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December 2021

The science of airflow... and its impact on hygiene

Written by Nathalie Leblond
Air Quality

Read our latest blog to understand how airflow can affect air quality and air hygiene in enclosed spaces, and how by understanding airflow, you can take the right steps to keeping the environment healthy and hygienic.

Media coverage over the last few months has shone a spotlight on the role that poor indoor air quality plays in the transmission of Coronavirus. But Coronavirus circulating in the air we breathe isn't the only thing we should be concerned about.

Indoor air can be contaminated with fine particles, gases, or bioaerosols - all of which have been shown to have negative effects on health, wellbeing, and productivity. 

Some facts about indoor air quality

Pathogens, pollen, pollution, dust and VOCs can all cause irritation for people with allergies or, in severe cases, illness and health problems. Dust, particles, and particulates can help viruses and bacteria move around the space and can settle in the human respiratory system, causing severe, long-term health effects. 

Carbon monoxide concentrations in the workplace can cause fatigue, reduced brain function, and impaired vision and coordination. Offices with carpets, which can be sources of aldehydes and VOCs, can have an excess of respiratory symptoms among office workers - as well as impaired productivity.

The presence of office cooling systems has been found to be associated with sick building syndrome (SBS). Office equipment, such as printers, photocopiers, and all-in-one office machines are reported to emit indoor air pollutants including particulate matter (PM), VOCs, and ozone, which are all linked to SBS symptoms.

Research shows that clean air, or higher-quality air, has been linked to improved productivity, increased focus, reduced stress/anxiety and even reduced employee sick leave

Assessing the cleanliness of your indoor air

Assessing the cleanliness of your indoor air

But the quality of indoor air is often overlooked for the simple reason that air (unlike - for example - polluted water) doesn't look dirty, and it's only on very rare occasions (for example, when someone is smoking indoors) that we have an olfactory clue that the air is polluted. This means that it's very hard to quantify just how polluted your indoor air actually is. However, experts estimate that it can be 2-5 times more polluted than the air outside! 

And sadly, taking all the other correct hygiene precautions - hand hygiene, surface disinfection and strict cleaning routines - doesn't equate to good air hygiene, unless you are actively cleaning your indoor air.

How do people feel about indoor air quality?

Rentokil Initial recently released a new global hygiene report, The Global Hygiene Reset. We surveyed 20,000 people across 20 countries - including South Africa - to build a global perspective of the pandemic’s influence on people’s attitudes, behaviours and expectations about hygiene.

Regarding air quality, the survey found that:

  • Globally, 79% of people rate indoor air quality as important to their health when thinking about visiting a public  venue. Providing clean air gives  people greater confidence to visit  public indoor spaces.  
  • 71% are more concerned about the impact of poor indoor air quality in a public venue on their health than before the COVID-19 pandemic
  • Over 72% of people globally are now more concerned about the spread of germs via the air they breathe indoors  in a public venue than before the  COVID-19 pandemic. Mitigating the  risks associated with poor indoor air  quality is crucial for our health and  wellbeing.  
  • 72% are more concerned about being indoors in a public venue with limited ventilation than before the COVID-19 pandemic 
  • 59% are more concerned about whether a business in a public venue has suitable systems in place to clean the indoor air effectively than before the COVID-19 pandemic
  • Most air pollutants cannot be seen  with the human eye and yet 68%  of people, globally, feel concerned  about the number of pollutants in  the air of a public indoor venue.  

So we know that indoor air is polluted with a whole host of things in addition to the Coronavirus, and that people are more worried about the quality of the air they breath indoors than they have ever been before. But how does all of this relate to airflow? 

Understanding the science of airflow: 

Understanding the science of air flow

Airflow is the movement of air. The primary cause of airflow is the existence of air, because air behaves in a fluid manner - meaning that particles naturally flow from areas of higher pressure to those where the pressure is lower.

When considering the movement of air within your building, the most important consideration should be not only how you deliver clean air to employees or customers, but also how you move polluted air away from their breathing zones. The breathing zone is defined as the space 15 - 20cm's from the mouth.

It's really not enough to simply open a window, for two reasons. Firstly, because the outdoor air you are bringing in may also be polluted with particulates (especially in polluted urban environments) and secondly, because opening a window may not necessarily draw the polluted indoor air away from someone's breathing zone - for example if they were sitting next to the window.

Airflow and the spread of infection

For years now, scientists who study fluid dynamics have been looking at how airflow in offices and other indoor environments play a role in the spread of infections. They've been asking questions like whether changing a room's airflow using air purification systems may help improve indoor air quality:  air purification systems such as VIRUSKILLER™, that draw polluted air away from the breathing zone, and move fresh, purified air into our breathing zones.

In addition to all the unwanted air pollutants mentioned earlier on, when people cough, sneeze, laugh, or talk, they spread thousands of droplets into the air. If they are unwell, these droplets - containing as many as hundreds of millions of infectious particles - are dispersed into the air, and can remain suspended for 3  -13 hours, until they enter someone else's breathing zone. Many normal activities - laughing, talking, even just sitting still and quietly breathing - also release aerosols and can increase the risk of infection spreading. 

VIRUSKILLER™ understands the science of airflow

ZA - Initial - LP Banner - VIRUSKILLER Webinar - Tackling Coronavirus in the Air

VIRUSKILLER™ air purification technology creates a unique airflow pattern that continuously draws contaminated air away from the breathing zone (by dragging dirty into the bottom of the unit)  and replaces it with clean, decontaminated air expelled from the top of the unit. 

This is why the placement of any VIRUSKILLER™ unit is extremely important. There should be no large pieces of furniture obstructing the airflow to and from the unit, as this can compromise the efficacy of the unit. Before installation, our hygiene experts do a full survey to ensure the optimal placement of the unit with regards to the airflow within the room. 

Good air quality enables people to feel safe and comfortable. It encourages productivity, and, importantly, a higher likelihood to return, be it to the office or a leisure facility. Originally developed in 2003 in response to the SARS outbreak, VIRUSKILLER™ is a game changer when it comes to strengthening the front line defence against poor indoor air quality.  

For more information on our range of VIRUSKILLER™ air purification units, download our VIRUSKILLER™ brochure, or contact one of our hygiene experts to find out more.

VIRUSKILLER Air Purification Brochure

Nathalie Leblond

Nathalie Leblond

I joined Rentokil Initial South Africa in 2004 as the PA to the MD, and after 6 months maternity leave I re-joined the Company in 2009 as the Marketing Co-ordinator for Rentokil. I'm now the Marketing Communication Manager for Rentokil Initial. I'm still terrified of cockroaches (Americana's only!) but the rest of the creepy crawlies we deal with don't really bug me (see what I did there?), so I guess I'm in the right industry! I am passionate about what we do here at Rentokil Initial and also write for our Hygiene Blog, which can be found at blog.initial.co.za, and our Ambius blog - https://www.ambius.co.za/blog. Life outside of Rentokil Initial mostly revolves around my daughter, who has just turned twelve, and my husband (who is a bit older). I love living in Cape Town and wouldn't trade living here for anywhere else in the world.

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