Lecture 4: Simulation Control, Location, and Weather Input 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 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  Version  Run Control  Location  DesignDay  SpecialDayPeriod  RunPeriod  DaylightSavingPeriod  GroundTemperature  GroundReflectance  Snow 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

6 Keyword: Version  IDD Description VERSION, \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

7 Keyword Example: Version  IDF Examples Version, 1.1; ! Shortened input format Version, 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

8 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

9 Keyword: Location  IDD Description (detailed, continued) N1, \field Latitude \units deg \minimum \maximum \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 \maximum \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 information Field is a decimal value Building site longitude (global position)

10 Keyword: Location  IDD Description (detailed, continued) N3, \field Time Zone \units hr \minimum \maximum \default 0.0 \note Time relative to GMT. Decimal hours. \type real N4 ; \field Elevation \units m \minimum \maximum< \default 0.0 \type real “Political” time zone N3 in hours Building site elevation N4 in meters Note

11 Keyword Example: Location  IDF Example or  Notes: Location affects the sun angles, air properties, etc. that the building experiences Location, DENVER, , , -7.0, ; Location, DENVER COLORADO, !- LocationName , !- Latitude {deg} , !- Longitude {deg} -7.0, !- TimeZone {hr (decimal)} ; !- Elevation {m}

12 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

13 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)

14 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

15 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

16 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 °C Must be zero or greater Mean coincident wet-bulb temperature in °C

17 Keyword: DesignDay  IDD Description (detailed) N4, \field Barometric Pressure \required-field \units Pa \minimum> \maximum< \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

18 Keyword: DesignDay  IDD Description (detailed) N6, \field Wind Direction \required-field \units deg \minimum 0 \maximum \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

19 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

20 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

21 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

22 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

23 Keyword Example: DesignDay  IDF Example DesignDay, 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} , !- 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

24 Keyword: DaylightSavingPeriod  IDD Description (shortened)  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

25 Keyword: DaylightSavingPeriod  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 Keyword—note all one word 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)

26 Keyword: DaylightSavingPeriod  IDD Description (detailed) A2; \field EndDate \required-field \memo Dates can be several formats: \memo / (month/day) \memo \memo in <Month) \memo Last in \memo can be January, February, March, etc. \memo Months can be the first 3 letters of the month \memo can be Sunday, Monday, Tuesday, etc. \memo 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 11 1st Sunday in April OR 1 Sunday in Apr Last Sunday in October

27 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

28 Keyword: SpecialDayPeriod  IDD Description (shortened)  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

29 Keyword: SpecialDayPeriod  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 Keyword—note all one word Unique identifying name

30 Keyword: SpecialDayPeriod  IDD Description (detailed) A2, \field StartDate \required-field \memo Dates can be several formats: \memo / (month/day) \memo \memo in <Month) \memo Last in \memo can be January, February, March, etc. \memo Months can be the first 3 letters of the month \memo can be Sunday, Monday, Tuesday, etc. \memo 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

31 Keyword: SpecialDayPeriod  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

32 Keyword Example: SpecialDayPeriod  IDF Example SpecialDayPeriod, Memorial Day, !- Holiday Name Last Monday in May, !- Start Date 1, !- duration (number of days) Holiday; !- SpecialDayType

33 Keyword: RunPeriod  IDD Description (shortened)  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 Keyword—note all one word 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 = \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  IDD Description (shortened)  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 Keyword: Run Control  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 Keyword: Run Control  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  IDD Description (shortened)  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 Temperature N2, \field February Ground Temperature N3, \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 Keyword—note all one word 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 Example or 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;

47 Keyword: GroundReflectances  IDD Description (shortened)  Purpose: to set the reflectance of the ground surrounding the building (affects radiation incident on building surfaces) GroundReflectances, N1, \field January Ground Reflectance N2, \field February Ground Reflectance N3, \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 Keyword—note all one word 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 Example or 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  IDD Description (shortened)  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 Keyword: Snow Ground Reflectance Modifiers  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 Keyword: Snow Ground Reflectance Modifiers  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 Example or Snow Ground Reflectance Modifiers, 1.5, !- Ground Reflected Solar Modifier 2.0; !- Daylighting Ground Reflected Solar Modifier Snow Ground Reflectance Modifiers, 1.5, 2.0;

54 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)