Streamline your workflow today by linking your project spreadsheets directly to the definitive standard in duct aerodynamics.
If you need the official data, you must purchase the tool from the ASHRAE Bookstore.
Air density (standard is ≈ 0.075 lb/ft³ or 1.2 kg/m³). Step 2: Incorporate Formula The fundamental formula used in the DFDB is: ΔP=C×Pvcap delta cap P equals cap C cross cap P sub v Δ P = Pressure Loss C = Loss Coefficient (from database) Pvcap P sub v = Velocity Pressure ( Step 3: Implement VLOOKUP/MATCH Tables
dll = ctypes.CDLL("C:/ASHRAE/ASHRAEDFDB.dll") dll.GetFittingData.argtypes = [c_long, c_double, c_double, c_double, ctypes.POINTER(c_double)]
There is no official, free direct download link for the ASHRAE Duct Fitting Database in Excel format. The data is a proprietary asset of ASHRAE. To link the data to Excel, you must either purchase the official software and use its export features or create your own calculation spreadsheet based on the equations provided in the ASHRAE Fundamentals Handbook (Chapter 21). ashrae duct fitting database excel link
Use XLOOKUP or INDEX/MATCH formulas on your main calculation sheet to retrieve coefficients based on fitting codes and aspect ratios. 2. Utilizing Third-Party HVAC Design Software Add-ins
Open the fitting or category you need within the ASHRAE DFDB application.
Go to ashrae.org → search "Duct Fitting Database" → Purchase the current version (approx. $250 for non-members). That is the only reliable, accurate, and legal Excel link you will ever need.
It contains loss coefficients ((C_o)) for thousands of fittings, including: Streamline your workflow today by linking your project
ASHRAE periodically updates loss coefficients based on new research. Ensure your external data connections or local source tables are updated to the latest version of the DFDB.
If you receive the database as a Microsoft Access file ( .accdb ), you can link it directly into Excel without opening Access.
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
Sum the column at the bottom of your sheet to instantly find your total external static pressure (ESP) requirements for fan selection. Best Practices for Maintaining Your Link Step 2: Incorporate Formula The fundamental formula used
The following tools provide the standardized loss coefficient data you need: Cloud-Based Subscription : The most up-to-date version is the ASHRAE Duct Fitting Database , accessible via an annual subscription. Mobile App (DFDB Lite) : A free version available on the Apple App Store
Do not use messy, unaligned cells. Convert your data ranges into official Excel Tables ( Ctrl + T ). Name your data table DuctRunTable . Use explicit columns: Fitting ID (e.g., CR3-1 for a common round elbow) Flow Rate (CFM or L/s) Velocity (FPM or m/s) Geometric Ratios (e.g., Loss Coefficient ( Cocap C sub o Step 3: Implement Dynamic Lookups
Ensure your Excel sheet correctly interprets the pulled data using standard fluid mechanics formulas: