The current standard for accessing the ASHRAE Duct Fitting Database is through an or a mobile application. Official Access Methods
This is a more comprehensive mobile version that includes over 240 fittings and is based on the full web application. Historical and Third-Party Downloads Download ASHRAE Duct Fitting Database rar
While "RAR" files of the are often searched for on third-party sites, the official software is no longer distributed as a standalone downloadable archive like a RAR or ZIP for general purchase. The current standard for accessing the ASHRAE Duct
A free version called Duct Fitting Database Lite is available for iPhone and iPad . It allows for quick pressure loss calculations in the field for a subset of common fittings. A free version called Duct Fitting Database Lite
The full version of the database is available via the ASHRAE Bookstore . It provides cloud-based access to loss coefficient tables for over 200 fittings and allows you to save work in project files.
Sites like HVAC Simplified or various Facebook engineering groups sometimes host direct download links to Google Drive folders containing older installer files.
You may encounter older versions (like ) on engineering forums or third-party file-sharing sites. Software Informer: Lists version 2.2 as a legacy reference.