Air Purifier vs. Dehumidifier: Which One Do You Need?

Which is better in the air purifier vs. dehumidifier debate? See which one is the best choice to improve the air quality in your home.

When it comes to improving the air quality in your home, most people turn to either a dehumidifier or an air purifier to solve their problems. While both of these work to get rid of the bad allergens in the air, they are not the same. These two devices serve different purposes; you may need one type, or in some cases, you may need both. So, when it comes to the air purifier vs. dehumidifier debate, how do you know which one is right for you?

Once you break down the functions of air purifiers and dehumidifiers, you will see that they serve different purposes.

An Overview of the Air Purifier

air purifier vs dehumidifier with moldy wall


An air purifier is a powerful device that cleanses the air of mold spores, allergens, dust mites, and other harmful toxins. Some of these allergens can come from normal household sources, like dust, pet dander, or even smoking.

However, most people invest in air purifiers to help get rid of a mold or mildew problem. Purifiers help clean the air after a mold or mildew issue. It is also important to note that air purifiers do not completely get rid of a mold infestation. They instead help to prevent the spread of one.

If you have a mold problem, an air purifier is beneficial, but you’ll need to tackle the issue that is causing the mold outbreak. Homes with poor ventilation and excess humidity are a breeding ground for mold and mildew. If you rely solely on an air purifier to get rid of mold, the mold could return because they do not work to remove moisture from the air.

How an Air Purifier Works

Understanding how an air purifier works will help you understand whether or not you need an air purifier vs. dehumidifier in your home.

If you find yourself suffering from allergies, dust mites, or a mold or mildew problem, you may need an air purifier. Air purifiers work to remove the air of the microscopic particles that are released into the air.

An air purifier works by circulating the air in a room through its filters. Most air purifiers have a minimum of two filters, or a two-filtration system while others have three or four. Once it pulls the air into its filtration system, the allergens and mold spores are then trapped and zapped inside. Clean, allergen-free air is released into the room, which improves the overall air quality in your home.

The Different Types of Filters

While a dehumidifier works through a refrigeration or air conditioning process, air purifiers work with a filtration system. There are several types of filters, and each targets a specific purpose.

Types of air filters include the following:

  • Activated Carbon filters remove bad odors and fumes in your home. This works well for homes with mold and mildew, which give off a particular stench that is difficult to get rid of. If you live or lived with smokers, the activated carbon filters help to eliminate lingering smells.
  • Ionizing filters use corona discharge to get rid of the particles in the air microscopically. This is also controversial because of ozone production.
  • True HEPA filters are high-efficiency particle air filters, which is a fancy way of saying it removes the dust particles from the air. On the more technical side of things, a true HEPA can remove particles that are microscopic from the air. This comes in handy with mold spores and other allergens, which are around 0.3 microns. Only true HEPA filters can zap substances that are that small, so if you have mold in your home, get an air purifier says true HEPA.
  • UV lights use an ultraviolet radiation light to zap the microbial germs and viruses in the air. These powerful lights are effective but extremely controversial. Some UV lights give off a harmful gas called ozoneExcess exposure to ozone can be detrimental to humans, so double check before you choose a purifier with this type of filter.

You should always look for an air purifier with at least a True HEPA and Activated Carbon filter.

air purifier vs dehumidifier clean home

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Which air purifier is right for you? This depends on the amount of space you want to cover, the features you want, and the quality of the air in your home.

If you need one for your entire home, you may need an industrial option or several medium sized purifiers to make sure it’s working properly. There are also air purifiers that work well in smaller spaces like bedrooms and bathrooms.

Read Air Purifier Reviews

Some popular features in the best air purifiers are:

  • Automatic timers or programmed settings
  • PlasmaWave filters that don’t emit any ozone
  • Quiet modes
  • Smart air sensors that detect a change in the air quality and automatically turns on.

Air Purifier Pros

  • Gets rid of the mold spores and allergens in the air in your home
  • Helps people with asthma, allergies, and other respiratory issues

Air Purifier Cons

  • Humidity isn’t affected much
  • Ozone emission is a health hazard

An Overview of the Dehumidifier

woman emptying out best small dehumidifier

Mariia Boiko / Shutterstock

Dehumidifiers do exactly what the name suggests: they get rid of the excess humidity in an enclosed space.

Whether you live in a warm, damp climate or your home isn’t properly ventilated, a dehumidifier can be beneficial if you have these issues. As we said above, trapped damp warm air inside of the home is dangerous for the air quality. Damp air creates a breeding ground for mold growth, and it also causes allergens and toxins to circulate.

A dehumidifier will work to get rid of all of the moisture and help to lessen the allergens and prevent mold growth. These are recommended for homes with humidity problems or even during the cold, wet months of the year where you can’t naturally ventilate your home.

You can check if your home needs a dehumidifier by using a smart thermostat or a hygrometer to read the humidity percentage.

How a Dehumidifier Works

Dehumidifiers don’t work the same way that air purifiers do. Dehumidifiers pull in the moist air in a room and separate the water through the metal coils. The water is then collected in a reservoir or a water tank, and the dry air is released back into the air.

If your dehumidifier has a water tank, you have to empty it periodically. Some of the larger, more advanced units have draining systems as an option so that you don’t have to empty the tank manually.

The Different Types of Dehumidifiers

Dehumidifiers come in all shapes and sizes and with several types of features to enjoy. There are industrial, heavy-duty filters that you may use in a basement or in a home that’s been flooded. Unless you have these issues, we would recommend using a small dehumidifier for the rooms in your home. The smaller units work surprisingly well enough to suck the moisture out of the air in a room.

The main types of dehumidifiers are:

  • Mechanical/Refrigeration is the process that we described above. The damp air is pulled in with a fan through cool metal coils that break it down into water. The cool, dry air is then released back into the room.
  • Absorption is a type of dehumidifier that uses material to absorb the water. For example, the Eva Dry 333 dehumidifier uses special absorption beads to absorb water. Once the beads are “full,” you recharge them.
dehumidifier near window

Mariia Boiko/Shutterstock

Dehumidifier Size

Many people like to use dehumidifiers in their RVs when they go on road trips. RVs can get stuffy and uncomfortable from the trapped air and body heat. A good small dehumidifier for an RV could significantly change the air quality inside. There are even some models, like the Eva Dry 333, that don’t require a power source at all.

The type of dehumidifier is measured by the amount of water it can hold and the coverage area. If you get a small dehumidifier but need it to work in a spacious living room, invest in one that covers enough square footage. These devices are usually separated into sizes, small, medium and large.

Choose the type of dehumidifier that is right for you. Please note that a smaller unit has better portability, is easy to use, and won’t take up too much space.

Read Small Dehumidifier Reviews

Dehumidifier Pros

  • Gets rid of a significant amount of humidity in your home
  • Helps prevent mold spores from latching on to a surface and spreading

Dehumidifier Cons

  • Doesn’t remove mold spores or toxins from the air

Air Purifier vs. Dehumidifier: Final thoughts

clean air living room


The Mold Problem

How can an air purifier vs. dehumidifier help you when it comes to the issue of mold?

If you find yourself in the middle of a mold or mildew infestation, first you need to assess how serious it is. Note that neither of these devices will completely get rid of mold. Mold is a serious issue and can cause health problems, so prioritize getting rid of it as soon as you see it.

They instead both work to prevent the spread of it through their functions. A dehumidifier gets rid of the moisture in the air, which creates dry air that doesn’t favor mold. An air purifier gets rid of the allergens and mold spores that are already in the air, which also helps to prevent the spread of mold.

Which One Is Right for Your Home?

When it comes to improving the air quality in your home, which one is right for you?

An air purifier is the right choice if you are allergy sensitive. Also, if you live in a home that is mold prone, it could be worth it to invest in a purifier. You’ll enjoy fresh, clean air that is rid of harmful toxins and bacteria. However, the main issue with air purifiers are the ozone emissions, so be careful.

On the other hand, an air purifier won’t get rid of the humidity in your home. If the air in your room is too damp, an air purifier won’t be effective. In this case, you’ll need a good dehumidifier to suck the moisture out of the air for you. The dry air will help lessen the allergies and mold spores, but a dehumidifier won’t completely get rid of them.

So, the answer is, it depends on your home and the people who live in it. Whichever one you choose, we promise that breathing in clean, fresh air is more than worth it.

Still not sure? Click next to read common signs that you need a dehumidifier.

air purifier vs. dehumidifier