"Kriechkeller" height - WUFI Plus error

[Thomas_GP]

Dear WUFI Users,

I'm trying to analyse in WUFI Plus the so-called "Kriechkeller". I'm analysing different height of the space, but I noticed, that the smallest spaces like 6 or 10 cm are not starting to calculate. An error "Unrealistic low inner temperature occurred (< 100dC)" has appeared. I see this error in WUFI first time. The simulation starts calculating, when I set the height of "Kriechkeller" about min. 18-19 cm. The space simulates with ventilation through openings and the use of an outside air ventilation module.

The case is slightly far from real Kriechkeller, but I want to see what is happening in low spaces under the floor, and if this is even possible to simulate in WUFI Plus. Can someone explain me, what the calculation doesn't start at low height? Has WUFI Plus any limitation?

Best regards
Thomas