. . . & lots more than just a conventional ductulator  

• Duct converter module to convert duct sizes between round, rectangular and oval duct.

•  rhoAIR module to find air density and other pyschrometric air properties at state point. see rhoAIR page ...

•  Louvre sizer module to size louvre opening required for structural opening.

•  Fan Motor kW module to calculate electrical power consumption.

•  Convert KW-Amp module to convert electrical KW - Amp, and calculate KVA.

•  Duct gauge/weight module to find duct weight, perimeter and surface area for rectangular, round and oval duct with built-in duct gauge selections (Standard (uncoated) Steel, Galvanized steel, Stainless steel and Aluminium duct).

•  Velocity guide Module to provide recommended duct velocity for main and branch duct.

• Threaded rod sizer module: Need to size and select hanger rod size, this tool is specially built for that purposes. It also calculates tensile stress and maximum load. See tRod Sizer page for explanation.

Note: Ductulator does not calculate fitting / dynamic loss. 

Built-in Features:

Unlike the conventional hand-held ductulator which is built for round duct sizing with equivalent rectangular duct sizes, velocity  & friction loss rate for round duct, pre-calculated for the duct roughness of 0.09mm and limited duct sizes, Ductulator offers you the flexibility in duct sizing for various duct shapes and different materials such as concrete duct, flexible duct, etc.

Ductulator is designed to offer you the greatest flexibility in duct sizing: 

• options for Equal Friction method, Velocity method, by Duct Dimensions or find Airflow.

• options for round or rectangular or oval duct shape.

• use Colebrook equation in solving friction factor. 

• use hydraulic diameter (not equivalent diameter of round duct) for rectangular and oval duct sizing.

• duct converter for round, rectangular & oval duct.

Ductulator gives you detail results like Flow area, Hydraulic diameter, Reynolds number, Friction factor and Velocity pressure, if you need it and save the results.

Duct Sizing Methods

Ductulator offers 4 commonly used methods of duct sizing:

1) The traditional Equal Friction Method of duct sizing is often preferred as it is easy to use and less time-consuming. This method uses a constant pressure loss per unit of duct length. Generally, 0.8 Pa/m (0.1 in.wc/100 ft) of constant pressure loss per meter run has been widely practised in duct sizing.

Because there are practically unlimited number of duct sizes for a given design air flow, the duct sizing problem is solved by iteration technique.

2) Velocity method is often used when acoustic requirements or minimum air transport/duct velocity is given. 

3) by Duct Dimensions method is generally used to find duct friction loss rate for an existing "as-built" duct. 

4) find Airflow method comes handy when you need to know how much airflow for a given existing or new duct sizes. 

Units in Ductulator

Both SI & IP units are available in Ductulator. 

Did you know? . . . (1) Equivalent cross-sectional Area! 

If you want the same duct friction loss rate, it is inappropriate to convert duct size based on equal cross-sectional area, be it from round to rectangular or square to rectangular. This is because rectangular duct is less efficient than round duct; rectangular duct is less efficient than square duct. See example below, the flow areas (ie, cross-sectional areas) are different for the same duct frictional loss rate. 

Did you know? . . . (2) Hydraulic diameter vs Equivalent diameter!  

For ducts with shapes that are not round, hydraulic diameter is not equal to equivalent diameter. For circular duct, hydraulic diameter is the same as the diameter of the round duct.

For any duct shapes, hydraulic diameter = 4 x cross-sectional area / perimeter. Ductulator uses this approach to find duct sizes.

For rectangular duct, equivalent diameter = 1.30 x {(Width x Height)0.625 / (Width + Height)0.25}. 

For oval duct, equivalent diameter = 1.55 x (cross-sectional area)0.625 / (perimeter)0.25.

Example 1: Duct Sizing at job site (in SI units)

An existing duct 600mm (W) x 500mm (H) carrying airflow of 8000 CMH needs to be flattened to 300mm (H) to achieve the desired ceiling height.

Find the new duct size.

Solutions:

Step 1: Find duct friction loss rate for the existing duct.

Step 2: Calculate new duct size with the given height constraint.

The following results are computed by the Ductulator: