Does a Dehumidifier Help with Mold?

Chances are you’ve encountered mold at some point in your life. Mold is found in food, medicine, and damp areas. According to the Environmental Protection Agency, approximately 33 percent of residential and commercial buildings in the United States harbor the prime conditions for mold growth.

Does a Dehumidifier Help with Mold?


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There are methods that you can to combat the growth of mold. When you combine multiple approaches, you have the best chance at keeping mold under control. One piece of advice is to get rid of water-damaged items within a day or two after a plumbing leak, large rainfall or flood.

When cooking or showering, you should ventilate your kitchen or bathroom, and it’s important to keep your gutters and roof in good repair to prevent leaks. Using a dehumidifier also helps by reducing one of the aggravators of mold growth – relative humidity.

Mold Defined

Mold is a fungus similar to mildew, mushrooms, and yeast, and it can grow outdoors as well as indoors. Mold grows both outdoors and indoors by feeding on organic material and water. As they grow, reproductive spores are released. Their enzymes break down dead plant matter and destroy common materials used in home construction such as wood, drywall, carpet, paint, and insulation.

Common Varieties of Mold

Common Varieties of Mold

Although there are as many as 300,000 molds known to the scientific community, some are more common than others, especially in indoor environments. Alternaria is one common indoor mold. This mold often grows on plants, and it’s a common trigger of asthma and hay fever. Aspergillus is another mold, which can pose a serious threat to those who are immunocompromised or have allergies.

Cladosporium, a non-toxic mold, triggers a number of allergy symptoms, such as hives, an itchy throat, a postnasal drip and watery eyes. While Penicillium is used in antibiotic production, it can spoil food and ruin leather.

Toxic Mold

Unlike non-toxic molds, toxic mold creates mycotoxins, which are poisonous. Exposure to toxic mold can cause a whole host of symptoms, including fatigue, headaches, and nausea. One well-known toxic mold in North America is called Stachybotrys chartarum, and it’s referred to as black mold. Chaetomium is another widespread toxic mold that often grows in water-damaged buildings, causing serious problems like memory loss, pulmonary hemorrhages, and chronic bronchitis.

Environments That Foster Mold Growth

Environments That Foster Mold Growth

There are no places where mold won’t grow, providing the proper conditions for mold growth are present. These conditions consist of three general components – a food source, moisture, and oxygen. Therefore, shady and damp areas can be rife with mold. Grass clippings and leaves are excellent food sources for mold and provide shade for the mold.

Inside of a home, warm temperatures can contribute to mold growth. How? Warm air is able to hold more moisture than cold air, leading to an increased likelihood of high relative humidity. When the humidity is high, mold growth is more apt to occur. Basements, bathrooms, and kitchens are three common areas where mold grows indoors because of excess air moisture, especially those rooms that lack ventilation.

How Mold Growth Starts

How Mold Growth Starts

Mold is a fungus that grows naturally in the environment. The spores that allow it to reproduce are attracted to food sources and wet areas. With a food source in place in a warm, moist area, the mold’s hyphae, or tiny hairs, wind around one another to create mycelium, which is a colony of mold.

It’s the hyphae that release spores into the air, and the mycotoxins in the toxic mold are located in the mold’s spores. From there, the spores become airborne, landing on surfaces that offer the right conditions for growth, and the cycle repeats itself.

Humidity’s Role in Mold Growth

High humidity is a major contributor to mold growth. Mold thrives in a room with a relative humidity of 60 percent or higher. However, when the relative humidity falls below 50 percent, the mold can no longer grow. Ideally, the humidity level indoors should range from 30 percent to 50 percent.

After regulating the relative humidity indoors for a week or more, the moisture source for mold spores will decrease, which means new spores won’t be able to generate. Lowering the humidity may prevent mold growth from occurring and inactivate existing mold, but a low relative humidity won’t kill mold that’s already grown.

When Existing Mold is Subject to Lower Humidity Levels

Related Post: Is a Dehumidifier Good or Bad for You?

When Existing Mold is Subject to Lower Humidity Levels

If the relative humidity in a room is below 50 percent, there is little risk of existing mold spreading to other places. Instead, the mold will stay dormant. A dehumidifier can help you control the relative humidity in your home. However, to get rid of existing mold once and for all, you must remove it manually.

Homes that have a mold presence require different treatments, depending on the origin and location of the mold. If the mold started after a leak, make sure to repair the pipe, roof or other cause. If there are water-logged materials that are facilitating mold growth, you must throw them away immediately. Mold growth in small areas can sometimes be removed by applying diluted bleach and elbow grease.

How Dehumidifiers Work

And their core, the process that dehumidifiers go through to lower the relative humidity is the same. All dehumidifiers pull in the air around it. Then, this air travels across a component that extracts the moisture from the air where it is dropped into the reservoir. Finally, the dry air is pushed out of the dehumidifier and into the room.

Most dehumidifiers are portable, allowing you to move them from room to room whenever you need them. To make sure the dehumidifier is keeping the relative humidity at a healthy level, you should place a hygrometer in the same room to measure the percentage of moisture in the air. The only instance when this isn’t necessary is if you have a dehumidifier with a built-in humidistat, which not only measures the relative humidity but also controls it automatically.

Types of Dehumidifiers

Types of Dehumidifiers

There are two kinds of portable dehumidifiers – refrigerant and desiccant. As the name suggests, refrigerant-style dehumidifiers act similar to refrigerators as they both condense humid air over a metal plate. Inside of a dehumidifier, a fan spins and draws humid air into the appliance where it condenses into the reservoir.

If a refrigerant dehumidifier operates at low temperatures, the coils can freeze. However, some of these dehumidifiers are equipped with a defrost feature to prevent damage to the dehumidifier.

The other type of portable dehumidifier is called a desiccant dehumidifier. With a desiccant dehumidifier, air is pulled into the dehumidifier where it passes through an adsorbent material known as a desiccant. Then, the water is released into the reservoir and drained manually or through a hose. Unlike refrigerant dehumidifiers, desiccant humidifiers can run at lower temperatures without freezing.

Mold Growth in a Dehumidifier

Mold Growth in a Dehumidifier

Even though mold control is a major reason to buy a dehumidifier, this appliance can become subject to mold growth if you don’t keep the dehumidifier clean on a regular basis. When the reservoir isn’t emptied once it’s full and the water is allowed to sit, the mold may grow around the water line in the reservoir.

If you see mold in the reservoir, the good news is that it’s easy to remove. Simply don a pair of rubber gloves and dump the stagnant water. Then, fill the reservoir with a gallon of water and a teaspoon of antibacterial dish soap. After swishing the solution, scrub the interior of the tank with a soft brush. Next, dump the water and rinse the reservoir.

At this point, you need to add a gallon of water and one-half cup of bleach. Again, swish the solution. Then, allow the solution sit for 10 minutes. Finally, you can empty the tank and rinse out the bleach residue. Make sure the reservoir is completely dry before you put it back on the dehumidifier.

Signs of Mold Damage in a Building

Signs of Mold Damage in a Building

Before you see a sign of mold, you may be able to detect it with your nose, particularly in areas with no or poor ventilation such as a windowless bathroom or an enclosed closet. If you smell a musty odor, start looking for signs that mold is present, such as water stains on your ceilings or walls.

You may also see mold spores, which look like clusters of black spots. These often grow on walls and in shower stalls, but they can be found anywhere. Also, white growths that are threaded in appearance are signs of mold growth. These white threaded structures are actually the mycelium mentioned earlier.

Health Symptoms of Indoor Mold Growth

Some signs of mold are not apparent to the eye or the nose. However, there are certain symptoms someone who is exposed to mold may experience. If you are having an allergy or asthma flare-up with no known cause, the mold may be the culprit. Even if you don’t have allergies or asthma, you may have a stuffy nose, dry skin, and irritated eye membranes. You may even cough or wheeze.

Health Symptoms of Indoor Mold Growth

Our Recommended Dehumidifiers

Best of the Best!
Vremi 22 Pint 1,500 Sq. Ft. Dehumidifier Energy...
hOmeLabs 4,500 Sq. Ft Energy Star Dehumidifier for...
Keystone 50 Pint Dehumidifier with Electronic...
Vremi
hOmeLabs
Keystone
1,500 Sq. Ft.
3,000 Sq. Ft.
4,500 Sq. Ft.
22 pints
35 pints
50 Pint
16.1 x 10.4 x 19.9 in
15.4 x 11 x 24.3 in
10.8 x 15.4 x 23.2 in
33.1 pounds
40 pounds
42 pounds
The Vremi removes up to 22 pints from the air per day. This Energy Star certified dehumidifier is fit to quickly and effectively absorbs moisture with minimal energy consumption.
This dehumidifier removes up to 35 pints (50 Pint 2012 DOE Standard) of water from the air per day. This moisture-removing beast is fit for any basement, cellar or large room, and it’s Energy Star certified
The Keystone 50-pint dehumidifier removes up to 50 pints of moisture from the air per day in a room up to 4500 square feet.
Best of the Best!
Vremi 22 Pint 1,500 Sq. Ft. Dehumidifier Energy...
Vremi
1,500 Sq. Ft.
22 pints
16.1 x 10.4 x 19.9 in
33.1 pounds
The Vremi removes up to 22 pints from the air per day. This Energy Star certified dehumidifier is fit to quickly and effectively absorbs moisture with minimal energy consumption.
hOmeLabs 4,500 Sq. Ft Energy Star Dehumidifier for...
hOmeLabs
3,000 Sq. Ft.
35 pints
15.4 x 11 x 24.3 in
40 pounds
This dehumidifier removes up to 35 pints (50 Pint 2012 DOE Standard) of water from the air per day. This moisture-removing beast is fit for any basement, cellar or large room, and it’s Energy Star certified
Keystone 50 Pint Dehumidifier with Electronic...
Keystone
4,500 Sq. Ft.
50 Pint
10.8 x 15.4 x 23.2 in
42 pounds
The Keystone 50-pint dehumidifier removes up to 50 pints of moisture from the air per day in a room up to 4500 square feet.

Last update on 2021-11-26 / Affiliate links / Images from Amazon Product Advertising API



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Sources
Best Dehumidifiers of 2021
Energy Star
Support for People with Aspergillosis
Consumer Reports

About the author

Hi I’m Alexander, founder of HouseholdMe.com and I’d like to say thank you for dropping by. Like most of you, the first thing I look at before buying something online is reviews or buying guides. By reading what other people say will help me gauge whether or not a product is good or not.  I am trying to help people find answers, solve problems, and get inspired.

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