Lecture 4: Simulation Control, Location, and Weather Input Material prepared by GARD Analytics, Inc. and University of Illinois at Urbana-Champaign under.

Lecture 4: Simulation Control, Location, and Weather Input

Material prepared by GARD Analytics, Inc. and University of Illinoisat Urbana-Champaign under contract to the National Renewable Energy

Laboratory. All material Copyright 2002-2003 U.S.D.O.E. - All rights reserved

2

Importance of this Lecture to the Simulation of Buildings

Every building is different in many ways: Location and exterior thermal environment Construction HVAC system

Exterior thermal environment is a driving force that determines how a building will respond

Energy efficient design requires an understanding of and a response to the exterior thermal environment

Thermal simulation requires information on the exterior thermal environment to properly analyze the building from an energy perspective

3

Purpose of this Lecture

Gain an understanding of how to control the exterior environment of the simulation Building Location Weather and Ground Temperature

Data Length of Simulation Other General Features of the Input

4

Keywords Covered in this Lecture

VersionRun ControlLocationDesignDaySpecialDayPeriodRunPeriodDaylightSavingPeriodGroundTemperatureGroundReflectanceSnow Ground Reflectance Modifiers

5

Quick Review of Relationship Between IDD and IDF Files

IDD: Input Data Dictionary File which defines what information

should be located in the user input file This file should NOT be modified

IDF: Input Data File User input file containing information

about the building and its primary and secondary systems

This file can be modified using a text editor or using the IDF Editor

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Keyword: Version

IDD DescriptionVERSION,

\unique-object

A1 ; \field Version Identifier

\required-field

Notes \unique-object means only one of these

are allowed per IDF file \required-field means this field must be

present in the description

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Keyword Example: Version

IDF ExamplesVersion, 1.1; ! Shortened input formatVersion, 1.1; !- Version Identifier

Notes: The Version identifier refers to a version of the

EnergyPlus program Updates in the EnergyPlus program may result

in changes to the IDD An error message will result if the IDF file

version does not correspond to the version of EnergyPlus being run

This course is based on EnergyPlus Version 1.1

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Keyword: Location

IDD Description (shortened)

IDD Description (detailed)

Location, A1 , \field Location Name N1 , \field Latitude N2 , \field Longitude N3 , \field TimeZone N4 ; \field Elevation

Location, \unique-object \min-fields 5 A1 , \field Location Name \required-field \type alpha

Only one per IDF file

All five fields are required

Information expected: a name

Field is a character string

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Keyword: Location

IDD Description (detailed, continued) N1 , \field Latitude

\units deg \minimum -90.0 \maximum +90.0 \default 0.0 \note + is North, - is South, degree minutes represented \note in decimal (i.e. 30 minutes is .5) \type real N2 , \field Longitude \units deg \minimum -180.0 \maximum +180.0 \default 0.0 \note - is West, + is East, degree minutes represented \note in decimal (i.e. 30 minutes is .5) \type real

Building site latitude (global position)

N1 in degrees

Limits (-90≤N1≤+90) and Default Value

Interpretation informationField is a decimal value

Building site longitude (global position)

10

Keyword: Location

IDD Description (detailed, continued) N3 , \field Time Zone

\units hr \minimum -12.0 \maximum +12.0 \default 0.0 \note Time relative to GMT. Decimal hours. \type real N4 ; \field Elevation \units m \minimum -300.0 \maximum< 6096.0 \default 0.0 \type real

“Political” time zone

N3 in hours

Building site elevation

N4 in meters

Note

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Keyword Example: Location

IDF Example

or

Notes: Location affects the sun angles, air

properties, etc. that the building experiences

Location, DENVER, 39.750, -104.870, -7.0, 1610.26;

Location, DENVER COLORADO, !- LocationName 39.750, !- Latitude {deg} -104.870, !- Longitude {deg} -7.0, !- TimeZone {hr (decimal)} 1610.26; !- Elevation {m}

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Keyword: DesignDay

IDD Description (shortened)DesignDay, A1 , \field DesignDayName N1 , \field Maximum Dry-Bulb Temperature N2 , \field Daily Temperature Range N3 , \field Wet-Bulb Temperature At MaxTemp N4 , \field Barometric Pressure N5 , \field Wind Speed N6 , \field Wind Direction N7 , \field Sky Clearness N8 , \field Rain Indicator N9 , \field Snow Indicator N10, \field Day Of Month N11, \field Month A2 , \field Day Type N12; \field Daylight Saving Time Indicator

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Keyword: DesignDay

Purpose: the DesignDay input syntax defines a single day of weather information

Design day simulations are often used for peak load or sizing calculations

Data required for this keyword can be found in a variety of places (see next slide)

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DesignDay Sources

MacroDataSets folder US, Canada, and International 2001 ASHRAE data

Datasets – US locations pre-1997 ASHRAE data, from BLAST library

*.ddy files Included in weather data zip files on web site 2001 ASHRAE data

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Keyword: DesignDay

IDD Description (detailed)DesignDay, \min-fields 14 A1 , \field DesignDayName \type alpha \required-field \reference DesignDays N1 , \field Maximum Dry-Bulb Temperature \required-field \units C \minimum> -70 \maximum< 70 \note \type real

Keyword—note all one word

14 fields (all) required

Unique character string name for design day

Other references to a design day in the IDF will expect an existing design day name

N1 is the maximum dry bulb temperature experience for this design day in degrees Celsius

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Keyword: DesignDay

IDD Description (detailed) N2 , \field Daily Temperature Range \required-field \units deltaC \minimum 0 \type real \note must still produce appropriate maximum dry bulb N3 , \field Wet-Bulb Temperature At MaxTemp \required-field \units C \minimum> -70 \maximum< 70 \type real

Range of temperatures expected

Units are °CMust be zero or greater

Mean coincident wet-bulb temperature in °C

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Keyword: DesignDay

IDD Description (detailed) N4 , \field Barometric Pressure \required-field \units Pa \minimum> 70000 \maximum< 120000 \type real \ip-units inHg N5 , \field Wind Speed \required-field \units m/s \minimum 0 \maximum 40 \ip-units miles/hr \type real

Outdoor barometric pressure (assumed constant for entire day) in Pascals

IP Units if interface accepts these units

Wind speed (assumed constant for entire day) in meters per second

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Keyword: DesignDay

IDD Description (detailed) N6 , \field Wind Direction \required-field \units deg \minimum 0 \maximum 359.9 \note North=0.0 East=90.0 \type real N7 , \field Sky Clearness \required-field \minimum 0.0 \maximum 1.2 \default 0.0 \note 0.0 is totally unclear, 1.0 is totally clear \type real

Wind direction (assumed constant for entire day) in degrees (assumes North is 0, East is 90, South is 180, etc.)

Sky clearness (assumed constant for entire day)

Maximum allows for altitude adjustment

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Keyword: DesignDay

IDD Description (detailed) N8 , \field Rain Indicator \minimum 0 \maximum 1 \default 0 \note 1 is raining, 0 is not \type integer N9 , \field Snow Indicator \minimum 0 \maximum 1 \default 0 \note 1 is Snow on Ground, 0 is no Snow on Ground \type integer

Rain flag (assumed constant for entire day) affects exterior convection coefficients

Rain flag (assumed constant for entire day) affects ground reflectance

Should be an integer value not a decimal number

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Keyword: DesignDay

IDD Description (detailed) N10, \field Day Of Month \required-field \minimum 1 \maximum 31 \type integer \note must be valid for Month field N11, \field Month \required-field \minimum 1 \maximum 12 \type integer

Numerical day of month (must be valid for month chosen)

Numerical month of the year

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Keyword: DesignDay

IDD Description (detailed) A2 , \field Day Type \required-field \note Day Type selects the schedules appropriate \note for this design day \type choice \key Sunday \key Monday \key Tuesday \key Wednesday \key Thursday \key Friday \key Saturday \key Holiday \key SummerDesignDay \key WinterDesignDay \key CustomDay1 \key CustomDay2

Type of day/day of the week for design day (may affect schedule values)

This field must equal one of these choices of keywords (note that none of these keywords has spaces)

This field is a choice of one of the options listed as \key

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Keyword: DesignDay

IDD Description (detailed) N12; \field Daylight Saving Time Indicator \minimum 0 \maximum 1 \default 0 \note 1=Yes, 0=No \type integer

Whether daylight savings time should be in effect for this design day

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Keyword Example: DesignDay

IDF ExampleDesignDay, DENVER COLORADO SUMMER, !- DesignDayName 32.8, !- Maximum Dry-Bulb Temperature {C} 17.8, !- Daily Temperature Range {C} 15.0, !- Wet-Bulb Temperature At MaxTemp {C} 84060.0, !- Barometric Pressure {Pa} 3.97, !- Wind Speed {m/s} 146.0, !- Wind Direction {deg} 1.10, !- Sky Clearness 0, !- Rain Indicator 0, !- Snow Indicator 21, !- Day Of Month 7, !- Month Monday, !- Day Type 0; !- Daylight Saving Time Indicator

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Keyword: DaylightSavingPeriod


Purpose: define the time frame during which daylight savings rules should apply

Note that this can be specific to location (not all sites use daylight savings time in the summer)

DaylightSavingPeriod, A1, \field StartDate A2; \field EndDate

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IDD Description (detailed)DaylightSavingPeriod, \unique-object \min-fields 2 \memo This object sets up the daylight saving period \memo for any RunPeriod. \memo Ignores any daylightsavingperiod values on the \memo weather file and uses this definition. \memo (These are not used with DesignDay objects.) A1, \field StartDate \required-field


Note: not used for design days and will override any information found on the weather file

Date when daylight savings goes into effect (details on format on next slide)

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IDD Description (detailed) A2; \field EndDate \required-field \memo Dates can be several formats: \memo <number>/<number> (month/day) \memo <number> <Month> \memo <Month> <number> \memo <Nth> <Weekday> in <Month) \memo Last <WeekDay> in <Month> \memo <Month> can be January, February, March, etc. \memo Months can be the first 3 letters of the month \memo <Weekday> can be Sunday, Monday, Tuesday, etc. \memo <Nth> can be 1 or 1st, 2 or 2nd, etc. up to 5(?)

Date when daylight savings period ends

Format information for start and end date of daylight savings time (see examples below)

Date examples:4/11 OR 11 April OR April 111st Sunday in April OR 1 Sunday in AprLast Sunday in October

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Keyword Example: DaylightSavingPeriod

IDF Examples

or

DaylightSavingPeriod, 1st Sunday in April, !- Start Date Last Sunday in October; !- End Date

DaylightSavingPeriod, 4/1, !- Start Date 31 October; !- End Date

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Keyword: SpecialDayPeriod


Purpose: to set up the occurrence of special days throughout the year or to override the values set in a weather file

Note: this information does not apply to design days

SpecialDayPeriod, A1, \field Holiday Name A2, \field StartDate N1, \field duration (number of days) A3; \field SpecialDayType

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IDD Description (detailed)SpecialDayPeriod, \min-fields 4 \memo This object sets up holidays/special days to be \memo used during weather file run periods. \memo (These are not used with DesignDay objects.) \memo Depending on the value in the run period, days \memo on the weather file may also be used. However, \memo the weather file specification will take \memo precedence over any specification shown here. \memo (No error message on duplicate days or \memo overlapping days). A1, \field Holiday Name \required-field


Unique identifying name

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IDD Description (detailed) A2, \field StartDate \required-field \memo Dates can be several formats: \memo <number>/<number> (month/day) \memo <number> <Month> \memo <Month> <number> \memo <Nth> <Weekday> in <Month) \memo Last <WeekDay> in <Month> \memo <Month> can be January, February, March, etc. \memo Months can be the first 3 letters of the month \memo <Weekday> can be Sunday, Monday, Tuesday, etc. \memo <Nth> can be 1 or 1st, 2 or 2nd, etc. up to 5(?) N1, \field duration (number of days) \minimum 1 \maximum 366 \default 1

Date when period starts; format similar to dates for daylight savings time

Length of special period in days

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IDD Description (detailed) A3; \field SpecialDayType \required-field \note SpecialDayType selects the schedules \note appropriate for each day so labeled \type choice \key Holiday \key SummerDesignDay \key WinterDesignDay \key CustomDay1 \key CustomDay2 \default Holiday

Type of day (see choices given in the \key list) this should be considered

Note the impact on schedules

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Keyword Example: SpecialDayPeriod

IDF ExampleSpecialDayPeriod, Memorial Day, !- Holiday Name Last Monday in May, !- Start Date 1, !- duration (number of days) Holiday; !- SpecialDayType

33

Keyword: RunPeriod


Purpose: to define the simulation period for EnergyPlus (program does not assume entire year simulation)

RunPeriod, N1 , \field Begin Month N2 , \field Begin Day Of Month N3 , \field End Month N4 , \field End Day Of Month A1 , \field Day Of Week For Start Day A2, \field Use WeatherFile Holidays/Special Days A3, \field Use WeatherFile DaylightSavingPeriod A4, \field Apply Weekend Holiday Rule A5, \field Use WeatherFile Rain Indicators A6; \field Use WeatherFile Snow Indicators

34

Keyword: RunPeriod

IDD Description (detailed)RunPeriod, \min-fields 10 N1 , \field Begin Month \required-field \minimum 1 \maximum 12 \type integer N2 , \field Begin Day Of Month \required-field \minimum 1 \maximum 31 \type integer


Starting date for period to be simulated; entered as two separate fields, both integer values

35

Keyword: RunPeriod

IDD Description (detailed, continued) N3 , \field End Month \required-field \minimum 1 \maximum 12 \type integer N4 , \field End Day Of Month \required-field \minimum 1 \maximum 31 \type integer

Ending date for period to be simulated; entered as two separate fields, both integer values

36

Keyword: RunPeriod

IDD Description (detailed, continued) A1 , \field Day Of Week For Start Day \note =<blank - use WeatherFile> \default UseWeatherFile \type choice \key Sunday \key Monday \key Tuesday \key Wednesday \key Thursday \key Friday \key Saturday \key UseWeatherFile

Day of week for starting date; can be used to override day of week specified on the weather file

Options for day of week for starting date

Note that this is not a “required” field due to the lack of the line that says “\required-field”; all fields after this point are also optional

37

Keyword: RunPeriod

IDD Description (detailed, continued) A2, \field Use WeatherFile Holidays/Special Days

\note If yes or blank, use holidays on Weatherfile. \note If no, do not use the holidays on Weatherfile. \note Note: You can still specify holidays/special days \note using the SpecialDayPeriod object(s). \type choice \default Yes \key Yes \key No A3, \field Use WeatherFile DaylightSavingPeriod \note If yes or blank, use period specified on Weatherfile. \note If no, do not use period as specified on Weatherfile. \type choice \default Yes \key Yes \key No

These two input fields are used to override the definition of holidays and daylight savings time period from the weather file.

The choices for these fields are simply a “yes” or a “no”.

38

Keyword: RunPeriod

IDD Description (detailed, continued) A4, \field Apply Weekend Holiday Rule

\note if yes and single day holiday falls on weekend, \note "holiday" occurs on following Monday \type choice \key Yes \key No \default No A5, \field Use WeatherFile Rain Indicators \type choice \key Yes \key No \default Yes A6; \field Use WeatherFile Snow Indicators \type choice \key Yes \key No \default Yes

These three input fields are used to override the definition of holiday weekend rules, presence of rain indicators, and presence of snow indicators from the weather file.

The choices for these fields are simply a “yes” or a “no”.

39

Keyword Example: RunPeriod

IDF Example

or

RunPeriod, 1, !- Begin Month 1, !- Begin Day Of Month 3, !- End Month 31; !- End Day Of Month

RunPeriod, 1, !- Begin Month 1, !- Begin Day Of Month 3, !- End Month 31, !- End Day Of Month Tuesday, !- Day of Week for Start Day Yes, Yes, Yes, Yes, Yes; !- Special Weather File Flags

40

Keyword: Run Control


Purpose: overall control of what the user wants EnergyPlus to simulate (design days and/or weather file runs, perform auto-sizing)

RUN CONTROL, A1, \field Do the zone sizing calculation A2, \field Do the system sizing calculation A3, \field Do the plant sizing calculation A4, \field Do the design day simulations A5; \field Do the weather file simulation

41


IDD Description (detailed)RUN CONTROL, \unique-object A1, \field Do the zone sizing calculation \type choice \key Yes \key No \default No A2, \field Do the system sizing calculation \type choice \key Yes \key No \default No A3, \field Do the plant sizing calculation \type choice \key Yes \key No \default No

Keyword—note that there IS a space between the two words

These will be discussed later in the semester

42


IDD Description (detailed, continued) A4, \field Do the design day simulations \type choice \key Yes \key No \default Yes A5; \field Do the weather file simulation \type choice \key Yes \key No \default Yes

Fields define whether or not to simulate design days (defined by the DesignDay input line) or an attached weather file (see RunPeriod input line)

Choices for both fields are simply “yes” or “no”

43

Keyword Example: Run Control

IDF Example

or

RUN CONTROL, No, No, No, No, Yes;

RUN CONTROL, No, !- Do the zone sizing calculation No, !- Do the system sizing calculation No, !- Do the plant sizing calculation No, !- Do the design day simulations Yes; !- Do the weather file simulation

44

Keyword: GroundTemperatures


Purpose: to set the ground temperatures experienced at the building location (impact on places where the ground is in contact with the building)

GroundTemperatures,N1 , \field January Ground TemperatureN2 , \field February Ground TemperatureN3 , \field March Ground Temperature. . . etc . . .N12; \field December Ground Temperature

45

Keyword: GroundTemperatures

IDD Description (detailed)GroundTemperatures, \unique-object \min-fields 12 N1 , \field January Ground Temperature \required-field \units C \type real \default 13


12 values, one per month

Repeated for each month of the year

Temperatures in Celsius; note that these are temperatures at the outside surface not “deep ground” temperatures

46

Keyword Example: GroundTemperatures

GroundTemperatures, 20.03, !- January Ground Temperature {C} 20.03, !- February Ground Temperature {C} 20.13, !- March Ground Temperature {C} 20.30, !- April Ground Temperature {C} 20.43, !- May Ground Temperature {C} 20.52, !- June Ground Temperature {C} 20.62, !- July Ground Temperature {C} 20.77, !- August Ground Temperature {C} 20.78, !- September Ground Temperature {C} 20.55, !- October Ground Temperature {C} 20.44, !- November Ground Temperature {C} 20.20; !- December Ground Temperature {C}

IDF Exampleor

GroundTemperatures, 20.03, 20.03, 20.13, 20.30, 20.43, 20.52, 20.62, 20.77, 20.78, 20.55, 20.44, 20.20;

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Keyword: GroundReflectances


Purpose: to set the reflectance of the ground surrounding the building (affects radiation incident on building surfaces)

GroundReflectances,N1 , \field January Ground ReflectanceN2 , \field February Ground ReflectanceN3 , \field March Ground Reflectance. . . etc . . .N12; \field December Ground Reflectance

48

Keyword: GroundReflectances

IDD Description (detailed)GroundReflectances, \unique-object \min-fields 12 N1 , \field January Ground Reflectance \default 0.2 \type real \minimum 0.0 \maximum 1.0 \units dimensionless


12 values, one per month

Repeated for each month of the year

Note: values for reflectance are highly dependent on the type of ground cover around the building—grass, dirt, concrete, asphalt, etc.

49

Keyword Example: GroundReflectances

IDF Exampleor

GroundReflectances, 0.2, !- January Ground Reflectance 0.2, !- February Ground Reflectance 0.2, !- March Ground Reflectance 0.2, !- April Ground Reflectance 0.2, !- May Ground Reflectance 0.2, !- June Ground Reflectance 0.2, !- July Ground Reflectance 0.2, !- August Ground Reflectance 0.2, !- September Ground Reflectance 0.2, !- October Ground Reflectance 0.2, !- November Ground Reflectance 0.2; !- December Ground Reflectance

GroundReflectances, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2;

50

Keyword: Snow Ground Reflectance Modifiers


Purpose: to account for the presence of snow and how that impacts the ground reflectance (weather files will indicate whether or not there is snow on the ground)

Snow Ground Reflectance Modifiers, N1, \field Ground Reflected Solar Modifier \minimum 0.0 \default 1.0 N2; \field Daylighting Ground Reflected Solar Modifier \minimum 0.0 \default 1.0

51


IDD Description (detailed)Snow Ground Reflectance Modifiers, N1, \field Ground Reflected Solar Modifier \minimum 0.0 \default 1.0 \note Value for modifying the "normal" ground reflectance \note when Snow is on ground when calculating the \note "Ground Reflected Solar Radiation Value“ a value of \note 1.0 here uses the "normal" ground reflectance \note Ground Reflected Solar = (BeamSolar*CosSunZenith \note + DiffuseSolar)*GroundReflectance \note This would be further modified by the Snow Ground \note Reflectance Modifier when Snow was on the ground \note When Snow on ground, effective GroundReflectance is \note GroundReflectance*"Ground Reflectance Snow Modifier" \note Ground Reflectance achieved in this manner will be \note restricted to [0.0,1.0]

52


IDD Description (detailed) N2; \field Daylighting Ground Reflected Solar Modifier \minimum 0.0 \default 1.0 \note Value for modifying the "normal“ daylighting \note ground reflectance when Snow is on ground \note When calculating the "Ground Reflected Solar \note Radiation Value“ a value of 1.0 here uses the \note “normal” ground reflectance \note Ground Reflected Solar = (BeamSolar*CosSunZenith \note + DiffuseSolar)*GroundReflectance \note This would be further modified by the Snow Ground \note Reflectance Modifier when Snow was on the ground \note When Snow on ground, effective GroundReflectance is \note GroundReflectance*"Ground Reflectance Snow Modifier" \note Ground Reflectance achieved in this manner will be \note restricted to [0.0,1.0]

53

Keyword Example: Snow Ground Reflectance Modifiers

IDF ExampleorSnow Ground Reflectance Modifiers, 1.5, !- Ground Reflected Solar Modifier 2.0; !- Daylighting Ground Reflected Solar Modifier

Snow Ground Reflectance Modifiers, 1.5, 2.0;

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Summary

Location and exterior thermal environment play a critical role in determine the thermal loads/energy consumption of a building

Many input keywords in EnergyPlus control what is being simulated For example: Version, Run Control, Location,

DesignDay, SpecialDayPeriod, RunPeriod, DaylightSavingPeriod, GroundTemperature, GroundReflectance, Snow Ground Reflectance Modifiers

EnergyPlus flexibility also results in user responsibility (having to define various parameters in the input file)

Lecture 4: Simulation Control, Location, and Weather Input Material prepared by GARD Analytics, Inc. and University of Illinois at Urbana-Champaign under.

Documents

field location

idf file version

version idf examples

version of energyplus

energyplus version

lecture version

input slide

location idd description