Here is what we know, or think we know, about COVID-19: it can spread through the air.
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." According to a news release from the National Institutes of Health on March 17, these respiratory droplets seem to be detectable in the air for as long as three hours.
Here is what we also know about hospital buildings and the way they are designed: 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 non-medical buildings that need to be occupied, maybe it would be a good idea to circulate air more, add more fresh outdoor air and increase filtration.
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 above information about droplets and medical facility design, it is a logical step to look at the possibility that in non-medical buildings that need to be occupied right now, maybe it would be a good idea to circulate air more; if possible, add more fresh outdoor air; 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 is not good for people’s lungs, and it is well documented that healthy lungs are positive when someone does get sick with this virus. 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 is a list of best practices that the building owners and facilities managers can be doing to enhance the indoor air quality of our 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.
Give your building a tune-up
Just because a building was designed for proper air flows 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.
Through the process of Testing, Adjusting and Balancing (TAB), technicians determine what the appropriate air flows are supposed to be in different spaces, then go through to verify that the spaces are achieving those airflows. If they aren’t, they are corrected.
It is essentially a tune-up for the building’s ventilation system. This can help to ensure all spaces are properly ventilated and in the process possibly help your building operate more efficiently.
Increase air circulation and outdoor air
As part of the TAB process, depending on how the system is designed, technicians can measure and possibly even adjust the amount of outdoor air coming into the building.
Based on how COVID-19 behaves, as noted above, 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 heading into cooling season in most parts of the country, so people wonder, "Won’t I use more energy having to condition more outdoor air and why is the green guy recommending that?"
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.
Use spaces designed for better ventilation
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.
Change out filters or even improve them
Regular filter changing should be part of any regular building maintenance plan. Often this can get overlooked or slip on maintenance schedules.
Make sure your building filters are not old. Old, dirty filters can slow down air movement, thus reducing the ventilation rates. In addition, consider adding a higher level of filter.
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.
Is it time to replace an old unit?
If you are inching towards a unit replacement, now just may be the ideal time.
First of all, 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 your building is unoccupied at the moment, it is a great time to be changing out equipment and not disrupting 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.
What are occupants experiencing?
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 as there would be little disruption to workflow.
Reduce toxic indoor contaminants
Lastly, 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.
Yes, energy is important, but the concept of 'green building' includes healthy people as well.
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, which is estimated to be 18 months away or more. But a combination of best practices — hand washing, social distancing, etc. — is clearly the approach for now.
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. As the delicate balance between health and the economy has come into sharper focus than any of us could have imagined, it is worth noting that long before COVID-19, Kaiser Permanente noted it is estimated that work absenteeism costs U.S. employers $1,685 per employee each year.
Even in non-pandemic scenarios, it can be smart business to spend some time focusing on healthy indoor environments for workers.
Please note I am not a medical professional. I am an architect. I study buildings, not the specific ways diseases spread, nor the human body’s response to those diseases. I have been reaching out to the medical community, and I will update this article with new information as I receive it.
This article originally appeared on Medium.