Duct Calculator

The Duct Calculator App for iPhone/iPad is a valuable tool for HVAC engineers, designers, and contractors to size ductwork accurately and efficiently on iOS devices. This app offers a modern approach to the traditional duct sizing wheel.

With this app, users can easily size both round and rectangular ductwork. The intuitive interface allows for quick adjustments of airflow, diameter, width, and height using sliders or by entering numbers directly into the calculator. Users can also lock specific dimensions to perform calculations specific to their design needs.

One of the key features of this app is the live update of calculated values. This allows users to immediately see the impact of any changes made to the inputs.

In addition to accurate calculations, the app provides velocity outputs for both round and rectangular ducts. Users can select from a range of duct roughness categories and work with both IP and SI units.

Designed for convenience, this app is ideal for HVAC designers and contractors who need quick calculations on-the-go. It offers flexibility in input methods, precise results, and an intuitive interface.

HOW TO USE:

Locking Dimensions:

• The lock symbols next to the duct dimensions indicate whether a dimension is locked during the calculation of new equivalent values when a dimension is updated.
• The Diameter can be locked or unlocked.
• The Width or Height can be locked, but not both.

Using the Sliders:

• Move the sliders for Airflow, Duct Diameter, Width, and Height to match the desired duct size for calculating velocity and pressure drop.
• The Diameter, Width, and Height will change accordingly to show their equivalent sizes.
• Changing the diameter will update either the equivalent Width or Height, depending on which dimension is unlocked.
• Changing the Width or Height will update the equivalent Diameter if it is unlocked, or the other rectangular duct dimension if the Diameter size is locked.

Direct Entry:

• Use the text boxes to directly edit the values for Airflow, Diameter, Width, and Height to quickly input exact numbers.
• Invalid entries will cause an error message, and corrections must be made before the calculations can be updated.

Output:

• The app provides calculated Velocity values for Round Duct and Rectangular Duct, as well as the Pressure Drop per Length value.

NOTES:

This application (App) is intended for use by qualified HVAC engineers and designers as a tool for designing air handling systems. It should not be considered a substitute for professional design services. If unsure, it is recommended to consult with a design professional.