Why have I seen the AC running at schools outside of normal hours?
Ensuring clean and healthy indoor air quality for our staff and students is a major goal of Oak Park USD. Most of our classrooms are not being used daily, and in order to keep the indoor air clean, it is necessary to run the AC and ventilation periodically. You may see AC units running for a one-hour “purge” outside of normal working hours. According to the State's Indoor Air Quality Guidelines, "Purging-type ventilation procedures should be used for at least one to two hours to flush the building of accumulated contaminants after a period of vacancy, e.g., weekends, evenings, and holidays." Running the AC units outside of normal hours minimizes energy consumption and enables the room to be suitable for use the following day should a teacher need to access the room to conduct distance learning instruction. Additionally, AC units above campus kitchens that support walk-in refrigerators and freezers must run constantly for safety reasons.