How to Use the Ashrae Duct Fitting Database for HVAC Design
How to Use the Ashrae Duct Fitting Database for HVAC Design
The Ashrae Duct Fitting Database (DFDB) is a valuable resource for HVAC engineers and designers who need to calculate the pressure loss of duct fittings in various duct systems. The DFDB contains loss coefficient tables for more than 200 types of round, rectangular, and flat oval duct fittings, as well as pictorial outlines of each fitting. The DFDB can be accessed online by annual subscription or downloaded as an app for iOS devices.
In this article, we will explain how to use the DFDB to perform pressure loss calculations for duct fittings in both I-P and SI units. We will also show you how to save and manage your projects, and how to access additional resources from ASHRAE related to duct design.
Ashrae Duct Fitting Databasel
How to Access the DFDB
To access the online version of the DFDB, you need to purchase a one-year subscription from the ASHRAE bookstore. You will receive an email with your login credentials and a link to the DFDB website. Once you log in, you will see the main interface of the DFDB, which consists of four tabs: Input, Output, Calculations, and Table Data.
To access the app version of the DFDB, you need to purchase it from iTunes for $9.99. You can install it on your iPhone, iPod touch, or iPad. Once you open the app, you will see a similar interface as the online version, but with some differences in layout and functionality.
How to Perform Pressure Loss Calculations
To perform pressure loss calculations for duct fittings using the DFDB, you need to follow these steps:
Select the duct function (supply, exhaust, or common) from the drop-down menu.
Select the duct shape (round, rectangular, or flat oval) from the drop-down menu.
Select the fitting type from the list of available fittings. You can use the search box or the filter options to narrow down your choices.
Enter the flow rate and the fitting dimensions in the input fields. You can switch between I-P and SI units by clicking on the toggle button.
Click on the Calculate button to obtain the loss coefficient data and the associated pressure loss for the selected fitting. You can view the results in the output tab, which shows a pictorial outline of the fitting, its name, description, and reference number.
You can also view the calculations tab, which shows the formulas and intermediate values used to calculate the loss coefficient and pressure loss. You can also view the table data tab, which shows the loss coefficient tables for different flow rates and dimensions for each fitting.
How to Save and Manage Projects
You can save your fittings into a project file using the DFDB. This allows you to store and transfer your data easily and efficiently. To save a project, follow these steps:
Click on the Save button at the top right corner of the interface.
Enter a name for your project and click on OK.
Your project will be saved as a .dfdb file in your local drive or device.
To open a project, follow these steps:
Click on the Open button at the top right corner of the interface.
Select a .dfdb file from your local drive or device and click on OK.
Your project will be loaded into the interface and you can view and edit your fittings as needed.
To delete a project, follow these steps:
Click on the Delete button at the top right corner of the interface.
Select a .dfdb file from your local drive or device and click on OK.
Your project will be deleted from your local drive or device.
How to Access Additional Resources
The DFDB is based on ASHRAE Standard 120-2017, which establishes uniform methods of laboratory testing of HVAC ducts and fittings to determine their resistance to airflow. You can purchase this standard from the ASHRAE bookstore or access it online if you are an ASHRAE member.
The DFDB also provides links 0efd9a6b88