ASHRAE Duct Fitting Database (DFDB)

The is a specialized tool for calculating pressure loss coefficients for over 220 duct fittings across round, rectangular, and flat oval geometries. While users often seek a "patched" PDF or software version to bypass licensing, the official and most reliable access is through legitimate ASHRAE technical resources . Current Versions and Availability

files used for coefficients), leading to incorrect pressure loss calculations. Integration Issues

By 2025, the HVAC industry is moving away from static PDFs entirely. Here is what is replacing them:

  1. Part 1: What is the ASHRAE Duct Fitting Database?

    ASHRAE Duct Fitting Database (DFDB)

    The is a specialized tool used by HVAC engineers to determine the pressure loss and loss coefficients (

    ), and total pressure loss calculations for supply, exhaust, and common duct systems.