In recent weeks there has been increasing public discussion about airborne transmission of the COVID-19 causing SARS-C oV-2 coronavirus. In an open letter published on 6 July 2020, 239 scientists from across the globe urged WHO to affirm the airborne transmission route and to address the issue in guidance. WHO responded to this letter by acknowledging “emerging evidence” of airborne transmission. Better Indoors were among the first to write to the UK authorities about the significance of airborne transmission and we are pleased that our expert views are at last being recognised.

But, what does “airborne” really mean? The coronavirus is spread through tiny water droplets that contain the virus that are emitted when people sneeze, cough, talk and even just breathe. The size of these droplets ranges from visible particles that fall out of the air under gravity onto surfaces and floors to invisible particles so small they remain suspended in the air. It is these tiny particles, known as aerosols, that greatly increase the transmission risk because they can spread over long distances carried by internal airflows and can be inhaled by people who are a long distance away from the source. Indeed, research has shown that infectious aerosols can remain in the air for up to 16 hours and can maintain infectivity for longer periods. We believe this is one of two main reasons why this virus spread so far and so quickly and has become a global pandemic. The other being people are highly contagious without showing any symptoms – termed asymptomatic.

What is the option to minimize the aerosol transmission of the virus?

There is a high risk of transmission in any busy household or commercial space. An infected person will release the virus via aerosols inside these spaces which will likely be inhaled by another person somewhere inside the space. Crowded spaces however cannot stay locked down permanently but there needs to be more effective mitigation than simply wearing masks, social distancing, wiping down surfaces and limiting numbers.

At Better Indoors we have been advocating since this emergency began that every building must be served with effective ventilation combined with a process of active air purification. In the UK, most buildings are built to minimum ventilation standards which means they predominantly rely on natural background ventilation, or opening windows. This method is often leads to problems of indoor air quality especially during the colder months and would need to be improved upon in order to create robust conditions to prevent virus transmission. Ventilation however does not physically remove infectious aerosols, it just moves them around and/or expels them from the property. Active air purification offers the capability to physically destroy airborne virus and other organics such as bacteria, odours, mould spores, VOCs and house dust.  Active differs from passive filtration/PCO type systems which must force all the air in a space through a unit to treat it which never guarantees all the air in a space is treated because it treats all the air and surfaces in a space simultaneously and continuously.  In short, an indoor space that has effective ventilation and active air purification offers the most effective defence against airborne transmission of COVID-19.

Please read our blog: Air Sanitation System To Fight Against Second Waves of COVID 19 which shares some great insights about the second wave of coronavirus, what would be its impacts and how you can reduce its risk.

On 11th May, Certain groups in UK were encouraged to return to work and people were allowed to go outside to exercise multiple times a day. June saw the reopening of non-essential business outlets, households mixing outside, certain year groups returning to school, reopening of indoor hospitality venues and ease in social distancing guidelines.

On the 4th of July pubs, cafes and restaurants in the UK opened their doors for customers. This has sparked warnings of a second wave of COVID-19 infections. Experts have repeatedly warned that the relatively swift easing of lockdown restrictions in UK risks cases rising again.

There is a high inherent risk of second waves of COVID-19 infections as lockdown measures as eased and people of all demographics, from homeowners, business owners, staff and customers are asking what can be done to avoid this risk. We deal with many such enquiries on a daily basis and are increasingly asked how our expertise assessing and specifying/retrofitting HVAC improvements and the use of our advanced air purification system can help reduce COVID-19 infection transmission and what makes our system different to the myriad of other options out there. It is clear the scientific community agree that in addition to social distancing, wearing masks and contact tracing measures, improved ventilation performance and air sanitization measures, perhaps combined with real time IAQ monitoring is also necessary to allow building occupants to feel confident risks are being managed properly and indoor spaces are in fact healthier.

Effective Ventilation Performance

Effective ventilation delivers dilution and displacement of indoor air with fresh (and filtered) outdoor air. This process can help eliminate build up of pollutants and contaminants on the indoor air and ineffective ventilation will do the opposite, leading to sick building syndrome risks. Effective ventilation performance can help reduce viral and bacteria organic loading in door spaces although it should be noted that it will not physically remove the particles – it will just move them and it will not do anything for surface deposits. We are experienced HVAC contractors and we have specialized in providing solutions that improve IAQ over the past 7 years – the very solutions that are now being demanded by government guidance and the scientific community. The vast majority of existing property stock in the UK is built to minimum ventilation standards and generally does not meet the performance requirements that are now being suggested. For existing buildings we can help building owners, FM managers and homeowners quickly understand their HVAC system performance and what measures may be necessary to retrofit improvements. For new builds our supply and fit total solution ensures effective ventilation performance for those who occupy the completed building.

Air Purification – Passive Systems

The vast majority of air purification systems are passive. These include filtration and chamber based systems that require the air to pass through them in order to be treated. One of the main problems with passive systems is they do not offer real time protection to virus or bacteria transmission in the air or on surfaces. A good example of this is the recent Qatar Airways flight from Doha to Athens where 12 passengers acquired the SARS-CoV-2 virus during the flight in an aircraft with HEPA filtration.

HEPA Filters

HEPA filters or High-Efficiency Particulate Air filters filter out particles that are as small as 0.3 microns with an efficiency of 99+%. However, viruses such as COVID-19 virus are far smaller than this so they can pass straight through and back out into the air.

UV Lights

UV-C is considered a genuine solution for COVID-19. The problem with this however is that efficacy of UV-C is only effective very close to the light source (within 5 cm) and has no effective against moving airborne particles. This is known science to experienced HVAC contractors like us who have worked with in-duct UV-C systems for many years. UV light strength is inversely proportional to the square of the distance to the light source.  This means that the UV-C light solutions that are currently being proposed for indoor spaces will not in fact be very effective at all.

Active Air Purification System – The Most Effective Way To Fight COVID 19

Better Indoors active air purification systems by pass these risks. Our technology is not passive and in fact turns an entire indoor space into a purification chamber by distributing safe concentrations of naturally occurring ionized oxidisers throughout the indoor space, treating all of the air and surfaces on a continuous basis. The distribution reaches into every cubic cm of air and surface space so is effective everywhere at all times. The efficacy of our technology has been tested by many nationally accredited laboratories and is proven to destroy bacteria and deactive viruses instantaneously the moment they are exposed to the treated air. The “sneeze test” demonstrated an immediate 99% reduction in airborne bacteria growth rates and an immediate 94% reduction in surface bacteria growth rates in any part of the treated air. Originally developed in response to bio-terrorism threats in airliner cabins post 9/11 in the US no passive HEPA or PCO system can perform like this.

Speak to us today to learn more about our world leading air purification solutions and how we can help protect your family, your workplace colleagues, your customers or your patients.