ICC Commercial Mechanical Practice Exam

The general purpose of a backdraft damper is to prevent unwanted airflow or backflow in a duct system. This is particularly important in systems where airflow needs to be controlled and directed to ensure efficient operation. A backdraft damper operates by allowing air to flow in one direction while closing off in the opposite direction, which helps to maintain the intended airflow path and prevents outside air from infiltrating the system when it is not needed. This not only improves energy efficiency by minimizing heat loss or gain but also enhances the overall performance of the heating, ventilation, and air conditioning (HVAC) system.

In the context of the other choices, increasing airflow would be more related to the design and sizing of ducts rather than a function of a damper. Equalizing pressure is typically handled through other means, such as balancing dampers or variable air volume systems, rather than solely through backdraft dampers. Reducing noise in duct systems is usually addressed by using sound attenuators or proper duct design rather than the primary function of a backdraft damper, which focuses on airflow control and prevention of reverse flow.