Revision history [back]

I do see a set point manager at the outlet of the HX. However, I do not see a set point at the AirLoopDOASSplitterInlet node.

SetpointManager:MixedAir,
  HEX-1-1 Heat Recovery Air Temp Manager,  !- Name
  Temperature,             !- Control Variable
  AirLoopDOASSplitterInlet,!- Reference Setpoint Node Name
  OA Supply Fan Inlet,     !- Fan Inlet Node Name
  AirLoopDOASSplitterInlet,!- Fan Outlet Node Name
  HEX Supply Air Outlet;   !- Setpoint Node or NodeList Name

Adding this set point manager did not correct the problem in V9.6.

SetpointManager:Scheduled,
  OA Air Temp Manager 20,   !- Name
  Temperature,             !- Control Variable
  OA Cooling Supply Air Temp Sch,  !- Schedule Name
  AirLoopDOASSplitterInlet;     !- Setpoint Node or NodeList Name

I updated this file to V22.2 and there is some other problem in the file that I have narrowed down to the DOAS air loop but not quite sure what the problem is.
The error (in the debugger) is ** Severe ** invalid vector subscript. This error is related to a bug where a HX in the DOAS air loop cannot autosize properly.

I corrected that problem and the simulation did run and now shows these errors with the set point managers.

** Warning ** SetpointManager:Scheduled="OA AIR TEMP MANAGER 1"
**   ~~~   ** ...setpoint node conflicts with another setpoint manager.
**   ~~~   ** ...conflicting setpoint manager = SetpointManager:MixedAir:"HEX-1-1 HEAT RECOVERY ECONOMIZER TEMP MANAGER"
**   ~~~   ** ...conflicting node name = OA SUPPLY FAN INLET
**   ~~~   ** ...control type variable = Temperature
** Severe  ** CalcMixedAirSetPoint: Missing reference temperature setpoint for Mixed Air Setpoint Manager HEX-1-1 HEAT RECOVERY AIR TEMP MANAGER
**   ~~~   ** Node Referenced =AIRLOOPDOASSPLITTERINLET
**   ~~~   **   use an additional Setpoint Manager with Control Variable = "Temperature" to establish a setpoint at this node.
** Severe  ** CalcMixedAirSetPoint: Missing reference temperature setpoint for Mixed Air Setpoint Manager HEX-1-1 HEAT RECOVERY ECONOMIZER TEMP MANAGER
**   ~~~   ** Node Referenced =AIRLOOPDOASSPLITTERINLET
**   ~~~   **   use an additional Setpoint Manager with Control Variable = "Temperature" to establish a setpoint at this node.
**  Fatal  ** Previous severe set point errors cause program termination

I added back in the set point manager for the AirLoopDOASSplitterInlet node (the SPM above) and the simulation runs successfully. I am not quite sure why adding this set point manager in V22.2 worked while trying this same correction in V9.6 did not. I do believe there is a problem with autosizing the HX in V9.6 and you will have difficulty getting this configuration to run in V9.6. I would suggest removing the HX from the DOAS air loop until this can be corrected.