When Clarkson University commenced its fall semester planning back in the spring, it looked to be a daunting task to safely bring more than 3,000 students back to its main campus in Potsdam for both in-person and online classes — especially for a university known for its personal, rigorous hands-on learning.

Questions like “Can classrooms be safely used?” and “Do we have enough classroom technology for online and hybrid classes?” were on the minds of faculty and administrators.

Engineers from Clarkson’s Center for Air Resources Engineering and Science (CARES) and experts from the University’s Office of Information Technology quickly went to work to make fall semester classes a reality, while still maintaining rigor in both learning and safety.

Suresh Dhaniyala, the Bayard D. Clarkson Distinguished Professor and co-director of CARES, took the lead on analyzing the performance of classroom ventilation systems.

“For the COVID-19 pandemic scenario, our focus was on knowing that any particles in the air could be evacuated quickly, so as to prevent cross-contamination between occupants,” says Dhaniyala.

An air exchange rate is the rate at which airflow is brought into a room and directly relates to the rate at which particles are removed from a room. A rate of 1 per hour implies that after one hour, the amount of fresh air brought in is equal to the volume of the room.

Most homes have air exchange rates of approximately 0.3 per hour.  At the other end of the spectrum, hospital operating rooms are required to have air exchange rates of 15 to 25 per hour.

“We evaluated our classroom air exchange rates using an aerosol injection system with particles of 500 nanometers to 5 microns, the same size as particles that escape from face masks and are responsible for airborne disease transmission,” says Dhaniyala. “We injected particles into each classroom and used sensors around the room to study the decay times.”

 Dhaniyala determined that many classrooms already had excellent air exchange rates of 6 to 10 per hour, significantly exceeding requirements. With an air exchange rate of 10 per hour, a particle injected during a class has a less than five percent chance of still being in that classroom after 20 minutes.

“We shared a few problem areas with University Engineer Michael Tremper, who was able to quickly adjust the ventilation systems in those spaces by using innovative engineering solutions,” says Dhaniyala.

At the same time, the classroom ventilation was being evaluated, teams from Clarkson’s Office of Information Technology were working to implement new technology into existing classrooms and to create new classrooms in non-traditional spaces like dining halls and larger multipurpose areas that could accommodate social distancing requirements.

“Our teams touched a total of 88 classrooms to ensure that every space is now equipped with a pen-touch display, webcam, microphone, and full lecture capture capabilities,” says Chief Information Officer Joshua Fiske. “Additionally, for faculty who are teaching online, we created a loaner pool of technology, which includes 100 pen-touch enabled 2-in-1 laptops, 50 standalone webcams, and 50 high-quality headphones and microphones.” 

Fiske says that from a physical perspective, every classroom has been “de-densified” to ensure six-foot distancing between seats. Both hand sanitizer and sanitizing wipes are available in every classroom, and each occupant is expected to wipe down their workspace both before and after use. Students and faculty must wear face coverings indoors — excluding students in their own residence hall room or apartment — and outdoors while within six feet of another person

Dhaniyala’s team continues to monitor air quality and ventilation to understand changes due to weather and occupancy. ” “The summer project was challenging because of the short time frame and limited personnel, but it has been a very rewarding experience,” he says. “We hope our findings will help the University to continue through the year without any major outbreaks.”

Fiske says although the first few days of online and hybrid classes were challenging to a few faculty and students, things have generally been running smoothly since. “We’re seven weeks into our online and in-person classes, and using Zoom technology is now second nature to our Clarkson community — just as it is now for many families and business people. Hopefully, our careful preparation has paid off in safer yet still engaging classes for our students.”