Autosizing

Simergy's approach to autosizing is the same that is used by EnergyPlus and described in detail in the EnergyPlus Input Output Reference Guide.

Required Inputs for Component Autosizing

The table identifies requirements to successfully do component autosizing (left column) and the location within the Simergy Interface where they are located (right column).

Requirements	Location in Simergy
Input file should contain a Simulation Control object	Template/Simulation Parameters references a SimSimulationParameters/SimulationControl/Default object. This template is assigned in the simulation workspace to a simulation configuration.
At least two SizingPeriod objects need to be included	Design Alternatives/Select Design Alternatives -The weather download service automatically downloads all 18 design days and imports them when they are available Tip: Location names without design days are indicated in italics in the Design Alternative workspace. Note: in order to adjust the design days or define new ones, go to the library or template workspace and switch to the Project Model.
Sizing: Parameters object included if applying global sizing	Template/System Parameters - the Global Sizing object is located in the Input Values table.
A Sizing:Zone object for each controlled zone that is unique	Systems/ZoneHVACGroups/Create/Edit workspace - A Sizing Object can be assigned to the system via the Sizing Property
A Sizing: System object for each HVAC Air Loop	Systems/Air Loops/Create/Edit workspace - A Sizing Object can be assigned to the system via the Sizing Property
A Sizing: Plant object for each Plant or Condenser Loop	Systems/Water Loops/Create/Edit workspace - A Sizing Object can be assigned to the system via the Sizing Property
A ZoneControl:Thermostat for each conditioned zone (even slave zones) must be included to be recognized as a 'conditioned zone' and included in the simulation	Template/Zone Conditions Template
Confirm that Summer Design Day and Winter Design Day Schedules are included	Design Alternatives/Select Design Alternatives - The 1 % Cooling (Winter Design Day) and 99% Heating (Summer Design Day) days are assigned to the Location Template by default. Note: In order to adjust The Summer and Winter Design days or to define new ones, the user can go to the Library or Template workspace and switch to the Project Model.
User must coordinate sizing inputs with actual simulation control inputs	Simergy automatically sets the Simulation Control Sizing to account for the Sizing Object that are assigned to the Loops. For example - If an air loop has a sizing object assigned, the "Do System Sizing Calculation" is automatically set to YES.

Note: Sizing:System and Sizing:Zone objects determine the supply temperatures for central heating and cooling loads. Other components such as heat recovery, fans, pumps and dehumidifiers are not factored into the sizing calculation.

Component Autosizing

Within the EnergyPlus Input Output Reference Guide Table 22 - Details of Autosizable Objects/Fields displays a large two column table that identifies the Component/Object and then the Autosizable Fields (Properties) that are associated with the component. A number of the library entries within the Libraries Categories for the content that is packaged with Simergy have these properties set to "Autosize", however it is important to always check. If a field/property can be "autosized", it will have "autosize" available from the drop down list.

Sizing Factors

The table shows the different places within Simergy where you can define sizing parameters.

Tip: At a basic level you can set sizing factors overall, at the Zone Group level, and at the individual component level for certain components. The thing to remember is that if you define a sizing factor at the Zone Group level it will override the global sizing factor.

Simergy Information	EnergyPlus Objects + Description
Libraries > Sizing Params Type = HvacDesign Sub Type = Sizing Related Template = Simulation Parameters	IDF = Sizing:Parameters You can specify an overall sizing factor, which will be applied to all the Zone Design Loads and Air Flow rates resulting from the zone sizing calculations.
Libraries > Sizing Params Type = HvacDesign Sub Type = ZoneSizing Related Template = Zone Conditions	IDF = Sizing:Zone You can specify a sizing factor for a specific Zone Group, which is applied to the calculated zone design loads and air flow rates. This sizing factor overrides the sizing factor described above.
Libraries > Plant Eqmt Type = Boiler, Chiller, ChillerHeater, and Cooling Tower Sub Type = <all associated with Types> Related Template = Water Loops	Boiler = Boiler:HotWater Boiler= Boiler:Steam Chiller = Chiller:Electric:EIR Chiller = Chiller:Electric:ReformulatedEIR Chiller= Chiller:Electric Chiller= Chiller:ConstantCOP Chiller= Chiller:EngineDriven Chiller= Chiller:CombustionTurbine Chiller= Chiller:AbsorptionIndirect Chiller= Chiller:Absorption Chiller= ChillerHeater:Absorption:DoubleEffect ChillerHeater= ChillerHeater:Absorption:DirectFired CoolingTower = CoolingTower:SingleSpeed CoolingTower = CoolingTower:TwoSpeed CoolingTower = CoolingTower:VariableSpeed You can specify a sizing factor that modifies the autosized component capacity and flow rates, which is applied after the global and zone group sizing factors. They are used to split the design load between multiple components, and they can change the autosizing of the associated loops and pumps. Rules for how sizing factors of plant components effect loops and pumps: Supply side branches - the sizing factors of all components in series on the branch are summed and the result becomes the branch sizing factor. If there is a branch pump its autosized design flow rate is multiplied by the branch sizing factor. Loop - if the average of the branch sizing factors is less than 1, the loop sizing factor is set equal to the sum of he branch sizing factors. If the average is greater than 1, the loop sizing factor is set equal to the maximum of the branch sizing factors. The loop sizing factor is applied to the loop design flow rate (if autosized) and to the loop pump flow rate (if autosized).

Mixing User-Specified and Autosized Inputs

Mixed user-specified and autosized inputs can be successfully used if the following points and suggestions are followed.

Requirements	How Simergy handles it?
Each component is autosized independently	The user has total control over which fields are set to autosize. Simergy contains validation rules that evaluate if the loop level sizing object is missing when any component has an autosize value assigned to it.
For a component it is recommended that all inputs are either autosized or are all user-specified
Sizing: Parameters object included if applying global sizing
Sizing information flows from sizing objects to components, so sizing calculations have no knowledge of user-specified values in a component. *Only exception is plant loop sizing that collects all component design water flow rates
If user wants to specify a zone or system air flow rate it should be done using the Sizing:Zone and Sizing:System objects.
The plant loop flow rates are sized from the total design demand of the components connected to each loop. The components demanding water need not be autosized for the plant loop autosizing to work successfully.

Component Sizing Output

The results of the component autosizing calculations to be viewed within Results Visualization the output variables must be included in the Output Request Set. A complete list of Objects with autosized fields is provided below. Source = EnergyPlus Input Output Reference Guide - Table 23.

The results of the component autosizing calculations are also reported in the eplusout.eio file. For each component field that has been autosized the component, component name, field description, and value are displayed as comma separated data on a line beginning with Component Sizing. For examples see the EnergyPlus Output Details and Examples document.

Object Name	Object Name
AirConditioner:VariableRefrigerantFlow	AirLoopHVAC
AirLoopHVAC:Unitary:Furnace:HeatCool	AirLoopHVAC:Unitary:Furnace:HeatOnly
AirLoopHVAC:UnitaryHeatCool	AirLoopHVAC:UnitaryHeatCool:VAVChangeoverBypass
AirLoopHVAC:UnitaryHeatOnly	AirLoopHVAC:UnitaryHeatPump:AirToAir
AirLoopHVAC:UnitaryHeatPump:AirToAir:MultiSpeed	AirLoopHVAC:UnitaryHeatPump:WaterToAir
AirTerminal:DualDuct:ConstantVolume	AirTerminal:DualDuct:VAV
AirTerminal:DualDuct:VAV:OutdoorAir	AirTerminal:SingleDuct:ConstantVolume:CooledBeam
AirTerminal:SingleDuct:ConstantVolume:FourPipeInduction	AirTerminal:SingleDuct:ConstantVolume:Reheat
AirTerminal:SingleDuct:ParallelPIU:Reheat	AirTerminal:SingleDuct:SeriesPIU:Reheat
AirTerminal:SingleDuct:Uncontrolled	AirTerminal:SingleDuct:VAV:HeatAndCool:NoReheat
AirTerminal:SingleDuct:VAV:HeatAndCool:Reheat	AirTerminal:SingleDuct:VAV:NoReheat
AirTerminal:SingleDuct:VAV:Reheat	AirTerminal:SingleDuct:VAV:Reheat:VariableSpeedFan
Boiler:HotWater	Boiler:Steam
Branch	Chiller:Absorption
Chiller:Absorption:Indirect	Chiller:CombustionTurbine
Chiller:ConstantCOP	Chiller:Electric
Chiller:Electric:EIR	Chiller:Electric:ReformulatedEIR
Chiller:EngineDriven	ChillerHeater:Absorption:DirectFired
ChillerHeater:Absorption:DoubleEffect	Coil:Cooling:DX:MultiSpeed
Coil:Cooling:DX:SingleSpeed	Coil:Cooling:DX:TwoSpeed
Coil:Cooling:DX:VariableRefrigerantFlow	Coil:Cooling:Water
Coil:Cooling:Water:DetailedGeometry	Coil:Cooling:WaterToAirHeatPump:EquationFit
Coil:Cooling:WaterToAirHeatPump:ParameterEstimation	Coil:Heating:DX:MultiSpeed
Coil:Heating:DX:SingleSpeed	Coil:Heating:DX:VariableRefrigerantFlow
Coil:Heating:Electric	Coil:Heating:Gas
Coil:Heating:Steam	Coil:Heating:Water
Coil:Heating:WaterToAirHeatPump:EquationFit	Coil:Heating:WaterToAirHeatPump:ParameterEstimation
CoilPerformance:DX:Cooling	CondenserLoop
Controller:OutdoorAir	Controller:WaterCoil
CoolingTower:SingleSpeed	CoolingTower:TwoSpeed
CoolingTower:VariableSpeed	EvaporativeCooler:Indirect:ResearchSpecial
EvaporativeFluidCooler:SingleSpeed	EvaporativeFluidCooler:TwoSpeed
Fan:ComponentModel	Fan:ConstantVolume
Fan:OnOff	FanPerformance:NightVentilation
Fan:VariableVolume	FluidCooler:SingleSpeed
FluidCooler:TwoSpeed	HeaderedPumps:ConstantSpeed
HeaderedPumps:VariableSpeed	HeatExchanger:AirToAir:SensibleAndLatent
HeatExchanger:WatersideEconomizer	HVACTemplate:Plant:Boiler
HVACTemplate:Plant:Chiller	HVACTemplate:Plant:Tower
HVACTemplate:System:DedicatedOutdoorAir	HVACTemplate:System:PackagedVAV
HVACTemplate:System:Unitary	HVACTemplate:System:UnitaryHeatPump:AirToAir
HVACTemplate:System:VAV	HVACTemplate:Zone:FanCoil
HVACTemplate:Zone:PTAC	HVACTemplate:Zone:PTHP
HVACTemplate:Zone:Unitary	HVACTemplate:Zone:VAV
HVACTemplate:Zone:VAV:FanPowered	HVACTemplate:Zone:WaterToAirHeatPump
PlantEquipmentOperation:ComponentSetpoint	PlantLoop
Pump:ConstantSpeed	Pump:VariableSpeed
Pump:VariableSpeed:Condensate	Sizing:System
SolarCollector:FlatPlate:PhotovoltaicThermal	ThermalStorage:ChilledWater:Mixed
ThermalStorage:ChilledWater:Stratified	WaterHeater:Mixed
WaterHeater:Stratified	ZoneHVAC:Baseboard:Convective:Electric
ZoneHVAC:Baseboard:Convective:Water	ZoneHVAC:Baseboard:RadiantConvective:Electric
ZoneHVAC:Baseboard:RadiantConvective:Steam	ZoneHVAC:Baseboard:RadiantConvective:Water
ZoneHVAC:EnergyRecoveryVentilator	ZoneHVAC:FourPipeFanCoil
ZoneHVAC:HighTemperatureRadiant	ZoneHVAC:IdealLoadsAirSystem
ZoneHVAC:LowTemperatureRadiant:Electric	ZoneHVAC:LowTemperatureRadiant:VariableFlow
ZoneHVAC:OutdoorAirUnit	ZoneHVAC:PackagedTerminalAirConditioner
ZoneHVAC:PackagedTerminalHeatPump	ZoneHVAC:TerminalUnit:VariableRefrigerantFlow
ZoneHVAC:UnitHeater	ZoneHVAC:UnitVentilator
ZoneHVAC:VentilatedSlab	ZoneHVAC:WaterToAirHeatPump
ZoneHVAC:WindowAirConditioner

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