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Airborne Transmission and COVID-19

A measured approach to risk mitigation

With advice from leading scientists and confirmation from the World Health Organisation

regarding airborne transmission of COVID-19, the basic message from our May 2020 advisory “restarting and operating buildings in a COVID-19 world” has not changed.

However, there are a number of additional strategies that Optimum Air is focused on delivering that will help mitigate health risks in our built environment.

01.Ventilation is more important than ever. Increasing ventilation rates is not as simple as opening up the fresh air dampers. Filtration, equipment loads and energy are all impacted, so we suggest you put strategies in place to ensure your specific ventilation requirements are met. A primary concern is that equipment does not cope with extreme demands of winter/summer conditions if ventilation is not a fully engineered solution. Energy and operations will be impacted significantly with higher ventilation rates. As outlined in our May COVID-19 advisory, alternatives exist that scrub the air within a space, using sorbent materials. This allows for control of IAQ variables such as PM2.5, PM10, VOC’s etc with the ventilation system then reprogrammed for “on-demand” ventilation based around CO2 or occupancy density sensors.

02. The deployment and treatments delivered by UV-C technology eliminates your HVAC systems as a potential source of coronavirus infection. Being able to communicate this to your employees and tenantsis an extremely powerful message. In addition to having a 98% + kill rate of coronavirus, the added benefit in a well-designed UV-C application is the continuous cleaning of cooling and heating coils, with a resultant decrease in pressure drop and a subsequent reduction in fan energy. Night-time ventilation purges and ongoing air stream disinfection strategies using variable speed drives on supply air fans allows for

significant after-hours conditioning of spaces for re-occupation.

03. Particular attention must be made to eliminating drafts in air distribution systems. Check air distribution design, particularly in the choice of diffusers and location relevant to the space served, rebalance air quantities and/or change air distribution outlets to better suit a particular environment or to eliminate a particular draft issue altogether.

04. By utilising your existing BMS infrastructure, you have the ability to measure and verify indoor air quality parameters by adding sensors where there are gaps in the required data. Information and intelligence gained from these sensors can then be utilised to change control parameters in the HVAC system and to provide instant feedback and information by way of easily accessible dashboards for employees, occupants and visitors.

Proactive communication is key.By providing data on IAQ in real-time,you have the ability to engage with your building’s occupants and provide themwith peace of mind.In doing so, youare able to demonstrate a highlyengaged level of transparency through prompt responses to issues as they arise.

05. The basic premise of social distancing has never been more important for workspaces. Virtual office grids use sophisticated, anonymous, video-based occupancy sensors to provide real-time feedback, allowing occupants the ability to self-regulate and maintain a safe workplace. This technology tracks and monitors occupancy and directional foot traffic flow to predict bottle necks and subsequent crowding ahead of time. A simple LED traffic light system in common areas can provide intuitive signals as to how densely populated a common space may be. Virtual offices of any size can be created to provide real time spacing and density data.

Use of the same system allows “on demand” cleaning of toilets and other common spaces. By having these sensors count human use of space, you can more proactively work with your cleaning contractors to create a response plan for cleaning and surface disinfection.

06. By introducing to your lifts an “in car” occupancy density system, a traffic light scheme can provide visual clues on safe entry into a lift. The installation and deployment of an air cleaning and sterilization system, as well as UV-C surface disinfection can be achieved through a simple reprograming of lift cars that take themselves off line to trigger UV-C sterilisation based on cumulative use data. This keeps the turnaround time to less than 10 mins per cycle and provides hospital grade surface sterilization based on demand, providing confidence to users and a positive commitment to the safety and well-being of building occupants.

If we follow the science, we can significantly reduce risk.

These strategies can provide buildings and facilities with a strong, measured, and tactical COVID-19 risk mitigation plan. All of these technologies are commonly deployed and

well-proven on a global scale, and are readily available for immediate deployment.


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