Ashrae Duct Fitting Database 2016 Fixed Jun 2026

for the theoretical basis of duct design and roughness factors used in the database. Browse the Ductsize Update Log from Elite Software

For a 250 mm diameter, 90° smooth radius elbow with R/D = 1.5, the engineer enters the airflow and elevation (for density adjustment), and the DFDB returns the appropriate C-value and pressure drop.

Around 30 years ago, the industry reached a consensus: instead of each manufacturer bearing the huge cost of product testing, the industry would be best served by a common library of duct performance data that could be expanded as needed. ASHRAE's Technical Committee TC 5.2, "Duct Design," was tasked with producing this common resource. The result was the ASHRAE Duct Fitting Database, built on rigorous, standardized test data. ashrae duct fitting database 2016

The modern DFDB is the result of decades of research. A pivotal step was Research Project , which aimed to enhance and expand the ASHRAE database. This research laid the groundwork by populating an accurate dataset and creating the first interactive program that would eventually evolve into the comprehensive DFDB software available today [1†L17-L22] [23†L13-L21].

: Elbows, tees, and transitions for circular systems. Rectangular Ducts : Common in commercial overhead systems. for the theoretical basis of duct design and

Purchasers receive a one-year subscription for cloud-based access to the DFDB ver. 6.00.05. This remains the preferred method for modern users, offering always-current data and no installation hassles.

, serves as a critical software tool for HVAC engineers to determine the pressure loss of over 200 different duct fittings. By providing accurate loss coefficients ( cap C sub o ASHRAE's Technical Committee TC 5

Find loss coefficient for a rectangular 90° smooth radius elbow, 24" x 12" duct, centerline radius = 12", no vanes.

: While the database focuses on geometry, remember that different materials (e.g., fiberglass vs. sheet metal) have different friction rates that must be combined with the fitting's dynamic loss. Duct Fitting Database - ASHRAE

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.

The DFDB was designed for integration into larger HVAC workflows. The ability to export CSV or XML outputs allows seamless data transfer into Excel spreadsheets, Revit models, and CFD analysis tools. This interoperability has made the DFDB a foundational data source for many third-party duct sizing and system simulation programs.