Start with fan-hour totals, temperature notes and the neighborhood air board. It is the source used to decide how residents can tell a normal reading from a maintenance interval; it is not the decision itself. The rule only works if the source describes conditions at the south vent trunk.

Known: the current file counts 64 fan hours recorded with a matching air sample, compared with 58 in the prior window. Asecond office compares the count with the posted operating state. The entries have dates and a named clerk.

Disputed: The plant totals are posted monthly. Nearby households want the maintenance hours listed on the same board. One side emphasizes the posted total; the other points to the fan is reduced during maintenance while the public board remains unchanged.

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 third, rain shift window 1 file remains open for its scheduled decision. The vent office will add maintenance intervals to each public reading.