Air Purifier vs Dehumidifier: In-Depth Comparison

Many believe that air purifiers and dehumidifiers are interchangeable. While others firmly withhold the air purifier vs dehumidifier argument. So, are air purifiers and dehumidifiers the same? No, they have widely different purposes and functions.

This article compares an air purifier and a dehumidifier, while also listing the pros, cons, functions, and types of both. Hopefully, it will help you select the one best for your needs.

Quick Comparison

The major distinction between an air purifier and a dehumidifier is how they enhance the indoor atmosphere.

An air purifier refines the air by processing it through a sequence of internal air filters. They filtrate dust, volatile organic compounds (VOCs), odors, airborne allergens, mold spores, pollen, and harmful particles out of the air.

Dehumidifiers remove excess moisture from the air and lower humidity levels. This makes the room cooler. The mold that flourishes in moist environments is threatened and ceases to exist.

It can be difficult to decide which one to buy for your home if you don’t know the unique attributes of air purifiers and dehumidifiers. 

To make this decision easy for you, let’s look at the pros and cons of having air purifiers and dehumidifiers. 

Air purifier vs dehumidifier

Air purifier – Pros & Cons

Air purifier purifies the air and keeps your space dust-free. Here are the pros and cons of air purifiers:

Air purifier

1. Eliminates VOCs and neutralizes unpleasant odors.

Most air purifiers come with an activated carbon filter. It expels VOCs, and unwanted odors caused by cooking, smoke, damp clothes, mold, or pets. This improves indoor air quality and lets you breathe fresh air.

2. Destroys harmful pollutants.

High-Efficiency Particulate Air (HEPA) filters trap 99.97% of microscopic organisms of 0.3 microns. They eradicate airborne contaminants harmful to health.


1. Expensive maintenance

For optimal efficiency, the pre-filter needs cleaning every two weeks, and the carbon and HEPA filters need timely replacement. These replacement filters are costly. An air purifier is time-consuming and expensive to maintain.

2. Revival of mold

True HEPA filter removes mold spores from the air but doesn’t reduce moisture. This leads the mold to regenerate.

Dehumidifier – Pros & Cons

A dehumidifier pulls moisture from the air and circulates dry air. Here are the pros and cons of a dehumidifier


1. Subsidies humidity

A dehumidifier’s primary function is to remove moisture from the air. It also gets rid of the musty odor from the dampened environment.

2. Remedial to allergy sufferers

Mold and dust mites cause allergy symptoms in many. They thrive in a moist environment. Dehumidifiers work to diminish the dampness and put an end to their existence.


1. Regular maintenance

Dehumidifiers collect condensation in an inbuilt container which must be emptied and cleaned multiple times a day as per use.

2. The surge in energy bills

Dehumidifiers run all day to maintain a favorable environment. Increased power consumption means higher energy bills.

Comparison Chart

The below chart is a quick summary of how these appliances differ.

Air Purifier



Removes dust, VOCs, odor, and harmful pollutants by using air filters

Draws out excessive moisture from the air and lowers the humidity

Humidity level:

Does not affect humidity

Used in places with more than 50% relative humidity

Additional component:

Dust, chemical gases, odor, smoke, pet dander, mold spores, pollens, bacteria, viruses, and allergens

Mold, dust mites, and mildew


People with allergies and respiratory ailments

People living in areas with high humidity or allergy sufferers

Basic functions of each device

Air purifiers and dehumidifiers have distinct functions which are as follows:

Air purifier – basic functions

Air filtration processes air through a sequence of pre-filter, carbon, and HEPA filters. Air purifiers work to remove smoke particles, dust, VOCs, odors, allergens, mold spores, and bacteria, and circulate clean air back into the room. Air purifiers do not change the room’s humidity levels.

Dehumidifier – basic functions

The ideal relative humidity level is 30-50%. A dehumidifier pulls out excess moisture from the air and recirculates dry air, similar to an air conditioner pushing out cool air. Mold and dust mites that grow in the damp environment are eradicated. Dehumidifiers do not purify the air.

Types of Air Purifiers

Air purifiers come with various types of air filtration technologies. Let’s have a look at them:

Air Purifiers

1. HEPA Technology

HEPA filtration uses a dense filter to trap 99.97% airborne microorganisms of 0.3 microns. It captures viruses, bacteria, chemicals, pet dander, airborne irritants, and mold spores.

2. Activated Carbon Technology

The activated Carbon air filter has molecular-sized pores with high absorbent potential. They eliminate VOCs and unwanted odors.

3. UV Technology

UV purifiers have a UV lamp. When microorganisms pass through UV light, they undergo cellular damage and get destroyed. They might not be a good option as they produce ozone.

4. Negative Ionizer

Ionic air purifiers discharge charged ions in the air and magnetically attach to airborne particles. The particles become heavy and drop down on surrounding surfaces. A negative ionizer doesn’t destroy them.

Types of Dehumidifiers

The most popular types of dehumidifiers are as follows:

Types of Dehumidifiers

1. Refrigerant Dehumidifiers

Refrigerants have a refrigeration system, much like air conditioners. The humid air is attracted to the cool surface of the fan’s metal plates. The air condenses, and the precipitation gets collected in the water tank, the rest of the air passes through an evaporator and cools down. The moistureless air then passes through a heated condenser and becomes warm. Dry and warm air is pushed back into the atmosphere.

2. Desiccant dehumidifier

Desiccant uses a desiccant wheel with a silica gel material. Damp air passes through the desiccant wheel. Water vapor is collected on the silica gel while the processed air gets expelled back into the room.

3. Heat pump Dehumidifier

Peltier Heat pump passes air through an extremely heated exchange coil. The moisture condenses and collects in the water tank while the dry air gets recirculated.

Air purifier vs Dehumidifier: Final Verdict

An air purifier is the right choice for you if you:

  • Have allergic reactions to pet dander, pollen, dust, or mold
  • Suffer from respiratory ailments like asthma or bronchitis
  • Want a dustless home
  • Live in high-smoke areas like wildfire-prone regions
  • Want an odorless room
  • Want to remove VOCs, allergens, and other toxic airborne particles from the air

A dehumidifier is a suitable choice for you if you:

  • Live in a 50% or more relative humidity level area
  • Have allergic reactions to mold and dust mites
  • Want to reduce mold growth
  • Want to subside musty odors from dampened walls, windows, or clothes


Do dehumidifiers improve air quality?

Yes, dehumidifiers improve indoor air quality. They draw out excess moisture from the air. This makes it less stuffy. The absence of moisture also destroys mold, thus improving air quality.

Should you use an air purifier or a dehumidifier in your basement?

It depends on the purpose of use. If you want ventilation or circulation of fresh air, install an air purifier. But if you wish to get rid of the clamminess and musty smell, use a dehumidifier. 

Will a dehumidifier cool down a room?

Yes, dehumidifiers cool down a room by drawing out the surplus moisture from the air responsible for making the air hot and sweaty.

Do dehumidifiers clean the air?

No, dehumidifiers do not clean the air. They work to maintain a favorable humidity level. Though they do get rid of airborne mold and mildew which lower the air quality.

An air purifier or dehumidifier for asthma?

Airborne contaminants and allergens trigger an asthma attack or shortness of breath. Air purifiers might be a better choice for asthma patients as it filters out such harmful particles.

An air purifier or a dehumidifier for allergies?

Allergy is caused by pet dander, allergens, mold spores, pollen, and dust. Air purifiers might be a better choice for allergy sufferers as it filters out allergy-causing particles.

An air purifier or dehumidifier for mold?

Mold needs a moist environment to grow. Dehumidifiers draw out excess moisture from the atmosphere. An absence of moisture curbs mold growth. Air purifiers only trap mold spores, it doesn’t uproot the cause entirely. Thus, a dehumidifier might be a better choice for mold.

An air purifier or dehumidifier for dust mites?

Air purifiers capture dust particles which is the energy source for dust mites. Dehumidifiers lower the humidity levels, which is crucial for the survival of dust mites. Air purifiers and dehumidifiers are both helpful for getting rid of dust mites.

Can you use an air purifier and a dehumidifier in the same room?

Yes, you can use a dehumidifier and air purifier in the same room. An air purifier cleans the room whereas a dehumidifier draws out unwanted moisture from the air and creates a pleasant environment.

Where should you place a dehumidifier?

Install a dehumidifier in a room with the highest dampness and place it in the center so that it covers the entire room instead of just a portion of it.

Does an air purifier dry out the air?

No, air purifiers do not dry out the air. They only purify the air. They do not change the air moisture levels.

Which is Best for You: An Air Purifier or Dehumidifier?

If you live in a high-humidity area with terrible air quality, it is wise to get both an air purifier and a dehumidifier. It will enhance your comfort and relief. We hope this air purifier vs dehumidifier comparison guide helped you decide. So, which device best suits your needs better? Please comment below!