In the second of three-related pieces, Grumpy Old Teacher (GOT) continues to think about the classroom that is full of students and what practices actually work to mitigate the risk of Covid-19 transmission. The first one Veni, Vidi, Vici may be found here.
In the 6th installment of her famous series, J.K. Rowling moves Professor Snape into the Defense Against Dark Arts position to the consternation of the students. In one of his first classes, Snape had this to say, ““The Dark Arts are many, varied, ever-changing, and eternal. Fighting them is like fighting a many-headed monster, which, each time a neck is severed, sprouts a head even fiercer and cleverer than before. You are fighting that which is unfixed, mutating, indestructible.”
He could have been describing the coronavirus that has been spawning new, more contagious, possibly more deadly variants as governments work to get their people vaccinated.
C’est la vie pandémique dans une école.
Covid is changing. We need to up our game if we are to continue to provide the best possible safety in classroom environments. For GOT, that has meant checking on the actual ventilation in the room. How safe is his classroom?
Last week, GOT published an early report. The hypothesis was that the CO2 readings, used as a proxy for ventilation, showed that the classroom air was not being exchanged with outdoor air in a way that refreshed the indoor air to keep it healthy. The CO2 readings themselves were not the concern. It was the increase that took place over three hours, an increase that continued until GOT opened the windows, that suggested that the exhalations of Covid-laden breath would increase in the classroom, which would mean that as the day went on, the probability of people in the room contracting the virus would also increase without stop.
This week, GOT continued to monitor the readings. Tuesday, the 16th, a day when GOT sits alone all day and teaches online, the readings went from 390 at 7 AM to 875 by the end of the day at 3 PM.
The significance of the increase is not the numbers, but the trend. It seems clear that GOT’s classroom does not have enough ventilation to prevent an accumulation of whatever is present in human exhalation.
The actual HVAC unit is mounted on the outside of the buiilding. The vent at top is the treated air that is blown into the classroom; the vent at bottom pulls air out of the classroom. The exhaust is mixed with fresh outdoor air. The problem is that this only happens when the unit is working. At other times, the classroom atmosphere is still and uncomfortable.
Prior to the pandemic, GOT had two fans that were set to slow–enough to stir the air and keep the atmosphere from a cloying oppression without blowing papers off desks and being annoying.
But, given the airborne transmission of the virus, the last thing to do would be to blow it all over the classroom. GOT put the fans away.
Wednesday, the 17th, when students would be in the classroom, action was in order. GOT opened the top windows in the classroom to see if they would provide ventilation for the room. That day, the readings increased but only to half the levels of the previous Friday. The readings two days later confirmed the same, in fact, the CO2 reading peaked at less than half of that recorded the first day.
You see how the window is opened. It is screened unlike the lower windows that are the emergency escape route should we need to evacuate and cannot use the hallway door. The advantage of the screen is that it keeps bugs out.
Oh, you haven’t lived until you see the panic and drama when a wasp flies into the room. High school teens think themselves tough, they may be ready to fight at the slightest insult and keep going until blood runs on the floor, but wait until a wasp is in the room! They cower.
Teens seem unable to grasp the principle that if they leave something alone, even a critter like a wasp, it will leave them alone. The wasp doesn’t want to sting. It wants to find a way out of the room without expending so much energy that it dies. Let it alone and let it get about its mission. But GOT digresses.
A new strategy is now part of the mix. Every day, GOT gets on a ladder and opens the top windows to keep the room aired. At the end of the day, he does it again to close them. Upping the game to keep the room healthy and safe as epidemiologists worry about a third surge of sickness and death as the variants take hold.
It seems simple: open the windows. But GOT’s building is over 50 years old–built in the days when even Florida did not have universal air conditioning and architects placed plenty of windows in the designs that could be opened in the heat to catch the prevailing breezes.
These days, buildings are built to stay closed. Energy efficiency dictates that minimal ventilation with outside air take place to reduce the cooling demands upon HVAC equipment. Not every teacher has windows to open.
They deserve better than to hear districts, boards, politicians, and the public say: c’est la vie.