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Query Duct

To modify a duct on the drawing, go to
Ribbon: DM HVAC→Ducts→  Query Duct
Pulldown Menu: DM HVAC→Duct Centerlines→Query Duct

Select the duct on the drawing to be queried.

Duct Information Dialog Box​

Changes can be made to the duct in the same way as when it was inserted. See the Common Duct Information section for more information.

The airflow information in the dialog box is specific to the Query Duct command.

  •   Press this button to recalculate the size of this duct. The current settings in the dialog box will be used.

  •  CFM: The volume of air traveling through this duct.

    Check the ☐ Lock box to lock the CFM at a specified value. If this box is unchecked, the CFM value is calculated based upon the airflow through the diffusers connected to the ductwork.

  •  CFM Diversity Factor: A diversity factor applied to the CFM value in this duct. The diversified CFM value is displayed in the CFM field and used for ductwork calculations. The full CFM value is passed to the next duct when the CFM values are calculated.

  •  Pressure Drop in this Section: The pressure drop through this duct. This is the pressure drop in the straight section of duct between the fittings. It is not a total pressure drop for the system and it does not include the fitting pressure drop.

    Check the ☐ Lock box to lock the Pressure Drop in this Section at a specified value.

  •  Pressure Drop in Previous Fitting: The pressure drop through the previous fitting. See the Previous and Next Ducts sections for more information about identifying the previous fitting.

  •  Static Pressure at end of Previous Duct (or Fan): The static pressure at the end of the previous duct just before the fitting or, if there is no previous duct, at the fan connected to this duct.

    Check the ☐ Lock box to lock the Static Pressure at end of Previous Duct (or Fan) at a specified value.

  •  Total Pressure at end of Previous Duct (or Fan): The total pressure at the end of the previous duct or, if there is no previous duct, at the fan connected to this duct.

  •  Total / Static Pressure at Start of this Duct (From Start): The total and static pressure at the start of this duct, as calculated from the fan.

  •  Total / Static Pressure at Start of this Duct (To End): The total and static pressure at the start of this duct, as calculated from the diffusers.

  •  Total / Static Pressure at End of this Duct (From Start): The total and static pressure at the end of this duct, as calculated from the fan.

  •  Total / Static Pressure at End of this Duct (To End): The total and static pressure at the end of this duct, as calculated from the diffusers.

  •  Velocity Pressure in this Section: The velocity pressure in this duct.

  •  Estimate Brake Horsepower (70% efficiency): The fan size required based upon the total pressure in the duct.

  •  Velocity: The velocity of the air flowing through this duct.

  •  Pressure Drop per 100 ': The pressure drop per 100 feet in this duct.

  •   Press this button to recalculate the velocity and velocity pressure in this duct. The duct size and airflow will not be recalculated.