A common and popular type of air purifier is an ionizer, sometimes known as ionic air purifiers. These air purifiers work by imparting an electrical charge to particles that pass through them. But are they effective at killing mold spores, or at least removing them from the air? We will take a close look at how ionizing technology works and explain whether or not they do the job of killing mold. Then we will discuss what air purifier technology is the best choice for you if you have a mold problem in your house.
If you have a mold or mildew problem in your car, you might be considering an ionizing air purifier for your car, since they are one of the few types of air purifiers available for in-car use. We will look at ionizers for cars as well.
Mold is a fungus that reproduces by emitting microscopic spores. These spores can float in the air, but eventually settle onto the ground or another surface. Mold spores are everywhere outdoors, but they can also be in your house. Unfortunately, there is not really a practical way to eliminate all mold spores, so your goal with an air purifier to is to reduce the amount of mold spores in the air in your home or car to low enough levels to prevent them from triggering allergies or other respiratory symptoms.
If you have a mold problem, it is important to clean up the mold and remove the moisture that allows it to grow. Otherwise the mold will grow back and keep emitting more spores.
Can ionizers kill or remove mold?
Ionizers work by adding an electrical charge to the particles that move through it, usually giving them a negative charge. As they float about the room, these negatively charged particles tend to stick to other positively charged particles with which they collide. These clumps of particles are heavier than the individual particles, causing them to fall out of the air onto surfaces much faster than they would in their original state. Charged particles might also stick to surfaces that have the opposite charge (often a TV screen or computer monitor). Some ionizers have a charged plate specifically designed to attract opposite charged particles to it. These are known as electrostatic purifiers, although they function in the same basic way as ionizers.
When mold spores go through an ionizer, they get an electrical charge, clump together with other particles, and fall out of the air. This results in mold spores on the floor, in your carpet or on your furniture, which is exactly what you want to avoid. The ionizer does nothing to kill or destroy the mold spores, it just makes them settle out of the air faster.
Thus the answer to our question is: No, ionizers do not kill mold spores. They also will not have any effect on mold growing in your house.
Why are ionizers ineffective against mold?
If there is sufficient moisture, the mold spores that pass through an ionizer and end up in your carpet, curtains, floor or furniture can grow into mold, which will release more spores. Even if they do not grow into mold, the spores can easily be kicked back into the air by air currents, which can be caused simply by you or your pet walking by. So ultimately the ionizer will have had no effect on the mold spores in your house.
Some ionizers are fanless, and while they are very quiet and energy efficient, only a very small quantity of air moves through them. Even if the ionizer was able to do anything about mold spores, it would take a very long time to fully purify the air in a room of mold spores, since it would rely on random air currents to carry spores through the ionizer by chance.
Ionizers may be marketed as freshening air. However, the way they function will not have any effect on odors or gases, including those caused by mold or mildew. While studies have found that negative ions in the air do not have any negative or positive effects on respiratory health (Alexander et al.,2013), ionizers create ozone as a by-product.
While ozone has an odor that might mask other odors, creating the illusion of “fresh” air, this gas does not actually remove any pollutants from the air. In fact, ozone is itself a pollutant. At high concentrations, ozone is toxic and acts as a lung irritant. The small amount of ozone generated by ionizing air purifiers is probably not enough to be harmful, unless you use it in a small enclosed space with no ventilation. However, these ozone levels are also not high enough to have any beneficial effect on pollutants in the air.
Be wary of air purifiers that claim ozone can sterilize the air in your home. Some professional cleaning companies use ozone to decontaminate rooms, but this requires special equipment and the rooms must be thoroughly aired out before anyone can enter it. For these reasons the EPA recommends against using ozone generating air purifiers in your home.
Moreover, since ionizers are not effective against mold spores, and because your car is a small enclosed space, using an ionizing air purifier in your car is not a good idea because the ozone concentrations could build up if the windows are closed. Solving a mold problem in your car will require a thorough drying, clean-up and airing out.
Mold killing technology that actually works
Electrostatic – An electrostatic air purifier is an ionizer that attracts charged particles to an oppositely charged plate (the collection plate). This has the advantage of removing the mold spores and concentrating them in a single place, which you can then wipe clean, rather than just letting it fall elsewhere in the room. Research has shown they often have an initial 60 percent single-pass removal rate for most particle sizes, though the charged plate gets dirty and efficiency declines quickly. Expect to be cleaning the collection plate frequently.
UV-C light – Mold spores and other microbes can be killed by ultraviolet light, known as UV-C light. However, to be effective, a powerful light and a lengthy exposure time is required. Residential UV-C air purifiers generally do not meet the criteria for effective mold spore destruction.
HEPA – A HEPA filter is a fabric mesh designed to trap 99.97 percent of particles down to 0.3 microns in size. Mold spores are usually larger than this, so HEPA filters are effective at removing mold spores from the air. However, the filters need to be changed regularly to maintain efficiency and prevent mold from growing on the filter media.
What does not work?
Some air purifier technologies are not effective against mold or mold spores.
Carbon – Carbon, or activated charcoal air purifiers, are intended for removing gaseous pollutants from the air, including volatile organic compounds (VOCs). However, they will not remove mold spores from the air at all. They may help against the mildew-y smell, but to get rid of the smell you really have to get rid of the mold. So a carbon filter will not be effective against mold.
Ozone generators – These air purifiers simply create ozone gas, which as we explained above, will not remove mold spores from the air. The ozone concentrations created by these generators will not be high enough to kill the mold spores—and if they were, you would be exposing yourself to potentially toxic ozone levels.
How to get rid of mold
According to the EPA, if the area of mold in your house is fairly small (less than 10 square feet), then you can clean it up yourself. Larger mold problems may require professional mold remediation. To clean up mold, cut away any soft or porous surfaces with mold on them, like carpets, wood or drywall. Porous items covered with mold should be thrown away. Use a cleaning solution (bleach is not necessary) and scrub the mold thoroughly off of any hard surfaces. Run and air purifier in the room while you are cleaning to help remove mold spores from the air.
Once the mold clean-up is completed, make sure you have also removed the source of the moisture that allowed the mold to grow, whether it was a leak, a flood or excessive humidity.