unventilated air layers and adaptive time step

[Sim1]

Hello, I am running an analysis with WUFI Pro 5 for a wall with two brick layers, two unventilated air layers and an external stone cladding. The air layers assumed are the ones with no additional moisture capacity.
Initially I had a high number of convergence failures (and different balance numbers) so I activated the adaptive time step (step: 4 and max stages: 10) and increased the grid from medium to fine. The new simulation shows 0 convergence failures but still different balance numbers. The water content in the three outer layers does not achieve dynamic stability for a 10 years simulation.
Should I use the standard air layers? Any other suggestions?

Many thanks for your help.

[Christian Bludau]

Hello Sim1,
the balances are more important than the convergence failures. But generally spoken in constructions with a high water uptake from rain and if there is liquid water forming for example in the air layer can cause numerical problems.
Try to use the other air layer. Also an other location with less precipitation may help or reducing the time step from for example 1h to 0.1h.
Please alos note, that a differnce in the balances can in many cases be accepted, if the difference is small related to the water uptake of the construction.
Christian

[Sim1]

Thank you Christian, I have tried to replace the air layers with no additional moisture capacity with standard air layers and now there are no convergence failures and the Balance 1 & 2 are equal or very similar. I have kept the adapted time step but reduced the step number to 2.
Thank you for your help!