Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I would take a look at the following post, which provides some general guidance for hydronic loop operation.
Control Strategies for Plant Loops
To accomplish the situation you have described above (in E+), one would use 'PlantEquipmentOperationSchemes' to enable/disable equipment under certain conditions (lockout chiller operation for OA temperatures below 10C in your scenario). I can't speak to DesignBuilder, but OpenStudio 1.8.0 does not expose the E+ operation Scheme 'PlantEquipmentOperation:OutdoorDryBulb' needed to lockout chiller operation based on OA dry bulb.
Once the equipment is enabled, a typical scheduled SetpointManager will establish the temperature setpoints of the active loop (13C in your scenario).
