Take a fresh look at your lifestyle.

How To Adjust The Airflow For An HVAC Duct Flex

Heating, ventilation, and air conditioning systems operate with ducts routed through a building to deliver heated or cooled air. As the name implies, Flex ducts bend around obstacles and curves without losing structural integrity so that air continues to flow through them. An adjustable damper is mounted within the flexible duct when it attaches to the main duct before branching. The damper control which can be seen when you visit website consists of a metal rod that extends from the side. Adjusting the airflow with the damper takes less than a minute. Things You Need

  • Folding Ladder
  • Flat Screwdriver


  1. Set up the ladder below the flexible duct at the joint with the main piping. A ladder is not necessary if you can reach the flexible duct, but recruit a helper to hold the ladder stable if you use a ladder.
  2. Insert the screwdriver into the slot at the end of the adjustment rod on the flexible conduit side.
  3. rotate the slot in the rod perpendicular to the duct to close the damper inside. This shuts off the airflow.
  4. Turn the groove in the stem, so it’s in line with the flexible duct to open it fully for maximum airflow.

Adjustment Principles

First and foremost, it should not be confused: regulating the airflows is not regulating them.

Regulating air flows means modifying the air supply to the premises according to indoor and or outdoor conditions and parameters. For example, if the pollution of a room exceeds a limit threshold, the flow rates can be automatically regulated upwards to evacuate this excess of indoor pollution.

Adjusting the air flows consists of carrying out the system’s complete adjustment just after its (complete!) Installation to allow it to reach the flow rates envisaged during the design. Therefore, it sets the drive vents and extraction control valves on fans, distribution systems, etc.

Therefore, adjusting an installation means ensuring the necessary airflow in each room. No more, no less. For the sake of comfort and energy savings. The installer usually carries out this operation before acceptance of the works to adjust the flow rates to the values ​​provided by the design office. But a later adjustment by the manager is sometimes necessary depending on the actual occupancy of the building.

  • Balancing is carried out under normal operating conditions, i.e.
  • with closed interior doors, unless current usage requires them to remain open
  • with closed exterior doors and windows
  • with the extraction in operation in the case of a double-flow system

Flow adjustment devices greatly favor it at the mouths and the top of the branches. Otherwise, adjustment diaphragms can be inserted into the ducts, but their use is less flexible. Visit website to view collections.

Comments are closed.