Do HEPA Filters Need to be Cleaned? - An Expert's Guide

If you've noticed a visible build-up of dust or particulate matter on your HEPA filter (it may look gray or dirty) or you've noticed reduced airflow through your portable air purifier, you may be wondering if it's time to clean the filter. However, experts suggest that HEPA filters should always be replaced rather than cleaned. Replacement filters can be expensive, so it's important to consider the cost when evaluating air purifiers. Washable or permanent HEPA filters are easy to maintain and can reduce the cost of replacement filters.

If your air purifier or vacuum uses a HEPA filter, consult the product manual before attempting to clean the filter. A washable HEPA filter should be rinsed with water at least once a month, while wetting a permanent filter that cannot be washed can ruin it. Rinse the washable filter until water passes through it clearly and allow it to dry completely before reinstalling it. Use a vacuum hose with a brush to remove contaminants from a filter that cannot be washed.

You can rinse the filter with water, remove excess dust, or remove it with a vacuum, but this can permanently damage the fiber mesh that allows the filter to remove particles from the air. Many of the best air purifier brands on the market come with a HEPA filter that is washable, allowing you to clean and reuse it. However, there is no standard for washable HEPA filters, and there have been no public studies that test the operation of these filters after they have been washed. While HEPA filters claim to remove particulates from the air and improve indoor air quality, they can be expensive, especially when you factor in ongoing replacement costs. There are several air purification technologies available, in addition to HEPA filters, that you can use to improve the air quality in your home. In practice, HEPA filters are made from a variety of materials, such as “thick glass fibers”, coated animal hair, plant fibers, synthetic fibers (such as polyester or nylon), synthetic foams, metallic wool, or expanded metals and sheets, according to the EPA.

Without a solid history of testing how to clean a HEPA filter with water or a vacuum, it's unclear how that cleaning can degrade its performance. HEPA filters can easily stop larger particles, but they can also clean microscopic particles of smoke from cooking or wildfires. If you have pet allergies, are concerned about wildfires, cigarette smoke, or airborne viruses, then it's worth spending more on a high-end HEPA filter. Levoit suggests replacing your HEPA filter every six to eight months, while both Honeywell and Winix claim their units last up to a year. Then, the PECO-HEPA Tri-Power filter combines the efficiency of HEPA particles with the destruction of the PECO, reducing the chances of mold or pollen fragments returning to the air. To meet the HEPA standard, a filter is estimated to remove 99.97 percent of 0.3 micron (or micrometer) sized particles from the air that passes through it.

Since there are no official standards for cleanable HEPA filters, there are no defined terms for the types of cleanable filters available. The low-cost filter had an approximately 10% lower performance than the manufacturer's recommended option when it came to stopping particulates, and had a resistance 22% lower than the recommended filter. This doesn't mean you should avoid low-cost HEPA filters, but your decision to use the cheaper option depends on the type of particulate pollution you're most concerned about. In conclusion, if you're looking for an effective way to improve indoor air quality and reduce particulate pollution in your home then investing in a high-quality HEPA filter is an excellent option. However, if you're looking for an affordable solution then consider using a low-cost HEPA filter and replacing it regularly according to manufacturer recommendations.