Nominal Capacity Reporting for Plant Heat Exchanger is Suspect

[EnergyArchmage]

Issue overview

The nominal capacity reported for the fluid to fluid HX appears to be too low. In the defect file, the predefined tablular report shows 600kW, yet during the simulation the device routinely runs at around 1,800kW. Need to check that the capacity calculation method is using the correct node inlet temperatures before calling calc routine.

Details

Some additional details for this issue (if relevant):

• Platform (Operating system, version)
• Version of EnergyPlus (8.5)
• helpdesk ticket number 11408,

  Checklist

Add to this list or remove from it as applicable. This is a simple templated set of guidelines.

• [x] Defect file added (https://github.com/NREL/EnergyPlusDevSupport/tree/master/DefectFiles/5000s/5775) Vienna Austria IWEC weather file
• [ ] Ticket added to Pivotal for defect (development team task)
• [ ] Pull request created (the pull request will have additional tasks related to reviewing changes that fix this defect)

[drewyh]

Hi @EnergyArchmage I can't see the defect file, but this may be caused by DualDeadbandSetpoints on one or both of the loops connected to the HX. If this is the case and there are no Sizing:Plant objects for the loops it uses the average of the hi/lo setpoints to determine capacity, which may explain it?