Modeling split and fan coil

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From the figure, it appears to show a split-system configured in an air loop, and a fan coil used as zone equipment. For those interested in the equipment simulation order, in EnergyPlus, air loop equipment are always simulated first. Zone equipment are simulated next and picks up (or adds to) the remaining zone load, if any. The zone equipment also has a priority based on the entry in the ZoneHVAC:EquipmentList object. Only a single zone equipment is listed in this example, however, multiple zone equipment objects can be listed and given operational priority as needed.

ZoneHVAC:EquipmentConnections,
  EAST ZONE,               !- Zone Name
  Zone2Equipment,          !- Zone Conditioning Equipment List Name
  Zone2Inlets,             !- Zone Air Inlet Node or NodeList Name
  Zone2Exhausts,           !- Zone Air Exhaust Node or NodeList Name
  Zone 2 Node,             !- Zone Air Node Name
  Zone 2 Outlet Node;      !- Zone Return Air Node Name

ZoneHVAC:EquipmentList,
  Zone2Equipment,          !- Name
  ZoneHVAC:FourPipeFanCoil,!- Zone Equipment 1 Object Type
  Zone2FanCoil,            !- Zone Equipment 1 Name
  1,                       !- Zone Equipment 1 Cooling Sequence
  1;                       !- Zone Equipment 1 Heating or No-Load Sequence

Regarding the operation of each of these equipment, the availability schedule can be used to turn the systems on and off using a schedule. For air loop equipment, availability schedules can be applied at the air loop, system, coil, or fan level.

AirLoopHVAC,
  Typical Furnace 1,       !- Name
  ,                        !- Controller List Name
  Furnace 1 Avail List,    !- Availability Manager List Name

AirLoopHVAC:Unitary:Furnace:HeatCool,
  GasHeat DXAC Furnace 1,  !- Name
  FanAndCoilAvailSched,    !- Availability Schedule Name

Coil:Cooling:DX:SingleSpeed,
  Furnace ACDXCoil 1,      !- Name
  FanAndCoilAvailSched,    !- Availability Schedule Name

Fan:OnOff,
  Supply Fan 1,            !- Name
  FanAndCoilAvailSched,    !- Availability Schedule Name

Similar for zone equipment, a system, coil, or fan level availability schedule may be used.

ZoneHVAC:FourPipeFanCoil,
  Zone1FanCoil,            !- Name
  FanAndCoilAvailSched,    !- Availability Schedule Name
  Fan Coil Availability Manager; !- Availability Manager List Name

Coil:Cooling:Water,
  Zone1FanCoilCoolingCoil, !- Name
  FanAndCoilAvailSched,    !- Availability Schedule Name

Fan:ConstantVolume,
  Zone1FanCoilFan,         !- Name
  FanAndCoilAvailSched,    !- Availability Schedule Name

Typically, systems and coils are scheduled on all the time and the fans are scheduled to be available as needed. This way, the night cycle availability managers can override the fan schedules and turn on system to condition the building at night as needed.

Noting the outdoor air in the figure, the fan can either be available all the time, or can be scheduled off at night and enabled (overridden) using the night cycle air loop availability manager (AvailabilityManager:NightCycle).

AirLoopHVAC,
  VAV Sys 1,                 !- Name
  VAV Sys 1 Controllers,     !- Controller List Name
  VAV Sys 1 Avail List,      !- Availability Manager List Name

AvailabilityManagerAssignmentList,
  VAV Sys 1 Avail List,      !- Name
  AvailabilityManager:NightCycle,  !- Availability Manager 1 Object Type
  VAV Sys 1 Avail;           !- Availability Manager 1 Name

AvailabilityManager:NightCycle,
  VAV Sys 1 Avail,           !- Name
  SysAvailApplicSch,         !- Applicability Schedule Name
  FanAvailSched,             !- Fan Schedule Name
  CycleOnAny,                !- Control Type
  1,                         !- Thermostat Tolerance {deltaC}
  7200.;                     !- Cycling Run Time {s}

To operate one equipment (e.g., air loop) at different times than another (e.g., zone equipment), the schedules for the air loop and fan coil should use opposing values where a 1 (on) is used in one case ... (more)