Fresh-Air Volume Is Not the Same as Total Airflow

One point must be clear: total airflow is not the same as fresh-air volume. Fresh-air volume is the amount of outdoor air supplied indoors, while total airflow may refer to a mixture of fresh air and recirculated indoor return air. If most of a unit's stated airflow consists of air repeatedly circulating indoors, its ventilation performance will be limited. Be sure to clarify this distinction before making a purchase.