AirLoopHVAC:DedicatedOutdoorAirSystem vector issue in sizing

[mjwitte]

Issue overview

User file fails here in debug:

EnergyPlus/src/EnergyPlus/Autosizing/SystemAirFlowSizing.cc

Lines 779 to 782 in ec7398a

	} else {
	auto &sysSizPeakDDNum = state.dataSize->SysSizPeakDDNum(this->curSysNum);
	if (this->airLoopSysFlag) {

this->curSysNum = 2, but state.dataSize->SysSizPeakDDNum size is only 1.

Seems related to the fixes in #10334 ?

Here's the call stack.

Details

Some additional details for this issue (if relevant):

• Platform (Operating system, version)
• Version of EnergyPlus 25.1-ec7398a
• Helpdesk ticket number 16791.

Checklist

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

• Defect file added EnergyPlusDevSupport\DefectFiles
• Ticket added to EnergyPlus Defect Complexity (Github Project)
• Pull request created (the pull request will have additional tasks related to reviewing changes that fix this defect)

[rraustad]

When CurSysNum > NumPrimaryAirSys, this indicates a DOAS system. From AirloopHVACDOAS:

state.dataSize->CurSysNum = state.dataHVACGlobal->NumPrimaryAirSys + this->m_AirLoopDOASNum + 1;
state.dataSize->CurOASysNum = this->m_OASystemNum;

SystemAirFlowSizing is called for the fans. This defect file has fans in the DOAS.

AirLoopHVAC:OutdoorAirSystem:EquipmentList,
  DOAS loop Outdoor air Equipment List,  !- Name
  Fan:SystemModel,         !- Component 1 Object Type
  DOAS loop DOAS AHU Supply Fan,  !- Component 1 Name
  Fan:SystemModel,         !- Component 2 Object Type
  DOAS loop DOAS AHU Extract Fan;  !- Component 2 Name

I don't see any checks for DOAS in this part of the SystemAirFlow sizing module, such as directly above in the heat recovery block or this from HeatingAirFlowSizing:

} else if (outsideAirSys(this->curOASysNum).AirLoopDOASNum > -1) {
    this->autoSizedValue =
        this->airloopDOAS[outsideAirSys(this->curOASysNum).AirLoopDOASNum].SizingMassFlow / state.dataEnvrn->StdRhoAir;