Harvesting heat from the sun is serious business in a Passive House, so the shading analysis must be accurate. The author relies on a Solar Pathfinder to determine shading conditions for the building site.
Using the Solar Pathfinder—an important tool in determining shading on sites that have complex shading conditions.
This WUFI-ORNL graph suggests that the total water content of an unvented roof assembly could rise if indoor conditions are similar to the base condition that WUFI-ORNL uses in its analysis.
Adding 1 ACH in a back-venting plane would give the roof assembly excellent drying potential. Actual venting will vary widely based on roof slope and wind speeds, so this analysis is used only to demonstrate basic hygrothermal principles, not to predict exactly how the roof will perform.