Sheet Metal & Air Conditioning Contractors’ National Association

Tools, CAD & Apps


  • SMACNA HVAC Duct Construction App

    The app will provide SMACNA compliant options for rectangular duct with dimensions from 1 inch to 120 inches for applications from negative to positive ten inch water gage.

    The scenarios for the app are limited to joint lengths of 4, 5, and 6 feet. The transverse connections are limited to T1 (flat drive), T5 (flat slip), T10, 11, and 12 (standing slips) and T25 a or b (TDC/TDF). Where appropriate the app will also provide options for intermediate reinforcement. The full range of reinforcement spacing options is 6, 5, 4, 3, 2 1/2, and 2 feet.

    In most cases the app will provide options for internal reinforcements and external reinforcements. Internal options are limited to EMT conduit tie rods and external reinforcements are limited to angles. Enough information is provided so users can choose other options from SMACNA's Standard.

    The output of the app is a written description of the duct as well as a graphic representation. Users can view the report on-screen or email it.

    The app does not provide every possible solution found in SMACNA's standard and it will not provide every detail. For example, the app does not provide requirements for the proper attachment of the reinforcements. The app is intended to be used in conjunction with SMACNA's HVAC Duct Construction Standard.

    Web Version

    (Available to SMACNA Members only)

    Android app on Google Play Download_on_the_App_Store_Badge_US-UK_135x40
  • SMACNA Air Duct Leakage App

    This simple to use but effective application is provided by the Sheet Metal and Air Conditioning Contractors' National Association (SMACNA). This tool allows engineers, architects, designers, and contractors to easily and accurately estimate the leakage of air from ductwork. It also allows a quick and easy way to determine the pass/fail mark for properly specified Duct Air Leakage Tests (DALT).

    Users can combine multiple sections of ductwork that vary by size and shape to calculate a total allowable leakage. The application uses the method outlined in SMACNA's HVAC Air Duct Leakage Manual, and provides suggested leakage classes from SMACNA's latest edition of the manual. The method used is compliant with ASHRAE 90.1, IECC, IGCC Version 2, IMC and the UMC.

    Free Web Version

    Android app on Google Play Download_on_the_App_Store_Badge_US-UK_135x40
  • SMACNA’s Round Industrial Duct Construction App

    This app allows the user to create an infinite number of solutions using the methods and formulas covered in SMACNA’s Round Industrial Duct Construction Standards Manual.

    Users can select spiral or welded duct, the duct material, various live loads such as snow and wind loading, various dead loads such as insulation and cladding, hanger spacing, air temperature, and particulate properties.

    Once the information is selected the app can generate several answers and the user can select which options to consider.  After selections are made the user can then create a full engineering report that outlines the procedure used to create the specific solution.

    Web Version

    (Available to SMACNA Members only)

  • SMACNA’s Downspout & Gutter Sizing Calculator

    The Sheet Metal and Air Conditioning Contractors' National Association (SMACNA) is now providing a simple and effective Downspout & Gutter Sizing Calculator. This tool allows engineers, architects, designers, and contractors to easily and accurately size downspout and gutters per SMACNA’s Architectural Sheet Metal Manual.

    The calculator’s Rain Intensity Wizard allows you to select the city nearest you and utilize the information taken from the tables in Architectural Sheet Metal Manual 7th Edition – 2012 for your calculations. The Rain Intensity per ASMM Table 1-2 uses the 5-minute Duration for a 10yr or 100yr storm, thereby providing a worst-case scenario for your downspout and gutter design. Since the Rain Intensity data is constantly being updated by the National Oceanic and Atmospheric Administration (NOAA), this calculator also allows the manual entry of the Rainfall Intensity, thereby allowing you to calculate per the local authority having jurisdiction in your area. For the most up to date rain intensity data, NOAA’s website is (Use Precipitation Intensity as your data type.)

    The gutter and downspout size required is highly dependent on the number of sections and length of those gutter sections and the number of the downspouts.

    • Adding additional sections of gutter thereby reducing the length of each section will reduce the size of the gutter required. Also, the gutter width relation to height may also be adjusted.
    • Adding additional downspouts will change the downspout volume resulting in smaller gutters/downspouts.

    You may manually enter the Design Area of the roof for the calculation or use the Design Area Wizard. This Wizard makes it easy to calculate the roof Design Area by providing various shape calculations and the calculation for Vertical Walls area per International Plumbing Code (IPC.)

    Web Version