While you cannot legally redistribute the full DFDB, ASHRAE provides sample excerpts in the ASHRAE Handbook CD (2005–2013 editions). Many engineers have built their own trimmed Excel tables from these samples.

The ASHRAE Duct Fitting Database (DFDB) is the digital manifestation of the tables, charts, and coefficients found in the ASHRAE Fundamentals Handbook (Chapter 34 – Duct Design) and the ASHRAE Duct Fitting Database CD/DVD.

It contains loss coefficients ((C_o)) for thousands of fittings, including:

Instead of manually reading complex logarithmic charts (like Chart 14-3 or 14-4 from the 1997 Handbook), the digital database allows engineers to compute dynamic losses instantly using standardized formulas: ( \Delta p = C_o \times P_v ) (where ( P_v ) is velocity pressure).

A: Absolutely. The ASHRAE coefficients are derived from real tests (ASHRAE RP-1293, etc.) and are widely accepted for energy modeling.

If you own a license or are using an academic version, follow this technical workflow:

Verdict: The Industry Standard, Finally Modernized. The ASHRAE Duct Fitting Database is an indispensable tool for mechanical engineers and HVAC designers. While the core data has been the gold standard for decades, the ability to link it directly to Microsoft Excel transforms it from a static reference manual into a dynamic calculation engine.

Here is the honest truth: ASHRAE does not provide a single, clickable link to download a static Excel file for the full database.

Why? Because the database is proprietary and actively maintained. ASHRAE licenses it through specific software partners (like Elite Software, Trane, and others) or via the official ASHRAE DFDB Module for third-party tools.

However, if you have access to the database (via a license or your firm’s software), you can link it to Excel.

Several commercial HVAC design software packages (e.g., Trane Duct Designer, Carrier HAP, Elite Software), as well as free tools like HVAC Solution or openDuct, include the ASHRAE database. Many allow export to CSV/Excel.

Workflow:

While not a full database download, this works if you only need specific fittings for a project.