Take a Deep Breath, We've Got You Covered
Ever since the pandemic has changed our world, there has been a lot of information pertaining to virus spread in the built environment. While a lot of research surrounding the coronavirus is still in development, there are a few critical things that will remain true. Currently, the key components to successfully mitigate virus spread are social distancing, handwashing, cleaning protocols, and proper air quality and ventilation. The design of the built environment around us can aid or hinder these strategies. As architects and engineers, we have been getting a lot of questions lately from clients and partners wanting to know what changes to make in their spaces to help mitigate virus spread, particularly focused around indoor air quality. M+A and leading engineering firm, CMTA, have come together to answer some of the most burning questions.
1. In your expert opinion, how do you think we can reduce the risk of virus spread in the built environment?
M+A: It’s important to note that we can’t eliminate risk, but we can reduce it. Looking at current research, it appears this virus is transmitted mainly through aerosols (virus in droplets expelled when we exhale, talk or cough), which means we have several main ways to reduce our risk:
- Stay away from people who are sick
- Social distance when in public, possibly more than six feet depending on activity and duration (6)
- Wash your hands frequently and don’t touch your face to reduce fomite transmission (9)
- Wear a face mask to reduce exposing others, in case you’re unknowingly an asymptomatic carrier
- Increase fresh air by opening windows or enhance air quality through air purification systems
CMTA: I agree with what M+A has said above. To expand on indoor air quality and the current technologies that exist to reduce the spread, there are several options to consider. The first option is increasing outside air to flush the building as many times as possible during occupied hours. This seems like a “no-brainer,” but there is actually a lot more thought that goes into this than just opening all windows, or outside air dampers in a building. High relative humidity levels can actually encourage the spread of viruses when relative humidity rises above 60%, so it is important to understand what the capabilities of your existing HVAC system are, and what impact that will have on building temperature and relative humidity. The second option is an air purification system that will actively destroy viruses and bacteria both in the air stream and on surfaces within the space(13).
2. Let’s dig a little deeper into air purification technology — What kinds of systems are out there and what would you recommend?
M+A: From a sustainability and a cost perspective, we would recommend bipolar ionization. It has an inexpensive first cost and minimal maintenance over time that can be combined easily with your annual HVAC maintenance. It’s a long-term investment with a short payback.
It’s important to note that most air purification systems do more than just help with our immediate needs mitigating virus spread. Most systems also help reduce VOCs (some Volatile Organic Compounds are known as carcinogens(14)), allergens, mold, and odors. Air quality is one of the key factors in making a space healthier for the occupants(12) — we can think more clearly and be more creative and productive, students achieve higher test scores, and patients recover faster. If there’s one key component of a healthy building to invest in, it’s air quality. Following the 3-30-300 rule(7), if companies spend $3 in utilities, $30 in rent, and $300 in payroll per square foot per year, investing in creating a healthier and happier workforce offers a significantly higher payback.
CMTA: There are a lot of air technologies out there, and much of them sound too good to be true, which is often the case. To help our clients navigate this sea of products, we’ve compiled this chart that compares the major technologies in areas that have the most impact on a building.
The chart above paints a picture of just how different each of these technologies are. The technology that I suggest, and one that I utilize personally in my house, is Bipolar Ionization. Bipolar Ionization uses a small electronic charge to create a plasma field filled with a high concentration of positive and negative ions. The negative ions contain an extra electron while the positive ions are missing an electron, resulting in an unstable condition. In an effort to re-stabilize, these bipolar ions seek out atoms and molecules in the air to trade electrons with, effectively neutralizing particulate matter, bacteria and virus cells, odorous gases and aerosols, and VOCs. In other words, it cleans the air of viruses, smells, and very small dust and dirt that a typical filter cannot catch. It also makes air filters more effective, including N95 masks.
A second benefit of this technology is that it also kills viruses on surfaces. Similar to the way that copper acts as an antimicrobial, the negative ions that are emitted by Bipolar attach themselves to surfaces, which in turn, negatively charges the surface. The negative charge prevents cell respiration, punches holes in the bacterial cell membrane, or disrupts the viral coat and destroys the DNA and RNA inside, which keeps the cell from replicating.
"There is a stigma associated with this technology around the fact that early versions created ozone as a byproduct. This has been rectified by lowering the electron volt potential of the ions that get broken down to under 12 eV. Since Oxygen (O2) has a eV value higher than 12, it cannot be ionized, and thus ozone (O3) cannot be produced."
The reasons I like this technology are: it's cheap, it's effective in both the air stream and on surfaces, it has little-to-no maintenance, and it's easy to retrofit into all unit types. It was also recently third-party tested by a CDC Affiliated Lab to neutralize SARS – CoV – 2 Virus (which causes COVID-19) by 99.4% in 30 minutes(15). In general, it’s a great way to improve indoor air quality (IAQ), without a high initial investment.
I think it offers a tremendous benefit to the long term indoor air quality in the building, especially in buildings with dense occupancies. What we are seeing in recent energy code changes is an effort to minimize envelope leakage in new buildings, which means bringing in more outside air through mechanical means. This consequently, is also the most expensive air to treat from a utility standpoint, so there is a constant battle between indoor air quality, and energy use. This type of technology helps bridge that gap by allowing us to reduce the outside that needs to be delivered to the building, by treating the internal air, thus saving energy, while still maintaining high indoor air quality within the building.
3. Implementing new Indoor Air Quality (IAQ) strategies into existing buildings can be expensive and complicated. What is the best approach for owners to take when considering making changes to their buildings?
M+A: The most important thing to do before moving forward with any IAQ strategies in an existing building is to assess your current building and its systems. We like to think our buildings are performing optimally, but the reality can be quite different. This is a great opportunity to reach out to professionals that can help evaluate your HVAC systems, and help you prepare them for upgrades. Nobody wants to put a band-aid on a broken arm — if your ventilation systems are old or aren’t operating as well as they should be, you may need to replace your systems. We would also recommend having a professional who understands the full picture and complexity of a building, as well as the daily functions of the people within each space, assess your facility. They may even recommend retro-commissioning to ensure systems are operating efficiently and meeting your current needs.
CMTA: The best recommendation I can give is don’t go at this alone. What we’ve talked about in this article is just the “tip of the iceberg” when it comes to implementing changes. Without a complete understanding of how the building is currently operating, it is impossible to make an impactful change without affecting some portion of the building from an operations standpoint. Take for example increasing outside air at the air handlers. Are the cooling and heating coils sized to accommodate this extra load during peak heating and cooling times? Will building temperatures and relative humidity be affected negatively? Is the heating and cooling plant able to accommodate that extra capacity? One simple change can have huge impacts downstream. An engineer and/or commissioning agent must be involved to assure that the changes implemented do not put the building and its occupants at risk.
Indoor air quality has a long term value beyond just adapting to the coronavirus. Good air quality is invaluable in many ways, since it directly affects our cognitive functions and productivity. As we adapt our offices and homes to have better indoor air quality, it’s important to remember a few key concepts: consult professionals, analyze and understand how your current systems are operating, and then adapt accordingly. There are many systems out there that can aid in achieving good air quality. We think bipolar ionization is one of the best solutions from a sustainability, cost, and efficacy standpoint. Indoor air quality is a long-term investment, but is also a critical component to occupant health and wellbeing.
If you have more questions regarding air quality in your buildings, please reach out to us.
- Allen and John D. Macomber, J. G., & Macomber, J. D. (2020, June 19). What Makes an Office Building "Healthy". Retrieved July 02, 2020, from https://hbr.org/2020/04/what-makes-an-office-building-healthy
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