The rapidly expanding vaccination program provides hope that the end of the COVID-19 pandemic is in sight. We also know that continued vigilance is still required. A model developed by Dr. Jeffrey Shaman of Columbia University estimates that lifting COVID restrictions now would lead to 29 million more infections over the next six months as we work to fully vaccinate the population, while strengthening restrictions would result in 19 million fewer cases. We still don’t know if vaccinated people who become infected can spread the virus to others, or how long immunity will last, or if any of the emerging variants of the virus might thwart the effectiveness of the vaccine. What this tells us is that we need a multilayered approach to protecting health. Like slices of Swiss cheese, each has holes in it, but if you stack one slice over another, the holes are covered, and you form a full barrier. Vaccines, masks, ventilation, filtration and other measures work together to reduce pathogen transmission risks.
Some potential “cheese slices” require public resources or individual actions outside the control of building professionals. Thankfully, there are effective measures in airborne pathogen removal strategies. Mounting evidence shows that respiratory aerosols are the primary means of SARS-CoV-2 transmission, and it’s not just COVID-19, as other pathogens are also spread through the air. Importantly, these are other airborne concerns in buildings that impact the health and well-being of building occupants, both directly and as respiratory irritants that increase susceptibility to other ailments.
The pandemic has accelerated health, wellness and technology trends in the built environment that were advancing before, and it has heightened attention to issues of poor ventilation and indoor air quality in existing buildings. The most effective measures we can take in new and existing buildings to reduce risks from the coronavirus also have broader health, wellness, productivity and business benefits, including:
- Harvard T.H. Chan School of Public Health’s COGfx study found that green buildings with increased ventilation significantly boost cognitive function in knowledge workers.
- A 2015 study of 3,000 fifth graders found higher math, reading and science scores in classrooms with improved ventilation.
- The “Emerging Trends in Real Estate 2021” survey by ULI/PwC found that over 82% of respondents agree or strongly agree that health and well-being will become more important in all sectors of commercial real estate.
Individuals, employers, building owners and communities want and need indoor environments that reduce illness risks, support occupant health, promote wellness and immune function, and boost productivity. The industry standard for ventilation design in commercial buildings is ASHRAE 62.1, Ventilation for Acceptable Indoor Air Quality. The word “acceptable” telling us that it is a minimum standard and not a guide to optimal ventilation design. Commercial buildings are typically equipped with less-then-optimal filtration, usually MERV 8 filters capable of removing less than 50% of PM2.5, airborne particulate matter 2.5 microns in size. Upgrading to MERV 13 filters allows the ventilation system to capture more than 90% of these small, hazardous particles, including airborne pathogens. We have learned that coughing, sneezing, singing and speaking expel virus-laden respiratory particles, including many in the range of 1 to 5 microns, that can travel long distances, remain suspended in the air for hours, and infect people who inhale them.
Designing for optimized ventilation and enhanced filtration is important, but monitoring and dynamic control of indoor air quality may be required to maintain healthy conditions and support other goals like energy efficiency and occupant comfort. While there is no practical means to monitor the presence of airborne pathogens in real time, we can track CO2, particulate matter, and even VOC concentrations as indicators for air change effectiveness and a proxy for the HVAC system’s ability to remove bioaerosols if present. The cost of sensors has come down and the quality has improved, making on-going IAQ monitoring feasible. These sensors can be linked to air handling units to reduce ventilation rates and save energy when occupant density decreases.
The other trend emerging from the pandemic is a move toward flexible work environments, and evolving smart building technology supports this as well. PropTech applications help facility managers with operational automation, artificial intelligence, access control, system performance, security and spatial analytics to boost efficient use of space. They can also enhance user experience for employees and guest with ease of scheduling collaboration and workspaces, registering responsive comfort preference (temperature, lighting, etc.), providing feedback on conditions needing cleaning or maintenance attention, and digitization of collaboration and interaction.
In short, buildings that go beyond minimum standards for indoor environmental quality will benefit from reduced risk and increased performance, desirability and health resilience. Optimization of fundamental engineering controls for indoor air quality, combined with smart building technology provide a comprehensive solution to enhance occupant health and wellness, reduce costs and boost efficiency, improve occupant experience, while providing assurance that health and safety have been prioritized. A smart building is a healthy building.
Alan Scott, FAIA, LEED Fellow, LEED AP BD+C, O+M, WELL AP, CEM, is an architect with over 33 years of experience in sustainable building design. He is a senior consultant with Intertek Building Science Solutions in Portland, Ore. To learn more, follow Scott on Twitter @alanscott_faia.