What is the minimum distance outdoor air intakes must be from waste air?

Outdoor air intakes are critical for maintaining indoor air quality, particularly in environments where air pollution is a concern. The minimum distance between outdoor air intakes and sources of waste air is established to prevent the recirculation of contaminated air back into the building’s air system.

The correct answer indicates a distance of 25 feet as the minimum required separation. This distance is sufficient to mitigate the risk of cross-contamination from exhaust systems, vents, or other sources of waste air which might introduce pollutants or unpleasant odors into the fresh air supply. The choice of this specific distance is based on standards and best practices that take into account airflow dynamics and typical atmospheric conditions, ensuring the health and safety of building occupants.

In contrast, other distances like 15, 35, or 50 feet may either not be enough to prevent contamination effectively or could be excessive, depending on the context and specific regulations that govern a given installation. Thus, 25 feet provides a balanced solution that aligns with both health guidelines and practical architectural considerations.