Equipment, Flex & Terminal Connections ยท Equipment & Terminals

VAV discharge rectangular duct

Terminal outlet

ConnectionFlanged or slip outlet
SupportIndependent duct support

Before you start

  • Confirm the VAV discharge dimensions, transition or connector detail, reheat-coil location, access-panel clearance, and outlet support.
  • Inspect the casing, flange, gasket surface, and downstream duct.
  • Verify the discharge duct will not load or distort the VAV casing.
  • Coordinate controls, reheat service, and access before installation.

Tools and materials

VAV discharge duct, approved flanged or slip-joint components, gasket, flexible connector if specified, fasteners, sealant, independent support, level, and hand tools.

Lay it out

  1. Establish the discharge centerline and elevation.
  2. Keep service and reheat access clear.
  3. Confirm the transition does not block panels or controls.

Set and support it

  1. Support the VAV independently.
  2. Support the discharge duct before closing the joint.
  3. Keep the flange faces square and parallel.

Make the connection

  1. 1

    Set the discharge duct to the VAV outlet.

  2. 2

    Install gasket or flexible connector if specified.

  3. 3

    Bring the joint together without pulling on the casing.

  4. 4

    Install fasteners evenly.

  5. 5

    Seal the joint.

  6. 6

    Load the duct support.

  7. 7

    Check the casing for distortion and confirm all panels open.

Check the install

  • The VAV casing remains square.
  • The discharge duct is independently supported.
  • The joint is fully seated and sealed.
  • Reheat and control access remains open.
  • No transition blocks service.

Common mistakes

  • Hanging the discharge duct from the VAV.
  • Using bolts to pull misaligned flanges together.
  • Blocking the reheat coil or access panel.
  • Stretching a flexible connector.

Stop and ask

Stop if the discharge transition blocks service, the casing distorts, the outlet size is wrong, or the duct cannot be independently supported.