Could Indoor Air Quality Become Part of the Post-Coronavirus Playbook?

Posted on 06/30/2020

According to the Centers for Disease Control and Prevention (CDC), it is thought that the COVID-19 virus can spread “through respiratory droplets produced when an infected person coughs, sneezes or talks.” The National Institutes of Health reports that these respiratory droplets have been detectable in the air for as long as three hours.

As we navigate opening businesses, public facilities, and offices back up for occupancy, considering ways we can promote safety for occupants becomes vital. Ventilation is an important aspect for the design of medical facilities, embraced to prevent the spread of airborne disease.

As engineer Gregory Hudson notes in his article “Ventilation Strategies for Healthcare Facilities,” “Appropriate ventilation, when properly applied and designed, can limit the spread of airborne pathogens throughout a healthcare facility.”

The question then becomes, if ventilation can help prevent the spread of airborne pathogens, and we work really hard at designing and implementing ventilation in medical facilities, might there not be strategies we could or should be implementing in other facilities that could be part of the many-pronged approach to limiting the spread of the coronavirus? The reality is that at some point we will reopen society, our economy and therefore our buildings, with the coronavirus still very much a highly contagious threat.

For the sake of this discussion, we will focus on commercial buildings because ventilation systems in residences can vary widely.

In most buildings, air comes into a space through some kind of a ventilation system. That air is usually a mix of recirculated air and fresh outdoor air. In most cases, that air is coming in cooled or heated as well, and combines the functions of both conditioning and ventilating the space. Most commercial building codes require a minimum amount of outdoor air to be coming into different spaces in a building. The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) has a detailed standard that is the reference for many of us in the field (ASHRAE 62.1). This standard is updated regularly.

However, just because there is a minimum doesn’t mean that a space can’t exceed minimum code requirements. Based on the information about droplets and medical facility design, it is a logical step to look at the possibility that in non-medical buildings that must be occupied right now, it might be a good idea to circulate air more, add more fresh outdoor air if possible, and increase filtration.

Another reason to ask ourselves what we can be doing to improve indoor air quality right now is because poor indoor air quality has known detrimental effects on the respiratory system, and it is well documented that people with compromised respiratory systems have worse outcomes than those whose respiratory systems are healthy. Many buildings designed in recent years according to the LEED or WELL building standards already adhere to higher thresholds of outdoor air flow and other strategies to improve indoor air quality for occupants.

The following are some best practices to discuss with building owners and facilities managers to enhance the indoor air quality of spaces where people need to be now, and/or prepare for when we will be together again. For currently unoccupied buildings, it makes sense to explore many of these strategies while a building is unoccupied, so that everything is in the best working order when people return.



Just because a building was designed for proper airflow doesn’t mean it is still operating that way. Over time, systems can slip, or people can do things such as close vents that are supposed to be left open.

The process of Testing, Adjusting, and Balancing (TAB), during which airflows are evaluated against what airflows should be in those given areas and adjusted to ensure optimal airflow, is essentially a tune-up for the building’s ventilation system. This can help ensure all spaces are properly ventilated and, in the process, help a building operate more efficiently.



Based on how COVID-19 behaves, as noted earlier, and how we ventilate for pathogens in medical facilities, it seems logical that moving more air and providing more outdoor air would be beneficial. In fact, the CDC’s Interim Guidance for Businesses and Employers to Plan and Respond to Coronavirus Disease (COVID-19) specifically mentions “Increase ventilation rates” and “Increase percentage of outdoor air.”

Note, we are in cooling season in most parts of the country, so people concerned with energy consumption and green initiatives might wonder, “Won’t I use more energy having to condition more outdoor air?” In reality, green buildings are a balancing act, and not all about energy. Yes, energy is important, but the concept of “green building” includes healthy people as well.



Ventilation in a building is determined space by space. A corridor has less fresh air than a meeting room because people are not staying in that space for any measurable period of time. So, in any building, there are likely to be better-ventilated spaces.

Where might those be in your building, and how might you consider what spaces to be in with that knowledge?

For example, we are working on a police facility. That facility has a crime lab that is negatively pressurized where all air in the room is exhausted (meaning none of it is recirculated). Perhaps that space would be a better space for a meeting for these first responders than the conference room, which has much less overall ventilation than the lab.



Regular filter changing should be part of any building maintenance plan. Often, this can get overlooked, or slip on maintenance schedules.

Both the LEED rating systems and the WELL standard use MERV-13 (or better) as the guidance for top-level filtration. There can even be ways to add on things such as high-efficiency particulate air or HEPA filters or ultraviolet light for greater levels of filtration and decontamination.



Many older buildings were not designed with ventilation systems that meet even today’s minimum standards. A new system retrofit can achieve that.

Also, if a building is unoccupied at the moment, it is a great time to change out equipment and not disrupt workflows. Getting the ventilation systems up to current standards before employees return could be helpful as we continue to combat the spread of this disease.



It is easy for many of us in the building professions to forget that, at the end of the day, it is the occupants for whom we are designing, constructing, and maintaining buildings.

Another green building and efficiency tool is the use of a survey. A simple occupant comfort survey can help identify issues from poor airflow to major issues such as mold.

Again, as the building is unoccupied, it might be the ideal time to do a survey and explore or fix issues since there would be little disruption to workflow.



Last, as we generally have become suddenly and acutely aware of respiratory health, we need to acknowledge the negative impact to respiratory health that so many materials and products used in our buildings can have.

Going forward, consider implementing policies for the use of greener cleaning products, integrated pest management programs that use fewer toxic chemicals, and lower-emitting paints and sealants, all of which contribute to healthier indoor spaces.

The LEED and WELL building standards include these and many other strategies for improving the indoor air quality that so many of us sit in day after day that can have lasting impacts on our respiratory health.

It has become clear that COVID-19 won’t be defeated with any singular silver bullet, at least until we get to a vaccine. The indoor environments we provide can help with our health and spread of disease, not only now, but even in the future to help things such as basic colds, the flu, or other health issues for people.

This article originally written by Joe Snyder, and appeared on Medium.