If you need the actual coefficients, you may also refer to or ASHRAE Fundamentals 2021 (Chapter 33) for the same basic data, though the dedicated 2016 database remains a specific historical version.

For current projects, use if possible, but many legacy systems still reference the 2016 coefficients. Always verify the fitting number and reference velocity definition when extracting $C$ values.

Summary

: Users can save selected fittings into a project file, which facilitates the calculation of total pressure drop along a "critical path" or the longest duct route. Units and Reporting : The software supports both

The real power of the emerges when paired with modern software. As of 2016, ASHRAE licensed the data to several platforms:

The total pressure loss across a fitting is: $$ \Delta p = C \times \left( \frac\rho V^22 \right) $$ where: