"Sealed schools" are ones in which the ventilation is not "natural."
"Sealed schools" are ones in which the students and teachers have no authority or ability to open a window or outside door.
"Sealed schools" have a higher CO2 level than the average "old" school.
FORCED AIR FLOW is a requirement. Many times this is inadequate: the air exchange is simply not enough, or the outside air being brought in is already heavily loaded with CO2.Sometimes these systems are not run properly; They are noisy, and some teachers and others don't like air blowing on them.
Sometimes the people in one part of the building can take it no longer and open the system. This means more inadequate service to the other parts of the building where the people may be suffering silently without opening the system.
And, sometimes these systems are allowed to get filthy. (Legionnaires' Disease. Warning: Many suffer from different ailments even where the systems are clean or where there is no "black" mold or "toxic" mold. Anaerobic organisms thrive on CO2).
(I believe you first need to be armed against the "leaky school" argument which has recently sprung up, so please read this).
Seattle school maintenance personnel claimed air was controlled for all schools centrally and sensors would let officials know if someone were "opening" the system.
Many school districts have acquired CO2 monitors, but it does not appear they are telling anyone, either parents or other schools, and they assume too high a level is still ok.
Mr. Weller of the Oregon Lung Association and the Oregon school officials, and representatives of The Oregonian newspaper did not want to discuss the situation. I suspect the article got over-looked by some editor. I am amazed it saw the light of day! Everyone that I talked to either wanted to "stone-wall," ignore it, or minimize it. That was several years ago before the killings started. How close is Springfield, Oregon to Eugene and Bethel?