Many fittings lack exact matches for your dimensions. Use FORECAST.LINEAR :
Example Workflow (concise)
An HVAC engineer designing a supply duct system uses the Excel database to: ashrae duct fitting database excel
For HVAC engineers, mechanical contractors, and energy modelers, few tasks are as tedious yet critical as calculating pressure losses in duct systems. Every elbow, transition, tee, and damper introduces friction that your fan must overcome. For decades, the industry standard for these calculations has been , specifically Chapter 34 (Duct Design). Many fittings lack exact matches for your dimensions
Loss = C * Pv
: Without specific third-party plugins, you must still manually find and move data into your Excel spreadsheets. Verdict and energy modelers