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This is a little confusing. You say that the condenser loop is always active. This means that the supply side (the air into the zone) is also always active. So if the VRF is not meeting the load then there must not be sufficient capacity to meet that load (ot the VRF does not know the load). It doesn't matter how much flow is in the condenser loop, that would just impact delta T on the water side, the sysytem would still be operational.

In your model you have a VRF system with a DOAS to each zone. I just checked and the VRF model does not account for the impact of other zone equipment on the operation of the VRF system (for developers: VRF uses OutputRequiredToCoolingSP instead of SequencedOutputRequiredToCoolingSP). What this means is that the VRF model does not know that the DOAS system has added additional load to the zone and therefore can't meet that load "in addition to" the zone load. This was a mistake in programming (if I have assessed this correctly). If you remove the DOAS does the VRF system operate as expected?

ZoneHVAC:EquipmentList, Thermal Zone: L1 C - Circulation Equipment List, !- Name SequentialLoad, !- Load Distribution Scheme ZoneHVAC:TerminalUnit:VariableRefrigerantFlow, !- Zone Equipment 1 Object Type VRF Zone Terminal 4, !- Zone Equipment 1 Name 1, !- Zone Equipment 1 Cooling Sequence 1, !- Zone Equipment 1 Heating or No-Load Sequence ZoneHVAC:AirDistributionUnit, !- Zone Equipment 2 Object Type ADU VAV No Rht, !- Zone Equipment 2 Name 2, !- Zone Equipment 2 Cooling Sequence 2; !- Zone Equipment 2 Heating or No-Load Sequence

This is a little confusing. You say that the condenser loop is always active. This means that the supply side (the air into the zone) is also always active. So if the VRF is not meeting the load then there must not be sufficient capacity to meet that load (ot the VRF does not know the load). It doesn't matter how much flow is in the condenser loop, that would just impact delta T on the water side, the sysytem would still be operational.

In your model you have a VRF system with a DOAS to each zone. I just checked and the VRF model does not account for the impact of other zone equipment on the operation of the VRF system (for developers: VRF uses OutputRequiredToCoolingSP instead of SequencedOutputRequiredToCoolingSP). What this means is that the VRF model does not know that the DOAS system has added additional load to the zone and therefore can't meet that load "in addition to" the zone load. This was a mistake in programming (if I have assessed this correctly). If you remove the DOAS does the VRF system operate as expected?

ZoneHVAC:EquipmentList, Thermal Zone: L1 C - Circulation Equipment List, !- Name SequentialLoad, !- Load Distribution Scheme ZoneHVAC:TerminalUnit:VariableRefrigerantFlow, !- Zone Equipment 1 Object Type VRF Zone Terminal 4, !- Zone Equipment 1 Name 1, !- Zone Equipment 1 Cooling Sequence 1, !- Zone Equipment 1 Heating or No-Load Sequence ZoneHVAC:AirDistributionUnit, !- Zone Equipment 2 Object Type ADU VAV No Rht, !- Zone Equipment 2 Name 2, !- Zone Equipment 2 Cooling Sequence 2; !- Zone Equipment 2 Heating or No-Load Sequence

This is a little confusing. You say that the condenser loop is always active. This means that the supply side (the air into the zone) is also always active. So if the VRF is not meeting the load then there must not be sufficient capacity to meet that load (ot the VRF does not know the load). It doesn't matter how much flow is in the condenser loop, that would just impact delta T on the water side, the sysytem would still be operational.

In your model you have a VRF system with a DOAS to each zone. I just checked and the VRF model does not account for the impact of other zone equipment on the operation of the VRF system (for developers: VRF uses OutputRequiredToCoolingSP instead of SequencedOutputRequiredToCoolingSP). What this means is that the VRF model does not know that the DOAS system has added additional load to the zone and therefore can't meet that load "in addition to" the zone load. This was a mistake in programming (if I have assessed this correctly). If you remove the DOAS does the VRF system operate as expected?

 ZoneHVAC:EquipmentList,
   Thermal Zone: L1 C - Circulation Equipment List,  !- Name
   SequentialLoad,          !- Load Distribution Scheme
   ZoneHVAC:TerminalUnit:VariableRefrigerantFlow,  !- Zone Equipment 1 Object Type
   VRF Zone Terminal 4,     !- Zone Equipment 1 Name
   1,                       !- Zone Equipment 1 Cooling Sequence
   1,                       !- Zone Equipment 1 Heating or No-Load Sequence
   ZoneHVAC:AirDistributionUnit,  !- Zone Equipment 2 Object Type
   ADU VAV No Rht,          !- Zone Equipment 2 Name
   2,                       !- Zone Equipment 2 Cooling Sequence
   2;                       !- Zone Equipment 2 Heating or No-Load Sequence

This is a little confusing. You say that the condenser loop is always active. This means that the supply side (the air into the zone) is also always active. So if the VRF is not meeting the load then there must not be sufficient capacity to meet that load (ot (or the VRF does not know the load). It doesn't matter how much flow is in the condenser loop, that would just impact delta T on the water side, the sysytem system would still be operational.

In your model you have a VRF system with a DOAS to each zone. I just checked and the VRF model does not account for the impact of other zone equipment on the operation of the VRF system (for developers: VRF uses OutputRequiredToCoolingSP instead of SequencedOutputRequiredToCoolingSP). What this means is that the VRF model does not know that the DOAS system has added additional load to the zone and therefore can't meet that load "in addition to" the zone load. This was a mistake in programming (if I have assessed this correctly). If you remove the DOAS does the VRF system operate as expected?

ZoneHVAC:EquipmentList,
  Thermal Zone: L1 C - Circulation Equipment List,  !- Name
  SequentialLoad,          !- Load Distribution Scheme
  ZoneHVAC:TerminalUnit:VariableRefrigerantFlow,  !- Zone Equipment 1 Object Type
  VRF Zone Terminal 4,     !- Zone Equipment 1 Name
  1,                       !- Zone Equipment 1 Cooling Sequence
  1,                       !- Zone Equipment 1 Heating or No-Load Sequence
  ZoneHVAC:AirDistributionUnit,  !- Zone Equipment 2 Object Type
  ADU VAV No Rht,          !- Zone Equipment 2 Name
  2,                       !- Zone Equipment 2 Cooling Sequence
  2;                       !- Zone Equipment 2 Heating or No-Load Sequence