Books Against Damp: A Storage Bound for Mould in the School Store

Stored textbooks in damp climates mould before they wear out. Using a stated humidity threshold for mould germination and a seeded synthetic store-room humidity series, this paper counts days at risk in a school term and the effect of simple cross-ventilation priced as louvres. The series is illustrative, not a site record, and the paper says so; the threshold arithmetic, not the weather, carries the conclusion. Computed results: days_above_65pct_baseline = 142, days_above_65pct_ventilated = 112, season_days = 180, vent_cost_usd = 25.0. Every number in this paper is produced by the accompanying script `compute.py`. SIMULATED, NOT MEASURED.