General

Equiduct returns multiple alternative duct sizes that are similar to an input duct size. The number of alternatives can range from a few to several dozen, depending on the parameters used to determine equivalency.

Alternative duct sizes are returned in color coded tables, where the colors generally indicate “Good”, “Better”, and “Best” with respect to equivalency.

Default parameters are included for evaluating equivalency, however all such parameters can be adjusted by the user.

Supported Shapes

Equiduct supports round, rectangular, and flat oval ductwork shapes, and can return equivalent duct sizes of the same shape as the input duct or of a different shape than the input duct.

The following equivalencies are supported: Rectangular to Rectangular, Rectangular to Flat Oval, Rectangular to Round, Flat Oval to Flat Oval, Flat Oval to Rectangular, Flat Oval to Round, Round to Rectangular, and Round to Flat Oval.

Versions

There are two versions of Equiduct — a licensed version intended for ductwork systems design professionals, and an unlicensed version intended for Architects, Contractors, and Owners interested in exploring alternative duct sizes and shapes that meet the design intent.

In general, the unlicensed version is identical to the licensed version, with the following exceptions:

Input airflows are limited to 100, 1,000, 10,000, and 100,000.

Printout notes are not editable.

Printouts have watermarks.

The unlicensed version of Equiduct is freely distributable.

Technical Information

Alternative rectangular duct sizes are calculated using the equation developed by Huebscher (1948).

Alternative flat oval duct sizes are calculated using the equations developed by Heyt and Diaz (1975).

Features

Supports both Inch‑Pound (IP) and International System (SI) units.

Supports round, rectangular, and flat oval duct shapes, and converts between the three.

Supports all combinations of temperature, relative humidity, and elevation.

Supports all roughnesses.

Supports straight flexible ductwork at customizable compression ratios.

Customizable compact views.

Limitations

Equiduct does not support gasses other than air.