Air Purifier vs. Dehumidifier: Which Is Right For You?

Air Purifier vs Dehumidifier: Which Is Right For You?

A question we receive frequently from our readers is: "I'm comparing an air purifier vs dehumidifier. Which should I get?" Air purifiers and dehumidifiers are both excellent options for anyone who suffers with asthma, allergies, dust sensitivities, and other such disorders. An air purifier circulates air through a filter, trapping dust and dirt and other bothersome contaminants. A dehumidifier removes humidity from the air and, along with it, mold and irritants that grow and spread in moist environments.

Let's cut to the chase: air purifier vs dehumidifier, which is better? Both an air purifier and dehumidifier are useful for creating cleaner, fresher air inside your home or office, but understanding their basic differences can help you decide on the best choice for your needs. In some cases, you might determine that both an air purifier and a dehumidifier are needed for improved air quality and better breathing!

Many homeowners fail to realize that mold is present in the air, and not just behind walls or clinging to the shower curtain! A certain amount of mold is harmless to humans, as its spores are filtered through the lungs as you breathe.

However, excessive mold in the air can lead to breathing difficulties in some people and especially those who are allergic to mold in particular, and an overly humid environment might allow or encourage mold to grow on drywall, along wood framework, underneath carpet padding, and elsewhere.

Air purifiers will trap and lock some mold from the air, but a dehumidifier is a better choice for removing mold from your home or office. Since mold needs moisture to thrive, pulling excess humidity from the air removes mold spores and, at the same time, makes an environment somewhat inhospitable for future mold growth.

Keeping the air dry will then result in easier breathing and less chance of mold developing along a room’s walls, underneath your carpets, and on other such surfaces.

Air Purifier vs. Dehumidifier: for Air Quality

While a dehumidifier will remove some airborne contaminants clinging to excess humidity in the air, an air purifier is designed specifically to improve a room’s air quality. An air purifier typically has a fan or pump that pulls air across or through a filter and then blows that air out the other side, circulating it throughout the room.

An air purifier’s filter will trap and hold many bothersome contaminants, including:

  • ​Dust
  • ​Smoke
  • ​Fumes
  • ​Residual cigarette ash
  • ​Pollen
  • ​Pet hair and dander
  • ​Human hair and skin cells
  • ​Bacteria
  • ​Some viruses

The number of contaminants removed by an air purifier will depend on the quality and type of filter you choose. A high-quality filter will trap microscopic irritants, while some air purifiers will use UV light to kill airborne bacteria and germs.

To decide if you need an air purifier vs. a dehumidifier for improved air quality, consider the contaminants in the air around you. If you’re in a very humid environment or your home has poor ventilation, chances are there is excessive mold in the air. In that case, you might need a dehumidifier for easier breathing. Removing trapped humidity and moisture will mean cleaner, fresh air that is free of that mold and other similar irritants.

However, if the air around you seems dusty or dry, if you have pets or a smoker in the home, or if you work in an office near a busy highway or production facilities, an air purifier is probably the best choice. An air purifier will remove dust created by nearby manufacturing companies or that gets kicked up by traffic, as well as residual smoke and whatever a pet might shed!

Air Purifier vs. Dehumidifier: for Allergies

To decide between an air purifier vs. a dehumidifier for allergies, first consider your allergies themselves! Some people are allergic to mold, as said, so that a dehumidifier is the best choice for better breathing and less irritation for your skin. A dehumidifier also removes dust mites and mildew, which can also alleviate your allergies.

Other people, however, are allergic to dust, pollen, pet dander, and the chemicals used in perfumes, paints, coatings, and other such materials. These irritants also tend to trigger asthma attacks, coughing fits, and the like.

A strong air purifier with a high-quality filter will remove these bothersome contaminants from the air, making it an excellent choice for those with allergies and asthma. An air purifier is also recommended for those who have skin sensitivities and allergies, trapping and locking bothersome airborne debris in a filter so that fewer irritants land on your skin throughout the day!

Air Purifier vs. Dehumidifier: for Humidity

A high-quality dehumidifier is the best choice for removing trapped humidity in the air, and for creating a more comfortable environment in tropical areas or during summer months when humidity levels increase. A strong dehumidifier can also remove excess moisture created by steam and boiling water, something to consider for restaurant owners or even homeowners who tend to boil lots of water on the stovetop!

Some dehumidifiers also work with a refrigerant unit so that air is cooled while humidity is removed. This added cooling can create a more comfortable atmosphere in summer months or in stuffy, overly warm homes with poor ventilation. 

​Choosing the Right Air Purifier

Now that you know a bit more about the differences and uses of an air purifier vs. a dehumidifier, you might consider some vital tips on choosing the right air purifier for your home. While you might have a certain budget for your air purifier, remember that you don’t want to shop based on cost alone! Consider these factors when opting for a high-quality air purifier:

​Room Size

An air purifier can only circulate and clean so much air, based on its size and filter capacity. Be sure you choose a purifier with the right capacity for the size of the room in which you’ll place it.

​Noise Level

Most, if not all, air purifiers will make some noise, but for bedrooms, living rooms, or your office, be sure to choose a model that is advertised as being “whisper quiet” or that has a noise-muffling feature.

​Electricity Costs

If you plan on using the air purifier for an extended time throughout the day, check it’s needed volts and amps or wattage. The higher the watts used, the more you’ll pay to run that air purifier!

​Type of Filter

Choosing the best type of filter for your new air purifier can be confusing, so note some essential features of the most common filtration systems on the market today:

  • ​HEPA filters are designed to remove the smallest airborne particles, making them an excellent choice for those with allergies or asthma. The one drawback to HEPA filters is that they may not neutralize odors or kill airborne viruses.
  • ​UV lamps are effective against living organisms, such as germs and bacteria. Some commercial kitchens even use UV lights to kill contaminants on countertops and other surfaces!
  • ​Carbon filters trap and remove fumes, smoke, and other pair articles that might get through a HEPA filter. Carbon filters are also most effective at eliminating odors.

When choosing a filter type for your new air purifier, note its expected lifespan and replacement costs as well as the contaminants it will trap and eliminate.

​Choosing the Right Dehumidifier

As with an air purifier, it’s vital that you take some time to shop and compare dehumidifiers and then choose a model that will work for your needs in particular, rather than simply buying a cheap piece of equipment that isn’t effective for your home or office. You also want to avoid simply choosing the most expensive model, assuming that it will work better somehow.

​Types of Dehumidifiers

  • ​A refrigerative dehumidifier run the air it circulates around a refrigerated coil, cooling it. Since moisture doesn’t evaporate well in warmer temperatures, that cooled air will be less humid as it circulates around the room.
  • ​Heat pumps pull warm air from a room and replace it with cooler air. This natural circulation will keep the air inside a space less humid overall.
  • ​Ionic membrane dehumidifiers use a type of pump that removes humidity at the molecular level. These specialty dehumidifiers are typically used in warehouses, production facilities, and industrial settings.


As with an air purifier, a dehumidifier can only circulate so much air, based on its own size, strength of its fan, and the like. Be sure you choose an appropriately sized model for your office, living room, or your entire house, as needed.

​Water Collection

Humidity removed from the air is then collected and drained from the dehumidifier. Note the type of drain when choosing a dehumidifier model; some residential models will have a tank or pan that needs emptying on a regular basis. Check the size of this pan and consider how often it would need emptying.

Some dehumidifiers will have a drain hose attached to the unit; note if you can hook that hose to a nearby sink. Otherwise, these models are more appropriate for basements, warehouses, or other rooms with concrete floors and a built-in drain.

What if you need both an air conditioner and dehumidifier?

You may have just read this article and realized that you actually need both of these appliances! After all, they provide different benefits even if they somewhat overlap.

Thankfully, there are new portable air conditioner dehumidifier combo devices on the market now to solve for exactly this problem. They are ideal if you cannot (or choose not) to install a permanent, ducted air conditioning unit in your home. They are powerful enough to cool and dehumidify very large rooms, and could be the perfect fit for you. Just click here to read our entire review of these incredible inventions.

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