Dampers – Basic HVAC

Dampers are devices installed in the ductwork of air systems to regulate the flow of air. They can be controlled manually or remotely and can be used to ensure a certain percentage of the return airflow is mixed with incoming air from outside. This helps ensure that healthy levels of fresh air are added to the recirculating air flow system.

Most sets of dampers consist of a U-channel frame with several connected sheet-metal blades which are driven by a small motor. The edges of the sheet-metal blades will have rubber seals to help provide a tighter barrier to air when in the closed position.

Types of Dampers

Dampers are divided into two categories depending upon how their blades rotate relative to each other. Opposed blade dampers are constructed so that adjacent blades rotate in opposite directions, while parallel blade dampers have all blades rotating in the same direction, similar to Venetian blinds.

Opposed Blade Dampers

Opposed blade dampers are ideal for applications requiring precise control of airflow. Their design facilitates a more even distribution of air, making them preferable in large scale HVAC systems where balanced airflow is crucial.

Parallel Blade Dampers

Parallel blade dampers, on the other hand, are often used in applications where the damper is either fully open or fully closed, such as in on/off control situations. They provide a more direct path for the airflow when open, causing less resistance.

Motor-Driven Dampers

Motor driven dampers that are part of larger commercial or industrial HVAC systems will have power-fail positions that they will revert to in the event of a loss of voltage. This fail-safe mechanism ensures that the system continues to operate safely even during power outages.

For a more in-depth look and to see various damper options, feel free to View Details.