E+ Fatal error: Convergence error in SolveForWindowTemperatures
Having adjusted the Relative Airflow and Absolute Airflow convergence tolerances, as well as the Maximum Number of Iterations under AirflowNetwork:SimulationControl, which solved an earlier fatal error (Error: Too many iterations in Airflow Network simulation), I have encountered the fatal error below and have run out of ideas for resolving it. A google search turned up a similar problem with E+ v7 over on the Design Builder Forum but without a solution.
The Airflow Network I am attempting to simulate includes several large window openings which I understand can cause errors due to the high airflow transfer between zones. Reducing the aperture sizes is an obvious solution, however, high airflow/transfer rates is a desired quality of this test simulation so I would prefer to retain the large window openings.
(Using e+ v8.3.0 x64) Thank you in advance
From the *.err file:
** Severe ** Convergence error in SolveForWindowTemperatures for window ZONE_1_WINDOW_005MM
** ~~~ ** During Warmup, Environment=RUN PERIOD 1, at Simulation time=09/29 08:30 - 08:32
** ~~~ ** Glazing face index = 1 ; new temperature =NANC ; previous temperature = 9.4479C
** ~~~ ** Glazing face index = 2 ; new temperature =NANC ; previous temperature = 13.9687C
** Fatal ** Program halted because of convergence error in SolveForWindowTemperatures for window ZONE_1_WINDOW_005MM
...Summary of Errors that led to program termination:
..... Reference severe error count=1
..... Last severe error=Convergence error in SolveForWindowTemperatures for window ZONE 1 WINDOW 005MM
The error is related to the calculation of conduction through the window panes. The problem could be related to the calculated zone temperature with the airflow network. Does the problem go away if you disable the airflow network? (This will help diagnose where the problem is, we can turn it back on after we've identified the root issue.)