varies dynamically based on geometry (aspect ratios, angles, turning vanes) and flow conditions (Reynolds number, volume flow ratios), static charts quickly become unmanageable. The Value of an Excel Link for HVAC Engineers
To effectively use an ASHRAE duct fitting link in Excel, you must have the following data points ready:
: These industry-standard loads and duct tools can export comprehensive node-by-node duct pressure profiles directly into Excel-compatible reports. 3. Custom SQL or Access Database Queries
The is a digital catalog of over 200 different round, rectangular, and flat oval duct fittings. For each fitting, the DFDB provides the published loss coefficients (K-values) needed to calculate the pressure drop in an HVAC system. ashrae duct fitting database excel link
If you link your calculation sheet to an external workbook containing the database, the formulas will break when you email the file to a client. to keep the file completely self-contained and portable. To help refine your calculation templates, tell me: Are you designing in Imperial (IP) or Metric (SI) units?
) based on geometry and flow rates. Engineers use these coefficients in the standard pressure loss equation:
Set up cells for the input parameters needed to calculate the pressure loss: (e.g., CD3-1 for a 90-degree round elbow). varies dynamically based on geometry (aspect ratios, angles,
allow you to generate reports that can be sent via email with a CSV/spreadsheet attachment
ASHRAE also offers the Duct Size Calculator, a quick reference tool for approximating duct sizes and equivalent sizes of sheet metal duct versus flexible duct. This tool includes sizing for metal ducts and flexible duct when compressed at 4%, 15%, and 30% straight line compression. It was developed through collaboration between ASHRAE TC 5.2 (Duct Design) and the Air Distribution Institute.
While not official ASHRAE products, some third-party tools and custom spreadsheets use the ASHRAE data for calculations. These are sometimes referred to as a "Duct Fitting Calculator," a "Excel-based software that uses VBA to perform the calculations". Using these tools may require careful verification of the underlying data source, as they may not be updated with the latest ASHRAE Handbook editions. Custom SQL or Access Database Queries The is
The database provides loss coefficient tables for over , covering round, rectangular, and flat oval designs.
Because fitting coefficients vary based on changing aspect ratios and velocity ratios, standard VLOOKUP is rarely enough. Use the more powerful INDEX and MATCH combination, or the newer XLOOKUP , to perform two-dimensional matrix searches on your ASHRAE_Data tab.
: Legacy versions (v5.0 and v6.0) are available through technical retailers like for approximately $155.00. How to Use the Data with Excel Many engineers use the ASHRAE software