School ventilation: “In May, [CDC] recommended that there should be five so-called air changes — the equivalent of replacing all the air in a room — per hour.”

Link. “Schools that combined better ventilation with filtration had 48 percent fewer cases …. A large study of schools in Italy … ventilation systems or devices that deliver clean air had an at least 74 percent lower risk of infection than students in classrooms with open windows.”

There’s a ton of unsent rescuer money, about 20% schools need spending to achieve standards. I wonder if spending rules are too complex or have legal risk to staff.