It's the Ventilation, Stupid. What schools can learn from the NYC Subway
From Schools to Subways, Ventilation Is The Key To Successful Re-openings.
Last week Governor Cuomo announced that schools statewide could open as scheduled. However, the Governor also noted, “if the teachers don’t come back, then you can’t really open the schools…If the parents don’t send their students, then you’re not really opening the schools.” Teachers, parents, and students are all feeling the anxiety of uncertainty as they consider personal decisions around returning to the classroom, what reopened school might look like, and whether the move will do more harm than good, as illustrated by this Yahoo News post, Dear Parents: You Are Being Lied To––8 Things You Should Know About Reopening Schools
You might be wondering, “how can it be safe for me to ride the subway, but not for my kids to go to school?” Or, as the always informed Florida Governor DeSantis noted, “But I’m confident if you can do Home Depot, if you can do Walmart, if you can do these things, we absolutely can do the schools.” Yet, New York getting the green light to open schools comes on the heels of numerous school closings in the South. The answer is obvious (just not to Gov. DeSantis): It’s the Ventilation, Stupid! (and the masks…wear your damn mask!)
Ventilation is an urgent concern, whether you’re talking indoor dining, retail shopping, returning to the office, or yes, returning to school. Don’t believe us? Read Zeynep Tufekci’s “We Need to Talk About Ventilation.” According to the New York Daily News, roughly 650 of the 1,500 New York City school “buildings surveyed in 2019 by city inspectors have at least one deficiency in their exhaust fans — a critical component of any ventilation system that pushes stale air out to make room for fresh air.”
So, what can schools learn from the subways? The New York Times is out with a fantastic data visualization, “What Happens to Viral Particles on the Subway,” that explains why ventilation is crucial, noting that “masks and social distancing are essential, but good airflow is also key to reducing the risk of exposure to the coronavirus.” They note how the subway’s ventilation system “moves air within cars more efficiently than restaurants, schools, and other indoor settings.” Shocker, we know, but subway cars do have a more robust ventilation system than many of our schools. Also important to note that each car continues to get cleaned with ultraviolet light each night.
So let’s move our classrooms to the subway! Well, not so fast. As The New York Times notes, the subway’s ventilation, “is not a guarantee to protect against the virus.” However, we can learn a lot from the MTA. Our schools need updated ventilation systems, which will cost a lot of money (and time). In New York City alone, there are 700 school buildings with no “supply fans” that draw in outside air, and more than 900 do not have a “heating and ventilating unit” meant to pull in outside air, heat it, and distribute through vents to the building.
A couple of months ago, we started talking to our friend Paul Soames at Ryan Soames Engineering about how our clients, some of whom are schools, can update their HVAC systems to ensure they are complying with state COVID-19 guidelines and regulations. He gave us some solutions to updating your HVAC system. They include:
- Installing Merv-13 Filters: Conventional air filters with an improved Minimum Efficiency Reporting Value (MERV) between 13 and 15 (MERV ratings range from one to sixteen, with sixteen being the best and used in operating rooms) can reduce droplet nuclei levels but are not likely to be effective at stopping any unattached virus participles. Note: many school buildings are old and therefore, may not be able to take filters larger than 13 (some may not even be able to take 13).
- Installing a Humidifier: Humidity is essential, as scientists believe extreme heat can curtail the spread of COVID-19. According to Fast Company, a Harvard infection control consultant who studied the spread of viruses in hospitals and nursing homes discovered a link between infection rates and humidity in inpatient rooms. She is “petitioning alongside companies that make sensors and humidifiers to improve air quality, for the CDC and WHO to adopt guidelines around safe humidity levels – specifically that indoor humidity should be kept between 40% to 60%.” Additionally, a recent Yale study showed that our respiratory, immune systems work better in higher humidity.
- Implementing a fresh air purge: A Fresh Air Purge system is used for flushing your office space with fresh air overnight. Purges are effective at lowering viral transmission because they fill the entire building (or parts of the building) with fresh filtered air. This can also be achieved by opening up windows in your office instead of using the HVAC system. However, many office buildings do not allow for windows to be opened. The challenge with Fresh Air Purges is they can increase costs by consuming more energy.
So, what does this mean for kids, teachers and parents? It’s going to be a difficult – and different – school year. There’s no way to avoid that. But what we can do is plan for a smarter and safer future. Everyone agrees that we need to open schools. We need to open up restaurants. We need to go back to our offices. But, we cannot be stupid – we need to pay attention to ventilation. We need to invest in updated ventilation systems for our schools, offices, restaurants and retail shops not just to fight COVID-19 but also to be better prepared to fight future pathogens. Our kids, our economy, and our future depend on it.