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.

There are two versions of Equiduct — a licensed version intended for ductwork systems design professionals, and an unlicensed version for all other users.

Equivalency

Alternative duct sizes are returned in a color coded table, 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.

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).

Unlicensed Version

The unlicensed version of Equiduct is intended for Architects, Contractors, and building Owners interested in exploring alternative duct sizes and shapes that meet the design reg. It allows such use with minimal technical knowledge and relatively few required inputs.

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.

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.