Does a Dehumidifier Help with Allergies?

High humidity makes your home an ideal environment for some common allergens. If you or anyone in the household experience allergies and asthma year round, it’s important to control the indoor humidity levels. The most effective way to reduce humidity in your home is to use a dehumidifier. 

Frigidaire FFAP5033W1 Dehumidifier

A good dehumidifier can effectively maintain optimal levels of humidity in your house. A relative humidity between 40 and 50 percent helps eliminate two common allergens at home – mold and dust mites. It can also greatly improve the indoor air quality through the added filters.

Here are some ways a dehumidifier can help alleviate allergies and asthma attacks:

Dehumidifiers Stop Mold Growth

Dampness and humidity encourage mold growth in your home. Mold is a fungus that can be found almost anywhere. It thrives on moisture and produces spores that travel through the air. When the spores find a damp surface in your home, they can start to grow there. 

Touching mold or inhaling mold spores may cause allergy symptoms such as sneezing, runny nose, eye and skin irritations. It can also lead to allergy-induced asthma attacks. Molds can be harmful both to allergic and non-allergic individuals.

Given enough moisture, molds can grow on almost any surface. But you can typically find them on wall corners, under bathroom sinks, toilets and bathtubs, wallpapers, wood, carpets, and furniture. They eat away the material which can cause severe damage to your belongings. 

A dehumidifier removes moisture from the air and controls indoor humidity. This makes your home environment comfortable for you and inhospitable for mold. Maintaining the humidity levels below 50 percent helps stop mold growth.

Aprilaire 1820 Crawl Space Dehumidifier

Dehumidifiers Eliminate Dust Mites

Dust mites are among the most common allergy and asthma triggers at home. They are microscopic insects that feed on dead skin cells. The ideal conditions for dust mites are around 70 percent relative humidity or above. They cannot survive when humidity levels drop to 50 percent.

Dust mites thrive in moist locations like your bed where you sweat and breathe. They usually multiply in bedrooms – on your mattress and beddings, and on carpets and furniture where dust accumulates. It is the dust mite waste products that trigger allergy symptoms similar to hay fever. 

You cannot remove dust mites completely. However, gaining control of the humidity and temperature in the room minimizes dust mite growth, reducing risks of allergy. Killing them is not enough. It is essential that you clean the room and wash the beddings regularly to remove their wastes and decaying bodies. You can find dust mite-proof covers for pillows and mattresses that may also be useful.

Dehumidifiers Improve Air Quality

Dust and bacteria tend to stay longer in humid air. Most dehumidifiers feature filters to remove pollutants in the air before it is processed inside the machine. You may use a dehumidifier and air purifier combination for a more thorough air filtration.

High humidity also makes the indoor air feel heavy or sticky. Humid air can’t absorb your sweat since it is already saturated with moisture. The more humidity in the air the more it becomes difficult to breathe. This is because the air contains high amounts of water vapor and lower oxygen molecules. This kind of environment is not only unpleasant but also harmful even to healthy individuals. 

Using a dehumidifier to control humidity keeps out excess moisture and odors, and ensures your health and comfort.

Signs of Excess Humidity

There can be a variety of causes of excess moisture in your space. In some cases, you may not be able to tell you have humidity issues until the damage has been done. Some common signs of high humidity are the following:

  • Condensation on windows, mirrors, or metallic surfaces;
  • Heavy or stuffy air;
  • A musty or moldy odor;
  • Water stains or damp spots on walls, floor, or ceiling;
  • Peeling of paint or wallpaper;
  • Mold and mildew growth in furniture or wall corners;
  • Rot and decay of wood;
  • Rust on metal.

If you notice any of these symptoms along with frequent allergic reactions, it may be time to install a dehumidifier in your home.

Factors to Consider When Choosing a Dehumidifier

In addition to allergies or asthma, high levels of moisture in the air may cause damages to your furniture and house structure. You can easily prevent these issues if you get the best dehumidifier for your house. 

Before you buy a dehumidifier, you need to consider a few factors in order to make the right purchase.


This is the amount of moisture in the air that your dehumidifier can remove in 24 hours. The size of the dehumidifier you need depends on several factors. This includes the area of the space and the volume of moisture. 

Obviously, a larger space requires a higher capacity. At the same time, more severe dampness and humidity call for a more powerful dehumidifier. It doesn’t mean that the biggest dehumidifier you can find is necessarily the best. Use only the right size dehumidifier for your space to maximize its effectiveness and efficiency. Alternatively, use a whole-house dehumidifier to control humidity for the entire home.


If your dehumidifier uses a tank to collect moisture, you need to empty and wash it frequently. Failure to do so may lead to mold growth inside the unit. For your convenience, choose a dehumidifier with an option for continuous drainage via gravity or pump. You will also need to clean the hose and remove any stagnant water which can attract mold and pests.


Modern home dehumidifiers usually have the auto defrost function. When temperature drops, the unit stops operating to melt the ice, and starts back up again. If your place gets particularly cold, look for a dehumidifier specially designed to operate in cooler climates.


To save on costs, you want a dehumidifier that you can use in different parts of your house. Full-size dehumidifiers typically have wheels and handles for easy movement. If you live in a small apartment and/or your moisture issues aren’t that severe, a mini model may be enough.

What about air purifiers and humidifiers?

Air purifiers also work to reduce allergens such as dust mites and mold. Similar to dehumidifiers, an air purifier can enhance indoor air quality, effectively minimizing allergies, asthma attacks and other respiratory problems.

While a dehumidifier sucks in moisture and exhausts dry air, an air purifier circulates air through a filter that catches airborne allergens like dust and mold spores. Additionally, air purifiers clean the air from smoke particles, pollen, pet dander, and bacteria. They do not control humidity or release dry air.

Honeywell HPA300 Air Purifier

On the other hand, humidifiers can help reduce allergy symptoms and skin irritation when the humidity is too low. Humidifiers work by adding moisture to the air. They are commonly used during the winter season when the air is cold and dry.

Pure Enrichment MistAire XL Ultrasonic Cool Mist Humidifier


High humidity creates a haven for common allergy triggers such as mold and dust mites. Reducing the humidity in your home makes it a hostile environment for these allergens and other airborne particles that may be health hazards. A dehumidifier, paired with an air purifier, is the best solution to excessive moisture and humidity indoors.

Dehumidifiers come in different sizes and with different features. It is essential to know the exact requirements of the space you need to dehumidify in order to make the most out of your investment.

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