Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Julien, I'm sure you've solved the problem by now, but the best results I've been able to get come with using a combination of Operation Schemes, EMS to actuate the schemes via their control scheme schedules and ensuring that the HX control type is set to OperationSchemeModulated or OperationSchemeOnOff. Each chiller and HX should be on its own branch. It doesn't seem to matter where the HX is in the branch order.
A subsequent issue with this strategy is that the chiller operation stops responding to a sequential loop load distribution scheme (I haven't tested optimum), and just runs the current plant equipment list uniformly. To get back to sequential, I manually set up the applicable load ranges within PlantEquipmentOperation:CoolingLoad. So in your case you would end up with three separate plant equipment lists.
I'm not sure if this is possible in OS, as I set this up by directly creating the IDF. Sorry!
