Lecture 17: VAV and Terminal Reheat Systems Material prepared by GARD Analytics, Inc. and University of Illinois at Urbana-Champaign under contract to the National Renewable Energy Laboratory. All material Copyright U.S.D.O.E. - All rights reserved

2 Purpose of this Lecture  Gain an understanding of how to: Define Air Loops and Zone Equipment input for various types of fan systems  VAV  Terminal Reheat  Review various keywords already covered and show how they interact to form a complete system definition

VAV Systems in EnergyPlus

4 VAV with Reheat and Outside Air Example  Air Loop contains the Mixed Air System, Supply Fan and the Cooling Coil  Outside air system will be discussed later in more detail  Zone Equipment Loop contains the Splitter, VAV Box Air Distribution Unit, the zones, and the Return Air Path with the Mixer.

5 VAV with Reheat Air Loop Air Primary Loop, Typical Terminal Reheat 1, !- Primary Air Loop Name Reheat System 1 Controllers, !- Name: Controller List Reheat System 1 Avail List, !- Name: System Availability Manager List 1.3, !- Primary air design volumetric flow rate {m3/s} Air Loop Branches, !- Air Loop Branch List Name, !- Air Loop Connector List Name Air Loop Inlet Node, !- ReturnAir AirLoop Inlet Node Return Air Mixer Outlet Node, !- ZoneEquipGroup Outlet Node Zone Equipment Inlet Node, !- SupplyAirPath ZoneEquipGroup Inlet Nodes Air Loop Outlet Node; !- AirLoop Outlet Nodes

6 VAV with Reheat Controller and Branch Lists CONTROLLER LIST, Reheat System 1 Controllers, !- Name Controller:Simple, !- Controller Type 1 Main Cooling Coil Controller; !- Controller Name 1 BRANCH LIST, Air Loop Branches, !- Branch List Name Air Loop Main Branch; !- Branch Name 1

7 VAV with Reheat Main Branch BRANCH, Air Loop Main Branch, !- Branch Name 1.3, !- Maximum Branch Flow Rate {m3/s} OUTSIDE AIR SYSTEM, !- Comp1 Type OA Sys 1, !- Comp1 Name Air Loop Inlet Node, !- Comp1 Inlet Node Name Mixed Air Node, !- Comp1 Outlet Node Name PASSIVE, !- Comp1 Branch Control Type FAN:SIMPLE:VariableVolume, !- Comp2 Type Var Vol Supply Fan 1, !- Comp2 Name Mixed Air Node, !- Comp2 Inlet Node Name Cooling Coil Air Inlet Node, !- Comp2 Outlet Node Name ACTIVE, !- Comp2 Branch Control Type

8 VAV with Reheat Main Branch (cont’d) COIL:Water:DetailedFlatCooling, !- Comp3 Type Detailed Cooling Coil, !- Comp3 Name Cooling Coil Air Inlet Node, !- Comp3 Inlet Node Name Air Loop Outlet Node, !- Comp3 Outlet Node Name PASSIVE; !- Comp3 Branch Control Type

9 VAV with Reheat System Availability Manager SYSTEM AVAILABILITY MANAGER LIST, Reheat System 1 Avail List, !- Name SYSTEM AVAILABILITY MANAGER:SCHEDULED, !- System Availability Manager type 1 Reheat System 1 Avail; !- System Availability Manager name 1 SYSTEM AVAILABILITY MANAGER:SCHEDULED, Reheat System 1 Avail, !- Name FanAndCoilAvailSched; !- Schedule name

10 VAV with Reheat Supply Fan FAN:SIMPLE:VariableVolume, Var Vol Supply Fan 1, !- Fan Name CoolingCoilAvailSched, !- Available Schedule 0.7, !- Fan Total Efficiency 600.0, !- Delta Pressure {Pa} 1.3, !- Max Flow Rate {m3/s} 0.20, !- Min Flow Rate {m3/s} 0.9, !- Motor Efficiency 1.0, !- Motor In Airstream Fraction , !- FanCoefficient , !- FanCoefficient , !- FanCoefficient , !- FanCoefficient , !- FanCoefficient 5 Air Loop Inlet Node, !- Fan_Inlet_Node Cooling Coil Air Inlet Node; !- Fan_Outlet_Node

11 VAV with Reheat Cooling Coil COIL:Water:SimpleCooling, Main Cooling Coil 1, !- Coil Name CoolingCoilAvailSched, !- Available Schedule autosize, !- UA of the Coil {W/K} autosize, !- Max Water Flow Rate of Coil {m3/s} 0.9, !- Leaving Relative Humidity of Coil Main Cooling Coil 1 Water Inlet Node, !- Coil_Water_Inlet_Node Main Cooling Coil 1 Water Outlet Node, !- Coil_Water_Outlet_Node Mixed Air Node 1, !- Coil_Air_Inlet_Node Main Cooling Coil 1 Outlet Node; !- Coil_Air_Outlet_Node

12 VAV with Reheat Cooling Coil Controller Controller:Simple, Main Cooling Coil Controller, !- Name TEMP, !- Control variable Reverse, !- Action FLOW, !- Actuator variable Air Loop Outlet Node, !- Control_Node Cooling Coil Water Inlet Node, !- Actuator_Node 0.001, !- Controller Convergence Tolerance: delta temp from setpoint {C} , !- Max Actuated Flow {m3/s} 0.0; !- Min Actuated Flow {m3/s}

13 VAV with Reheat Zone Supply Air Path ZONE SUPPLY AIR PATH, TermReheatSupplyPath, !- Supply Air Path Name Zone Equipment Inlet Node, !- Supply Air Path Inlet Node Zone Splitter, !- KEY--System Component Type Zone Supply Air Splitter; !- Component Name

14 VAV with Reheat Zone Splitter ZONE SPLITTER, Zone Supply Air Splitter, !- Splitter Name Zone Equipment Inlet Node, !- Inlet_Node Zone 1 Inlet Node, !- Outlet_Node_1 Zone 2 Inlet Node, !- Outlet_Node_2 Zone 3 Inlet Node; !- Outlet_Node_3

15 VAV with Reheat Zone Return Air Path ZONE RETURN AIR PATH, TermReheatReturnPath, !- Return Air Path Name Return Air Mixer Outlet, !- Return Air Path Outlet Node Zone Mixer, !- KEY--System Component Type 1 Zone Return Air Mixer; !- Component Name 1

16 VAV with Reheat Zone Mixer ZONE MIXER, Zone Return Air Mixer, !- Mixer Name Return Air Mixer Outlet, !- Outlet_Node Zone 1 Outlet Node, !- Inlet_Node_1 Zone 2 Outlet Node, !- Inlet_Node_2 Zone 3 Outlet Node; !- Inlet_Node_3

17 VAV with Reheat Zone Equip Configuration CONTROLLED ZONE EQUIP CONFIGURATION, RESISTIVE ZONE, !- Zone Name Zone1Equipment, !- List Name: Zone Equipment Zone1Inlets, !- List Name: Zone Inlet Nodes, !- List Name: Zone Exhaust Nodes Zone 1 Node, !- Zone Air Node Name Zone 1 Outlet Node; !- Zone Return Air Node Name

18 VAV with Reheat Zone Equipment List ZONE EQUIPMENT LIST, Zone1Equipment, !- Name AIR DISTRIBUTION UNIT, !- KEY--Zone Equipment Type 1 Zone1TermReheat, !- Type Name 1 1, !- Cooling Priority 1; !- Heating Priority

19 VAV with Reheat Air Distribution Unit AIR DISTRIBUTION UNIT, Zone1TermReheat, !- Air Distribution Unit Name Zone 1 Reheat Air Outlet Node, !- Air Dist Unit Outlet Node Name SINGLE DUCT:VAV:REHEAT, !- KEY--System Component Type 1 Zone 1 VAV System; !- Component Name 1 NODE LIST, Zone1Inlets, !- Node List Name Zone 1 Reheat Air Outlet Node; !- Node_ID_1

20 VAV with Reheat VAV Terminal Unit SINGLE DUCT:VAV:REHEAT, SPACE1-1 VAV Reheat, !- Name of System ReheatCoilAvailSched, !- Availability schedule for VAV System SPACE1-1 Zone Coil Air In Node, !- Damper Outlet Node SPACE1-1 ATU In Node, !- Damper Inlet Node 0.33, !- Maximum air flow rate {m3/s} 0.3, !- Min air flow fraction SPACE1-1 Zone Coil Water In Node, !- Control node COIL:Water:SimpleHeating, !- Reheat Component Object SPACE1-1 Zone Coil, !- Name of Reheat Component , !- Max Reheat Water Flow {m3/s} 0.0, !- Min Reheat Water Flow {m3/s} SPACE1-1 In Node, !- Reheat Air Outlet Node 0.001, !- Convergence Tolerance REVERSE ACTION; !- Damper Heating Action

21 VAV with Reheat Reheat Coil COIL:Water:SimpleHeating, SPACE1-1 Zone Coil, !- Coil Name ReheatCoilAvailSched, !- Available Schedule 300., !- UA of the Coil {W/K} , !- Max Water Flow Rate of Coil {m3/s} SPACE1-1 Zone Coil Water In Node, !- Coil_Water_Inlet_Node SPACE1-1 Zone Coil Water Out Node, !- Coil_Water_Outlet_Node SPACE1-1 Zone Coil Air In Node, !- Coil_Air_Inlet_Node SPACE1-1 In Node; !- Coil_Air_Outlet_Node

Terminal Reheat Systems in EnergyPlus

23 TermReheat Controller and Branch Lists CONTROLLER LIST, Reheat System 1 Controllers, !- Name Controller:Simple, !- Controller Type 1 Main Cooling Coil Controller; !- Controller Name 1 BRANCH LIST, Air Loop Branches, !- Branch List Name Air Loop Main Branch; !- Branch Name 1

24 TermReheat Main Branch BRANCH, Air Loop Main Branch, !- Branch Name 1.3, !- Maximum Branch Flow Rate {m3/s} FAN:SIMPLE:VariableVolume, !- Comp1 Type Var Vol Supply Fan 1, !- Comp1 Name Air Loop Inlet Node, !- Comp1 Inlet Node Name Cooling Coil Air Inlet Node, !- Comp1 Outlet Node Name ACTIVE, !- Comp1 Branch Control Type COIL:Water:DetailedFlatCooling, !- Comp2 Type Detailed Cooling Coil, !- Comp2 Name Cooling Coil Air Inlet Node, !- Comp2 Inlet Node Name Air Loop Outlet Node, !- Comp2 Outlet Node Name PASSIVE; !- Comp2 Branch Control Type

25 TermReheat System Availability Manager SYSTEM AVAILABILITY MANAGER LIST, Reheat System 1 Avail List, !- Name SYSTEM AVAILABILITY MANAGER:SCHEDULED, !- System Availability Manager type 1 Reheat System 1 Avail; !- System Availability Manager name 1 SYSTEM AVAILABILITY MANAGER:SCHEDULED, Reheat System 1 Avail, !- Name FanAndCoilAvailSched; !- Schedule name

26 TermReheat Supply Fan FAN:SIMPLE:ConstVolume, Supply Fan 1, !- Fan Name FanAndCoilAvailSched, !- Available Schedule 0.7, !- Fan Total Efficiency 600.0, !- Delta Pressure {Pa} 1.3, !- Max Flow Rate {m3/s} 0.9, !- Motor Efficiency 1.0, !- Motor In Airstream Fraction Air Loop Inlet Node, !- Fan_Inlet_Node Cooling Coil Air Inlet Node; !- Fan_Outlet_Node

27 TermReheat Cooling Coil COIL:Water:SimpleCooling, Main Cooling Coil 1, !- Coil Name CoolingCoilAvailSched, !- Available Schedule autosize, !- UA of the Coil {W/K} autosize, !- Max Water Flow Rate of Coil {m3/s} 0.9, !- Leaving Relative Humidity of Coil Main Cooling Coil 1 Water Inlet Node, !- Coil_Water_Inlet_Node Main Cooling Coil 1 Water Outlet Node, !- Coil_Water_Outlet_Node Mixed Air Node 1, !- Coil_Air_Inlet_Node Main Cooling Coil 1 Outlet Node; !- Coil_Air_Outlet_Node

28 TermReheat Cooling Coil Controller Controller:Simple, Main Cooling Coil Controller, !- Name TEMP, !- Control variable Reverse, !- Action FLOW, !- Actuator variable Air Loop Outlet Node, !- Control_Node Cooling Coil Water Inlet Node, !- Actuator_Node 0.001, !- Controller Convergence Tolerance: delta temp from setpoint {C} , !- Max Actuated Flow {m3/s} 0.0; !- Min Actuated Flow {m3/s}

29 TermReheat Zone Thermostat ZONE CONTROL:THERMOSTATIC, Zone 1 Thermostat, !- Thermostat Name RESISTIVE ZONE, !- Zone Name Zone Control Type Sched, !- Control Type SCHEDULE Name SINGLE HEATING SETPOINT, !- Control Type #1 Heating Setpoint with SB, !- Control Type Name #1 SINGLE COOLING SETPOINT, !- Control Type #2 Cooling Setpoint with SB; !- Control Type Name #2

30 TermReheat Thermostat Setpoints SINGLE HEATING SETPOINT, Heating Setpoint with SB, !- Name Heating Setpoints; !- Setpoint Temperature SCHEDULE Name SINGLE COOLING SETPOINT, Cooling Setpoint with SB, !- Name Cooling Setpoints; !- Setpoint Temperature SCHEDULE Name

31 TermReheat Zone Supply Air Path ZONE SUPPLY AIR PATH, TermReheatSupplyPath, !- Supply Air Path Name Zone Equipment Inlet Node, !- Supply Air Path Inlet Node Zone Splitter, !- KEY--System Component Type Zone Supply Air Splitter; !- Component Name

32 TermReheat Zone Return Air Path ZONE RETURN AIR PATH, TermReheatReturnPath, !- Return Air Path Name Return Air Mixer Outlet, !- Return Air Path Outlet Node Zone Mixer, !- KEY--System Component Type 1 Zone Return Air Mixer; !- Component Name 1

33 TermReheat Zone Splitter ZONE SPLITTER, Zone Supply Air Splitter, !- Splitter Name Zone Equipment Inlet Node, !- Inlet_Node Zone 1 Inlet Node, !- Outlet_Node_1 Zone 2 Inlet Node, !- Outlet_Node_2 Zone 3 Inlet Node; !- Outlet_Node_3

34 TermReheat Zone Mixer ZONE MIXER, Zone Return Air Mixer, !- Mixer Name Return Air Mixer Outlet, !- Outlet_Node Zone 1 Outlet Node, !- Inlet_Node_1 Zone 2 Outlet Node, !- Inlet_Node_2 Zone 3 Outlet Node; !- Inlet_Node_3

35 TermReheat Zone Equip Configuration CONTROLLED ZONE EQUIP CONFIGURATION, RESISTIVE ZONE, !- Zone Name Zone1Equipment, !- List Name: Zone Equipment Zone1Inlets, !- List Name: Zone Inlet Nodes, !- List Name: Zone Exhaust Nodes Zone 1 Node, !- Zone Air Node Name Zone 1 Outlet Node; !- Zone Return Air Node Name

36 TermReheat Zone Equipment List ZONE EQUIPMENT LIST, Zone1Equipment, !- Name AIR DISTRIBUTION UNIT, !- KEY--Zone Equipment Type 1 Zone1TermReheat, !- Type Name 1 1, !- Cooling Priority 1; !- Heating Priority

37 TermReheat Air Distribution Unit AIR DISTRIBUTION UNIT, Zone1TermReheat, !- Air Distribution Unit Name Zone 1 Reheat Air Outlet Node, !- Air Dist Unit Outlet Node Name SINGLE DUCT:VAV:REHEAT, !- KEY--System Component Type 1 Zone 1 VAV System; !- Component Name 1 NODE LIST, Zone1Inlets, !- Node List Name Zone 1 Reheat Air Outlet Node; !- Node_ID_1

38 TermReheat VAV Terminal Unit SINGLE DUCT:VAV:REHEAT, SPACE1-1 VAV Reheat, !- Name of System ReheatCoilAvailSched, !- Availability schedule for VAV System SPACE1-1 Zone Coil Air In Node, !- Damper Outlet Node SPACE1-1 ATU In Node, !- Damper Inlet Node 0.33, !- Maximum air flow rate {m3/s} 0.3, !- Min air flow fraction SPACE1-1 Zone Coil Water In Node, !- Control node COIL:Water:SimpleHeating, !- Reheat Component Object SPACE1-1 Zone Coil, !- Name of Reheat Component , !- Max Reheat Water Flow {m3/s} 0.0, !- Min Reheat Water Flow {m3/s} SPACE1-1 In Node, !- Reheat Air Outlet Node 0.001, !- Convergence Tolerance REVERSE ACTION; !- Damper Heating Action

39 TermReheat Reheat Coil COIL:Water:SimpleHeating, SPACE1-1 Zone Coil, !- Coil Name ReheatCoilAvailSched, !- Available Schedule 300., !- UA of the Coil {W/K} , !- Max Water Flow Rate of Coil {m3/s} SPACE1-1 Zone Coil Water In Node, !- Coil_Water_Inlet_Node SPACE1-1 Zone Coil Water Out Node, !- Coil_Water_Outlet_Node SPACE1-1 Zone Coil Air In Node, !- Coil_Air_Inlet_Node SPACE1-1 In Node; !- Coil_Air_Outlet_Node

40 Summary  This lecture highlighted the EnergyPlus input necessary to define most VAV and Terminal Reheat systems Air loop and zone equipment input Thermostat input Fan and coil component input Controller input