Do Air Purifiers Prevent The Spread of Covid?

With traces of Covid-19 still lingering in the Australian community in 2024, many people are wondering if air purifiers can protect them and their family against the spread of the virus. 

There are conflicting thoughts on whether air purifiers can reliably capture airborne Covid-19 particles, with some arguing against their efficacy pointing out that a typical coronavirus particle is smaller than the minimum size a HEPA filter can capture, however as others point out, virus particles are always bonded to something larger like aerosols and water droplet – which can be reliably trapped via HEPA filtration. Read on to learn more. 

Please note this article is not meant to constitute medical advice but merely discuss the research on the use of air purifiers for minimising Covid transmission.

Air Purifiers Vs Covid-19

The best air purifiers available in Australia all feature a HEPA filter. These types of filters are effective at trapping and removing viral particles from the air down to 0.3 microns in size.  However, a typical Coronavirus particle is around 0.1 microns in size meaning it can potentially pass through the extremely small gaps in the HEPA filter.

Despite this, research has shown that HEPA filters can still be effective at trapping airborne Covid-19 particles for two reasons:

1. Covid-19 virus particles are always are bonded to larger particles generated by sneezing, coughing and talking which are around 1 micron in size.

2. Naked Covid-19 particles alone would rarely travel in a perfectly straight direction meaning there’s a high likelihood they’ll be captured by a HEPA filter.

However, it’s important to note that air purifiers can only capture airborne Covid-19 particles, and can’t remove particles that are attached to surfaces around the home or office. 

What Happens After The Virus is Trapped?

Now that we know that’s its possible air purifiers with HEPA filters are effective in preventing the spread of airborne Covid-19 particles, it’s important to consider what happens to the virus particles once they’re inside your air purifier. 

In order to remain effective, air purifiers’ HEPA filters must be changed regularly. However, its thought the Covid-19 virus can survive on a surface for several hours or even days – this can potentially expose the person who’s changing the filter to a concentrated area of viral particles. 

The EPA suggests that gloves, goggles and an N-95 mask should be worn when changing the filter of your air purifier if it’s been in the presence of Covid-19, doing so outdoors if possible. `

air purifier removing dust

Air Purifiers in Action Against Covid-19 in Australia

Perhaps the greatest endorsement of their effectiveness for reducing the spread of Covid-19, air purifiers have been deployed across schools and hospital settings throughout Australia – with some experts going as far to suggest they should be installed in every classroom.

A Cambridge University study also found that  2 small domestic air purifiers in a single hospital room could remove 99% of aerosols, including those containing viral particles, within 5 and a half minutes.