Our typical approach to any client worried about the spread of COVID-19 or any similar contagion in their building is to address indoor air quality (IAQ). How do we mitigate the spread of viruses or any other unwanted pollutant or contaminant in the air? We have 3 tried and true methods that can be used in conjunction to form a reliable and robust IAQ strategy.
1. Fresh Outside Air
Ventilating a building with fresh outside air dilutes contaminated air. It reduces the total amount of a potential pathogen in the air, thereby reducing the likelihood of transmission. The typical approach is to install CO2 monitors in a space. As the levels of CO2 rise, the ventilation increases until the CO2 levels are reduced. CO2, in this case, directly correlates to the potential for inhaling and exhaling a virus. There are two caveats to simply adding more fresh air to the space–which will show why opening a window is not a comprehensive solution. The first is the conditioning of the air. The fresh air must be cooled or heated, and it must enter the space at an ideal humidity–too much variance from ideal temperature and humidity might encourage the transmission or growth of a virus. The second is that fresh air isn’t always so fresh. If your building is next to a parking garage or the subway, or it is ragweed season, you might be curbing the spread of COVID-19 but introducing a whole host of other problems, which leads to the second IAQ strategy.
2. Filtration
You should filter everything you breathe inside a building. The fresh outside air should be filtered, the recirculated inside air should be filtered. Think of it like this: you wouldn’t drink water with poop in it. Why would you breathe air with poop in it? Quality filtration can have a significant effect in reducing the amount of contaminants in the air. We recommend at least MERV 13 filters. Ideally, there would be HEPA-level filtration everywhere, but the energy and capacity required to push air through a HEPA filter is impractical for most spaces. If you had a small space requiring the highest level of filtration, a dedicated HEPA-level system would be justified. MERV 13 represents the best filtration with the least resistance to airflow. Most commercial air handlers use MERV 8 filters which fall significantly short regarding certain sized particles. Upgrading to MERV 13 is harder than simply changing filters, but it can certainly be accomplished for a relatively small expenditure.
3. Elimination
The third point is the most reliable way to avoid spreading viruses through your building. It is simple–but not so simple: if you are sick, stay home. If you can eliminate the cause of the virus from ever entering your airstream, there is nothing to dilute or filter. We know, however, this is easier said than done. This is a management/culture issue. We recommend educating the occupants of your building to identify symptoms and to know when to stay home. And we recommend having a culture where employees are encouraged to prioritize their health.
4. Maintenance
Preventative maintenance saves building owners and administrators the most money consistently. It is, however, usually the least funded. Not only will it save you tons in repairs and replacements, but it is also your key defense against the spread of contagion and therefore absences. Suppose you have high-quality ventilation, excellent filtration, and a robust work culture focused on employee health–how do we know it’s working? We always recommend a comprehensive maintenance strategy, integrated with basic real-time monitoring. At the very least, we need to monitor CO2 in the space to know we are getting enough fresh air. Routine maintenance of motors, fans, pulleys, and louvers is essential. And, my personal favorite–Change your filters! You can have the best equipment and the best strategy, but if it doesn’t work, it doesn’t help.
Conclusion
We will never fully prevent or control sickness. However, we can certainly affect its spread by using an integrated IAQ strategy. By nurturing a culture of health and safety, we make a pre-emptive strike, reducing the potential for contamination within our workspaces. Next, by diluting the build-up of contaminants within the air stream with fresh outside air, we reduce the viral load. With quality filtration, we capture a significant amount of remaining particles. With a robust maintenance and monitoring strategy, we ensure the ongoing health of our building and, therefore, the ongoing health of our people.
