Classroom Ventilation Priced per Learning-Ready Hour: A Sizing Method for Natural-Ventilation Openings in a Hot-Climate Classroom

SIMULATED, NOT MEASURED. A sizing method for natural-ventilation openings in a hot-climate classroom (40 pupils, 60 m2) using a CO2 mass balance with coupled wind and stack airflow and a steady thermal balance over a synthetic 1,080-hour school year. The smallest openings meeting CO2 <=1,000 ppm in >=90% of hours are 0.7 m2 inlet and 0.7 m2 outlet (94.8% compliance, US$443.20 materials), but only 97 of 1,080 hours are learning-ready because temperature fails in 983 hours, giving US$0.594 per learning-ready hour. Nothing has been built or used by children.