Air purifiers fitted with HEPA filters are recommended by some bodies to help mitigate the risk of airborne virus transmission. But what’s a fair picture of their capabilities and how can purifiers best be deployed as part of an air quality strategy?
What is an air purifier?
Air purifiers are typically made of a filter (or multiple filters) and a fan designed to suck in and circulate air. As air moves through the filter, pollutants and particles are captured while clean air is pushed back out into the surrounding space. Filters are usually made of paper, fibreglass or mesh, and require regular replacement to maintain efficiency. They can range from small and portable domestic units, to wheeled and wall-mounted, high capacity commercial products.
What is a HEPA filter?
A HEPA filter also known as a ‘High-Efficiency Particulate Air Filter” is designed to meet specific HEPA standards.
These standards state that filters must be able to capture over 99.97% of all particulate pollution which would include pollen, dust, mold, tobacco smoke and PM2.5 (among the smallest of all atmospheric particules).
“To meet the HEPA standard, the filter must remove 99.97% or more of all particles which are 0.3 microns (micrometers) in diameter. That means for every 10,000 particles that are 0.3 microns in diameter, only three should pass through.”
HEPA technology was first developed for use in gas masks during the First World War, and was later adopted by scientists involved in the ‘Manhattan Project’ looking to protect themselves from radioactive particles (but don’t try that home).
In the 1960s the product become commercialised and the technology is now used to provide the highest standard of air purification in domestic, commercial, medical and industrial settings.
Are HEPA filters effective in ‘trapping’ airborne viruses?
There is evidence to suggest that HEPA filters are effective in trapping some viruses, although currently no filter or purifier can claim to capture and eliminate COVID-19.
Even so, modern air purifiers fitted with HEPA filters have impressive capabilities and a good evidence base for their effectiveness in some key areas. For example, the Aeramax professional range are:
- Certified to be effective in reducing airborne concentrations of influenza A (H1N1) aerosol in a test chamber, reaching 99.9% airborne virus reduction within the first 35 minutes of operation.
- Certified to capture 99.97% of pollutants at 0.3 microns
- Can capture more than 97.8% of pollutants at 0.1-0.15 microns, via IBR Laboratories test data
So, there’s plenty of reasons why (in the current climate) air quality and purification should be a topic of increasing interest for employers.
Air purification & the promise of wellness and productivity
But even before Covid, worker sickness and sick building syndrome had been impacting levels of absenteeism and productivity in modern offices. The way that cold and flu sweeps through teams in a normal business year is evidence of the way breathing unpurified and recirculated air in poorly ventilated buildings can help the spread of illness.
And according to some reports, even in normal years this kind of ill-health costs the UK economy anywhere between £32 billion and £72 billion per annum, So it’s an area worth focusing on, regardless of the current pandemic.
But this study from the Harvard Medical School suggests poor air quality results, not just in colds and flu, but in impaired cognitive performance at work, too.
When the quality of air circulating in offices improves, so does productivity and creativity:
“We found that breathing better air led to significantly better decision-making performance among our participants... The results showed the biggest improvements in areas that tested how workers used information to make strategic decisions and how they plan, stay prepared, and strategise during crises. These are exactly the skills needed to be productive in the knowledge economy.”
According to the Harvard professors Allen and Macomber in their new book “Healthy Buildings: How Indoor Spaces Drive Performance and Productivity” the move towards healthier and harder working environments can be supported ‘by the use of portable air purifiers’.
Workers need reassurance
But anecdotal evidence from across the FM industry is showing that the presence of purifiers in the office, can act as concrete evidence for nervous workers that employers are listening to the evidence and doing everything they can to make their workplaces as safe as possible.
Experts are also pointing out a growing trend amongst workers to bring their own air quality monitoring devices into the workplace, to check on and ensure their own safety.
It seems that investing in technology to improve air quality may pay dividends as employers try to persuade more workers that their offices are safe environments to return to.
A few tips for using air purifiers as part of your office air quality strategy
- Make sure you choose an air purifier whose capacity matches the rated room size. Some manufacturers are quite vague about these performance capabilities, so it’s worth checking properly before you buy
- Make sure the unit is properly serviced and the filters changed regularly to ensure it’s actually doing what is intended. Filters can quickly become clogged and performance compromised if they are not looked after.
- HEPA is a specific standard - choosing ‘HEPA like’ or ‘HEPA type’ filters will not necessarily guarantee you the quality that the regulated product will deliver. A true HEPA filter is made of highly dense paper, which is composed of very thin fibres with distances between 0.3 and 2.0 microns
Finally, when it comes to delivering work wellbeing in the Covid pandemic, employers should consider and implement three essential components for protection against virus transmission.
Taking the evidence in the round. the best advice continues to be that a proactive office hygiene solution should consist of three essential components:
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Washing hands
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Sanitising surfaces
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Cleaning the air for protection against person-to-person virus transmission.
We’ve teamed up with AeraMax Professional® commercial grade air purifiers to become an official distributor. To find out more about how you can purify the air in your office, please get in touch.
