Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Plant loop control is generally handled by two categories of input objects in EnergyPlus and OpenStudio. Time of operation and component sequencing is handled by PlantEquipmentOperationScheme objects, while the actual plant supply temperature is dictated by setpoint managers. OpenStudio supports most of the setpoint managers that EnergyPlus offers including OA reset based SPM, scheduled setpoint, dual (hi / low) scheduled setpoint, follow OA temp, and several more. OpenStudio does not yet give you complete control over all of the available types of plant operation schemes, including one or two that would allow you to completely disable certain components under certain conditions or time of year. Those additional operation schemes will come in OpenStudio 1.9 this fall. For now OpenStudio generates heating and cooling load operation schemes for you depending on the type of component you have on the plant. Chillers and other cooling equipment will be put on a PlantEquipmentOperation:CoolingLoad, and boilers et al will go on the similar heating load object. In this scheme the components will available for all load ranges for all hours of the simulation. In OpenStudio if you place setpoint managers directly after the plant components, as opposed to only on the supply outlet node, OpenStudio will generate a component setpoint operation scheme like @aparker described here. Again you will have much more control over these operation schemes when 1.9 rolls out.
Another option is EMS. Sometimes the setpoint managers and operation schemes are not enough to get you exactly what you need. In that case you can write EMS logic to do just about anything you can dream up. In OpenStudio you would inject EMS code into you idf file using an EnergyPlus Measure.
This is a pretty short reply for such a large topic. Hopefully the links are enough to point you in the right direction, and perhaps others will reply with more information. If you post a narrative of a particular control scheme that you are trying to model, I think we can provide better guidance.
