Research on COVID-19 may have given us an even better understanding of how ventilation can impact disease spread. While early health messaging focused on transfer of the virus by touch and how long the virus could live on surfaces, later studies led experts to emphasize the importance of masking and good building ventilation.
As a result, there’s been a new discussion around how poor ventilation and filtration in buildings may be making it easier for disease to spread.
The conversation could influence air quality testing in construction — encouraging companies to improve on-site ventilation and architects to design buildings with improved air filtration systems.
COVID-19 is somewhat unique among diseases, but the virus that causes it has a lot in common with other respiratory viruses, like the flu.
To start, it mostly spreads via droplets suspended in the air, called aerosols. When someone coughs, talks or even exhales, some of these droplets spread into the air.
The deader the air flow is in a building, the easier it is for these droplets to linger and collect. Good ventilation keeps air moving and replaces indoor air — reducing the density of droplets indoors or removing them altogether. This can potentially help slow the spread of disease or even break the chain of transmission between people sick with COVID-19.
There’s also evidence that good building filtration can capture these droplets, further slowing or even preventing possible spread.
We also have data on the relationship between ventilation and disease spread unrelated to COVID-19.
In general, the science shows that better ventilation means less disease spread. Filtration can also help here. Even once COVID-19 vaccines become widely available, good air quality will still be valuable in stopping or slowing the spread of certain illnesses.
Air Quality Testing May Become More Important Than Ever
The best way to know if a ventilation setup is working well is with air quality testing. Construction companies use various tests to estimate indoor air quality — like non-dispersive infrared (NDIR), gas chromatography with thermal conductivity (GC/TC) or gas chromatography with mass-selective detectors (GC/MSD).
These tests provide an in-depth analysis of indoor air quality, giving building owners the best possible idea of what particles and pollutants building inhabitants may be exposed to.
If air quality tests yield an undesirable result, building owners can then take simple steps to improve on-site ventilation and filtration. For example, a building could change air filters more frequently or use stand-alone air filters. Even something as simple as opening windows can also help improve air flow and quality.
It may also become more popular to design buildings with stronger air filtration systems that carry away unclean air. These systems may be more costly and energy-intensive to run. Fine filter media (ratings F5-F9), for example, can capture extremely small particles. However, they tend to cost more. And because they capture more particles than lower-performance filters, they may not last as long.
However, the potential benefits of an upgrade may easily be worth the investment.
Renovations can also help. Some buildings, due to design oversights, don’t have easy-to-access HVAC filters. These buildings have been a problem during the pandemic, as it’s difficult to make small adjustments to filter type that can help keep indoor air quality good.
How Indoor Air Quality Might Change
It’s hard to tell what the long-term impact of COVID-19 will be on our habits and preferences, but there’s some evidence to suggest people may come away from the pandemic with higher standards for cleanliness and public health.