Revision history [back]

The choices for tolerance limit and number of warm up days are in the Building object. Initialization convergence warnings typically occur when the HVAC system does something different on successive warm up iterations. For example, if humidity control is used and the reheat coil kicks in every other iteration, or when a HX is used for heat recvoery and the supply air flow rate fluctuates. If the "out-of-tolerance" value is low you can usually move on with the simulation by increasing the tolerance to avoid the warning. If the value is high you might consider doing something different during the warm up period to allow better convergence (e.g., make reheat or the HX unavailable during the warm up days).

Building,
  Building,                !- Name
  30.,                     !- North Axis {deg}
  City,                    !- Terrain
  0.04,                    !- Loads Convergence Tolerance Value
  0.4,                     !- Temperature Convergence Tolerance Value {deltaC}
  FullExterior,            !- Solar Distribution
  25,                      !- Maximum Number of Warmup Days
  6;                       !- Minimum Number of Warmup Days