyde into the air. The general range for humidity in a residential home is 40 to 60% relative humidity.

Not all wooden fixtures will release this harmful indoor air pollutant. The main source of formaldehyde from wooden fixtures are the planks used in hardwood floors.

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Humidifiers, Bacteria and Viruses

The EPA regularly conducts a Community Water System Survey. In the last survey took place in 2006 and it indicates not all community water systems treat their water.

It is reasonable to assume there are unwanted contaminants in your drinking water. (Remember Flint, Michigan?) Adding bacteria and other pathogens to the air you breathe is not helpful, especially during cold and flu season. If you use a humidifier be sure you take steps to ensure you are using clean the water. This can mean using filtered or distilled water. Alternatively you can use a humidifier bacteriostat solution or other means to keep bacteria from multiplying in your humidifier reservoir.

There are also humidifiers that comes equipped with ultraviolet lights designed to destroy bacteria, viruses and molds that may be present in water. The two top models on the market today are the Honeywell HCM350W Germ Free Cool Mist Humidifier and the Vicks V3900 Germ Free Cool Mist Humidifier.

Check out this article that provides an in-depth review of the Honeywell HCM350W Germ Free Cool Mist Humidifier. Alternatively, check out either of these products on Amazon by clicking the links below.

Air Purifiers

Unlike humidifiers, these devices are used for getting rid of contaminants such as dust from the air. Air purifiers are extremely beneficial for people who suffer from asthma or allergies. In fact, doctors and healthcare professionals often recommend patients to use air purifiers to decrease the frequency and intensity of those conditions.

Both asthma and allergies are the result of airborne particles. As such, the removal of these particulates can provide considerable relief to the patients. Some of these particulates can pollutants and contaminants that are dangerous for those patients. An air purifier can redirect the air in a room to pass through filters with can capture the particulates and remove them from the room.

Air purifiers can also have another benefit. They can clear a room of smoke, pet dander and unwanted odors. Smoke, as caused by cigarettes, can result in the formation of an undesirable smell in the room. Some purifiers are capable of getting rid of the smell so that people can breathe more easily inside the room. The dangerous chemicals in the smoke can also be eliminated.

However, air purifiers need to more maintenance and cleaning as compared to humidifiers. Frequent cleaning is essential to keeping the purifier functioning efficiently. Additionally, these devices produce a considerable amount of ions. Most purifiers are effective at only one of their functions. They can either clear out dust effectively or eliminate the smells. Only a few can do both efficiently.

Do You Need an Air Purifier?

Quite a few situations exist for which an air purifier can be very helpful. We list a few of them below.

Please be aware that some people are very sensitive to dust mites. It may be impossible to reduce the number of dust mites enough to eliminate symptoms of a dust mite allergy.

  • Your room has smells – a purifier with an active carbon filter will be the most helpful in this situation
  • Allergy flare-ups
  • You have recently got your room painted, varnished or disinfected
  • You often need to get rid of cooking smells in a hurry
  • There is a dust mite problem
  • You or one of your home’s occupants has a severe chest condition like COPD or emphysema
  • Pet hair or dander is causing sneezing and watery eyes

In the case of paints, disinfectants and varnishes, the products tend to contain toxic particles and volatile organic compounds. These can be quite dangerous. As such, you need to make sure that you are getting an air purifier which is designed to eliminate these particulates from the air.

In the case of serious chest conditions, you need to ensure that the air purifier is capable of getting rid of smoke, pollen and dust. These particulates can increase the symptoms and problems of Chronic Obstructive Pulmonary Disease and more.

Indoor Air Pollutants

There are two general types of air pollutants, gaseous and particulate. Oftentimes, the most immediate solution to built up indoor air pollutants is to simply ventilate the room by opening the window. If weather conditions do not permit this an air purifier is the next best solution. When smoke or allergens are the problem the outside air quality will determine whether or not opening the window is the best way to make your air more breathable.

Alternatively, it may be the most practical to remove the source of air pollution. For example, if someone is smoking inside they could smoke outdoors. The allergens pets produce, dander and hair, are much more difficult to entirely remove from your home. If you have an indoor pet an air purifier is the most practical way to deal with the allergens they produce.

Air purifiers built to reduce gaseous pollutants must have a filter containing a sorbent. The most common example of this is an active carbon filter. HEPA filters are designed to manage particulates. In the next section we list several examples of pollutants from both categories.

Examples of Gaseous Indoor Air Pollutants

  • Fumes from common household cleaners like bleach and ammonia
  • Fumes from paint and nail polish
  • Gaseous emissions from wooden furnishings – for an in-depth explanation, see the section about wooden furnishing in the humidifier portion of this article.
  • Carbon monoxide – air purifiers do not capture this dangerous chemical
  • Radon – another pollutant that cannot be managed by an air purifier. We discuss radon in more detail further down the page.
  • Smoke – this intentionally appears in both the gaseous and particulate categories

Examples of Particulate Indoor Air Pollutants

  • Pollen
  • Pet dander and hair
  • Dust mites – air purifiers can reduce the number of dust mites in your home. However, it may be impossible to remove enough dust mites to eliminate allergic reactions to dust mites. Some people are very sensitive to the allergens dust mites produce.
  • Airborne bacteria, viruses and mold
  • Airborne particles generated by cooking
  • Smoke – this intentionally appears in both the gaseous and particulate categories

The images below are all clickable links that will take you to the product listing on Once you are there you can explore other product listings as well. These images include a selection of the top air purifiers on the market today. They all feature HEPA filters for particulate air pollutants and active carbon filters for gaseous air pollutants.


Radon is a very specific kind of indoor air pollutant. It falls into the gaseous pollutant category. Radon is a radioactive gas that enters homes through small cracks in the basement. Most newer homes are built with radon resistance features. If you live in an older home or are unsure if your home was constructed with radon resistant features you can get some peace of mind by using an at home radon testing kits.

Radon is an important indoor air pollutant to manage. While dust and allergens are irritating, radon is cancerous. One way to remove radon from the basement of a home is by using a radon mitigation system. They generally consist of extra duct work and a specially designed fan. Using an air purifier is not a recommended method to manage radon and its decay products.

In-Duct Air Purifier

In-duct air purifiers are a very specific addition to whole home air purification systems. Normally the ventilation system in a home contains a HEPA air filter that is part of the furnace. This is a nearly universal feature of the heating and cooling systems in homes. However, these filters are not part of an in-duct air purifier.

In-duct air purifiers belong in the ultraviolet germicidal irradiation (UVGI) cleaners. They use ultraviolet light to help destroy viruses, bacteria and mold spores. They can help eliminate airborne pathogens in your home. However, UGVI cleaners are not a substitute for a filter designed to remove particulates from the circulating air in your home.

Do I need to clean my air ducts?

Did you know the EPA recommends getting your air ducts cleaned? They say you should especially do this if the following conditions are present:

  • There is visible mold growth in your ventilation ducts
  • Ducts are clogged with excessive dust or debris, such as pet hair
  • Insects or rodents have made a home in your ductwork

Other circumstances that may require you to get your air ducts cleaned include:

  • Recent renovations to your home – this can generate a ton of dust no matter how carefully you or the renovator worked. This can also be the case if your home was newly built. There is a lot of interior work that goes on after the ductwork is already installed.
  • There are multiple pets in your home, or just one that sheds more fur than usual – for example in the springtime when the weather warms up
  • This is one of the first things you should to when you move in to a new home. Make sure to place this as a high priority on your list if the previous owners smoked or owned pets.
  • If someone in your home is severely allergic to mold, pollen and other indoor air pollutants, make air duct cleaning part of your allergy symptom management plan.

Below is a list of Amazon Home Services that can help you maintain indoor air quality. Be sure to check if the service is available in the area where you live.

Best Air Purifier on the market

The Choice

Ultimately, both of these devices have their own limitations. Both of them require cleaning and maintenance on a regular basis. There are quite a few types of humidifiers and air purifiers in the market. The choice will ultimately depend on your specific requirements and aims.

You may even contact a healthcare professional to advice you on the kind of device that you require. The conditions of your home can also affect your choice. In some cases, your existing medical conditions will also affect your selection between humidifier vs air purifier.

Both humidifiers and air purifiers are beneficial in ensuring that the air you breathe inside your home is of a high quality. As such, it is a good idea to research all the options open to you thoroughly before you make your choice. A little effort now can help you considerably in the long run.

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