Great news about the efficacy of the Pfizer vaccine which offers a great hope that we are finally rounding the corner in our battle with COVID-19, in particular if we’re unfortunate enough to catch it. However, a better approach to reduce the risk of catching COVID-19 in the first place. As we become more aware about the transmission of COVID-19, so we have become more aware of the impact of Ventilation in reducing the risks of catching COVID-19. The standard COVID-19 secure definition relies upon natural ventilation, leaving doors and windows open so there is a good circulation of air which can reduce in any viral concentration.

Although the benefits of natural ventilation are well known, the practicality of regularly exposing the young and elderly to the colder winter air is somewhat less beneficial. When combined with the additional costs of heating, the economic and health benefits become doubtful for what is a rather primitive and poorly thought-through solution- ask any parent of a child being taught in a classroom with open windows how conducive this is to effective learning.

A better, more effective, more practical, and overall cheaper solution is the use of SMART ventilation.  Using a combination of UVC light to inactivate the virus, HEPA filters to trap larger particulates, sensors to detect the air quality, a closed loop control systems, and an application to provide real-time information and enable personalised alerts, SMART ventilation solutions offer a safe and practical way to make our enclosed spaces safe again.

To put into perspective, consider the following risk spectrum which shows where SMART Ventilation sits compared to the natural ventilation suggested in your program and is recommended to make a space COVID-19 secure.

The highest risk is no ventilation. In an environment with no natural ventilation, the virus can remain in the air for over 3 hours. So, in environments like lifts, internal meeting or training rooms, patient 0 could introduce the infection at lunch time and the environment still be contagious by late afternoon. 

The recommended approach and one adopted by many “COVID-19 Secure” policies such as schools and others, is the use of natural ventilation. This means opening windows and doors to allow a draught, or natural ventilation to displace the potentially infected air thereby diluting or dispersing the viral load. There are various simulations which show how this is more effective than no ventilation. However, there are practical limitations especially during the colder winter months, as a result to exposure to cold air and draughts and the additional heating costs to heat the fresh, cold air as well as the disruption to the normal way of working.

Fan or air conditioning can help disperse the viral load, which doesn’t remove any airborne virus or particulates but just distributes over a wider area, thereby diluting the viral load.

HEPA filters have been around for many years and depending upon HEPA class, are very good at trapping small particles for example those that may trigger respiratory illnesses such as asthma. However, they are not good at trapping very small particles such as COVID-19 although there is some emerging evidence that HEPA filters can trap the larger particles that COVID may have landed upon. So, whilst not effective, HEPA filters should be part of the solution.

The next level of ventilation to reduce risk is the use of UVC, Ionisation or Ozone based purifiers. These devices inactivate the virus by exposing to a harmful environment, often referred to as the kill chamber.  However, these environments are not only harmful to the virus and other very small organisms, but they are also harmful to humans too. This means that typically such solutions can only be used once the space has been evacuated. Also critical to the effectiveness of the solution is the period of time the air dwells in the kill chamber. Too short a period and not enough of the virus is deactivated, which gives a false sense of security. This is also counter intuitive, since if we do not feel a good flow of air, we assume the device is not working, when in fact the opposite is true. If we’re not careful, we end up with a very expensive fan, that merely distributes the air and any virus more widely around our space. 

SMART ventilation offers the lowest risk. SMART ventilation combines UVC lamps, HEPA filters, control systems, internal and external sensors, some data analytics and real time feedback usually in the form of a mobile app which can generate personalised alerts.  SMART ventilation can be used whilst the space is occupied and is used in conjunction with whatever ventilation solution (if any) already exists. As these devices are designed to run from a standard wall socket, they are easy and quick to install. This offers the best protection since the air is constantly being rejuvenated so should an infected person come into the workspace any virus can be quickly inactivated whilst it is still airborne.

One company which has such SMART Ventilation solutions in beta are Rejuvenair.  A single Rejuvenair unit can process a space of 60m2 in 15 minutes, plugs into a standard 13amp socket and uses a similar amount of electricity as a 100W light bulb. Following a natural ventilation approach would require the repeated heating of the same 60m2 space. This would consume more energy, generate greater carbon emissions on top of being a less practical and effective solution compared to SMART ventilation. The Rejuvenair solution is quick and easy to install and most importantly does not require any difficult, costly, time consuming alterations to the existing ventilation system.

The feedback from these early units has been very positive, so much so, the Beta sites will not return the units!!! They have also provided anecdotal evidence that so far this flu season (and up to the start of the recent lockdown) the number of staff being off sick due to traditional seasonal illnesses is much lower than usual (although social distancing may also have an effect).

Although returning safely to our workplaces, schools and other enclosed spaces is paramount, the impact of air quality on people working and living in these enclosed spaces is also being better understood. We are familiar with Sick Building Syndrome. The role CO2 levels have on the wellbeing of workers or the attentiveness of pupils is also well documented (“The Impact of CO2 on Children’s Learning”, 2020). The sensors currently measure CO2, temperature and humidity and this data can be feedback to a Smartphone App, Wall display or any other connected device,  giving real time feedback and alerts when safe thresholds are being reached so the appropriate action can be taken. The solution can be extended to support other sensors, for example a to check if the room is occupied, or even incorporate a COVID sensor should one become available.

Whilst we may never be completely free of COVID-19 for the foreseeable future, we can take steps to minimise our risk to catching it. Ventilation is a key step. However, dealing with the virus whilst it is still in its aerosol form, using SMART ventilation, offers the lowest risk. 

At IoT Horizon we have identified that any strategy to successfully opening an enclosed space requires three elements, Contact Tracing (because the other two elements are not fool-proof), SMART Ventilation (to tackle the virus when airborne) and Fomite Cleaning (tackling the virus when it lands on a surface) and SMART Ventilation should be the first line of defence.

So, whilst the vaccine announcement is good news and offer hope about a return to normal living, the role ventilation, especially SMART Ventilation, plays should not be overlooked. Utilising SMART ventilation in our work, education, health and leisure spaces means that we will not need to rely so heavily on these new vaccines.

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