What is the primary function of a backdraft damper in ductwork?

The primary function of a backdraft damper in ductwork is to prevent backflow of air. This device is essential in ensuring that air only moves in the intended direction within the ventilation system. When the system is operational and air is being pushed through the duct, the damper remains open to allow this flow. However, when the system is not in use or if there is a pressure change that could cause air to flow backward, the damper automatically closes, creating a barrier to stop any unwanted backdrafts.

By preventing backflow, backdraft dampers help to maintain indoor air quality and energy efficiency, as they reduce the likelihood of outside air entering and disrupting the conditioned environment. Additionally, preventing backflow can protect the system components from potential damage caused by the introduction of moisture and contaminants from external sources. Thus, the effectiveness of heating, cooling, and ventilation systems is greatly enhanced by the proper functioning of backdraft dampers.