Air Purifier vs Dehumidifier – Which One is Right For You?

Josh Mitchell

Written By

Josh Mitchell

Expert Reviewed By

Holly Curell

Last Updated On

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Key Takeaways

  • Air purifiers clean the air using its specialized filters and thus help improve the air quality index. They do not impact the humidity in your room.
  • Dehumidifiers help remove moisture from the air. They help against diseases and negative impacts arising from high humidity.
  • You can use both of these together as they can both promote healthy air quality by impacting different characteristics of the air.

Air purifiers and dehumidifiers are powerful machines that can significantly improve indoor air quality. However, I’ve encountered many people unaware of how they work or which one to choose (you might need both).

As someone intimately familiar with these machines and who has struggled with allergies and respiratory issues, I know firsthand the benefits of having these tools in your home.

Whether dealing with mold, dust, or if you simply want to improve your breathing, read on to discover the first step towards a healthier indoor environment!

Air Purifiers Vs Dehumidifiers: Key Comparisons

An air purifier removes airborne pollutants like dust, smoke particles, and pollen. It also prevents mold build-up by eliminating spores from the air.

A dehumidifier’s primary function is to eliminate excessive moisture and reduce humidity levels. It doesn’t filter the air but can help remove allergens like mold and dust mites that thrive in humid environments.


Air Purifier



An air purifier circulates and filters the air, trapping particles such as dust, smoke, and allergens to improve air quality.

Dehumidifiers are designed to lower the humidity levels in the air by removing excess moisture from the surrounding area.

Humidity Levels


Air dehumidifiers are typically used in areas where the humidity levels exceed 50%.


Filter, Adsorbents, Ionizing, UV light, Ozone generators.

Air conditioners, Mechanical/refrigerative, Adsorption/desiccant, Electronic, Ionic membrane,Makeshift


Air conditioners, Mechanical/refrigerative, Adsorption/desiccant, Electronic, Ionic membrane, Makeshift

Dehumidifiers are a helpful tool in alleviating allergies by reducing the levels of moisture in the air, which can decrease the growth of mold, dust mites, and mildew.

Dehumidifiers Vs Air Purifiers: When Should You Use Each?

For Removing Mold

An air purifier can help remove mold spores from the air while you work on physically removing the mold from surfaces.

If the source of your mold problem is high humidity, purchase a dehumidifier to reduce moisture levels and prevent mold growth in the future.

If you don’t have a mold problem but want to ensure that mold spores and other contaminants do not enter your indoor air, then an air purifier can be a good investment.

Verdict: Air purifier and dehumidifier

For Allergies

If you’re suffering from seasonal and environmental allergies, an air purifier can help remove allergens like pet dander, smoke, bacteria, and pollen from the air.

An air purifier with a true HEPA and carbon filter can capture 99.7% of contaminants, effectively combating most allergens. The best air purifiers for allergy sufferers typically have multiple stages of filtration, including a pre-filter, carbon filter, HEPA air filter, and UV light.

Verdict: Air purifier

For Babies

As a parent, you want the best for your kids, so you both an air purifier and a dehumidifier in their room. An air purifier can help keep them healthy by removing harmful contaminants like dust, mold, and pollen.

A dehumidifier will maintain the appropriate humidity levels in the room to prevent dry skin and other discomforts. Some air purifiers and dehumidifiers also come with diffusers, allowing you to use essential oils to create a calming and soothing environment for your children.

Verdict: Dehumidifier and air purifier

For Dust Mites

If you’re struggling with dust and dust mites in your home, an air purifier can help remove them from the air. Look for an air purifier that features a true HEPA filter that can capture particles as small as 0.3 microns and a dust prefilter that can capture larger particles like dust and hair. This will help ensure your indoor air is clean and free of irritating particles that can cause respiratory problems.

Verdict: Air purifier

For Smoke

We recommend using an air purifier to effectively remove tobacco or cooking smoke. Look for models with a high smoke CADR (Clean Air Delivery Rate) number that indicates the machine’s effectiveness in eliminating smoke particles from the air.

In addition, opt for air purifiers that feature a carbon or charcoal filter, which can help to remove smoke odors. Choosing models with true HEPA filters is also beneficial as it can capture smoke particles and other pollutants as small as 0.3 microns.

Verdict: Air purifier

For Basements

Basements are prone to excess moisture when the surrounding soil is wet, leading to mold growth and unpleasant odors. A dehumidifier can help reduce the basement’s humidity level to an acceptable range.

Once the humidity is under control, you can use an air purifier to eliminate mold spores, dust, or bacteria that might have accumulated in the air. Again, look for an air purifier with a HEPA filter and activated carbon air filter to effectively remove these pollutants from your basement.

Verdict: Dehumidifer and air purifier

How Dehumidifiers Work To Remove Moisture

Dehumidifiers are effective at reducing indoor humidity to the recommended 30-50% range. I like to keep my indoor humidity at 40%

Dehumidifiers draw in warm and moist air and pass it over a cold coil, causing the water vapor to condense into water droplets. These droplets are then collected in a container or drained continuously through a hose. The machine then releases drier air back into the room using a fan.

Certain models may include a humidistat that monitors and adjusts the humidity levels. However, it’s important to note that not all dehumidifiers have this feature, so be sure to check the specifications before purchasing.

Here are a few of the most common types of dehumidifiers and how they work:

  • Mechanical/refrigerative dehumidifiers are the most common type. They draw in moist air over a refrigerated coil with a small fan. They thrive in higher ambient temperatures where the relative humidity is over 45%.
  • Air conditioners inherently act as dehumidifiers, removing moisture from the air as they cool it.
  • Adsorption/desiccant dehumidifiers use a unique humidity-absorbing material that moves along a belt exposed to lower-temperature air. Air is reused after being heated to remove humidity, typically at levels of 35% or lower.
  • Electronic dehumidifiers use a Peltier heat pump to generate a cool surface for condensing water vapor from the air. They have no moving parts and are quieter but less energy-efficient, making them more suitable for smaller humidifiers.
  • Ionic membrane dehumidifiers use a specialized type of ionic membrane to move humidity in or out of sealed enclosures at the molecular level. These devices are used primarily in industrial areas with fuel cell, chemical, or water improvement applications.
  • Makeshift dehumidifiers, like window air conditioner units, function similarly to mechanical/refrigerative dehumidifiers by sending their heat exhaust back into the room.

How Air Purifiers Clean Air

Your indoor air can contain harmful contaminants that should be removed as quickly as possible. Air purifiers work by pulling in polluted air and filtering out impurities. The best air purifiers I’ve come across use filters like HEPA filters and activated carbon filters. Others use methods like electrostatic precipitation or UV-C light to remove contaminants.

Here are a few of the most common types of purifiers and how they work:

  • Filter air purifiers use HEPA (High-Efficiency Particulate Air) filters, prefilters, carbon filters, or ULPA (Ultra-Low Penetration Air) filters to circulate air and trap dust particles.
  • Ionizing purifiers use corona discharge, creating a small but powerful electrical field that uses oppositely charged particles to collect and settle out of the air.
  • Ozone generators convert oxygen molecules in the air into ozone, which reacts with and breaks down certain pollutants. However, they are controversial and not recommended by many health organizations due to potential health risks associated with ozone exposure.
  • Adsorbent purifiers use an adsorbent material, such as activated carbon or zeolite, to absorb and trap odors, fumes, and chemicals in the air.
  • UV light purifiers use ultraviolet radiation to render some microorganisms sterile, which can help to reduce the spread of germs and viruses in the air. However, they are only effective against some types of contaminants. They may not be sufficient as the sole method of air purification.

People Also Ask (FAQs)

Can you use a dehumidifier and air purifier together?

You can use a dehumidifier and an air purifier together. Dehumidifiers reduce humidity levels to improve indoor air quality, while air purifiers remove harmful particles from the air to provide cleaner, healthier air.

Can you buy a combo all-in-one air purifier and dehumidifier that does both?

You can buy combo dehumidifiers and air purifiers. These options can be the best of both worlds for some consumers. They are also relatively affordable.

How do air purifiers and dehumidifiers compare in terms of price?

In terms of price, dehumidifiers generally cost slightly more than air purifiers since they contain a compressor. Depending on the brand and filtration level, some air purifiers cost hundreds of dollars. Dehumidifiers cost more when they have a compressor and cover a larger surface area.

How do air purifiers and dehumidifiers compare regarding maintenance?

Air purifiers generally require less maintenance than dehumidifiers. Air purifiers require filter replacements every few months, while dehumidifiers require more frequent cleaning and water removal.


Through my extensive experience, it’s evident that air purifiers and dehumidifiers are crucial for improving indoor air quality. Countless individuals suffering from allergies and respiratory issues have experienced a marked improvement in their symptoms by utilizing these machines.

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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.

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Midea U Shaped Window Air Conditioner

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