Positive closure dampers

Positive closure dampers

PCD's prevent air flow through the equipment that is shut down.

Installing positive closure dampers

  • guarantees year-round reliable operation
  • helps maintain the cooling tower

These dampers feature multiple damper blades installed within a rigid frame, which are opened or closed by a motor actuator with spring return. Opening the dampers puts the spring under tension. The actuator keeps it there with minimal power until the motor power supply is cut by external control contact or power failure. The energy stored in the spring then automatically closes the damper when the actuator is de-energized.

This installation creates external static pressure, which may either reduce the thermal capacity of the standard unit or require adjustment of the fan speed and motor.

PCD's come with a plenum underneath to give access to the spray system.

Want to maintain full thermal performance? Contact your local BAC representative for correct fan motor sizing.