Ashrae Duct Fitting Database Excel May 2026

This article is a deep dive into what this database is, why it matters, how to get it, and how to leverage it to shave hours off your design time. The ASHRAE Duct Fitting Database is a digital compilation of loss coefficients for virtually every standard duct fitting used in commercial and industrial HVAC systems. Historically, these values were locked in PDFs or printed tables. Today, ASHRAE provides this data in structured formats—including Microsoft Excel.

=FORECAST.LINEAR(Your_Aspect_Ratio, Known_Coefficient_Range, Known_Aspect_Ratio_Range) Some coefficients are only valid at turbulent flow (Re > 4000). Add a conditional check: ashrae duct fitting database excel

=XLOOKUP([@Fitting_Ref], ASHRAE_DB[A:Fitting_Code], ASHRAE_DB[Loss_Coefficient]) If you have variable geometry (e.g., a transition where W1/W2 changes), use XLOOKUP with approximate match to find the closest geometric parameter. With coefficient C , velocity pressure Pv (in inches w.g. or Pa), the loss is: This article is a deep dive into what

Loss = C * Pv