Determining the rate at which indoor air is replaced with outdoor air involves assessing factors like room volume, ventilation system capacity, and infiltration rates. For instance, if a 1000 cubic foot room has a ventilation system supplying 100 cubic feet of outdoor air per minute, the air exchange rate is 6 per hour. This metric is often expressed as air changes per hour (ACH) or cubic feet per minute (CFM).
Understanding and managing this process plays a vital role in maintaining healthy indoor air quality. Historically, natural ventilation through windows and doors provided the primary means of air exchange. Modern buildings, however, often rely on mechanical ventilation systems to control this process more precisely, thereby reducing the spread of airborne contaminants, managing humidity levels, and enhancing thermal comfort. Proper ventilation is crucial for occupant health, productivity, and overall well-being.
