pyidf.simulation_parameters module

Data objects in group “Simulation Parameters”

class pyidf.simulation_parameters.Building

Bases: pyidf.helper.DataObject

Corresponds to IDD object Building Describes parameters that are used during the simulation of the building. There are necessary correlations between the entries for this object and some entries in the Site:WeatherStation and Site:HeightVariation objects, specifically the Terrain field.

loads_convergence_tolerance_value

field Loads Convergence Tolerance Value

Loads Convergence Tolerance Value is a fraction of load

Default value: 0.04

value <= 0.5

Parameters:value (float) – value for IDD Field Loads Convergence Tolerance Value Raises:ValueError – if value is not a valid value Returns:the value of loads_convergence_tolerance_value or None if not set Return type:float

maximum_number_of_warmup_days

field Maximum Number of Warmup Days

EnergyPlus will only use as many warmup days as needed to reach convergence tolerance.

This field’s value should NOT be set less than 25.

Default value: 25

Parameters:value (int) – value for IDD Field Maximum Number of Warmup Days Raises:ValueError – if value is not a valid value Returns:the value of maximum_number_of_warmup_days or None if not set Return type:int

minimum_number_of_warmup_days

field Minimum Number of Warmup Days

The minimum number of warmup days that produce enough temperature and flux history

to start EnergyPlus simulation for all reference buildings was suggested to be 6.

When this field is greater than the maximum warmup days defined previous field

the maximum number of warmup days will be reset to the minimum value entered here.

Warmup days will be set to be the value you entered when it is less than the default 6.

Default value: 6

Parameters:value (int) – value for IDD Field Minimum Number of Warmup Days Raises:ValueError – if value is not a valid value Returns:the value of minimum_number_of_warmup_days or None if not set Return type:int

name

field Name

Default value: NONE

Parameters:value (str) – value for IDD Field Name Raises:ValueError – if value is not a valid value Returns:the value of name or None if not set Return type:str

north_axis

field North Axis

degrees from true North

Units: deg

Parameters:value (float) – value for IDD Field North Axis Raises:ValueError – if value is not a valid value Returns:the value of north_axis or None if not set Return type:float

solar_distribution

field Solar Distribution

MinimalShadowing | FullExterior | FullInteriorAndExterior | FullExteriorWithReflections | FullInteriorAndExteriorWithReflections

Default value: FullExterior

Parameters:value (str) – value for IDD Field Solar Distribution Raises:ValueError – if value is not a valid value Returns:the value of solar_distribution or None if not set Return type:str

temperature_convergence_tolerance_value

field Temperature Convergence Tolerance Value

Units: deltaC

Default value: 0.4

value <= 0.5

Parameters:value (float) – value for IDD Field Temperature Convergence Tolerance Value Raises:ValueError – if value is not a valid value Returns:the value of temperature_convergence_tolerance_value or None if not set Return type:float

terrain

field Terrain

Country=FlatOpenCountry | Suburbs=CountryTownsSuburbs | City=CityCenter | Ocean=body of water (5km) | Urban=Urban-Industrial-Forest

Default value: Suburbs

Parameters:value (str) – value for IDD Field Terrain Raises:ValueError – if value is not a valid value Returns:the value of terrain or None if not set Return type:str

class pyidf.simulation_parameters.ConvergenceLimits

Bases: pyidf.helper.DataObject

Corresponds to IDD object ConvergenceLimits Specifies limits on HVAC system simulation timesteps and iterations. This item is an advanced feature that should be used only with caution.

maximum_hvac_iterations

field Maximum HVAC Iterations

Default value: 20

value >= 1

Parameters:value (int) – value for IDD Field Maximum HVAC Iterations Raises:ValueError – if value is not a valid value Returns:the value of maximum_hvac_iterations or None if not set Return type:int

maximum_plant_iterations

field Maximum Plant Iterations

Controls the maximum number of plant system solver iterations within a single HVAC iteration

Smaller values might decrease runtime but could decrease solution accuracy for complicated plant systems

Default value: 8

value >= 2

Parameters:value (int) – value for IDD Field Maximum Plant Iterations Raises:ValueError – if value is not a valid value Returns:the value of maximum_plant_iterations or None if not set Return type:int

minimum_plant_iterations

field Minimum Plant Iterations

Controls the minimum number of plant system solver iterations within a single HVAC iteration

Larger values will increase runtime but might improve solution accuracy for complicated plant systems

Complex plants include: several interconnected loops, heat recovery, thermal load following generators, etc.

Default value: 2

value >= 1

Parameters:value (int) – value for IDD Field Minimum Plant Iterations Raises:ValueError – if value is not a valid value Returns:the value of minimum_plant_iterations or None if not set Return type:int

minimum_system_timestep

field Minimum System Timestep

0 sets the minimum to the zone timestep (ref: Timestep)

1 is normal (ratchet down to 1 minute)

setting greater than zone timestep (in minutes) will effectively set to zone timestep

Units: minutes

value <= 60

Parameters:value (int) – value for IDD Field Minimum System Timestep Raises:ValueError – if value is not a valid value Returns:the value of minimum_system_timestep or None if not set Return type:int

class pyidf.simulation_parameters.HeatBalanceAlgorithm

Bases: pyidf.helper.DataObject

Corresponds to IDD object HeatBalanceAlgorithm Determines which Heat Balance Algorithm will be used ie. CTF (Conduction Transfer Functions), EMPD (Effective Moisture Penetration Depth with Conduction Transfer Functions). Advanced/Research Usage: CondFD (Conduction Finite Difference) Advanced/Research Usage: ConductionFiniteDifferenceSimplified Advanced/Research Usage: HAMT (Combined Heat And Moisture Finite Element)

algorithm

field Algorithm

Default value: ConductionTransferFunction

Parameters:value (str) – value for IDD Field Algorithm Raises:ValueError – if value is not a valid value Returns:the value of algorithm or None if not set Return type:str

maximum_surface_convection_heat_transfer_coefficient_value

field Maximum Surface Convection Heat Transfer Coefficient Value

Units: W/m2-K

Default value: 1000.0

value >= 1.0

Parameters:value (float) – value for IDD Field Maximum Surface Convection Heat Transfer Coefficient Value Raises:ValueError – if value is not a valid value Returns:the value of maximum_surface_convection_heat_transfer_coefficient_value or None if not set Return type:float

minimum_surface_convection_heat_transfer_coefficient_value

field Minimum Surface Convection Heat Transfer Coefficient Value

Units: W/m2-K

Default value: 0.1

Parameters:value (float) – value for IDD Field Minimum Surface Convection Heat Transfer Coefficient Value Raises:ValueError – if value is not a valid value Returns:the value of minimum_surface_convection_heat_transfer_coefficient_value or None if not set Return type:float

surface_temperature_upper_limit

field Surface Temperature Upper Limit

Units: C

Default value: 200.0

value >= 200.0

Parameters:value (float) – value for IDD Field Surface Temperature Upper Limit Raises:ValueError – if value is not a valid value Returns:the value of surface_temperature_upper_limit or None if not set Return type:float

class pyidf.simulation_parameters.HeatBalanceSettingsConductionFiniteDifference

Bases: pyidf.helper.DataObject

Corresponds to IDD object HeatBalanceSettings:ConductionFiniteDifference Determines settings for the Conduction Finite Difference algorithm for surface heat transfer modeling.

difference_scheme

field Difference Scheme

Default value: FullyImplicitFirstOrder

Parameters:value (str) – value for IDD Field Difference Scheme Raises:ValueError – if value is not a valid value Returns:the value of difference_scheme or None if not set Return type:str

inside_face_surface_temperature_convergence_criteria

field Inside Face Surface Temperature Convergence Criteria

Default value: 0.002

value >= 1e-07

value <= 0.01

Parameters:value (float) – value for IDD Field Inside Face Surface Temperature Convergence Criteria Raises:ValueError – if value is not a valid value Returns:the value of inside_face_surface_temperature_convergence_criteria or None if not set Return type:float

relaxation_factor

field Relaxation Factor

Default value: 1.0

value >= 0.01

value <= 1.0

Parameters:value (float) – value for IDD Field Relaxation Factor Raises:ValueError – if value is not a valid value Returns:the value of relaxation_factor or None if not set Return type:float

space_discretization_constant

field Space Discretization Constant

increase or decrease number of nodes

Default value: 3.0

Parameters:value (float) – value for IDD Field Space Discretization Constant Raises:ValueError – if value is not a valid value Returns:the value of space_discretization_constant or None if not set Return type:float

class pyidf.simulation_parameters.ProgramControl

Bases: pyidf.helper.DataObject

Corresponds to IDD object ProgramControl used to support various efforts in time reduction for simulation including threading This object is currently disabled

number_of_threads_allowed

field Number of Threads Allowed

This is currently used only in the Interior Radiant Exchange module – view factors on # surfaces

if value is 0, then maximum number allowed will be used.

Parameters:value (int) – value for IDD Field Number of Threads Allowed Raises:ValueError – if value is not a valid value Returns:the value of number_of_threads_allowed or None if not set Return type:int

class pyidf.simulation_parameters.ShadowCalculation

Bases: pyidf.helper.DataObject

Corresponds to IDD object ShadowCalculation This object is used to control details of the solar, shading, and daylighting models

calculation_frequency

field Calculation Frequency

enter number of days

this field is only used if the previous field is set to AverageOverDaysInFrequency

0=Use Default Periodic Calculation|<else> calculate every <value> day

only really applicable to RunPeriods

warning issued if >31

Default value: 20

value >= 1

Parameters:value (int) – value for IDD Field Calculation Frequency Raises:ValueError – if value is not a valid value Returns:the value of calculation_frequency or None if not set Return type:int

calculation_method

field Calculation Method

choose calculation method. note that TimestepFrequency is only needed for certain cases

and can increase execution time significantly.

Default value: AverageOverDaysInFrequency

Parameters:value (str) – value for IDD Field Calculation Method Raises:ValueError – if value is not a valid value Returns:the value of calculation_method or None if not set Return type:str

maximum_figures_in_shadow_overlap_calculations

field Maximum Figures in Shadow Overlap Calculations

Number of allowable figures in shadow overlap calculations

Default value: 15000

value >= 200

Parameters:value (int) – value for IDD Field Maximum Figures in Shadow Overlap Calculations Raises:ValueError – if value is not a valid value Returns:the value of maximum_figures_in_shadow_overlap_calculations or None if not set Return type:int

polygon_clipping_algorithm

field Polygon Clipping Algorithm

Advanced Feature. Internal default is SutherlandHodgman

Refer to InputOutput Reference and Engineering Reference for more information

Parameters:value (str) – value for IDD Field Polygon Clipping Algorithm Raises:ValueError – if value is not a valid value Returns:the value of polygon_clipping_algorithm or None if not set Return type:str

sky_diffuse_modeling_algorithm

field Sky Diffuse Modeling Algorithm

Advanced Feature. Internal default is SimpleSkyDiffuseModeling

If you have shading elements that change transmittance over the

year, you may wish to choose the detailed method.

Refer to InputOutput Reference and Engineering Reference for more information

Parameters:value (str) – value for IDD Field Sky Diffuse Modeling Algorithm Raises:ValueError – if value is not a valid value Returns:the value of sky_diffuse_modeling_algorithm or None if not set Return type:str

class pyidf.simulation_parameters.SimulationControl

Bases: pyidf.helper.DataObject

Corresponds to IDD object SimulationControl Note that the following 3 fields are related to the Sizing:Zone, Sizing:System, and Sizing:Plant objects. Having these fields set to Yes but no corresponding Sizing object will not cause the sizing to be done. However, having any of these fields set to No, the corresponding Sizing object is ignored. Note also, if you want to do system sizing, you must also do zone sizing in the same run or an error will result.

do_hvac_sizing_simulation_for_sizing_periods

field Do HVAC Sizing Simulation for Sizing Periods

If Yes, SizingPeriod:* objects are exectuted additional times for advanced sizing.

Currently limited to use with coincident plant sizing, see Sizing:Plant object

Default value: No

Parameters:value (str) – value for IDD Field Do HVAC Sizing Simulation for Sizing Periods Raises:ValueError – if value is not a valid value Returns:the value of do_hvac_sizing_simulation_for_sizing_periods or None if not set Return type:str

do_plant_sizing_calculation

field Do Plant Sizing Calculation

If Yes, Plant sizing is accomplished from corresponding Sizing:Plant objects

and autosize fields.

Default value: No

Parameters:value (str) – value for IDD Field Do Plant Sizing Calculation Raises:ValueError – if value is not a valid value Returns:the value of do_plant_sizing_calculation or None if not set Return type:str

do_system_sizing_calculation

field Do System Sizing Calculation

If Yes, System sizing is accomplished from corresponding Sizing:System objects

and autosize fields.

If Yes, Zone sizing (previous field) must also be Yes.

Default value: No

Parameters:value (str) – value for IDD Field Do System Sizing Calculation Raises:ValueError – if value is not a valid value Returns:the value of do_system_sizing_calculation or None if not set Return type:str

do_zone_sizing_calculation

field Do Zone Sizing Calculation

If Yes, Zone sizing is accomplished from corresponding Sizing:Zone objects

and autosize fields.

Default value: No

Parameters:value (str) – value for IDD Field Do Zone Sizing Calculation Raises:ValueError – if value is not a valid value Returns:the value of do_zone_sizing_calculation or None if not set Return type:str

maximum_number_of_hvac_sizing_simulation_passes

field Maximum Number of HVAC Sizing Simulation Passes

the entire set of SizingPeriod:* objects may be repeated to fine tune size results

this input sets a limit on the number of passes that the sizing algorithms can repeate the set

Default value: 1

value >= 1

Parameters:value (int) – value for IDD Field Maximum Number of HVAC Sizing Simulation Passes Raises:ValueError – if value is not a valid value Returns:the value of maximum_number_of_hvac_sizing_simulation_passes or None if not set Return type:int

run_simulation_for_sizing_periods

field Run Simulation for Sizing Periods

If Yes, SizingPeriod:* objects are executed and results from those may be displayed..

Default value: Yes

Parameters:value (str) – value for IDD Field Run Simulation for Sizing Periods Raises:ValueError – if value is not a valid value Returns:the value of run_simulation_for_sizing_periods or None if not set Return type:str

run_simulation_for_weather_file_run_periods

field Run Simulation for Weather File Run Periods

If Yes, RunPeriod:* objects are executed and results from those may be displayed..

Default value: Yes

Parameters:value (str) – value for IDD Field Run Simulation for Weather File Run Periods Raises:ValueError – if value is not a valid value Returns:the value of run_simulation_for_weather_file_run_periods or None if not set Return type:str

class pyidf.simulation_parameters.SurfaceConvectionAlgorithmInside

Bases: pyidf.helper.DataObject

Corresponds to IDD object SurfaceConvectionAlgorithm:Inside Default indoor surface heat transfer convection algorithm to be used for all zones

algorithm

field Algorithm

Simple = constant value natural convection (ASHRAE)

TARP = variable natural convection based on temperature difference (ASHRAE, Walton)

CeilingDiffuser = ACH-based forced and mixed convection correlations

for ceiling diffuser configuration with simple natural convection limit

AdaptiveConvectionAlgorithm = dynamic selection of convection models based on conditions

Default value: TARP

Parameters:value (str) – value for IDD Field Algorithm Raises:ValueError – if value is not a valid value Returns:the value of algorithm or None if not set Return type:str

class pyidf.simulation_parameters.SurfaceConvectionAlgorithmOutside

Bases: pyidf.helper.DataObject

Corresponds to IDD object SurfaceConvectionAlgorithm:Outside Default outside surface heat transfer convection algorithm to be used for all zones

algorithm

field Algorithm

SimpleCombined = Combined radiation and convection coefficient using simple ASHRAE model

TARP = correlation from models developed by ASHRAE, Walton, and Sparrow et. al.

MoWiTT = correlation from measurements by Klems and Yazdanian for smooth surfaces

DOE-2 = correlation from measurements by Klems and Yazdanian for rough surfaces

AdaptiveConvectionAlgorithm = dynamic selection of correlations based on conditions

Default value: DOE-2

Parameters:value (str) – value for IDD Field Algorithm Raises:ValueError – if value is not a valid value Returns:the value of algorithm or None if not set Return type:str

class pyidf.simulation_parameters.Timestep

Bases: pyidf.helper.DataObject

Corresponds to IDD object Timestep Specifies the “basic” timestep for the simulation. The value entered here is also known as the Zone Timestep. This is used in the Zone Heat Balance Model calculation as the driving timestep for heat transfer and load calculations.

number_of_timesteps_per_hour

field Number of Timesteps per Hour

Number in hour: normal validity 4 to 60: 6 suggested

Must be evenly divisible into 60

Allowable values include 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60

Normal 6 is minimum as lower values may cause inaccuracies

A minimum value of 20 is suggested for both ConductionFiniteDifference

and CombinedHeatAndMoistureFiniteElement surface heat balance algorithms

A minimum of 12 is suggested for simulations involving a Vegetated Roof (Material:RoofVegetation).

Default value: 6

value >= 1

value <= 60

Parameters:value (int) – value for IDD Field Number of Timesteps per Hour Raises:ValueError – if value is not a valid value Returns:the value of number_of_timesteps_per_hour or None if not set Return type:int

class pyidf.simulation_parameters.Version

Bases: pyidf.helper.DataObject

Corresponds to IDD object Version Specifies the EnergyPlus version of the IDF file.

version_identifier

field Version Identifier

Default value: 8.4

Parameters:value (str) – value for IDD Field Version Identifier Raises:ValueError – if value is not a valid value Returns:the value of version_identifier or None if not set Return type:str

class pyidf.simulation_parameters.ZoneAirContaminantBalance

Bases: pyidf.helper.DataObject

Corresponds to IDD object ZoneAirContaminantBalance Determines which contaminant concentration will be simulates.

carbon_dioxide_concentration

field Carbon Dioxide Concentration

If Yes, CO2 simulation will be performed.

Default value: No

Parameters:value (str) – value for IDD Field Carbon Dioxide Concentration Raises:ValueError – if value is not a valid value Returns:the value of carbon_dioxide_concentration or None if not set Return type:str

generic_contaminant_concentration

field Generic Contaminant Concentration

If Yes, generic contaminant simulation will be performed.

Default value: No

Parameters:value (str) – value for IDD Field Generic Contaminant Concentration Raises:ValueError – if value is not a valid value Returns:the value of generic_contaminant_concentration or None if not set Return type:str

outdoor_carbon_dioxide_schedule_name

field Outdoor Carbon Dioxide Schedule Name

Schedule values should be in parts per million (ppm)

Parameters:value (str) – value for IDD Field Outdoor Carbon Dioxide Schedule Name Raises:ValueError – if value is not a valid value Returns:the value of outdoor_carbon_dioxide_schedule_name or None if not set Return type:str

outdoor_generic_contaminant_schedule_name

field Outdoor Generic Contaminant Schedule Name

Schedule values should be generic contaminant concentration in parts per

million (ppm)

Parameters:value (str) – value for IDD Field Outdoor Generic Contaminant Schedule Name Raises:ValueError – if value is not a valid value Returns:the value of outdoor_generic_contaminant_schedule_name or None if not set Return type:str

class pyidf.simulation_parameters.ZoneAirHeatBalanceAlgorithm

Bases: pyidf.helper.DataObject

Corresponds to IDD object ZoneAirHeatBalanceAlgorithm Determines which algorithm will be used to solve the zone air heat balance.

algorithm

field Algorithm

Default value: ThirdOrderBackwardDifference

Parameters:value (str) – value for IDD Field Algorithm Raises:ValueError – if value is not a valid value Returns:the value of algorithm or None if not set Return type:str

class pyidf.simulation_parameters.ZoneAirMassFlowConservation

Bases: pyidf.helper.DataObject

Corresponds to IDD object ZoneAirMassFlowConservation Enforces the zone air mass flow balance by adjusting zone mixing object and/or infiltration object mass flow rates. If either mixing or infiltration is active, then the zone air mass flow balance calculation will attempt to enforce conservation of mass for each zone.

adjust_zone_mixing_for_zone_air_mass_flow_balance

field Adjust Zone Mixing For Zone Air Mass Flow Balance

If Yes, Zone mixing object flow rates are adjusted to balance the zone air mass flow

and additional infiltration air flow may be added if required in order to balance the

zone air mass flow.

Default value: No

Parameters:value (str) – value for IDD Field Adjust Zone Mixing For Zone Air Mass Flow Balance Raises:ValueError – if value is not a valid value Returns:the value of adjust_zone_mixing_for_zone_air_mass_flow_balance or None if not set Return type:str

infiltration_balancing_method

field Infiltration Balancing Method

This input field allows user to choose how zone infiltration flow is treated during

the zone air mass flow balance calculation.

AddInfiltrationFlow may add infiltration to the base flow specified in the

infiltration object to balance the zone air mass flow. The additional infiltration

air mass flow is not self-balanced. The base flow is assumed to be self-balanced.

AdjustInfiltrationFlow may adjust the base flow calculated using

the base flow specified in the infiltration object to balance the zone air mass flow. If it

If no adjustment is required, then the base infiltration is assumed to be self-balanced.

None will make no changes to the base infiltration flow.

Default value: AddInfiltrationFlow

Parameters:value (str) – value for IDD Field Infiltration Balancing Method Raises:ValueError – if value is not a valid value Returns:the value of infiltration_balancing_method or None if not set Return type:str

infiltration_balancing_zones

field Infiltration Balancing Zones

This input field allows user to choose which zones are included in infiltration balancing.

MixingSourceZonesOnly allows infiltration balancing only in zones which as source zones for mixing

which also have an infiltration object defined.

AllZones allows infiltration balancing in any zone which has an infiltration object defined.

Default value: MixingSourceZonesOnly

Parameters:value (str) – value for IDD Field Infiltration Balancing Zones Raises:ValueError – if value is not a valid value Returns:the value of infiltration_balancing_zones or None if not set Return type:str

class pyidf.simulation_parameters.ZoneCapacitanceMultiplierResearchSpecial

Bases: pyidf.helper.DataObject

Corresponds to IDD object ZoneCapacitanceMultiplier:ResearchSpecial Multiplier altering the relative capacitance of the air compared to an empty zone

carbon_dioxide_capacity_multiplier

field Carbon Dioxide Capacity Multiplier

Used to alter the capacitance of zone air with respect to zone air carbon dioxide concentration

Default value: 1.0

Parameters:value (float) – value for IDD Field Carbon Dioxide Capacity Multiplier Raises:ValueError – if value is not a valid value Returns:the value of carbon_dioxide_capacity_multiplier or None if not set Return type:float

generic_contaminant_capacity_multiplier

field Generic Contaminant Capacity Multiplier

Used to alter the capacitance of zone air with respect to zone air generic contaminant concentration

Default value: 1.0

Parameters:value (float) – value for IDD Field Generic Contaminant Capacity Multiplier Raises:ValueError – if value is not a valid value Returns:the value of generic_contaminant_capacity_multiplier or None if not set Return type:float

humidity_capacity_multiplier

field Humidity Capacity Multiplier

Used to alter the capacitance of zone air with respect to moisture or humidity ratio

Default value: 1.0

Parameters:value (float) – value for IDD Field Humidity Capacity Multiplier Raises:ValueError – if value is not a valid value Returns:the value of humidity_capacity_multiplier or None if not set Return type:float

temperature_capacity_multiplier

field Temperature Capacity Multiplier

Used to alter the capacitance of zone air with respect to heat or temperature

Default value: 1.0

Parameters:value (float) – value for IDD Field Temperature Capacity Multiplier Raises:ValueError – if value is not a valid value Returns:the value of temperature_capacity_multiplier or None if not set Return type:float