An experimental trial of a new method to balance industrial exhaust ventilation systems was performed. Although balance by design is considered preferable, many ventilation systems incorporate dampers to balance the system to a different airflow distribution after installation. The "target hood static pressure" method aims to minimize the time, effort, frustration and confusion invested in the balancing effort. It requires only one and one-half adjustment rounds, can be prepared as a computerized spreadsheet, and substitutes hood static pressure readings for airflow traverse readings. The method also minimizes the system static pressure to the least possible, thereby keeping friction losses at a minimum. Since the resulting distribution errors range less than the measurement error of pitot tube measurements, no method can be demonstrated as being better. |