Bypass Dampers

Balance your bypass duct with the push of a single button!

Available in round and rectangular sizes, EWC Controls’s model SBD bypass dampers make bypass set-up simpler than ever.

Smart Bypass Dampers

No measuring instruments are required. No weights to adjust. No springs to crank. The SBD is ACCA Manual Zr compliant. As an added benefit of the unique blade design and the smart, self-balancing feature of the SBD, there is no need to install and setup a separate bypass balancing hand damper.


See it in action!

The model CLBD Bypass Damper is an easy and economical way to manage system static pressure, in a zoned HVAC system.

Damper adjustment is easily achieved by increasing or decreasing the force applied to the bypass damper blade, until the desired static pressure is achieved.

CLBD Bypass Damper

Due to the constant load applied to the damper blade and the unique magnetic latch, the CLBD Bypass Damper can be installed in any position on your bypass duct-work, to manage the HVAC system’s static pressure during zoned operations.

By-pass Dampers

The CLBD minimizes bypass volume, while still preventing the HVAC system static pressure from rising above the selected Static Pressure set-point. The CLBD is a basic, cost effective Bypass Solution for Constant Speed or Variable Speed “zoned” HVAC systems.

Note: This drawing of the Bypass damper, Balancing Hand Damper, and Related duct work is intended to serve only as a guide. Your actual duct work layout and components may differ. Use the graphic as a guide when planning or designing a Zone system regardless of the Equipment type, Duct layout and Airflow configuration.
Size CFM

The EBD (Electronic By-Pass) style are self-contained units that give you the static control mounted to the damper.

It is an “all-in-one” design that makes the installation process much easier than most electronic by-pass dampers. The static pressure can be adjusted in the field between 0.5″ to 4″ of pressure. This is done by the turn of a set-screw. Requires 24VAC to operate. Tubing and pitot tube are included.

Model EBD


Round Sizes: 8″, 10″, 12″, 14″, 16″, 18″

Model EBD (Rectangular)


Rectangular Sizes: 12″ X 8″, 12″ X 10″, 12″ X 12″, 20″ X 8″, 20″ X 10″, 20″ X 12″

Model PS-4


Model PS-4 pressure switch available separately for use with URD and ND style dampers.

Model PRD


Model PRD pressure regulating damper is a single blade, steel, barometric damper with a counter-balanced weighted arm. The PRD provides an economical solution for bypassing excess air when zone dampers close. Damper adjustment is done by adjusting the supplied weights and by offsetting the arm.

Size CFM
12″ X 8″
12″ X 10″
12″ X 12″
20″ X 8″
20″ X 10″
20″ X 12″

Other sizes available upon request.

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