The ASHRAE Duct Fitting Database (DFDB) is a professional software tool used to calculate pressure losses in HVAC duct systems . While ASHRAE does not provide a standalone Excel file,

• Build manually – Transcribe from Handbook tables (time-consuming but precise).
• Third-party sources – Some engineering sites and GitHub repositories offer curated Excel files (check license and accuracy).
• Convert from official CD – If you have the ASHRAE Duct Fitting Database (CD or download), you can export tables to CSV then to Excel.

If you prefer not to build from scratch, several industry sources offer Excel-based solutions:

Typical Contents of an Excel Version

• Included with ASHRAE Handbook (CD/DVD or digital download) for members.
• Some versions available via ASHRAE’s “Duct Fitting Database” product (paid).
• Not generally free; copyright protected by ASHRAE.

Third-Party Tools:

Many HVAC engineers use custom-built Excel templates (like the MEP Excel Duct Fitting Calculator ) that reference ASHRAE codes and coefficients.