Does a Dehumidifier Clean the Air?


In today’s world of outdoor pollution, clean air inside our homes and buildings is a must. And so, the appliances and devices that promise to provide just that are very important.

Dehumidifiers can make a big difference to air quality in our homes because it decreases humidity, but can it really clean the air? Dehumidifiers alone do not clean the air directly. They only help to maintain the humidity levels in buildings by removing excess moisture. This is still important though – keeping humidity levels under control can keep mold, bacteria, viruses, and and other microbes from growing in the air.

In the United States, indoor air quality (IAQ) is mostly defined by the relative amount of pollutants in indoor air related to the outside air. This means that in terms of the definition of cleaning the air, the air purifying device has to remove the stale air or filter pollutants from the air coming into the building.

While dehumidifiers indirectly improve air quality by slowing the spread of mold, bacteria and viruses, can they really clean the air?

The answer to that question requires more detail.


What Is Clean Air?

As there is no universal way to regulate air quality across the globe, there is no single definition what it really means.

Outdoor air quality oftentimes is defined by factory and vehicle emissions, for example.

The U.S. Environmental Protection Agency’s has set regulations for six outdoor air pollutants. The EPA further states that indoor air can be two to six times more polluted than the air outside, but surprisingly, there are no set federal regulations for indoor air.

The EPA itself just has recommendations, but many states have Indoor Air Quality Acts written into their laws.

Research shows that breathing clean air contributes in a significant way to our health and well-being, so it’s still a good idea to heed the EPA’s recommended levels for certain pollutants. Even if the laws are lax in your own state.


Why Is Clean Air Necessary?

It cannot be denied that air pollution is a significant risk to your health.

According to the World Health Organization (WHO), by breathing cleaner air, the chances of stroke, lung cancer, heart disease, and respiratory diseases can be easily reduced.

Sadly, the WHO states that 4.3 million people globally die from indoor air pollution every year.

Carbon monoxide, mold, pollen, dust, pet dander, volatile organic compounds (VOCs), lead, and asbestos can make up most of the air pollutants found inside a home.

Because these pollutants are such small molecules, especially carbon monoxide and VOCs, they can directly enter into the lungs and stay lodged there for years, causing immediate or long-term harm.


Can a Dehumidifier Reduce Dust in the Air?

The primary function of a dehumidifier is as its name implies – to reduce humidity.

But they go beyond that.

Microbial pollutants like dust mites, mold, and mildew require water to survive and reproduce.

The dust particles that you see floating in a random ray of sunlight contain dead dust mites and their waste.

By regularly cleaning your home along with using a good quality dehumidifier; you can help the indoor air quality by cutting off the water source those microbial pollutants need to thrive.

Although, you’ll still need an air purifier to remove dust and those other particles from the air.


Primary Function of Dehumidifier:

A dehumidifier’s primary function is to remove excess moisture from the air and bring down the level of humidity in a room.

Remember that while this device does not clean or filter air, it does help remove allergens like dust mites and mold, which thrive in a moist or humid environment. With a humidity level of less than 50%, these sources of allergies and asthma can wither and die. 


What Does a Dehumidifier Do?

While your dehumidifier cannot and does not actually do the dusting for you, it is still sufficient enough to filter out most of the dust in the air passing through its filter.

What happens is this –

Dehumidifiers suck the ambient air in through its vent. Then, the excess moisture in the surrounding air is extracted in the machine, which collects in the water collection tank below.

By doing this, the dehumidifier decreases the level of humidity in your home. These devices then push the air through a purification filter, which captures dust, pollen, and other spores or bacteria present in the air.

The air that comes out of the machine is cleaner, fresher, and much better smelling than the one that entered it. You can easily observe the build-up of dust on the filters after some time, the same dust which would have been otherwise floating all-around your home.

To summarize, a dehumidifier reduces the moisture levels in the building, which reduces the ability for bacteria and dust mites to live and spread throughout the place.


Do Dehumidifiers Really Clean the Air?

It is worth repeating; dehumidifiers do not clean the air like an effective air purifier.

The only thing these appliances can do is to help maintain the humidity levels within a space by removing excess moisture.

But, and this is important to note, a dehumidifier can indirectly clean the air by preventing mold, bacteria, and harmful dust mites from thriving and reproducing.

(Dust mites are microscopic organisms that usually make allergy and asthma sufferers feel worse in high humidity. They live in bedclothes, drapes, rugs, and the air in our home.)

Not only do those organisms use water to live and reproduce, they also use water droplets to give them some weight.

Imagine a dust particle floating in the air. It’s easier to get rid of it through natural ventilation just by opening the air. But when dust is allowed to accumulate, clump up, and gets sticky with moist air, it’s harder to get rid of it because it tends to deposit on furniture, floors, fixtures, and wall surfaces.

Some dehumidifiers have built-in filters that remove these stubbornly deposited dust and allergens, but still, the clean air provided by these dehumidifiers is not a match against the powerful air circulation that a good quality air purifier can provide.


Dehumidifiers Help Eliminate Dust Mites

Dehumidifiers manage to improve the overall indoor air quality within the building by removing excessive levels of humidity.

But dehumidifiers also perform another essential task: eliminating dust mites.

As mentioned above, household dust mites are microscopic particles that can live anywhere, from your clothing to carpets to air. They are a common cause of many allergy-related symptoms and asthma.

They especially thrive in humid and warm climates. As the dehumidifiers keep the overall humidity in your house at an acceptable level; therefore, the environment in which dust mites survive and thrive is also eliminated as a side benefit.


Getting Rid of Musty Smell

Especially in the damp and humid areas, a dehumidifier is a heaven-sent as it reduces that obnoxious, unbearable musty smell that comes from the mold and bacteria by removing any excess moisture present in the room.

Not only does this make the indoor air quality much better, but it also makes the air smell fresher and cleaner in general.


Built-in Filters in Dehumidifiers

Many dehumidifiers come with a primary filter. Some are equipped with better filters, but they are a bit more expensive.

Then there are those to which you can add a charcoal filter or a pre-filter on top of a 2-inch pleated filter.

These filters do provide cleaner air, but the quality of the filtration is still not up to the mark with the HEPA filtration standards found in air purifiers. Simply put, air purifiers provide better filtration compared to dehumidifiers with built-in filters.


Natural Ventilation

Dusting out our room, opening the doors and windows regularly, all of these small tips can work wonders paired with a dehumidifier. Like we said earlier, it does not dust our home, but it can prevent the growth of dust mites. So don’t forget to open a window while cooking or to air out and to brush our room regularly.

It’s the simplest and cheapest way to get some fresh air into your home.


But Does a Dehumidifier Purify the Air?

Sort of, but not really. You can easily understand this if you have read the above information.


Related Questions

What is better? An air purifier or dehumidifier?

It depends. If you are looking for a device that cleans the air, then an air purifier is the better option as it cleans the air by circulating the room’s perspective through a series of filters, getting rid of smoke, allergens, dust, etc.

However, if you want to tackle mold growth, a dehumidifier is the better choice. And that is without considering any underlying health condition you might have, so be careful when making your choice. 


Can we get dehumidifiers that also purify the air? 

Actually, yes, you can. Some dehumidifiers contain a primary air filter and the ones to which you can add a charcoal filter or a pre-filter on top of a pleated filter. Keep in mind that while this will not provide you the best filtration compared to an air purifier, it will keep the air you breathe cleaner.


Where can we use a dehumidifier?

It is possible to use dehumidifiers in:

  • Boats
  • Cars
  • Collections
  • Garage & Basement
  • Greenhouse & Hydroponics
  • Guns & Gun Safe
  • Household Use
  • Kitchen & Bathroom
  • RV & Camper


Are there any bad effects of using a dehumidifier?

Yes, there are, but these side effects are rare, not a usual outcome. Also, all side effects are simply based on the fact that this device makes the air dry.

  • Dehumidifiers make the air drier, which is not a requirement if you are already living in a dry climate, e.g., a desert or high-altitude area.
  • Too much dry air can make conditions like pneumonia worse.
  • Skin and hair can be affected.
  • In some cases, you should need to be conscious of your body’s hydration level while using a dehumidifier.
  • Running a dehumidifier when you have a dry cough or stuffy nose makes it worse.


What precautions should be taken while using a humidifier?

While a humidifier does the opposite of a dehumidifier, it’s also important to know its side effects for comparison’s sake. 

  • Humidifiers make the air very humid if they are run nonstop or for long periods without any break, which can worsen the condition of an asthmatic patient.
  • Filling the humidifier with tap water may irritate your lungs from the airborne minerals from water.
  • A dirty humidifier can be very harmful as it may harbor bacteria and fungi, which are released into the air. So don’t forget to clean it regularly and adequately.
  • Cleaning the humidifier with products that contain chemicals or bleach may also irritation to the respiratory system.


How do I choose the right dehumidifier for my home?

It all depends on your requirements. Think about your budget, as dehumidifiers can get expensive in larger rooms. Find the square footage of the room or area where you want to use it and find a dehumidifier that meets your required capacity.

Take outdoor temperatures into account as dehumidifiers have a harder time removing moisture in colder rooms without any insulation.

Here’s a good place to start to choose the right one.


What are the sources of indoor air pollutants?

Any source that releases gases or particles into the air can be considered as the primary cause of indoor air pollution. These may include:

  • Fuel-burning combustion appliances
  • Tobacco products
  • Building materials and furnishings
  • Deteriorated asbestos-containing insulation
  • Products for personal care, household cleaning, and maintenance, or hobbies
  • Newly installed flooring, upholstery, or carpet
  • Central cooling and heating systems and humidification devices
  • Excess moisture

Furniture or cabinetry made of certain pressed wood products

  • Improperly fitted or malfunctioning appliances like a gas stove, which can emit significantly more carbon monoxide in such a case
  • Inadequate ventilation (by not bringing in enough outdoor air to dilute and dissipate the  releases from indoor sources and by not transferring indoor air pollutants out of the region)
  • High humidity