DC schools have a ventilation problem. This dad is helping, one 'cube' at a time.
As students return to the classroom amid a delta variant surge, one D.C. dad is manufacturing DIY air-filtration cubes — and wants others to do the same.

As millions of students returned to the classroom on Monday amid growing concerns about the coronavirus delta variant and rising youth COVID infections, one Washington, D.C., dad took it upon himself to provide his community with a little extra protection — using some air filters, a box fan, and a whole lot of duct tape.
The Centers for Disease Control and Prevention has said that beyond masking and vaccination for those who are eligible, proper ventilation is among the most effective tools to prevent the spread of COVID-19 in schools. The American Rescue Plan, President Joe Biden’s COVID stimulus package, provided upwards of $100 billion to elementary and secondary schools to help ensure a safe reopening for the 2021-2022 school year, with the Department of Education stressing that improving school ventilation was key to ensuring safe in-person instruction.
In Washington, officials in the city’s Department of General Services released a detailed plan to update public schools’ HVAC systems, and the initiative was recognized as a 2021 project of the year by the D.C. chapter of the Construction Management Association of America, the department director highlighted to the American Independent Foundation.
Yet in the lead-up to Monday’s reopening, reports of shoddy HVAC and ventilation equipment began to pile up. After months of complaints from staff and a deluge of local media reports, officials said a long-outstanding HVAC issue at Powell Elementary School finally received a “temporary fix” until the parts arrive to provide proper repairs.
Meanwhile, in a virtual town hall on Thursday, D.C. council member Charles Allen decried, “HVAC systems that aren’t working as they need to, spot coolers being used in spaces,” telling parents and education leaders, “If I sound frustrated, it’s because I am.”
D.C. teachers have taken to social media to highlight issues in their own classrooms and ask leaders for help. The executive director of the Washington Teachers’ Union told local outlet WTOP that there are “ongoing issues with HVAC and ventilation systems at some school sites that will require immediate attention before schools resume on Monday.”
Enter Peter Krupa, a 40-year-old translator and father who lives in the Eckington neighborhood of Washington. Though he has no engineering or construction experience — aside from owning a “junky row house” and facing the “constant battle of putting it back together” — Krupa in a matter of days worked to construct nearly 30 DIY air-filtration devices, which have been donated to teachers and educators throughout the District.
Krupa first got the idea after hearing an NPR story about Corsi-Rosenthal Cubes, box-like devices named for the duo who designed them, a University of California, Davis, engineering school dean and the Tex-Air Filters CEO. To make them, a box fan is inserted into a cube made of four MERV 13 air filters, which help strip the air of larger particles the virus could be floating on. Devices of this kind, held together by a cardboard base and some duct tape, have proven to be a cheap and efficient way to mitigate airborne COVID transmission in poorly ventilated spaces.
“I just heard this story and I kind of put two and two together,” Krupa recalled in a phone interview with the American Independent Foundation. “I’ve got a pretty good network in D.C. I know how to kind of put things together. I’ve got a minivan. Let’s give it a shot.”
Through Twitter posts and a GoFundMe campaign, Krupa has raised over $4,000 to manufacture 29 of the devices so far, and the requests keep coming in, he said. His conversations with teachers have revealed that most D.C. classrooms are “pretty well equipped” with HEPA filters. But ESL rooms, libraries, psychologist’s offices, and other secondary spaces are seriously lacking.
Asked about reports of HVAC issues in D.C. schools, Department of General Services Director Keith Anderson said in a statement to the American Independent Foundation that his agency “has, and continues to be, committed to ensuring the safety of students, teachers, and staff regarding air filtration, ventilation, and comfort in preparation for the fall back-to-school in-person season.”
On the role of private citizens like Krupa stepping in to provide extra help, Anderson added that, “DGS supports and relies on the science and work of industry experts that created the District’s plan and cannot comment or support any other devices brought in from outside of District government.”
“Obviously, I would like DCPS to kind of, like, see these cracks that we’re filling and for them to decide to take that over,” Krupa said of the role government officials should play in school ventilation efforts.
It’s not just Washington schools that face problems with ventilation. A 2020 report from the Government Accountability Office found that at least half of schools required HVAC attention in 40% of public school districts, and that was before the pandemic set in. In New York City, at least 1,500 classrooms were still undergoing ventilation repairs as students returned to school, according to WNYC, while some states have policies that restrict how dollars can be spent on such repairs. In Baltimore, public school officials maintain a list of schools without proper air conditioning and ventilation, many of which close early on especially hot and humid days.
Despite this, Krupa is pressing on — and already has requests for 20 more cubes. He highlighted how easy it is to construct the cubes out of equipment you can buy from your local hardware store with step-by-step instructions and tutorial videos available online.
“Your first one will take 40 minutes and then your second one takes 20 minutes,” Krupa said. “It’s a pretty easy learning curve.”
The reaction from teachers is what keeps him going.
“I think it’s kind of a relief to a lot of them,” Krupa said. “It’s really encouraging to them, I think, to see how many people really care about what’s happening.”
Published with permission of The American Independent Foundation.
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