Start with fan settings, air readings and the branch occupancy map. It is the source used to decide how to compare an air reading when the fan setting changes during inspection; it is not the decision itself. The rule only works if the source describes conditions at the North Fan chamber.
Known: the current file counts 75 readings with a fan setting and occupied branch attached, compared with 77 in the prior window. Anew route file opens with an entrance, branch and service named. The entries have dates and a named clerk.
Disputed: The maintenance office posts a single average. Residents ask for the reading at the occupied branch during the change. One side emphasizes the posted total; the other points to the fan is lowered during a stone inspection near one return shaft.
Why it matters: the decision determines which residents can rely on the service and which staff must carry out the change. The file does not settle that by itself.
Next: The Year second, vent change window 1 file remains open for its scheduled decision. The fan board will pair each reading with its setting and branch name.
