What is the minimum ventilation airflow rate required per square foot of floor area?

The minimum ventilation airflow rate required per square foot of floor area is often specified for maintaining indoor air quality in residential and commercial buildings. In the context of North Carolina Mechanical Code, the correct answer reflects the standard practices and recommendations established by relevant guidelines, such as the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).

Option B, which states 0.05 cfm per square foot, aligns with established minimum ventilation rates for providing adequate indoor air quality in most occupied spaces. This rate is designed to ensure that there is sufficient fresh air to dilute indoor pollutants, thereby promoting healthier living and working environments.

Other choices present higher airflow rates that may exceed typical ventilation needs for many standard spaces, which could result in unnecessary energy consumption without significantly enhancing air quality. The selection of 0.05 cfm is seen as a balanced approach, providing adequate ventilation while still being efficient.