Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Based on the first warning about approach temperature and a search of the source code it appears that this CoolingTower:VariableSpeed specified the "CoolToolsCrossFlow" model type which sets the range for approach at 1.11 - 11.11 C.
Without the full idf to see what else is happening, I would suggest switching to the "YorkCalc" model which sets the approach range to 1.11 - 40.0 C. If that doesn't control well, I would try one of the other cooling tower types, either CoolingTower:SingleSpeed or CoolingTower:TwoSpeed.
