So what type of family are the ones they already have in that data base? if it is something that acts as a diffuser, it would be an air terminal family.
I suspect that data base needs some sort of loadable family. That would be duct fitting, air terminal or duct duct accessory family. " ducts" themselves are not loadable, those are system families. system families only can be transferred from one project to another. those don't have an rfa-file you could save separately.
How is that family yo create to be different from a standard duct? i assume if you create something for designers, it is something that isn't already easily usable from oob Revit.
Revit Version: R2026.4.2
Hardware: i9 14900K, 64GB, Nvidia RTX 2000 Ada 16GB
Add-ins: ElumTools; Ripple-HVAC; ElectroBIM; Qbitec