Tompkins Weekly

‘Tinkerer’ develops filter system for virus


Justin Michener’s filter system developed for the Robin’s Nest preschool uses a window fan to draw air down through a virus filter on top. The cube of filters below slows the air coming out to reduce unwanted circulation. Photo by Justin Michener.

Justin Michener is the volunteer facilities director for the Board of Directors at the Robin’s Nest preschool.

A stay-at-home dad for his two sons, Michener is also a trained electrician and heating ventilation and air conditioning (HVAC) technician and a self-described “tinkerer.”

Lansing at Large by Matt Montague

When the Board decided to reopen the school in September, Michener wanted to make the facility as safe as possible.

“So, the Robin’s Nest is like a lot of older structures,” he said. “It was originally purposed as a residence and is now being used as a commercial building. It doesn’t have a way to bring in fresh, clean air or filter it.”

Even most big commercial building HVAC systems are not designed to filter airborne diseases, he noted.

The biggest challenge in removing aerosols that can transport the COVID-19 virus from any building is circulation, Michener said. A building’s HVAC systems are designed to move cool or warm air around.

“The problem with aerosols [that transfer viruses] like COVID is that, when you move air from one end of the room to another, even if you are filtering the air, the air can move past one person with a viral load who is excreting that aerosol into the air and then be drawn past other people,” he said.

Forced air systems also move air vertically — warm air starts low and moves upward to even out the temperature in the space.

“That’s exactly the thing you don’t want to do,” Michener said.

So, if you want to keep the kids in a preschool safe, filtering is good, but air circulation is bad. Michener began to think on this problem.

“My wife studies health policy in the government department at Cornell, so she’s in the thick of all this research, and I’ve been telling her about the things I learned as an HVAC technician,” he said.

Michener went online to watch simulations of how HVAC systems spread COVID-19 in an office space.

“So, I was thinking about those things — filtering air and keeping it from moving. Those were the two goals — filter air but don’t create circulation,” he said.

His solution is simple.

Michener’s system began with a MERV 13 filter designed to trap airborne viruses. Beneath it, he mounted a standard box fan that draws air down through the filter. He had seen similar ad hoc filters used on construction job sites to keep dust down.

However, “you still have air currents and turbulence,” as he explained.

To slow that air down, Michener built a four-sided box of MERV 11 air filters and set it beneath the window fan. One filter in and four out evens out the inflow and outflow.

“You can hold a piece of toilet paper next to it, and it doesn’t move at all,” Michener said. “That’s the idea — trapped and contained. It’s like using a sponge to clean up a puddle — you set it in the middle and let it absorb.”

The device — MERV 13 filter, window fan and cube of four MERV 11 filters — stands about 2 feet tall and uses about $80 worth of materials. Michener made them as simple as possible to cut costs.

“The box the fan came in is used to hold the MERV 13 filter,” he said.

Michener estimates that each unit can move between 1,500 to 2,000 cubic feet of air per minute. That means that each classroom gets two devices while the 15-by-45-foot common space has five. There are a total of eight at the school.

“We also have an exhaust fan running, and the teachers have cracked the screen doors to bring in fresh air,” Michener said.

At the end of the day, each teacher sprays their top filters with alcohol three times with the fan on to draw the alcohol down to kill any remaining viruses and the system is ready for reuse.

He had the devices built and in place two weeks before Robin’s Nest reopened. The teaching staff helped Michener place the units and figure out how to keep active preschoolers from destroying them.

“The kids all wear masks and are told not to touch others’ masks — so they are telling them this is a mask for the school building,” he said. “It’s a simple way to keep the virus down, away from noses and contained. If it helps one person, it’s worth it.”

In Brief:

Browsing by Appointment at Lansing Library

The Lansing Community Library will begin “browsing by appointment” Oct. 20, an addition to their current curbside service.

Patrons can make an appointment by visiting lansinglibrary.org/make-an-appointment.

Each appointment is 30 minutes long. All patrons must wear a mask and adhere to established in-person guidelines. Those with a medical exemption to not wear a mask must use the curbside pickup service.

Appointments are mostly for browsing books. Many services will not be available during appointments, including computer use, seating and toys. The library has separate hours for senior citizens. Call 607-533-4939 to schedule a senior appointment.

Lions to Make Chicken

The Lansing Lions will be holding a chicken barbecue Saturday, Oct. 17, beginning at 10:30 a.m. at the Town Hall Barbeque Pavillion. The meal includes Dave Hatfield’s famous barbecue chicken, salt potatoes and beans. All proceeds to benefit Lansing Lion’s High School Scholarship Fund.

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