Air Purifier vs Dehumidifier – Key Differences & Types

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Air Purifier vs Dehumidifier

We often take our ability to breathe for granted by thinking it’ll be safe, sustaining, and accessible. But it’s a fact of life in this modern world that multiple environmental factors make respiration uneasy, unsettling, or perhaps even challenging.

Luckily, air purifiers and dehumidifiers can enhance the air quality around us.

If you suffer from respiratory problems, you might ask what the distinction between an air purifier and a dehumidifier is. Besides, how do they function and help manage bothersome symptoms of illnesses like allergies and asthma? 

An air purifier uses an air filter to capture air-borne contaminants and recirculate purified air. On the other hand, a dehumidifier pulls out excess water vapor from the air to reduce the overall humidity levels. 

Read on as I differentiate between these life-saver machines and help you make the best decision for your indoor air quality requirements.

Related: Best Dehumidifier for Bedroom – 6 Desiccant & Compressor Models

Air Purifier Vs. Dehumidifier – How Do These Differ?

From the primary function of each to their various types, here are the key differences between your air purifier and dehumidifier. 

  • Primary Function 

Let’s understand the primary function of each device in detail below. 

Air Purifier 

By forcing the air in your home through several inner filters, air purifiers eliminate harmful impurities indoors, as air indoors can be five times as polluted as outdoors

A HEPA filter-equipped air purifier (the most widely used type) can capture and hold airborne contaminants as small as 0.3 microns. 

However, too much moisture can bring back mold because it cannot control the humidity levels in a home. 


A dehumidifier’s main job is to remove excess water vapor from the air to reduce moisture levels.=

Despite neither clearing nor filtering the air, this device helps remove allergens like dust mites and mold that flourish in moist or humid environments. 

Note: These causes of respiratory problems undulate and die at humidity below 50%.

Related: Best Dehumidifier for Basement – Top 5 Options in 2023

  • Main Types

Thanks to evolving technology, there are many air purifiers and dehumidifiers. Let’s first understand the types of air purifiers. 

Air Purifier

The five common types of air purifiers with distinct applications and working principles are: 

  • HEPA Air Purifiers

High-Efficiency Particulate Air, or HEPA in short, is a special air filter that removes airborne particles as small as 0.3 microns!=

The HEPA filters are effective in capturing 99.7% of these smallest particles. The filters gradually clean the air by trapping all tiny particle materials.

  • Activated Carbon Air Purifiers

Activated carbon (carbon produced from carbonaceous source materials) is sufficiently porous to absorb the odor-causing particles. It offers a substantial surface area for the adsorption step. 

The ability of activated carbon to capture pollutants in its membranes is one of its specialties. Since the contaminants are never released into the atmosphere, it aids in avoiding air contamination.

Note: Activated carbon can’t capture viruses and bacteria. 

  • Ionizer Air Purifiers

As the name suggests, ionizers purify the air through ions. Magnetically drawing the contaminants in, these ionizers utilize the negative ions in the process. 

Although less effective, ionizer air purifiers might help locate the pollutants. 

The ionization type of air purifier is not advised if you wish to install one in your home. 

  • Ultraviolet Light Air Purifiers 

A UV light air purifier uses UV rays to kill air-borne pollutants. 

  • Ozone Generators Air Purifiers

Some air purifiers contain ozone generators to absorb odors. You’ll mostly find these machines in hotels and not in homes. This is because they emit a significant amount of ozone, making the room unsuitable for the next 24 hours. 


There are mainly two types of dehumidifiers, as discussed below. 

  • Mechanical/Refrigerative 

This kind is the most prevalent and operates by using a small fan to draw moisture from the air over a chilled coil. At high-temperature conditions where the humidity level is over 45%, condensed air is effectively collected.

Note: A refrigerative dehumidifier has a similar function as a regular refrigerator. Hence, the name. 

Related: What Size Dehumidifier Do I Need – Consider These Factors

  • Adsorption/Desiccant 

Yes, you guessed it right! A desiccant dehumidifier utilizes “desiccant” to absorb excess water vapor from the air. In most models, a huge wheel containing desiccant turns slowly through the incoming air stream to absorb any accompanying moisture. 

Note: Due to minimal internal components, a desiccant dehumidifier tends to be smaller than its counterparts. Also, it’s suitable for colder climatic conditions. 

Related: What Should I Set My Dehumidifier At? Answer By Room & Humidity Level

  • Working 

Below is how each works and the various internal components.

Air Purifier 

As the name suggests, an air purifier purifies or sanitizes the air around you. Thus, it’s the opposite of an air filter, which merely filters the pollutants from the air. 

Coming to the working of an air purifier, the setup is pretty straightforward, with a series of internal fans to suck in air and a filter. 

The fans suck in polluted air, passing through the polluted filter for purification. Once done, the purifier recirculates this clean air back into the room. 


A home dehumidifier is typically housed in a floor-standing cabinet. It has a humidistat that activates the appliance when the air humidity in the area reaches a certain level. 

Like a fridge, it draws air into the unit and passes it over a series of chilly coils. As a result, water vapor condenses on the coils and gathers in a water reservoir. 

In the next stage, a fan draws the cold air over heated coils, returning it to the area as more heat.

Related: Dehumidifier Not Collecting Water – Reasons and Solutions

  • Maintenance 

Another critical difference between the machines is their overall maintenance. 

Air Purifier 

Changing the filter on your air purifier every 5 to 6 months is necessary for maintenance. If your system contains plates, you must remove them and run them through the dishwasher weekly to clean them.

Note: Different air filters (for example, pleated, washable, fiberglass, electronic, HEPA, etc.,) have different life spans. Furthermore, outdoor air quality, pets, and usage also influence how often a filter needs to be changed.  

You can also follow online guides to clean your air purifier.


Every several months, your dehumidifier’s buckets and coils must also be cleansed. You can further examine your dehumidifier for frost while cleaning it. 

In contrast to using an air purifier, this upkeep improves the productivity of your dehumidifier. 

  • Hazards 

Here are a few hazards associated with air purifiers and dehumidifiers. 

Air Purifier 

Among all the purifier types, the one with ozone generators releases harmful ozone gas into the atmosphere. If exposed for a long time, it can harm the cells inside the lungs and respiratory airways. 


Coming to dehumidifiers, running such a device for extended periods may lead to excess dryness in the air. As a result, you may face rough and dry skin, more water needs, etc. 

Air Purifier Vs. Dehumidifier – Comparison Table

The following table summarizes the differences between an air purifier and a dehumidifier. 

Parameters Air Purifier  Dehumidifier 
Primary Function  Purifies the air to eliminate air-borne impurities Dehumidifies the air, or, in other words, pulls out excess water vapor from the air to reduce the dampness in the space
Removes What? Dust, pet dander, mold spores, bacteria, smoke, etc. Dust mites, mildew, mold, etc.
Suggested Humidity  N/A Between 30% to 50%
Main Types HEPA, Ionizers, Ozone Generators, Activated Carbon, and Ultraviolet Mechanical/refrigerative and Adsorption/desiccant
Hazards Ozone generators release harmful ozone gas into the atmosphere, leading to respiratory illnesses. Running a dehumidifier for a long time makes the air excessively dry, leading to skin problems, etc. 

When To Choose Between An Air Purifier And Dehumidifier? 

It can be challenging to understand which machine you need to resolve the persistent air issues at your home. 

If the above differences couldn’t help much, below are some pointers to determine if an air purifier or a dehumidifier is for you. 

An air purifier is for you if:

  • The air indoors doesn’t seem as clean as it’d be, leading to respiratory issues 
  • You want to neutralize unpleasant odors, usually found in aerosol sprays, wall paints, upholstered furniture, etc.
  • You’re experiencing frequent flu and the common cold resulting from tiny air-borne pathogens.

A dehumidifier is for you if:

  • You can’t take musty odors anymore
  • You want to eliminate dust mites or stop their spread
  • There are visible wet stains on the walls or ceiling 
  • The windows get quickly covered with condensation 

In a nutshell, buy an air purifier if the air quality seems poor and a dehumidifier if moisture in the air seems higher. 

Air Purifier vs Dehumidifier FAQs

  • Which Is Better: Air Purifier Or Dehumidifier?

Ans: While both machines can benefit those with allergies, an air purifier is the safest alternative. 

Air purifiers remove bacteria, mold spores, dust, allergies, and animal dander from the air. On the other hand, a dehumidifier can restrict the spread of mold and dust particles by monitoring relative humidity. 

  • Do Air Purifiers Remove Humidity?

Ans: Does an air purifier dry out the air? The answer is “no.” 

Air purifiers can only enhance the quality of the air indoors by eliminating irritants present in the air. They cannot lower relative humidity.  Remember that the air purifier will not affect the humidity while the air is cleaned and improved.

  • Does An Air Purifier Make A Difference?

Ans: The simple answer is yes. But an air purifier probably won’t eliminate or neutralize all the irritants in your house.  This is because numerous particles can accumulate on hard surfaces like your walls and soft materials like furnishings, mattresses, and carpeting, which most air purifiers can’t act upon. 

  • Can You Run An Air Purifier And Dehumidifier At The Same Time?

Ans: Yes, you can simultaneously run an air purifier and a humidifier in the same space. However, there’s a catch.

If your air purifier is based on carbon filtration, always keep your humidifier a few feet away from the former when using both simultaneously. This is so because the activated carbon filters can easily be harmed by too much humidity in the air.

If your air purifier doesn’t use carbon filters, you can keep them closed.


So, there you go. Although they aim to reduce or eliminate allergens in your home, air purifiers and dehumidifiers function differently. 

I hope this article helped you better differentiate between an air purifier and a dehumidifier. Choose one carefully for your home conditions and location, and enjoy a clean, safe, and fresh air breath! 

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