Ashrae Duct Fitting Database Version. 6.00.05 May 2026

The ASHRAE Duct Fitting Database (DFDB) Version 6.00.05 is a high-precision digital tool designed for HVAC engineers to calculate pressure loss across complex duct networks. Developed by ASHRAE in collaboration with Carmel Software Corporation, this version serves as the industry standard for determining duct fitting loss coefficients (C-factors). Key Features of Version 6.00.05

Software Integration: The ASHRAE Duct Fitting Database is frequently integrated into HVAC design software like Autodesk Revit to automate pressure loss calculations across entire duct systems. Duct Fitting Database - ASHRAE ashrae duct fitting database version. 6.00.05

Validate with actual measurements post-commissioning. The database is a predictor, not a guarantee of real-world losses. Compare and feed back field data to refine. The ASHRAE Duct Fitting Database (DFDB) Version 6

  1. Launch the viewer and select "Search by Category" → "Elbows – Round."
  2. Filter parameters:
    • Diameter (in or mm): 12 inches
    • Radius/Diameter ratio (R/D): 1.5
    • Reynolds number (auto-calculated if you enter velocity, air density, and viscosity).

    6. Usage guidance & best practices

    • Use the fitting entry whose geometry/conditions most closely match the actual fitting; avoid extrapolating beyond specified Re range.
    • For transitional fittings, pick entries matching inlet/outlet aspect ratios and takeoff angles.
    • When only K is provided and you need equivalent length: Le = (K * D) / f where f is friction factor — this requires an iterative or assumed f; using Le/D when provided is simpler.
    • Round ducts: apply Le/D directly. Rectangular ducts: convert to hydraulic diameter for consistent use.
    • For low-Re or turbulent-laminar transitional flows, use entries with appropriate Re limits or perform CFD/experimental validation.

    ASHRAE Duct Fitting Database (DFDB) version 6.00.05 is the critical maintenance release of the version 6 software, widely used by HVAC engineers for calculating pressure losses in duct systems Launch the viewer and select "Search by Category"

  3. Keep an eye on cumulative lifecycle impacts: