Duct shape (round/rectangular), fitting code, airflow (CFM or L/s), and physical dimensions.
While the official standalone desktop application is excellent for checking a single fitting, it falls short when engineering a complex, building-wide duct network. Building a custom tool in Excel offers distinct advantages:
While the official ASHRAE DFDB software provides a robust interface for searching, integrating these values into an spreadsheet allows for efficient calculation, automated workflows, and custom reporting. This guide covers how to leverage Excel to streamline your duct design process using ASHRAE data. What is the ASHRAE Duct Fitting Database? ashrae duct fitting database excel
For straight ducts, you'll need to calculate the friction loss using the Darcy-Weisbach equation. This requires solving for the friction factor, which is done using the Colebrook equation for turbulent flow.
Use Excel's sheet protection to lock the Fitting_DB tab. Accurately entering data tables takes hours; accidentally overwriting a cell with a typo can compromise future engineering designs. This guide covers how to leverage Excel to
Where $\Delta P$ is the pressure loss, $C$ is the fitting loss coefficient, and $P_v$ is the velocity pressure. The hard part isn't the math; it is finding the correct $C$-value, which changes based on geometry (e.g., the radius of an elbow or the aspect ratio of a duct).
While the standalone ASHRAE DFDB software is useful, an format offers several advantages: This requires solving for the friction factor, which
). Include a correction factor input cell if designing for high-altitude projects.
The main calculation engine containing individual rows for each duct section and fitting. Fitting Code, CFM, Velocity,