Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
There is indeed a "None" ducts option, which you can see here. This file defines the full set of options available.
That said, you're probably confused as to why the None ducts option is not used in the housing characteristics probability distribution you're looking at. This is because the duct option specified (say, "10% Leakage, Uninsulated") is simply not used in the model when a building has non-ducted HVAC systems (boilers, electric resistance, etc). In the case of mini-splits, we also currently designate them as non-ducted HVAC systems, so it doesn't matter whether you specify the duct system as "None" or "10% Leakage, Uninsulated".
