Best Air Purifiers for Mold of 2023 | U.S. News - U.S. News & World Report

Things To Consider When Buying Air Purifiers for Mold

Filter Type: According to our experts, high-efficiency particulate air (HEPA) filters and activated charcoal filters combined provide the best purification for mold. "You need a filter that removes fine particles using HEPA media" and gases "through adsorption (with a 'd') or other methods, without adding harmful substances to the air in the process, and while treating enough air to stay ahead of the recontamination rate," says Allen Rathey, director of the Indoor Health Council.

He notes that the goal is to lower the concentration of airborne spores and mold fragments and not to eliminate all airborne mold particles: "Even dead mold can be unhealthy to breathe, but you will never reduce those levels to zero, as mold spores are everywhere indoors and out."

Michael Rubino of HomeCleanse says that air purifiers for mold should meet HEPA status at a minimum: "This means they remove 99.97% of particles as small as 0.3 microns, which will ensure particles like spores are removed." If the air purifier can eliminate particles smaller than 0.3 microns, Rubino says that's even better.

However, Rathey says HEPA filters do not remove gasses like microbial volatile organic compounds (mVOCs): "This is the source of that musty smell, and purifiers using activated carbon can help remove these odors." Thus, it's best to find a unit that features both a HEPA filter and an activated carbon filter.

Clean Air Delivery Rate (CADR): The CADR is determined by multiplying the room's length and width to get the square footage. This number can be compared to the recommended room size. Not all air purifiers include a CADR, but when one is included, it's typically for dust, VOCs, and pollen – not specifically for mold.

"Mold spores are 'particles' that stay airborne for a long time, and while HEPA filters are good at trapping mold spores and other small particles such as mold fragments and pollen fragments, the air purifier needs to treat enough air to make a difference, so you need to have the right CADR, a number that explains how large a room the unit will treat," Rathey explains.

Room Coverage: The suggested or recommended room size is usually listed by the manufacturer. Rubino says this factor should always be checked before purchasing a unit. "If the room is larger than the machine is able to properly handle, you won't get the filtering benefits," he warns.

Noise Level: Most companies note the air purifier's noise level. Some companies will provide a range such as 18-46 decibels (dB), which means the noise level is 18 dB on the lowest setting and 46 dB on the highest setting. Other companies just provide one number, which usually refers to the noise level on the highest setting.

Additional Features: Wi-Fi connectivity to smartphones and voice assistants is another feature that may or may not appeal to you. Some air purifiers also have timers, and some may have pre-filters and panels that come in an assortment of colors.

While some air purifiers also have a UV light to kill mold, Rathey says to be cautious about this feature. "Some companies tout other technologies such as UV light and electrostatically charged media, but there is no silver bullet as all technologies have limitations, and some technologies add their own pollutants to the air such as ozone," he says.

Maintenance: All air purifiers require some degree of maintenance. Usually, the pre-filter needs to be vacuumed at least once a month, but depending on how often you use the machine, it could require weekly or biweekly vacuuming. The sensors may also need to be cleaned but refer to the owner's manual.