By the time the 1970s came around, "hygienic architecture" was a thing of the past — a bygone era of classroom design that featured big windows and open glass doors, and at times, outdoor learning spaces. Natural light and a cross-breeze were eventually replaced by fluorescents and ventilation systems, and by the '70s the schools looked less like atriums and more like malls, or prisons. And the windows didn't just shrink in classrooms, they disappeared. Look over the history of school design, and it's not hard to see a post-pandemic future with vastly different structures replacing those we have today. But when the city's teachers and students re-enter the classroom this September, many will be stepping into those windowless rooms of the past.

A Brooklyn public school classroom,1902, encircled in windows.

Windowless or not, "schools are going to become hotbeds for the infections," Dr. Irwin Redlener, director of the Pandemic Resource and Response Initiative at Columbia, told WNYC's Brian Lehrer this week. The further spread of COVID-19 is "almost inevitable if we are in fact going to even hold some classes in real time in real classrooms."

Like other schools in the city, P.S. 503 in Sunset Park, an elementary school that is co-located with another elementary school (P.S. 506), contains many windowless classrooms.

"The entire ground floor on our side of the school building is underground and has no windows," a teacher at P.S. 503, who asked not to be named, told Gothamist, noting some simply call the school: The Basement.

"Teachers advocated for not using any of the underground classrooms," the teacher told us, "a request which administration seemed sympathetic to.  However, in order to accommodate a third of our school population as per the Department of Education mandate, the school is being required to use as many rooms as necessary, so they opted to use the underground windowless rooms in their reopening plan."

Additionally, one room will be used for students or staff members who fall ill — this "isolation room" will be separate from the nurse's office, and neither has a window. Students will also eat lunch inside the windowless classrooms.

Dr. Stephen Morse, an epidemiologist at Columbia University, told Gothamist that ideally lunches should be "supervised outdoors, with good hand hygiene." If indoors, distancing and ventilation will be important.

Nathaniel Styer, Deputy Press Secretary for the DOE, confirmed the plan to use these classrooms, and told us the school "has a fully functional and operational HVAC system and all HVAC systems are having their filters upgraded." Yet, as some schools get upgraded HVAC systems, and others do not, both health experts and the city have promoted open windows as a way to reduce the spread of COVID-19.

While visiting a Queens public school with a window shortage last week, Mayor Bill de Blasio said, "The doctors usually say... open the windows... That's the most amazing thing about all this is in all my conversations over months and months, fresh air, just direct fresh air is one of the single best things you can do."

This kind of instruction to open windows, which has been passed along by city officials to teachers, comes simultaneously with the DOE's plan to hold classes in windowless rooms.

While the DOE will allow a max of 14 people in each classroom (11 students, plus up to 2 teachers and a paraprofessional), at P.S. 503 they intend to have a max of 10 people per a room at a time, to help with distancing. And to help with the air quality, families voted at a recent PTA meeting to use $8,100 of funds to purchase nine air purifiers, one for each classroom. This is over half of the PTA's current budget.

"Forcing parents to use their own money to purchase equipment to (hopefully) rectify a glaring health and safety issue that the DOE has not addressed is in my opinion outrageous," the P.S. 503 teacher told us. "It also raises serious questions about equity. Some schools have million-dollar PTA budgets and will easily be able to make their schools safer with purchases similar to this, while other schools may struggle to even do what my school is doing."

Can any amount of money make a return to classrooms 100% safe? In short, no.

It's "hard to say" if indoor standalone HEPA air purifiers could help in a closed room, Morse told us—"I’d use it if I had these units, but I wouldn’t expect too much from them. I think most scientists would say, based on the best available current evidence, is that if you have to be indoors, open the windows.  If you can’t do that, I think you’re going further down the scale and looking at ways to make the best of a less than optimal situation, given that the best options aren’t available.  I’d personally be uncomfortable doing this in a school."

Morse also expressed concern about holding class in a windowless room, no matter what kind of precautions are being taken. "I’m surprised at how many windowless rooms there seem to be, and even more surprised they would be considered — restaurants wouldn’t do it. I think we need to use the best protection measures in the schools, because of the inherent risks.  I’d feel very anxious with anything less.  If we can’t allow something in a restaurant, we definitely shouldn’t do it in the schools. I thought the city was being very careful, so I’d have to ask what other precautionary measures they’re taking." 

"Improving the HVAC system (with filters and increased flow) can help, but is insufficient," he added.

While MERV filters can be installed in the HVAC system to filter small particle aerosols, Morse told us even that is not a perfect solution. "I’m assuming these are older systems," he told us. "These filters provide good protection against fine-particle aerosols, but most HVAC systems are generally too high up in the room to prevent droplet transmission at close quarters, which is how we believe most of the transmission occurs, or touching the face with contaminated fingers or objects."

These filters should, however, be able to "prevent or reduce movement of the virus through the HVAC system, for example from room to room," like we saw on cruise ships. A DOE spokesperson told us they plan to use replace air filters in buildings with central HVAC systems, from MERV 8 to MERV 13. The latter is the standard; the highest filtration comes with a MERV 17.

Instead of relying on filters, however, Morse said that the HVAC system in many buildings can be set to increase the number of room air changes per hour, which is beneficial — the system "can often be set to use 100% outside air, [which is] more expensive, but safer than recycling the air and also better for the filters, and will improve ventilation." Styer, from the DOE, told us that this is part of their plan, to open outside air dampers to maximize outside air supply.

Distancing and mask compliance will also be important in returning to classrooms, Morse said, but pointed out that while "we’re probably in better shape than many other places, this is no time to let down our guard. We still need to be especially careful not to become complacent."

Along with good ventilation, testing is vital to reopening schools safely. "If it were up to me, I’d test for virus everyone in the school just before school starts and send home for two week isolation anyone who’s positive," Morse said. This is called "gateway testing," and Morse said "it could have prevented some of the problems we saw with schools in other states."

Testing is not currently mandated in the city's plan to reopen public schools (teachers have been asked to get tested before the start of school, and then are encouraged to get tested monthly); students aren't required to get tested before first day.

A windowless room at P.S. 503

The HVAC has been an issue in "the basement," as well as the rest of the building, for years, the teacher at P.S. 503 told us, "Rooms are either excessively hot or excessively cold." Concerns have been raised in the past, and continue to be raised, but the teacher told us that "no DOE representative has addressed teacher or parent concerns at our school. Our superintendent has not addressed teacher or parent concerns either."