How Can Air Purifiers Help With Mold?

Published on 08/02/2022 · 8 min readMold is a common contaminant in homes! One of the best ways to reduce the negative effects of breathing mold is using an air purifier. Keep reading to learn more!
Gunnar O, Air Quality Expert
By Air Quality Expert Gunnar O

Photo by Hamish Duncan

Mold and Its Effects

Our living spaces are subject to many types of indoor air pollutants. Odors, pet dander, and other harmful particles are not only a nuisance but can cause allergies or other health issues. Out of all of these airborne contaminants, one of the biggest hazards in indoor air is mold. Often caused by a lack of ventilation, high humidity levels, serious flood damage, and excessive moisture from leaky pipes or older roofs, mold can easily find its way into your home. Mold is in the air we breathe daily, but excessive mold exposure and breathing in airborne spores are known to cause various health issues.

If you have new allergy symptoms without an obvious cause or outside of their typical season, you may be experiencing effects from a mold growth problem. Mold spores are not visible, and, often, mold is hidden, so it can be hard to identify if this is the culprit. If you know your problem is due to mold, the best way to eliminate it from your home is to fix the moisture source and remove any moldy furniture, fixtures, wood, or drywall.

An air purifier can also help remove mold spores from your environment. They can filter the mold spores out of the air, which helps negate the negative health effects of mold exposure. Choosing the right air purifier for mold is important because not all purifiers are equal in filtration quality. Fortunately, some standards between filters are easily identified with a little bit of knowledge. That said, filters aren’t the only thing that you need to pay attention to when choosing an air purifier, as many other features come in handy specifically for mold.

An Overview of Air Purifiers

Filter Types

Air purifiers use various filter types and other technology to remove particulates from the air we breathe. Air purifiers can remove dust, pollen, and other allergens from the air by using a fan to pass air through a filtration system. An actual High-Efficiency Particulate Air (HEPA) air purifier filters out mold spores by using a fan to blow the air over a HEPA filter. HEPA filters are in many of the best air purifiers.

These filters can trap 99.7% of airborne particles down to 0.3 microns in size. Most airborne mold spores are much larger than this, so they are easily trapped in HEPA filters. Along with removing mold spores, HEPA filters help remove smoke, viruses, bacteria, and other asthma-causing particulates from the air.

When choosing the best air filter for your situation, you should decide on the type of filtration and extra technology you might need. A true HEPA filter (versus a HEPA-type or HEPA-like filter) is a great start, but some purifiers also have added filtration that can have even more advantages. For example, activated carbon filters help filter and remove odors that can be left behind from mildew. These can also help remove Volatile Organic Compounds (VOCs) from the air, which are smaller in size than can be captured by a HEPA filter.

Some purifiers use an Ultraviolet C Lamp (UV-C) in combination with the filter with hopes of killing mold spores, viruses, and other bacteria. Ultraviolet Germicidal Irradiation (UVGI) air purifiers use UV lamps to destroy the spores. Still, the time required for UV light to do so versus the time they are actually exposed to the UV light in these filters is a common criticism of these devices. Also, many mold spores are UV-resistant; therefore, this added purification would not be beneficial. Photocatalytic Oxidation (PCO) air purifiers try to bypass this problem by incorporating a photocatalyst to help break down contaminants. These are also not as effective with mold but are another option to help with additional airborne particulates.

Ionic purifiers use built-in ionizers that create electrically charged molecules that attach to airborne contaminants. Once attached, the particles collect on a plate within the purifier and are removed from the air in the room. These purifiers are sometimes under scrutiny because of their tendency to cause molecules to attach to other surfaces within the room and their production of ozone while ionizing. These types of purifiers can help with mold spores but are not necessary.

Purifier Size

Photo by Onur Dongel

It is also important to determine the square feet of your room to calculate the proper air purifier size for your space. Not only can the proper size purifier impact your indoor air quality, but it can prevent you from excessive filter changes. Most filters list their ideal room size and/or their Clean Air Delivery Rate (CADR), so you know how much coverage the purifier will provide. The general rule of thumb is to have your CADR equal to two-thirds the size of your room. The CADR is usually provided independently for pollen, dust, or smoke but not for mold, so the listed maximum room size is generally more accurate when determining a mold air purifier. If neither of these is listed, you'll often find the Cubic Feet per Minute (CFM) listed. Typically, you want 100 CFM per 250ft2 of room you hope to purify.

Also, air purifiers require occasional filter replacements to filter mold spores or other contaminants effectively. Not only does this keep your purifier running well and cleaning your air properly, but it also reduces the chance of mold growing on your filter. Therefore, it is wise to consider the cost of replacement air filters when choosing your air purifier.

Other Considerations

Other considerations when choosing an air purifier are variable fan speeds, sleep mode for quieter filtration, smart technology for automatic filtration, or portability to use in various spaces. Some purifiers even have a sensor to alert you when you are due for a filter change.

Best Air Purifier Features for Mold


The best air purifier for mold is a purifier with a true HEPA filter properly sized for your room. An activated carbon filter is a great addition when looking for an air purifier for mold because it can help remove the smells often associated with a mold-infested home. Mold spores can quickly turn into more mold. Therefore, a purifier with a washable pre-filter is a great idea because this will allow you to clean your filter easily.


Mold is unlike smoke or pollen in that it tends to not go away after a short time. When filtering mold, it is best to run your air purifier 24/7 to ensure that you properly filter the spores out of the air and not breathe them in. An Energy Star-certified air purifier is an excellent choice because your filter will meet Environmental Protection Agency (EPA) performance standards for energy consumption and will cost you less to run. Some purifiers are also Asthma and Allergy Friendly certified, which gives even more confidence that the spores will be properly filtered rather than redistributed through the room.

Smart Technology

Purifiers with smart technology are a great idea because they offer more convenience and better usage of your time. For example, the Alen BreathSmart series has a smart sensor that not only displays the air quality status but automatically adjusts purifying power when harmful air particles are detected. Purifiers with an Air Quality Indicator (AQI) either on the purifier or via a smartphone app are also great for mold detection to determine the hazard level and if your mold problem is getting better or becoming worse with time.


If your filter is only going to be used in one place, then you likely don’t need a portable filter. Still, a portable option is a great choice if you will be moving between locations that may have a mold problem and don’t want to leave a stationary filter at each location. Also, if the purifier is going to be used in a room where you will be sleeping, then a quieter sleep mode is a nice feature to have. Some people do not mind the noise generated from an air filter, but it is nice to know that it can be quieted if needed.

Do Air Purifiers Help With Mold?

Photo by Ujjwal Arora

Yes, air purifiers help with mold. Mold in your home or workspace can be detrimental to your health, but as mentioned previously, air purifiers can help negate some of the ill effects of breathing in mold spores. Although the best cure for a mold problem is to stop the source of the moisture and remove the mold, the spores can still linger. An air purifier can ensure that mold damage can cause no further health effects.

Final Thoughts

There are many options to consider when choosing an air purifier for mold. Filter type, purifier size, certifications, smart technology, and portability all play factors in deciding the right kind of purifier for your needs. A true HEPA filter air purifier will do the trick for mold, but for best filtration, an activated carbon filter is also a great addition. A smart sensor that can detect contaminant levels and also adjust filtration levels depending on the amount needed is a great feature in an air purifier for mold. Also, Energy Star certification is a bonus because you can continuously filter without worrying about your electric bill. If the filter is in your bedroom, then a quiet night mode is an important feature to reduce noise. Lastly, a properly sized air purifier for your room with a replacement filter that fits into your budget is crucial.

With so many features to balance and complexities associated with picking the properly-sized purifier, it is best to talk to an expert about your needs and desires. Our Experts here at Curated know the entire field of purifier products and help folks just like yourself find the right purifier daily. For advice on the best purifier for you, please fill out our short survey. Then, your Air Purification Expert can point you in the right direction.

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