Do Air Purifiers with HEPA Filters Reduce Covid-19 Transmission at Home?

With the ongoing pandemic, many are seeking ways to improve indoor air quality and reduce the transmission of the SARS-CoV-2 virus, which causes the dreaded Covid-19. Air purifiers with HEPA filters have gained popularity as a potential solution. Let's explore whether these devices can help reduce the spread of the virus.

Effectiveness of HEPA Filters Against SARS-CoV-2

Yes, of course, air purifiers can play a role in reducing Covid-19 transmission, especially those with HEPA filters. HEPA filters are designed to capture minute particles from the air, including allergens like dust, pollen, and mold spores. The distinguishing factor is the fiber size of HEPA filters, which is typically composed of fiberglass and can trap particles as small as 0.01 microns. This makes them highly effective in removing the SARS-CoV-2 virus, which has a size of 0.125 microns.

Studies have shown that HEPA filters can trap up to 99.97% of particles as small as 0.3 microns. Although SARS-CoV-2 is slightly larger, HEPA filters still perform exceptionally well in capturing it. Other contaminants that HEPA filters effectively remove include bacteria, fungi, and harmful indoor pollutants like smoke, dust, and pollen grains.

Correct Usage of Air Purifiers

However, the effectiveness of air purifiers relies heavily on their proper use. Many people make the mistake of stopping the purifier when their symptoms improve, which is often too early. Allergies and the SARS-CoV-2 virus can both cause symptoms to recur within minutes after exposure. Therefore, it is crucial to run the air purifier continuously to maintain a clean air environment.

Buying the Right Air Purifier

When selecting an air purifier, several factors come into play, including the room's size and the CADR rating. CADR stands for Clean Air Delivery Rate, which measures the volume of air the purifier can clean in an hour. CADR values are typically measured in cubic feet per minute (CFM).

Room Size and CADR

Bedroom (up to 350 square feet): Choose an air purifier with a coverage area of 370-400 square feet and a CADR of 150 to 250 CFM. Living Room (350 to 700 square feet): Opt for a coverage area of 400-750 square feet with a CADR of 250 to 350 CFM. Entire House (beyond 700 square feet): Consider an air purifier with a coverage area of 800-1200 square feet and a CADR value of 400 CFM or higher.

These guidelines help ensure that the air purifier is effective in the room size you need. In addition to coverage area and CADR, consider the importance of HEPA and activated carbon filters. These filters not only trap contaminants like bacteria and viruses but also remove odors, smoke particles, and other common allergens.

Be wary of brands that cut production costs by using lower-quality fans, as this can affect the air purifier's efficiency. Proper circulation of air is crucial for maintaining optimal indoor air quality.

On 5th July 2021 at 5:12 PM, I purchased an air purifier based on this knowledge.