Building Ventilation in the Fight Against COVID-19
Building ventilation systems with proper indoor/outdoor air exchange coupled with supplemental measures can help stop the spread of the coronavirus in its tracks.
As the COVID-19 era takes hold, much emphasis is being put on social distancing, washing your hands thoroughly, and sanitizing anything and everything that you come in physical contact with. While all well and good, one very important aspect is consistently left out of the picture: building ventilation systems.
Why are building ventilation systems so important? It's pretty straight forward in that the coronavirus, which causes the respiratory infection known as COVID-19, is spread through inhaling airborne particles, including viral ones. Thus, a single person can infect a whole number of people in one building, even when in entirely separate rooms, if the building's ventilation system simply recirculates air throughout the building. A perfect example of this comes from the Diamond Princess cruise ship, where at least 700 out of 3,700 people onboard were infected with the coronavirus (a much higher rate than in Wuhan, China, where the virus originated), even as people were quarantined to their rooms. Another example is with the measles, another easily in-air transmissible virus: A young girl at school from just one room infected 28 of her classmates located throughout the school, even though 97% had been vaccinated.
How ventilation systems can increase the spread of the coronavirus
Indoor air recirculation is the main culprit. It is by preventing outdoor air from entering and keeping indoor air recirculating throughout a building that the airborne particles ejected from coughing and sneezing get carried from room to room, posing an infection risk to those exposed.
What's more, indoor air recirculation serves as a gateway to transmit droplet nuclei, the smaller types of airborne particles expelled from coughing and sneezing. This poses an augmented infection risk, as these droplet nuclei hang in the air for much longer periods of time, thus increasing the chance that someone will inhale them. This is demonstrated by several cases where the coronavirus infected the lower respiratory tract, which only smaller airborne particles can reach.
How ventilation systems can help STOP the spread of the coronavirus
When deployed correctly and in conjunction with supplemental methods, ventilation systems can play a big role in stopping the spread of the novel coronavirus:
Indoor/outdoor exchange. Ensuring a consistent indoor/outdoor airflow, even by just opening up your windows for set periods of time, can dilute viral airborne contaminants.
High-powered air filters. Buildings often employ inefficient air filters that do little to nothing to deal with infectious airborne particles. Using a highly efficient air filter (ex. MERV rating of 13 or higher), as places such as hospitals do, can capture more than 80% of viral airborne particles.
Portable air purifiers. When equipped with HEPA filters, they can capture some 99.97% of airborne particles.
Humidifiers. Whether small and portable or incorporated into your building's ventilation system, maintaining humidity at 40 to 60% minimizes virus’s ability to survive.
The mass of measures in place in across the world, from social distancing and lockdowns to increased attention to hand-washing and surface sanitization, produce varying degrees of results. To provide full-fledged protection, however, the problems of buildings' ventilation systems need to be addressed. What's encouraging is that these problems are easily solvable, and the key is creating sufficient awareness and the propensity to take action. By optimizing the ventilation system in your house, building, structure, etc., the transmission of the coronavirus and other viral diseases is brought to a minimum.