I have a lot of "No Loss Defined" warnings appearing and they are all associated with fittings that do not have an associated loss coefficient from the ASHRAE Table. These are fittings that are can be found in the duct fitting database but Revit is not populating them with the proper fitting designation. Is there a way to fix this?
The most common causes for the "No Loss Defined" warnings are as follows; fittings in certain conditions do not have loss information from an ASHRAE table, have no loss information specified (if loss is set to specified in the family), have no flow (so there is no loss), and Fittings with multiple paths (Tees, Crosses, Wyes), for which Revit does not support Loss Method (so it greys out the parameter).
From the sound of it, I'm guessing the fittings are those with multiple paths. The reason that multiple paths are not supported is that there is no place within Revit to store or manage the mulitple ASHRAE values, so REvit greys out the parameter.
But in the duct systems always use a a tees, crosses and wyes. So it´s not funcional to design and calculate the ducts systems.
Agreed. The duct pressure loss calculations are worthless if they just disregard tees, wyes, crosses, etc.
AutoDesk has known about this issue for years, yet they refuse to do anything about it. I don't understand why they introduce a feature that is like 90% of the way there and then they never finish fixing it.