Introduction to EnergyPlus - Jordan University of Science and …mzali/courses/Fall14/Arch 754/slides... · 2014-11-17 · Oct 2012 Introduction to EnergyPlus - Part 1 - EnergyPlus

Introduction to EnergyPlus

October 2012, EnergyPlus v7.2.0Material prepared by GARD Analytics, Inc. under contract to the U.S. Department of Energy.

All material Copyright 2002-2012 U.S. Department of Energy and GARD Analytics, Inc.All rights reserved.

Oct 2012 Introduction to EnergyPlus - Part 1 - EnergyPlus Overview 2

Acknowledgements

The following have contributed to the development of these workshop materials:

D.B. Crawley - Bentley Systems (formerly U.S. Department of Energy)M.J. Witte, R.H. Henninger - GARD Analytics

T.L. Cornell – (formerly GARD Analytics)N. Long – National Renewable Energy Laboratory

R.J. Liesen – U.S. Army CERL (formerly Univ. of Illinois at Urbana-Champaign)R.K. Strand – Univ. of Illinois at Urbana-Champaign

C.O. Pedersen – COP Associates (formerly Univ. of Illinois at Urbana-Champaign)L.K. Lawrie - DHL Consulting (formerly U.S. Army CERL)

W.F. Buhl, F.C. Winkelmann – (formerly Lawrence Berkeley National Laboratory)

Current funding - National Renewable Energy Laboratory (NREL) Prior funding – National Renewable Energy Laboratory (NREL), Lawrence Berkeley

National Laboratory (LBNL), and National Energy Technology Laboratory (NETL) by subcontract through the University of Central Florida/Florida Solar Energy Center


EnergyPlus Team U.S. Department of Energy, DC Lawrence Berkeley National Laboratory, CA National Renewable Energy Laboratory, CO Oak Ridge National Laboratory, TN Pacific Northwest National Laboratory, WA Florida Solar Energy Center, FL DHL Consulting, CO GARD Analytics, IL Oklahoma State University, OK University of Illinois at Urbana-Champaign, IL


EnergyPlus Team

GARDUIUCNREL

DHLLBNL

PNNL

ORNLDOE

OSU

FSEC


Part 1 – EnergyPlus Overview


Part 1 Outline

EnergyPlus Background and ConceptsStructure and Simulation ManagersFeatures and Capabilities EnergyPlus ComponentsInput and OutputUser InterfacesOpenStudio Plugin


Version Status

Current version 7.2.0, October 2012

Twice yearly updates—April and October

Keep old versions installed Default path has version number: EnergyPlusV7-2-0 Useful for revisions to past work Old installers and passwords are not available

Workshop Materials are primarily 7.2.0


What is EnergyPlus?

Fully integrated building & HVAC simulation program Based on best features of

BLAST (U.S. Dept of Defense) and DOE-2.1E (U.S. Dept of Energy)plus many new capabilities

Windows XP/Vista/7/8, Linux, Mac 32-bit and 64-bit versions

Main install is simulation engine and select utilities Interfaces available separately

Info at www.energyplus.gov


EnergyPlus Concepts

Simple input/output file structuresNo surface, zone or system limits

Defaults to 500 zones per air handler and 500 coils per plant loop, but this can be increased by editing master file (IDD) if needed

Other software linked in AIRNET, multi-zone air flow combining wind-

induced flow and air distribution system DElight complex daylighting Slab & Basement, 3-d heat transfer preprocessors


EnergyPlus Structure withIntegrated Simulation Manager

Third-PartyUser

Interfaces

Update

Feedback

Zone

Conditions

Heat andMass

BalanceSimulation

BuildingSystems

Simulation

Building Description

Calculation Results

Da t

a

EnergyPlusSimulation Manager

Data

Data

Data

Data

DescribeBuilding

DisplayResults

Dat

a

Window 5Calcs

AirflowNetwork

Ground HtTransfer

FutureModules

SPARK

PollutionModels

On-SitePower

FutureModules


Integrated Simulation Manager

Simultaneous simulation of loads, systems and plant Building Heat Balance Manager HVAC System Simulation Manager

Air and water loops are solved iteratively at each time step Not a single-pass calculation as in some other hourly

simulation tools Tighter coupling between the air- and water-side of the

system and plant Loads “not met” result in zone temperature and

humidity changes Allows capacity limits to be modeled more realistically


Loads Features and Capabilities

Heat Balance Method Room and surface heat balance every time step Conduction, convection, radiation

Sub-hourly time steps Default is six 10-minute timesteps per hour

Room air models Default is “well-stirred” with uniform temperature Other options: displacement vent, cross vent,

UFAD, Mundt, user-defined temperature patterns


Loads Features and Capabilities (cont’d)

Room surface heat transfer 1-D heat transfer Uniform surface temperatures Uniform long and short wave radiation Diffuse radiating and reflecting surfaces Internal heat sources (optional)

Time dependent conduction - thermal mass Conduction transfer functions (default) Optional finite difference model

Optional variable properties to model phase-change materials


Loads Features and Capabilities (cont’d)

Moisture Models Effective Moisture Penetration Depth (EMPD)

Simplified moisture model Moisture absorbed/released, no transport through

surfaces Estimates moisture interactions between the space air

and interior surfaces and furnishings

Combined Heat And Moisture Finite Element Heat and moisture transfer model (advanced feature) MaterialProperty:HeatAndMoistureTransfer:*


HVAC Features and Capabilities

Flexible specification of HVAC equipment Components arranged on loops Not limited to predefined system configurations

“HVACTemplates” for standard system configurations

More than one system may serve a zone e.g. Dedicated outdoor air system

plus fan coil units


EnergyPlus Components

Installing EnergyPlusEnergyPlus Folders

ShortcutsDocumentation


Installing EnergyPlus

After installation the EnergyPlus directory will contain the following subdirectories (if default components are selected):

Default path is C:\EnergyPlusV7-2-0

BACKUP DataSets Documentation Example Files MacroDataSets

PostProcess PreProcess WeatherData


DataSets and MacroDataSets Folders

DataSets – Predefined Objects Materials Constructions Schedules Chillers Holidays and more

MacroDataSets ##def blocks for parametric batch runs Utility rate tariffs and emissions factors for

37 utilities (2000-2005 data) Solar collector performance data PV performance data


Documentation Folder

Documentation User & Developer

Documentation Bookmarks to

Navigate Searchable &

Indexed PDF Format Adobe Reader 8.0 or

higher recommended (www.adobe.com)

Requires Adobe Reader 7.0 minimum


Documentation

Documentation Main Menu C:\EnergyPlusV7-2-0

\Documentation\EPlusMainMenu.pdf

Start All Programs EnergyPlus V7-2 Programs EnergyPlus Documentation Main Menu

User & Developer Documentation

Indexed –“Press to Search Documents”


ExampleFiles Folder

Over 400 example inputs Named by key feature,

5ZoneSupRetPlen.idf = “5 zone system with supply and return plenum”

ExampleFiles.xlsTable of key features

ExampleFiles-ObjectsLink.xlsLookup by object class name

Many concepts bestlearned by example

BasicsFiles – tutorial examples, see “Getting Started” doc


WeatherData Folder

EPW WeatherData 5 locations included in standard install Download additional EPW weather files at

www.energyplus.gov 1000s of sites available worldwide

DDY Files ASHRAE Design Days and Location in EnergyPlus syntax Included in weather zip files from www.energyplus.gov


Weather Data(epw file)

Weather year for energy use comparisonsHourly data typical, can be subhourlyCan be less than a full yearData include temperature, humidity, solar,

wind, rain and snow flags, rainfall, etc. Interpolated for EnergyPlus time steps

Solar values are mid-hour average or total All other values are on-the-hour instantaneous Linear interpolation for each time step


Start Menu Shortcuts

Start Programs EnergyPlus V7-2 Programs Documentation Main Menu EP-Launch – home base IDFEditor – input file editor Readme Uninstall Weather Converter

Part 2 - Building Envelope and Internal Loads



Oct 2012 Introduction to EnergyPlus - Part 2 - Building Envelope and Internal Loads 2

Part 2 Outline

Building Envelope OverviewMaterials and ConstructionsBuilding GeometrySolar and Shadowing OptionsZonesTypes of Surfaces Internal LoadsOpenStudio Plugin for SketchUp


Building Envelope Overview

MaterialsConstructionsSurfacesZonesBuilding


Materials and Constructions

Materials define single layers Brick, Concrete, Glass, etc. Material definition includes thickness For different thickness of same material, must

define a new material

Constructions define sets of material layers Exterior wall = Brick+Insulation+Gypsum Board

See Input Output Reference –Surface Construction Elements


Materials for Opaque Surfaces

Material Has thermal mass Roughness affects convection coefficients Thickness, conductivity, density, and specific heat Absorptances (see later slide for details)

Material,PLASTERBOARD-2, !- NameRough, !- Roughness0.01000, !- Thickness {m}0.16000, !- Conductivity {W/m-K}950.000, !- Density {kg/m3}840.00, !- Specific Heat {J/kg-K}0.900000, !- Thermal Absorptance0.600000, !- Solar Absorptance0.600000; !- Visible Absorptance


Materials for Opaque Surfaces (cont’d)

Material:NoMass Has no thermal mass Specify only thermal resistance, absorptance, and

roughness

Material:AirGap Also no thermal mass, just resistance Cannot be an outside layer, no absorptances This is a fixed resistance, does not model

convective circulation within the airspace nor radiant transfer across the airspace

Specify effective resistance for different orientation, thickness, etc.


Material Absorptances

Thermal Absorptance Fraction of incident long wavelength radiation that

is absorbed by the material Used when calculating the long wavelength

radiant exchange between various surfaces

Visible Absorptance Fraction of incident visible wavelength radiation

that is absorbed by the material Used when calculating the amount of incident

visible radiation absorbed by various surfaces


Material Absorptances (cont’d)

Solar Absorptance Fraction of incident solar radiation that is

absorbed by the material Used when calculating the amount of

incident solar radiation absorbed by various surfaces

Solar radiation includes the visible spectrum as well as infrared and ultraviolet wavelengths


Relating Absorptance to Other Properties

Not all handbooks publish “absorptance”

For thermal Absorptance = Emissivity = Emittance

For solar and visible for opaque materials Transmittance = 0.0 thus, Absorptance = 1.0 - Reflectance


Materials for Windows

WindowMaterial:Glazing WindowMaterial:Glazing:RefractionExtinctionMethod

WindowMaterial:Gas Air, Argon, Krypton, Xenon, or Custom

WindowMaterial:GasMixture Mixture of Air, Argon, Krypton, Xenon

WindowMaterial:ShadeWindowMaterial:BlindWindowMaterial:Screen


Simple Window Properties Option

WindowMaterial:SimpleGlazingSystemSimple properties

U-factor Solar Heat Gain Coefficient (normal) Visible Transmittance (normal)

Converted into simple glazing layer with angular dependence

Use only when no detailed glazing data is available


Construction

List material layers from outside to insideConvection coefficients (film layers) are

added automatically Several convection models to choose from Coefficients vary with conditions User may specify fixed coefficients

Construction,CEILING39, !- NameC5 - 4 IN HW CONCRETE, !- Outside LayerE4 - CEILING AIRSPACE, !- Layer 2E5 - ACOUSTIC TILE; !- Layer 3


Constructions with FramingEnergyPlus surfaces are 1-D heat transfer

with homogeneous layersOption 1 - Surfaces described in 2 parts

2 Construction objects Framed section (e.g. Brick, Wood, Gypsum Board) Insulated section (e.g. Brick, Insulation, Gypsum Board)

2 Surface objects of appropriate area

Option 2 – Composite construction Use 3-D heat transfer tool from ORNL to model

full thermal bridge effects Tool generates homogeneous layers which results

in equivalent thermal performance


DataSets for Materials and Constructions

EnergyPlus\DataSets\ ASHRAE_2005_HOF_Materials.idf CompositeWallConstructions.idf (very limited)

WindowBlindMaterials.idf WindowConstructs.idf WindowGasMaterials.idf WindowGlassMaterials.idf WindowScreenMaterials.idf WindowShadeMaterials.idf


Building Geometry

Coordinate SystemGeometry Rules

BuildingSolar and Shadowing Options

Zone


Coordinate System

Three dimensional (3D) Cartesian coordinate system

Right hand coordinate system X-axis points east Y-axis points north Z-axis points up

Y Axis

X Axis

Z AxisBuilding and/or Zone North Axis


Geometry Rules (cont’d)World Coordinates

All surface coordinates refer to global origin Building and Zone north axes ignored Zone origins ignored

or Relative Coordinates Zone origins relative to building origin Surfaces relative to zone origins Subsurfaces relative to zone origins Building and Zone north axes are used


Geometry Rules (cont’d)

or Relative Coordinates with all Zone Origins at (0,0,0) All surface coordinates refer to global origin Building and Zone north axes are used

Daylighting Reference Pt Coordinates Separate option for world or relative Default is relative to zone origin


Relative Coordinate Options

Building North Axis Relative to true north Rotates about bldg origin

Zone North Axis Relative to building north Rotates about zone origin

Zone Origin Relative to building origin

(0,0,0)

Surface vertices in zone coordinates

True North Building North Axis

+30 degrees

Zone North Axis

(0,0,0)Building Origin

Zone Origin (x, y, z)


Building Object

North axis Rotate entire building (relative coordinates only)

Terrain Alter wind speed vs. height Impacts detailed exterior convection coefficients

Convergence tolerances for warmup days Initial day of each environment (design day or run

period) repeats until tolerances are met “Loads Initialization did not Converge” warning if

max warmup days limit is reached Can specify max number of warmup days


Solar Distribution Options

Specified in the Building objectMinimalShadowing

No exterior shadowing except from door and window reveals

All direct beam solar radiation incident on floor If no floor, direct beam solar distributed to all

surfaces

FullExterior Exterior shadowing caused by all surfaces (heat

transfer and shading), door and window reveals All direct beam solar radiation incident on floor


Solar Distribution Options (cont’d)

FullInteriorAndExterior Exterior shadowing same as FullExterior Direct beam solar radiation falls on all surfaces in

the zone in the direct path of the sun’s rays Solar entering one window can leave through

another window Zone must be convex:

A line passing through the zone intercepts no more than two surfaces

An L-shaped zone is not convex

For non-convex zones, either split them up or use FullExterior option


Convex Zones

Convex zones Non-Convex zones


Exterior Solar Reflection

In Building object Solar Distribution field, add “WithReflections”

FullExteriorWithReflectionsFullInteriorAndExteriorWithReflections

For Walls, Roofs, Windows, etc. Uses exterior material absorptance/reflectance properties

For Shading Surfaces ShadingProperty:Reflectance Specifies the reflectance properties of a shading surface Single value, not scheduled Can specify specular and diffuse fractions


Zones

Thermal Zones A zone is an air mass and associated

surfaces, internal gains, HVAC, etc. Group rooms by thermal similarity Not necessarily a contiguous space Can be multiplied

EnergyPlus only models what is explicitly described Missing wall does not let air in Missing roof does not let sun in Gaps or voids between zones do nothing


Zone ObjectZone origin and north axis used with relative

coordinates and for daylightingOptional zone multiplierConvection options override global settingZone,

SPACE1-1, !- Name0, !- Direction of Relative North {deg}0, !- X Origin {m}0, !- Y Origin {m}0, !- Z Origin {m}1, !- Type1, !- Multiplier, !- Ceiling Height {m}, !- Volume {m3}, !- Zone Inside Convection Algorithm; !- Zone Outside Convection Algorithm


Surfaces

Types of SurfacesShading SurfacesBuilding Surfaces

Shading RulesSurface Geometry


Types of Surfaces

Building Surfaces Walls, roofs, floors, windows, doors, internal mass, etc. Always associated with a Zone Transfer and store heat Often called “heat transfer surface” Cast shadows Reflect solar (optional)

Shading Surfaces Cast shadows Reflect solar (optional) No heat transfer May hold other elements such as photovoltaic panels


Shading Surfaces

Automatically mirrored to shade in both directions Can describe facing

either way Will show twice in lists of

surfaces, original and mirrored

Optional transmittance schedule Default is always opaque


Shading Surfaces (cont’)

Optional reflectance Default is non-reflecting ShadingProperty:Reflectance Specify specular and diffuse

reflectances Must also turn on

“withReflections” option in Building object

Three types Site Building Zone/Surface


Site Shading

Always world coordinates relative to global origin

Never rotatese.g. neighboring

building, mountain, existing trees

Shading:SiteShading:Site:Detailed


Building Shading

Always relative to global origin

Rotates with building north axis

e.g. canopies, fences, parking deck, new trees

Shading:BuildingShading:Building:

Detailed


Zone/Surface Shading

World or relative coordinates

Rotates with building north axis

Rotates with zone north axis

e.g. fins and overhangs near a window or door


Zone/Surface Shading

Shading:Zone:DetailedRelative to a window or

door Shading:Overhang Shading:Overhang:Projection Shading:Fin Shading:Fin:Projection


Shading Rules Exterior building surfaces cast

shadows Shadows only cast in hemisphere in

direction of outward facing normal A roof extended beyond walls will

not cast shadows downward Need downward facing overhang

surface Shading surfaces are

bi-directional (unless disabled) All surfaces reflect solar as diffuse

inside zone Interior surfaces do not cast

shadows But they do block daylighting See next slide?! ?!


Attics, Roofs, Overhangs

Shading Surfaces vs. Heat Transfer Surfaces

Conditioned

AtticAttic

Conditioned


Building/Heat Transfer Surfaces

Walls, roofs, floors, windows, doors Inside environment is always a zoneOutside environment

Exterior with or without wind and sun Other zone (interzone heat transfer) Adiabatic (like internal mass) Ground (GROUND TEMPERATURES) User-Specified (OtherSideCoefficients) Special models (OtherSideConditionsModel) Slab or Basement ground temps


Building/Heat Transfer Surfaces

Detailed Building Surface Objects 3 or more vertices, must specify x,y,z for every vertex BuildingSurface:Detailed

Walls, Roofs, Floors, Ceilings FenestrationSurface:Detailed

Windows and Doors

Simple Building Surface Objects Wall:Exterior, Wall:Interior, etc. Rectangular Starting vertex, height, width, tilt, azimuth

InternalMass No geometry position, just construction type and area


Zone 1

Zone 2

Zone 3

Pair of walls between Zones 1 and 3



Interzone SurfacesMatched pair of surfaces

One surface in each zone Surfaces reference each other Reverse order of

construction Describe both in input OR Describe one in input and

auto generate the other

Surface adjacent to more than one zone must be split(see example on next slide)


BuildingSurface:Detailed,Zone 1 Ceiling, !- NameCEILING, !- Surface TypeCLNG-1, !- Construction NameZone 1, !- Zone NameSurface, !- Outside Boundary ConditionPlenum Floor 1, !- Outside Boundary Condition Object. . .

BuildingSurface:Detailed,Plenum Floor 1, !- NameFLOOR, !- Surface TypeCLNG-1R, !- Construction NamePLENUM-1, !- Zone NameSurface, !- Outside Boundary ConditionZone 1 Ceiling, !- Outside Boundary Condition Object. . .

Construction, CLNG-1, !- NameMAT-CLNG-1, !- Outside LayerCC03; !- Layer 2

Construction, CLNG-1R, !- NameCC03, !- Outside LayerMAT-CLNG-1; !- Layer 2

Interzone SurfacesExample 1

Reverse Material Order

Matched Surfaces Reference Each Other


BuildingSurface:Detailed,Zone 1 Ceiling, !- NameCEILING, !- Surface TypeCLNG-1, !- Construction NameZone 1, !- Zone NameZone, !- Outside Boundary ConditionPLENUM-1, !- Outside Boundary Condition Object. . .

CONSTRUCTION, CLNG-1, !- NameMAT-CLNG-1, CC03; !- Outside Layer, Layer #2

Interzone SurfacesExample 2

Explicitly input only one of the two surfaces

Specify “Zone” as Outside Boundary Condition

and Name of adjacent zone

Adjacent surface generated internally


Windows and Doors

FenestrationSurface:DetailedWindows, Doors, Glass Doors

Only windows and glass doors transmit sunlight Skylights are entered as a window Can have interior windows

Must be placed on a base surfaceFenestration surface area is subtracted

from base surfaceCannot completely cover base surface –

must leave a small perimeter


Simple Window and Door Objects

Window, Window:InterzoneDoor, Door:InterzoneGlazedDoor, GlazedDoor:InterzoneStarting x,z coordinates are always lower left

corner of window/door relative to lower left corner of base surface

Simple surface origin is always relative to lower left corner of base surface, (no matter what is input for GlobalGeometryRules, see later slide)


Door and Window Details

Outside reveal defined by window vertices

WindowProperty:FrameAndDivider specifies details of frame, sill, inside reveal, etc.

Fenestration surface area is glazing only

Frame is outside this area and subtracts more from base surface

Windows can have a multiplier

InsideRevealSurface

Wall

Wall

Inside SillDepth

Glazing

Sill

OutsideRevealDepth

OutsideRevealDepth

InsideRevealDepth

Inside SillDepth

Glazing

Frame

(b)(a)

Wall

OutsideRevealSurface

InsideRevealDepth


Geometry RulesVertex-based

Specify 3D coordinates of each corner of a surface As viewed from the outside of the surface Specify global rules used for all surfaces

Surface starting position Upper Left, Upper Right, Lower Left, Lower Right

Order of vertex entry Clockwise, Counterclockwise

GlobalGeometryRules,UpperLeftCorner, !- Starting Vertex PositionCounterClockWise, !- Vertex Entry DirectionWorld; !- Coordinate SystemRelative, !- Daylighting Reference Point Coordinate SystemRelative, !- Rectangular Surface Coordinate System


Horizontal SurfacesFlat roofs face up (tilt = 0)Floors face down (tilt = 180)Where’s the upper left corner if it’s flat?

Can choose any vertex as starting point

BUT . . . Choose equivalent starting point for subsurfaces Skylights, roof hatches, trap doors, etc. For example, start roof and skylight at NE corner This avoids “surface does not surround

subsurface” error


Inside Outside or Centerline?

Walls have thickness for heat transferWalls have no thickness for geometryWhat dimensions to use?

For most conventional construction, use whatever is convenient from the plans

Typically, outside dimensions for exterior surfaces, centerline for interior surfaces

For very thick constructions, use centerline dimensions to get proper amount of thermal mass

Zone volume may be specified in Zone object as needed, otherwise computed from surfaces

Standards, such as 90.1, may specify which to use


Surface Geometry CheckingDrawing

Open idf in OpenStudio SketchUp plugin Output:Surfaces:Drawing, DXF; Output:Surfaces:Drawing, VRML;

Lists Output:Table:SummaryReports, EnvelopeSummary; Output:Surfaces:List, Details;

List surfaces with area, type, azimuth, tilt, etc. eio file, comma-separated, view in spreadsheet

! <Zone/Shading Surfaces> <Zone Name>/#Shading Surfaces # Surfaces! <HeatTransfer/ShadingSurface> <Surface Name> <Surface Class> <Base Surface> <Construction>! <Units>Zone_Surfaces ZONE ONE 4HeatTransfer_Surface ZN001:WALL001 WALL R13WALL

Nominal U (w/o film coef) Area (Net) Azimuth Tilt ~Width ~Height Reveal{W/m2-K} {m2} {deg} {deg} {m} {m} {m}

0.44 69.67728 180 90 15.24 4.57 0


Zone Internal Loads

Lights See daylighting presentation for controls

People Optional thermal comfort reports

Equipment Electric, Gas, Hot Water, Steam, Other Specify fraction radiant, latent, and

“lost” (exhausted, no gain to space) Remainder is sensible convective gain

Visual Tools for CreatingEnergyPlus Geometry

OpenStudiohttps://openstudio.nrel.gov/

Simergy (in beta)http://simergy-beta.lbl.gov/

Other Third-Party Toolshttp://energyplus.gov/other_tools.cfm



OpenStudio Plugin for SketchUp

Trimble SketchUp Intuitive 3-D drawing software Free or pro version

OpenStudio Plugin adds EnergyPlus functionality toSketchUp 3-D environment


OpenStudio Plugin VersionsKey Differences

Legacy OpenStudio Plugin Read/Write EnergyPlus Input Files (idf) Unsupported idf objects untouched Run EnergyPlus and view results in SketchUp

OpenStudio Plugin with OpenStudio Application Read/Write OpenStudio Model Files (osm) Import/Export EnergyPlus Input Files (idf) Unsupported idf objects are lost Run EnergyPlus and view results outside SketchUp Advanced geometry creation tools and scripts Integration with Building Component Library


OpenStudio Plugin Tasks

Create and edit building geometryAdd internal gains and daylightingAdd simple ideal HVAC systemSelect some reporting optionsRun EnergyPlus simulation and display resultsSee online tutorials


Create Building Geometry


View/Edit Geometry


Edit a Zone


Info Tools


Run Simulation (Legacy)


Run Simulation (Legacy)


Data Visualization


Data Visualization


OpenStudio Plugin Limitations

HVAC Systems are added/edited in OpenStudio application or other tools

Not a translator from SketchUp to E+ Cannot automatically convert a SketchUp model Must create SketchUp building surfaces with

OpenStudio active Most common approach is to trace over existing

model Some existing objects can be converted with

copy/paste-in-place (see tutorials) Some loose objects can be projected onto model

OpenStudio Application Features

Simulation settingsSpaces/Stories/Thermal ZonesEnvelope Materials/ConstructionsInternal GainsHVAC SystemsRun scriptsRun simulation and

view resultsOct 2012 Introduction to EnergyPlus - Part 2 - Building Envelope and Internal Loads 63

Part 3 –Input Structure, Global Inputs, Output and

Auxiliary Tools



Oct 2012 Introduction to EnergyPlus - Part 3 - Input/Output, Global Inputs and Auxiliary Tools 2

Part 3 Outline

Input Object StructureGlobal InputsOutputAuxiliary Tools

EP-Launch IDF Editor Other Software Tools


General Philosophy of Input/Output/Weather

Designed for interfaces yet human readableSimple, free-format text filesComma-separated “Object-based”

Objects describe a part of the model e.g. Surface object, Fan object, Report object Objects may be in any order within the input file All cross-referencing is explicit within the objects


Input/Output Files

Input Data DictionaryThis file is created byEnergyPlus developers.

Input Data FileThis file will be createdby UserObject,data,data,…,data;Object,data,data,…,data;

Input Data Dictionary(IDD)

EnergyPlus ProgramMain Program

Module

Module

Module

Module

Module

Module

File Types:Standard ReportsStandard Reports (Detail)Optional ReportsOptional Reports (Detail)InitializationReports

Overview of File Format:HeaderData DictionaryData

Note: These files will be created by EnergyPlus.

Output Files

Out

put P

roce

ssor

Input Data File (IDF)


Input Object Structure Begin with object type followed by comma Alpha and Numeric fields in exact order Fields separated by commas Last field followed by semi-colon Commas are necessary placeholders Alpha fields 100 characters maximum, pushed to UPPERCASE Can have more than one field on a line “!” exclamation point begins comments “!-” automatic end-line comment, IDF Editor and Transition will overwrite these

Site:Location,CHICAGO_IL_USA TMY2-94846, !- Name41.78, !- Latitude {deg}-87.75, !- Longitude {deg}-6.00, !- Time Zone {hr}190.00; !- Elevation {m}

Output:Variable, *, Outdoor Dry Bulb, hourly;


Input Error Detection

Errors reported in ERR output file Input Processor checks field type, max, min,

required fields, based on IDD specificationsSimulation modules perform additional checks Inputs are not processed sequentiallyCertain errors will terminate program before

all input retrieved by simulation modulesHINT: Fix errors at the top of the err file

first – later ones may be false due to confusion of earlier errors


Units

EnergyPlus idf always in SI units IDF Editor has option to view/edit in IP units

Schedule types must be tagged with units Writes idf file in SI units

EnergyPlus outputs in SI units Optional IP units for some reports

EP-Launch has IP units option for output View Options Miscellaneous “Convert ESO/MTR to IP Units” Main csv and Meter.csv outputs in IP units


Global Inputs

SchedulesLocation and Environment

Simulation Control


Schedules

Can be used to influence scheduling of many items, including: Occupancy density Occupancy activity Lighting Thermostatic controls Shading element density


ScheduleTypeLimits

ScheduleTypeLimits,Fraction, !- Name0.0, !- Lower Limit Value1.0, !- Upper Limit ValueCONTINUOUS; !- Numeric TypeDimensionless; !- Unit Type

ScheduleTypeLimits,Temperature, !- Name-60, !- Lower Limit Value200, !- Upper Limit ValueCONTINUOUS; !- Numeric TypeTemperature; !- Unit Type

Used to validate schedule values and assign units (optional but recommended)

Facilitates IP units in IDF Editor and other interfaces


Schedule:Day:HourlySchedule:Day:Hourly,Weekday People, !- NameFraction, !- Schedule Type0.0, !- Hour 10.0, !- Hour 2. . .0.5, !- Hour 8 (7-8am)1.0, !- Hour 91.0, !- Hour 10. . .1.0, !- Hour 15 (2-3pm)1.0, !- Hour 160.5, !- Hour 170.1, !- Hour 180.0, !- Hour 19. . .0.0; !- Hour 24 (11-12pm)

The day schedule description is a name and 24 hourly values

Other forms Schedule:Day:Interval Schedule:Day:List Can handle subhourly

schedule changes Schedule:File

Hour 1 is Midnight to 1am


Schedule:Week:Daily

Schedule:Week:Daily,People Normal Week, !- NameWeekend People, !- Sunday Schedule:Day NameWeekday People, !- Monday Schedule:Day NameWeekday People, !- Tuesday Schedule:Day NameWeekday People, !- Wednesday Schedule:Day NameWeekday People, !- Thursday Schedule:Day NameWeekday People, !- Friday Schedule:Day NameWeekend People, !- Saturday Schedule:Day NameHoliday People, !- Holiday Schedule:Day NameWeekday People, !- SummerDesignDay Schedule:Day NameHoliday People, !- WinterDesignDay Schedule:Day NameAnnual Mtg People, !- CustomDay1 Schedule:Day NameTraining People; !- CustomDay2 Schedule:Day Name

The week description has an identifier and 12 names corresponding to previously defined Schedule:Day:* objects


Schedule:Year

Schedule:Year,Office People, !- NameFraction, !- Schedule TypePeople Normal Week, !- Schedule:Week Name 11, !- Start Month 11, !- Start Day 15, !- End Month 131, !- End Day 1People Summer Week, !- Schedule:Week Name 26, !- Start Month 21, !- Start Day 28, !- End Month 231, !- End Day 2People Normal Week, !- Schedule:Week Name 39, !- Start Month 31, !- Start Day 312, !- End Month 331; !- End Day 3

Annual schedule Associates a Schedule:Week:* with a range of datesMay reference up to 53 different Schedule:Week:* objects


Schedule:Compact

Schedule:Compact,Minimum Outside Air, !- NameFraction, !- Schedule Type Limits NameThrough: 12/31, !- Field 1For: Weekdays SummerDesignDay, !- Field 2Until: 24:00, !- Field 30.15, !- Field 4For: Weekends WinterDesignDay Holidays AllOtherDays, !-Field 5Until: 24:00, !- Field 60.05; !- Field 7

Annual schedule declared in a single object


Location and Environment

LocationDesign DayRun Period

Special DaysDaylight Saving TimeGround Temperatures


Site:Location

Latitude, longitude and time zone determine solar angles and intensities

Elevation used for standard air density Used to convert air volume flow rates to mass flow

Predefined Site:Location object in *.ddy files included with weather data

Site:Location,CHICAGO_OHARE_INTL_IL_USA Design_Conditions, !- Name41.98000, !- Latitude {deg}-87.90000, !- Longitude {deg}-6.000000, !- Time Zone {hr}201.0000; !- Elevation {m}


SizingPeriod:DesignDaySingle-day simulation

Simulation initialized by repeating day until results agree within tolerances specified in Building object

Drives autosizing calculationsCan also be simulated to produce outputDay types

Heating Cooling Dry Bulb Cooling Dew Point Cooling Wet Bulb Others as desired


SizingPeriod:DesignDay Cooling Example

Chicago Ohare Intl Ap Ann Clg .4% Condns DB=>MWB, !- Name7, !- Month

21, !- Day of MonthSummerDesignDay,!- Day Type

33.3, !- Maximum Dry-Bulb Temperature {C}10.5, !- Daily Dry-Bulb Temperature Range {C}

DefaultMultipliers, !- Dry-Bulb Temperature Range Modifier Type, !- Dry-Bulb Temperature Range Modifier Schedule Name

Wetbulb, !- Humidity Condition Type23.7, !- Wetbulb at Maximum Dry-Bulb {C}

, !- Humidity Indicating Day Schedule Name, !- Humidity Ratio at Maximum Dry-Bulb {kgWater/kgDryAir}, !- Enthalpy at Maximum Dry-Bulb {J/kg}, !- Daily Wet-Bulb Temperature Range {deltaC}

98934., !- Barometric Pressure {Pa}5.2, !- Wind Speed {m/s} design conditions vs. traditional 3.35 m/s (7mph)230, !- Wind Direction {Degrees; N=0, S=180}No, !- Rain {Yes/No}No, !- Snow on ground {Yes/No}No, !- Daylight Savings Time Indicator

ASHRAETau, !- Solar Model Indicator, !- Beam Solar Day Schedule Name, !- Diffuse Solar Day Schedule Name

0.455, !- ASHRAE Clear Sky Optical Depth for Beam Irradiance (taub)2.050; !- ASHRAE Clear Sky Optical Depth for Diffuse Irradiance (taud)


SizingPeriod:DesignDay Heating Example

Chicago Ohare Intl Ap Ann Htg 99% Condns DB, !- Name1, !- Month

21, !- Day of MonthWinterDesignDay,!- Day Type

-16.6, !- Maximum Dry-Bulb Temperature {C}0.0, !- Daily Dry-Bulb Temperature Range {C}

DefaultMultipliers, !- Dry-Bulb Temperature Range Modifier Type, !- Dry-Bulb Temperature Range Modifier Schedule Name

Wetbulb, !- Humidity Condition Type-16.6, !- Wetbulb at Maximum Dry-Bulb {C}

, !- Humidity Indicating Day Schedule Name, !- Humidity Ratio at Maximum Dry-Bulb {kgWater/kgDryAir}, !- Enthalpy at Maximum Dry-Bulb {J/kg}, !- Daily Wet-Bulb Temperature Range {deltaC}

98934., !- Barometric Pressure {Pa}4.9, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15

mph)270, !- Wind Direction {Degrees; N=0, S=180}No, !- Rain {Yes/No}No, !- Snow on ground {Yes/No}No, !- Daylight Savings Time Indicator

ASHRAEClearSky, !- Solar Model Indicator, !- Beam Solar Day Schedule Name, !- Diffuse Solar Day Schedule Name, !- ASHRAE Clear Sky Optical Depth for Beam Irradiance (taub), !- ASHRAE Clear Sky Optical Depth for Diffuse Irradiance (taud)

0.00; !- Clearness {0.0 to 1.1}

Note ZERO Clearness = NO SUN


SizingPeriod:DesignDay Day Type and Schedules

Use day type to control schedules Schedules can have different 24-hr profiles for

every day type, including WinterDesignDay and SummerDesignDay

Examples WinterDesignDay

Set internal loads schedules to zero SummerDesignDay

Set people schedules to full occupancy Set thermostat schedules to have

no setback for design day autosizing


SizingPeriod:DesignDay Data Sources

*.ddy files Included in weather data zip files on web site 2009 ASHRAE data

MacroDataSets folder Locations-DesignDays.xls Links to regional design day dataset files for 7

WMO regions and California CTZ 2009 ASHRAE Fundamentals data


Sizing with Weather Periods

Multi-day design sizing periodData from weather file

SizingPeriod:WeatherFileDaysUse a weather file period for design sizing calculations

SizingPeriod:WeatherFileConditionType Use a typical or extreme period contained in the epw weather file created heuristically from the weather file data for design sizing calculations


RunPeriodSpecifies weather file simulation periodSimulation initialized by repeating first day of

RunPeriod until results agree within tolerancesMay have multiple RunPeriods, but no overlap

RunPeriod,1, !- Begin Month1, !- Begin Day of Month12, !- End Month31, !- End Day of MonthMonday, !- Day of Week for Start DayNo, !- Use Weather File Holidays and Special DaysNo, !- Use Weather File Daylight Saving PeriodNo, !- Apply Weekend Holiday RuleYes, !- Use Weather File Rain IndicatorsYes, !- Use Weather File Snow Indicators1; !- Number of Times Runperiod to be Done


RunPeriodControl:SpecialDays

Add holidays and special days for weather runStandard weather files have no holidays

defined12 Day types: Sunday-Saturday, Holiday,

SummerDesignDay, WinterDesignDay, CustomDay1, CustomDay2

USHolidays-DST.idf in datasets folderRunPeriodControl:SpecialDays,

Special Convocation Week,!- Name9/8, !- Start Date5, !- Duration {days}CustomDay1; !- Special Day Type


RunPeriodControl:DaylightSavingTime

Overrides weather file DST period (if present)Standard weather files have no daylight

savings period definedPredefined object in ddy fileMultiple date formats valid:

“MM/DD” “DD <Month>” “<Month> DD”<Nth or Last> <Weekday> in <Month><Month> can be 3 char or full name<Weekday> is Sunday, Monday, etc.

RunPeriodControl:DaylightSavingTime,1st Sunday in April, !- Start DateLast Sunday in October; !- End Date


SimulationControl

Control sizing calculations, if present Control environment

Simulate sizing periods, if present Simulate weather run periods, if present

HINT: Start with Sizing Periods only, with hourly output – faster – easier to understand the data – when running well, then switch to annual weather run

SimulationControl,Yes, !- Do Zone Sizing CalculationYes, !- Do System Sizing CalculationYes, !- Do Plant Sizing CalculationYes, !- Run Simulation for Sizing PeriodsNo; !- Run Simulation for Weather File Run Periods


Types of Output

Output Report CommandsSummary and MonthlyReportsReport Data DictionaryReport VariablesReport Meters


Output Report CommandsOutput:Constructions;

Output:Surfaces:Drawing, DXF;

Output:Surfaces:List, Details;

Output:Table:TimeBins . . .

Output:Table:Monthly . . .

Output:Table:SummaryReports,Annual Building Utility Performance Summary;

OutputControl:Table:Style, HTML, InchPound;

List material and construction properties *.eio

Produce drawing of surfaces *.dxf

List all surfaces with area, tilt, construction, etc. *.eio

Bin report for specified variable

Monthly report for specified variables

Annual energy use report

Set table reports to csv, tab, txt, or html and select units option


Summary and Monthly Reports

“Table” output file csv, tab, txt, or html

Output:Table:SummaryReports Annual Building Utility Performance Summary

(or ABUPS or BEPS) AllSummary (all available summary reports) AllMonthly (all available monthly reports)

Output:Table:Monthly Custom monthly reports


Example - ABUPS


Example – ABUPS (cont’d)


Example - Envelope Summary


Output Reporting Flexibility

Select any variables available for outputSpecify output at time step, hourly, daily,

monthly, or environment intervalsSchedule each output variableSelect various meters by resource and

end-use


Report Data Dictionary (RDD and MDD Files)

Default Format, underlines indicate variable names . . .

Zone,Average,Outdoor Dry Bulb [C]HVAC,Sum,Zone/Sys Sensible Heating Energy[J]

Alternate Format as IDF objects . . .

Output:Variable,*,Outdoor Dry Bulb,hourly; !- Zone Average [C]Output:Variable,*,Outdoor Dew Point,hourly; !- Zone Average [C]

Lists available output variables for a given input file Must request in idf file:

Output:Variable Dictionary; (default format)Output:Variable Dictionary, IDF; (as objects)

.rdd file for report variables, .mdd file for meters


Output Variable Commands

Output:Variable, EAST ZONE, Zone Mean Air Temperature, Timestep;

Output:Variable, *, Zone Mean Radiant Temperature, Daily, Report Schedule;

Mean air temperature, only for EAST ZONE, every timestep

Mean radiant temperature, for all zones, daily average, only when “Report Schedule” is >0


CSV File SampleDate/Time Environment:Outdoor

Dry Bulb [C](Monthly)ZONE ONE:Zone/Sys Sensible Heating Energy[J](Monthly)

ZONE ONE:Zone/Sys Sensible Cooling Energy[J](Monthly)

ZONE ONE:Zone/Sys Air Temp[C](Monthly)

July 25.58495468 0.00E+00 19028775.23 24.4112152January -17.77778 253868837.1 0.00E+00 20.28659003January -4.63546707 4144370093 0.00E+00 20.43495965February -2.23312872 3151142586 0.00E+00 20.46221742March 1.603242608 2545318797 0.00E+00 20.54348182April 8.370677083 1431785319 324853.0522 21.20071107May 15.30398185 639305402.1 51404202.22 22.43806808June 21.09550347 164326207.4 145308752.2 23.40095162July 23.49973118 65628804.19 244539864.1 23.81873695August 21.75707325 96943677.86 103740404 23.32673507September 18.11458333 346023544.8 45088296.07 22.40959675October 11.73642473 1065565115 714539.5928 21.18788477November 4.232118056 2260965068 0.00E+00 20.49516327December -2.566599462 3853388966 0.00E+00 20.46126771


Meters

Accumulate multiple outputs Standard meters and user-defined meters Appropriate variables are grouped onto “meters” for

reporting purposes Values are put onto the *.mtr output file Meter component details in *.mtd output file Meter names applicable for the simulation are shown

on the .mdd file Meter names are of two forms:

<ResourceType>:<MeterType> <EndUseType>:< ResourceType >:<MeterType>


Input for Meters

Output:Meter, Electricity:*, Hourly;

Output:Meter, Electricity:Facility, monthly;

Output:Meter:MeterFileOnly, Cooling:Electricity, monthly;

Output:CumulativeMeter orOutput:CumulativeMeter:MeterFileOnly

Meter:Custom Meter:CustomDecrement

All electric meters, for all end uses and all levels

Master electric meter

Cooling equipment, report only to Meter.csv file

Report cumulative values

User-defined meterSubtract from a meter


Meter Details – Example

Zone lighting power consumptionmtd output lists all applicable meters

Meters for 674,SPACE1-1:Zone Lights Electric Consumption[J]

OnMeter=Electricity:Facility [J]OnMeter=Electricity:Building [J]OnMeter=Electricity:Zone:EAST ZONE [J]OnMeter=GeneralLights:Electricity [J]OnMeter=GeneralLights:Electricity:Zone:EAST ZONE [J]


Meter Details – Example (cont’d)

GeneralLights:Electricity end-use metermtd output lists all variables connected

to that meterFor Meter=GeneralLights:Electricity [J], ResourceType=Electricity, EndUse=GeneralLights, contents are:SPACE1-1:Zone Lights Electric ConsumptionSPACE2-1:Zone Lights Electric Consumption SPACE3-1:Zone Lights Electric ConsumptionSPACE4-1:Zone Lights Electric ConsumptionSPACE5-1:Zone Lights Electric Consumption


err Errors Output – always review this!eio Initialization and other Output –

environments, constructions, global settings, sizing, etc.

Table.html Table-style Reportsdxf Drawing of Building Surfacesrdd Report Data Dictionary – list of valid

report variables for a particular runmdd Meter Data Dictionary – valid

report meters for a particular run

Commonly Used Output Files


Commonly Used Output Files (cont’d)

eso Standard Output – numeric dataopen in xESOView utility

csv Numeric Output - csv spreadsheet of eso data (txt, tab formats optional)

Meter.csv Numeric Meter Output - csv spreadsheet of meter data(txt, tab formats optional)

mtd Meter Details –meter definitions

svg HVAC diagram

For more details see Output Details and Examples document


Auxiliary Tools

Run-time Tools EP-Launch

Input/Output Tools IDF Editor HVAC-Diagram


EP-Launch

“Home base” for using EnergyPlusSelect and edit input filesRun EnergyPlus simulationOpen output files Run utility programs such

as Slab and Basement preprocessorsRun groups of simulations


EP-Launch

View output files

Run utilities

Select weather file

Run EnergyPlus

Select and edit input file

Access EnergyPlus documentation


EP-Launch SetupView Options

Select viewers for text, DXF, VRML, spreadsheet, SVG, HTML, ESO, and PDF files

AutoFind for default windows association or select by browsing

Associate idf files withEP-Launch (double-click)


View Results

“All” tab Direct one-button access to output files Shading indicates which files are present Hover over button for file description


View Results (cont’d)

“Sets” tab Open groups of output files Predefined groups by type of file Customizable groups of files


Multiple Runs with EP-Launch

Can queue up multiple single runsCan save a list of runs in a group fileUser option for number of simultaneous

simulations (applies to both methods) View Options Command Window Typically set to

equal number of cpu cores


IDF Editor

EnergyPlus input editorTable view of input dataSave options (File menu)

Write objects in standard order e.g. RunPeriod, all Material objects, all Construction

objects, all Zone objects, etc. Files may be rearranged – can be good or not so good

Write objects in original order New objects at top or at bottom

Option for special format for certain objects


IDF Editor

Select object type from class list

Objects shown here for selected class

Pull-down list of keywords or references when applicable

Description of entry, max and min when applicable

Copy/Paste objects from IDF Editor or Text File

Note: Always hit enter or leave cell to save entry


OpenStudio Results Viewer

Line plotsFlood plotsDifference plotsIlluminance maps


OpenStudio Results Viewer

Opens EnergyPlus SQlite output Must request this in idf

Output:SQLite, Simple; (or SimpleAndTabular)

Output:Variable and Output:Meter data

In v7.1 not supported directly in EP-Launch Open ResultsViewer separately Then open files to plot


HVAC-Diagram

Postprocessor creates svg diagram of HVAC system Does not support all system configurations


Other Software Tools

xEsoView statistics and graphs

directly from eso output http://xesoview.sourceforge.net

Text file editor highly recommend going beyond standard ones search web for “text editor” to find options multi-window, split window, column select, syntax

highlighting and more

Part 4 – Daylighting and Ground Heat Transfer



Oct 2012 Introduction to EnergyPlus - Part 4 - Daylighting and Ground Heat Transfer 2

Part 4 Outline

Daylighting Lighting Controls Other Factors Outputs

Ground Heat Transfer


Daylighting

Daylighting:Controls Calculates illuminance from daylight Split flux method

Daylighting:DELight:Controls Advanced radiosity method, complex fenestration Does not support external shading

Only one type per zoneMay use different types in same run Interior windows are supported


Daylighting:Controls

Sensible and Latent

Beam Solar

Sky Diffuse

Ground Diffuse

Light Control 2

Light Control 1

Uncontrolled

Reference Pt 2

Reference Pt 1


Electric Lighting Control

Electric lights full-on assumed to provide the setpoint illuminance – regardless of schedule

Electric lighting control system simulated to determine fraction of lighting for each lighting zone

Based on daylighting illuminance level regardless of actual electric lighting input power

Zone lighting electric reduction factor passed to thermal calculation

Heat gain from lights and power input reduced


Continuous Dimming

Minimum input power fractionFractional input power

1.000

1.0

Minimum lightoutput fraction

Fractionallight output

Increasing daylightilluminance

Zero daylightilluminance


Stepped Lighting Control

Daylight illuminance

Fractionalinput power

1.0

00

Illuminance set point

Step 1

Step 2

Step 3


Daylighting:Controls Inputs

1 or 2 illuminance reference points Specific point(s) in zone (X,Y,Z position) World or relative coordinates depending on option

specified in GlobalGeometryRules Shown as small circles in dxf drawing Illuminance setpoint(s) [lux]

1 to 3 lighting zones Specify fraction of lighting power for each zone Fraction controlled by reference point 1 Fraction controlled by reference point 2 Uncontrolled (implied if Fraction1+Fraction2<1)


Daylighting:Controls Inputs (cont’d)

Lighting control type Continuous – stay on at minimum Continuous – turn off at minimum Stepped – automatic Stepped – manual with probability Minimum lighting output and power levels

Glare control of window shades Direction of view Maximum glare level Only with Daylighting:Controls


Ground Reflectance

Site:GroundReflectance 12 monthly valuesAffects:

Solar gains Daylighting

Site:GroundReflectance:SnowModifier Alters reflectance when snow on ground


Ground Shading

Beam reflects from ground as diffuseWhen solar reflection option is active,

portions of the ground are shaded

Beam

A B C

Beam

Ground Ground


Calculate Solar Reflection From Exterior Surfaces

In Building objectAdd “WithReflections” to solar distribution If FullExteriorWithReflections or

FullInteriorAndExteriorWithReflections, then: Building shadows affect ground reflected solar All exterior heat transfer surfaces automatically

reflect according to their surface properties Shading surfaces reflect only if

ShadingProperty:Reflectance is also specified Impacts daylighting and solar heat gain


Solar Reflections from Obstructions

Beam

Sky diffuse

Beam

Beam

Solar Reflection from Obstructions

(a) (b) (c)


Solar Reflections from Building Surfaces

Window

Wall


Shading Surfaces

Direct and sky diffuse shadingDiffuse from ground

If solar distribution option in Building obejct is “FullExteriorWithReflections” or “FullInteriorAndExteriorWithReflections”, then affected by shading from building surfaces

Otherwise controlled by “View Factor to Ground”

Transmittance (optional) Opaque unless Transmittance Schedule specified Solar and visible transmittance assumed equal Non-diffusing - does not change direction of light


Shading Surfaces for Daylighting (cont’d)

Reflectance (optional) Default is no reflection from shading surfaces Part specular and part diffuse Must specify global option for solar reflection and

shading surface reflectance object (see next slide)

Interior obstructions Opaque Reflecting if a heat transfer surface Non-reflecting if a shading surface


Special Daylighting Devices

DaylightingDevice:Tubular Tube properties

FenestrationSurface:Detailed TubularDaylightDome TubularDaylightDiffuser Dome

Pipe

Diffuser

Daylit Zone

Transition Zone

Exterior Roof


Special Daylighting Devices (cont’d)

DaylightingDevice:Shelf Inside BuildingSurface:Detailed object Outside Shading:Zone:Detailed object

DaylightingDevice:LightWell Applied to a window object

Daylit Zone

Outside Shelf Inside Shelf

Window


Daylighting Modeling Guidelines

Window positions are important Pay attention to shading

Zone multipliers Beneficial to get room proportions correct Can only use if external shading not

affected by zone position


Representative Room with Zone Multiplier

Zone Multiplier = 4

IW-1

Room-1IW-2

IW-3


Daylighting in Interior Zones

A

B C DInterior window –

daylighting passes through

Exterior window


Daylighting withInterior Obstructions

Default Method (split-flux) Initial illuminance distribution blocked Inter-reflected illuminance not blocked Interior surfaces included in zone-average

reflectance calculation

DElight Method (radiosity) Initial illuminance distribution not blocked Inter-reflected illuminance blocked Interior surfaces included in reflection calculations


Daylighting Outputs

Output Variables Daylight Illum at Ref Point 1 [lux] Glare Index at Ref Point 1 [] Ltg Power Multiplier from Daylighting [] Daylight Illum at Ref Point 1 from Window[lux] Daylight Luminance of Window As Viewed From

Ref Point 1[cd/m2]

Output:IlluminanceMap


Illuminance MapWindows


Illuminance MapTubular Daylighting Device


Ground Heat Transfer

IssuesSlab and Basement PreprocessorsEnergyPlus Ground Temperatures


Ground Heat Transfer Issues

Problem Conduction calculations in EnergyPlus are one-

dimensional Ground heat transfer calculations are two or

three-dimensional Ground heat transfer time scale is much longer

than building and HVAC

Solution 3-d ground heat transfer preprocessors Produce monthly ground contact temperatures to

use in EnergyPlus simulation


Ground Temperatures

Undisturbed ground temperatures from weather file and most sources

EnergyPlus ground temperature

No soil layer in slab construction, just concrete and finish materials


Site:GroundTemperature:BuildingSurface

Specifies the outside surface temp for surfaces in contact with the ground (e.g., slab floors, basement walls)

Site:GroundTemperature:BuildingSurface, 17.740, !- January Ground Temperature {C} 17.490, !- February Ground Temperature {C} 17.452, !- March Ground Temperature {C} 18.964, !- April Ground Temperature {C} 19.217, !- May Ground Temperature {C} 19.280, !- June Ground Temperature {C} 20.833, !- July Ground Temperature {C} 21.121, !- August Ground Temperature {C} 21.185, !- September Ground Temperature {C}21.167, !- October Ground Temperature {C} 19.640, !- November Ground Temperature {C} 19.362; !- December Ground Temperature {C}


Ground Temperatures (cont’d)

Three sets of ground temperatures are tabulated in the weather file.

Ground temperatures are for “thermally undisturbed” soil with a diffusivity of 2.3225760E-03 {m**2/day}.

These values are not appropriate for computing building floor losses.

!- Monthly Calculated "undisturbed" Ground Temperatures °Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

!0.5 m 9.8 9.5 10.1 11.5 13.4 15.1 16.3 16.7 16.0 14.6 12.8 11.0!2.0 m 11.0 10.4 10.6 11.4 12.6 14.0 15.1 15.7 15.6 14.8 13.5 12.1!4.0 m 12.0 11.4 11.3 11.6 12.4 13.3 14.2 14.8 14.9 14.5 13.8 12.8


Ground Temperature Preprocessors

EnergyPlus . . . \PreProcess\GrndTempCalcCompute ground temperatures

Monthly values Outside temperature

boundary condition for a particular surface in contact with the ground.

Documentation in AuxiliaryPrograms.pdf

Run from EP-LaunchUtilities tab


Ground TemperaturePreprocessors (cont’d)

Slab.exe utility will calculate: Monthly core, perimeter, and average ground

temperatures Given a description of the floor slab, perimeter

insulation, the monthly average indoor temperature, the soil conditions and the weather file for a given location

Basement.exe utility similar for basement floor and walls


Using Ground Temperatures from Slab Program

Average ground temperatures All floor slab surfaces:

Outside Boundary Condition = Ground Input average ground temperatures in

Site:GroundTemperature:BuildingSurface object


Using Ground Temperatures from Slab Program (cont’d)

Core and Perimeter temperatures SurfaceProperty:OtherSideCoefficients allows any schedule

to be applied as the outside surface boundary condition of a surface

Input perimeter and core monthly ground temperatures in two separate schedule objects

Create two SurfaceProperty:OtherSideCoefficients objects, one which uses the core temp schedule and one for the perimeter schedule

Describe separate surfaces for core and perimeter floor slabs (using the same perimeter depth as in the Slab program)

Perimeter and Core floor slab surfaces: Outside Boundary Condition=OtherSideCoefficients

Reference the corresponding SurfaceProperty:OtherSideCoefficients object


Partially Integrated in idf

GroundHeatTransfer:* objects in EnergyPlus IDD –duplicate the slab and basement idf objects

Preprocessor will extract, run slab/basement New EnergyPlus surface boundary conditions:

GroundSlabPreprocessorAverage, GroundBasementPreprocessorAverageFloor, etc.

Preprocessor will replace these with “OtherSideCoefficients” and insert objects and schedules using the output from slab/basement


Ground Temperatures without the Preprocessors

EnergyPlus defaults to 18C year-roundIndoor air temperature less 2C is a

reasonable default to use for most commercial buildings

Residential applications highly recommend using Slab or Basement preprocessor.


Other Ground Temperatures

Site:GroundTemperature:Shallow Specifically for the Surface Ground Heat

Exchanger and should probably be close to the average outdoor air temperature for the location

Site:GroundTemperature:Deep Specifically for the ground heat exchangers

that would use "deep" (3-4 m depth) ground temperatures for their heat source


Alternate Method for Ground Heat Transfer

Modeling Ground Heat Transfer using C and F Factors for Building Energy Code Compliance Special outside boundary condition for surfaces =

GroundFCfactorMethod Construction:CfactorUndergroundWall Construction:FfactorGroundFloor Site:GroundTemperature:FCfactorMethod

(optional, otherwise defaults to average monthly air temperature delayed by 3 months)

Part 5 – HVAC Overview andHVAC Templates for Standard

System Configurations



Oct 2012 Introduction to EnergyPlus - Part 5 - HVAC Overview and Templates 2

Part 5 Outline

HVAC OverviewHVAC Template OverviewCurrent HVAC Template ObjectsUsing HVAC Template ObjectsHVAC Template Example Inputs/Results


HVAC Input Overview

Flexible specification of HVAC equipment connections (nodes, branches and loops).

Hierarchical set of objects Loops (air, chilled & hot water, condenser) Supply and demand sides Topology of sides: branches, splitters, and mixers Branches: components along a single duct or pipe Zone Equipment: components directly serving a

zone (AHU terminal units, fan coils, etc.) Nodes: store component inlet & outlet conditions


Air Loop

HVAC StructureAir Loop

NorthZone

EastZone

WestZone

Plant Supply SideCooling Loop

ChW Pump

CoolingTower

Cond. Pump

Cond. Supply Side Loop

Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter

Plant Demand SideCooling Loop

Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat

Cond. DemandSide Loop

CondenserBypass

Outdoor AirMixing Box

Relief Air

Outdoor Air

VAV Box:ReHeatBoiler

Plant Supply SideHeating Loop

HW Pump

Chiller

Byp

ass

Bypass

Supply Side

Central Duct

OA System

Fan

ChW Coil (air side)

Demand Side

Ducts to Zones

VAV Terminal Units

HW Reheat Coils(air side)

Zones

Return Ducts


HVAC StructureChW Plant Loop

Chilled Water Loop

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass

Supply Side

Pump

Chiller (ChW side)

Demand Side

ChW Coil (water side)


HVAC StructureCondenser Loop

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass

Supply Side

Pump

Cooling Tower

Demand Side

Chiller (condenser side)

Condenser Water Loop


HVAC StructureHW Plant Loop

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass

Supply Side:

Pump

Boiler

Demand Side:

HW Reheat Coils (water side)

Hot Water Loop


Zone 1

LocalCon-

vectiveUnits

Air-AirHP

UnitHeater/Vent-ilator

Fan CoilWindowAC

HighTemp

Radiant/Con-

vective

LowTemp

Radiant

Base-boardsRadiatorsHigh

TempRadiators

LowTemp

RadiantPanels

SelectOne

Select One

Return AirPath

Zone Exhaust Fan (Opt.)

NoneDualDuct

ConstantVolume

(CV)

SingleDuct CVReheat

DualDuctVAV

SingleDuctVAV:

Reheat

Local Conv. Unit AlternativesHi Temp Rad/ConvAlternatives

Low Temp RadAlternatives

Select One

Select OneAir

DistributionUnit

Options

ZoneSupply AirSplitter

AirDistribution

Unit

Water-AirHP &

GroundSource

HP

Diagram from Input Output Reference (not all equipment types are included)

HVAC StructureZone Equipment

Air distribution unit served by a central

air loop

Some single-zonesystems are

air-loop based

e.g. Unitary DX cooling with gas furnace

Self-contained zonal unit

No central air loop required

May be served by water loop

e.g. Fan Coil, PTAC,

Radiant


HVAC Component Types

Simple Components input; initialize; calculate; report Example: electric heating coil, chiller

Compound Components assembled from multiple simple components simulated sequentially with overall control Example: VAV terminal unit with reheat coil

Complex Components component may be a system Example: Unitary furnace with DX cooling


EnergyPlus Nodes

A node is the point at which a component, such as a source or a load, is connected to the system.

Fan Inlet

Fan Outlet

Nodes

CoilInlet

CoilOutlet

Nodes

Gas Heating Coil

Fan


EnergyPlus Nodes (cont’d)

Nodes connect components in HVAC networkStore network state data

e.g. temperature, humidity, mass flow rate, average pressure at current barometric pressure (air only)

Store control information e.g., set points

Node data is component fluid input and output data



Components have one or more pairs of inlet/outlet nodes Fan:

Air inlet node, Air outlet node

Chilled Water Coil: Air inlet node, Air outlet node, CHW inlet node, CHW outlet node

CHWS CHWR

Water Nodes

Chilled Water Coil

Air Nodes



Components read inlet node data and write outlet node data

Most components “know” nothing more than their respective input specifications and inlet/outlet node data

Each zone has at least a single node for the zone air conditions

Node data available for output reporting various state and control data Temperature, humidity, flow, setpoints, etc.


Simplified Water Loop Example with Nodes

Boiler

Boiler Outlet Node

Supply-Side LoopDemand-Side Loop

±HW Circ Pump

Heating Coil

HW Supply inlet Node

HW Supply Outlet Node

HW Demand Inlet Node

HW DemandOutlet Node

Heating CoilInlet Node

HW Pump Outlet Node

Inlet Pipe

Exit Pipe

Heating CoilOutlet Node

HW Supply Outlet Pipe

HW Supply Bypass Pipe

Bypass


Example System3-Zone VAV Reheat

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass


Detailed HVAC Input Example3-Zone VAV Reheat Supply Side AirLoopHVAC

AirLoopHVAC:ControllerList Controller:WaterCoil (central chilled water coil controller)

AvailabilityManagerAssignmentList AvailabilityManager:Scheduled (supply fan time clock)

BranchList Branch

AirLoopHVAC:OutdoorAirSystem (outdoor air mixer/economizer) AirLoopHVAC:OutdoorAirSystem:EquipmentList

OutdoorAir:Mixer AirLoopHVAC:ControllerList

Controller:OutdoorAir OutdoorAir:NodeList

Fan:VariableVolume (supply fan) Coil:Cooling:Water (central chilled water

15 input objects to describe air loop supply side


Detailed HVAC Input Example3-Zone VAV Reheat Demand Side AirLoopHVAC:SupplyPath

AirLoopHVAC:ZoneSplitter (ducted supply splitter to zones)

ZoneControl:Thermostat ThermostatSetpoint:DualSetpoint (zone thermostat)

ZoneHVAC:EquipmentConnections (3x1 per zone) ZoneHVAC:EquipmentList

ZoneHVAC:AirDistributionUnit AirTerminal:SingleDuct:VAV:Reheat (VAV reheat terminal unit)

Coil:Heating:Water (hot water reheat coil)

AirLoopHVAC:ReturnPath AirLoopHVAC:ZoneMixer (ducted return mixer from zones)

6+3x5=21 input objects to describe air loop demand side


HVAC Template Overview

HVACTemplate objects provide a less detailed way to specify select HVAC system configurations

Example: 3-Zone VAV Reheat air loop(supply and demand sides) HVACTemplate:Thermostat HVACTemplate:Zone:VAV (3x1 per zone) HVACTemplate:System:VAV Only 3 input objects instead of 26 or more

Input fields for basic system options Built-in defaults for other data Automatically sets up loops, branches, and nodes Expanded file saved as output


HVAC Template Input Flow

User adds HVACTemplate objects to idf input along with building etc.

Preprocessor ExpandObject scans idf file for HVACTemplate objects Comments out HVACTemplate objects Replaces them with corresponding

detailed idf objects Resulting file saved as expidf output

EnergyPlus reads the expidf file These steps automatically

managed by run utility(EP-Launch, OpenStudio, etc.)

Expidf file can be renamed, edited, and used as a new idf file

idf inputHVACTemplate:System:VAV

ExpandObjects

EnergyPlus

expidf output! HVACTemplate:System:VAV

AirLoopHVACBranchlistBranch

Coil:Cooling:Water. . . and more . . .


HVACTemplateCurrent Zone Equipment

Zone Thermostat Ideal Loads Air System Fan CoilPackaged Terminal Air Conditioner (PTAC)Packaged Terminal Heat Pump (PTHP)Water to Air Heat Pump (WAHP)


HVACTemplateCurrent Central Systems

Packaged Furnace w/ DX Air ConditionerPackaged Air-to-Air Heat PumpPackaged DX VAV VAV Single Duct w/ Reheat Fan Powered VAV w/ ReheatDedicated Outdoor Air System

Combines with FanCoil, PTAC, PTHP, and WAHP

Chilled/Hot Water Supply LoopsChillers, Boilers and Cooling Towers


HVACTemplateCurrent Options

Baseboard HeatZone-level supply and return plenumsSystem-level supply and return plenumsHeat recoveryDehumidification controlsHumidification controls . . . and more


HVACTemplate:Thermostat

Dual Setpoint with Deadbandcontrol type at all times

Specify constant or scheduled setpointsReferenced by HVACTemplate:Zone:* objects

HVACTemplate:Thermostat,

Office Thermostat, !- Name

Heating Setpoints, !- Heating Setpoint Schedule Name

, !- Constant Heating Setpoint {C}

Cooling Setpoints, !- Cooling Setpoint Schedule Name

; !- Constant Cooling Setpoint {C}


HVACTemplate:Zone:IdealLoadsAirSystem

Zone-level objects for ideal air system Sums space cooling and heating loads Does not include HVAC system ventilation

(outdoor air) loads

Simple inputs Zone name Thermostat name

HVACTemplate:Zone:IdealLoadsAirSystem,

SPACE1-1, !- Zone Name

Office Thermostat; !- Template Thermostat Name


HVACTemplate:Zone:Unitary Zone-level objects for unitary system

Zone and thermostat names Name of unitary system serving this zone Supply air and outdoor air flow rates and other options

HVACTemplate:Zone:Unitary,SPACE1-1, !- Zone NameFurnace DX 1-1, !- Template Unitary System NameAll Zones, !- Template Thermostat Nameautosize, !- Supply Air Maximum Flow Rate {m3/s}, !- Zone Heating Sizing Factor, !- Zone Cooling Sizing Factorflow/person, !- Outdoor Air Method0.00944, !- Outdoor Air Flow Rate per Person {m3/s}0.0, !- Outdoor Air Flow Rate per Area {m3/s-m2}0.0, !- Outdoor Air Flow Rate per Zone {m3/s}, !- Supply Plenum Name, !- Return Plenum NameNone, !- Baseboard Heating Type, !- Baseboard Heating Availability Schedule Nameautosize; !- Baseboard Heating Capacity {W}


HVACTemplate:System:Unitary

Air loop objects for unitary systemSchedulesSet pointsOutdoor air controlsHeat recovery optionsHVACTemplate:System:Unitary,

Furnace DX 1-1, !- Name

FanAvailSched, !- System Availability Schedule Name

SPACE1-1, !- Control Zone Name or Thermostat Location Name

autosize, !- Supply Fan Maximum Flow Rate {m3/s}

Continuous, !- Supply Fan Operating Mode Schedule Name. . . More . . .


HVACTemplate:System:Unitary – Example (1 of 3)

HVACTemplate:System:Unitary,Furnace DX 1-1, !- NameFanAvailSched, !- System Availability Schedule NameSPACE1-1, !- Control Zone or Thermostat Location Nameautosize, !- Supply Fan Maximum Flow Rate {m3/s}Continuous, !- Supply Fan Operating Mode Schedule Name0.7, !- Supply Fan Total Efficiency600, !- Supply Fan Delta Pressure {Pa}0.9, !- Supply Fan Motor Efficiency1, !- Supply Fan Motor in Air Stream FractionSingleSpeedDX, !- Cooling Coil Type, !- Cooling Coil Availability Schedule Nameautosize, !- Cooling Coil Capacity {W}autosize, !- Cooling Coil Rated Sensible Heat Ratio3, !- Cooling Coil Rated COP. . . More . . .



Gas, !- Heating Coil Type

, !- Heating Coil Availability Schedule Name

autosize, !- Heating Coil Capacity {W}

0.8, !- Gas Heating Coil Efficiency

, !- Gas Heating Coil Parasitic Electric Load {W}

autosize, !- Maximum Outdoor Air Flow Rate {m3/s}

autosize, !- Minimum Outdoor Air Flow Rate {m3/s}

, !- Minimum Outdoor Air Schedule Name

DifferentialDryBulb, !- Economizer Type

NoLockout, !- Economizer Lockout

19, !- Economizer Upper Temperature Limit {C}

4, !- Economizer Lower Temperature Limit {C}

, !- Economizer Upper Enthalpy Limit {J/kg}

. . . More . . .



, !- Supply Plenum Name, !- Return Plenum NameBlowThrough, !- Supply Fan PlacementCycleOnAny, !- Night Cycle Control, !- Night Cycle Control Zone Name, !- Heat Recovery Type, !- Sensible Heat Recovery Effectiveness, !- Latent Heat Recovery EffectivenessNone, !- Dehumidification Control Type, !- Dehumidification Control Zone Name60.0, !- Dehumidification Setpoint {percent}None, !- Humidifier Type, !- Humidifier Availability Schedule Name0.000001, !- Humidifier Rated Capacity {m3/s}2690.0, !- Humidifier Rated Electric Power {W}, !- Humidifier Control Zone Name30.0; !- Humidifier Setpoint {percent}


HVACTemplate VAV System

HVACTemplate:Zone:VAV Zone terminal unit, variable volume, reheat

optional, baseboard heat optional

HVACTemplate:Zone:VAV:FanPowered Zone terminal unit, fan-powered variable volume,

reheat optional, parallel or series, baseboard heat optional

HVACTemplate:System:VAV Variable air volume (VAV) air loop with optional

heating coil and optional preheat.


HVACTemplate Chilled Water Plant

HVACTemplate:Plant:ChilledWaterLoop Plant and condenser loops to serve all

HVACTemplate chilled water coils, chillers, and towers.

HVACTemplate:Plant:ChillerHVACTemplate:Plant:Tower


HVACTemplate Hot Water Plant

HVACTemplate:Plant:HotWaterLoop Plant loops to serve all HVACTemplate hot

water coils and boilers.

HVACTemplate:Plant:Boiler

HVACTemplate Detailed Object Reference

HVACTemplate Connection Objects HVACTemplate:Plant:Chiller:ObjectReference HVACTemplate:Plant:Tower:ObjectReference HVACTemplate:Plant:Boiler:ObjectReference

Use with Detailed Plant Objects e.g. Chiller:Electric:EIR Direct control over chiller specifications User specifies performance curves



HVACTemplate Example idf – Unitary Zone

HVACTemplate:Zone:Unitary,NORTH PERIMETER, !- Zone NameNorth Zone Unitary, !- Template Unitary System NameOffice Thermostat, !- Template Thermostat Nameautosize, !- Supply Air Maximum Flow Rate {m3/s}, !- Zone Heating Sizing Factor, !- Zone Cooling Sizing Factorflow/person, !- Outdoor Air Method0.00944, !- Outdoor Air Flow Rate per Person {m3/s}0.0, !- Outdoor Air Flow Rate per Area {m3/s-m2}0.0, !- Outdoor Air Flow Rate per Zone {m3/s}, !- Supply Plenum Name, !- Return Plenum NameNone, !- Baseboard Heating Type, !- Baseboard Heating Availability Schedule Nameautosize; !- Baseboard Heating Capacity {W}


HVACTemplate Example expidf – Unitary Zone

Sizing:Zone,NORTH PERIMETER, !- Zone Name14, !- Zone Cooling Design Supply Air Temperature {C}50, !- Zone Heating Design Supply Air Temperature {C}0.008, !- Zone Cooling Design Supply Air Humidity Ratio

{kg-H2O/kg-air}0.008, !- Zone Heating Design Supply Air Humidity Ratio

{kg-H2O/kg-air}flow/person, !- Outdoor Air Method0.00944, !- Outdoor Air Flow Per Person {m3/s}0.0, !- Outdoor Air Flow Per Zone Area {m3/s-m2}0.0, !- Outdoor Air Flow Per Zone {m3/s}, !- Zone Heating Sizing Factor, !- Zone Cooling Sizing FactorDesignDay, !- Cooling Design Air Flow Method0, !- Cooling Design Air Flow Rate {m3/s}, !- Cooling Minimum Air Flow Per Zone Area {m3/s-m2}, !- Cooling Minimum Air Flow {m3/s}0, !- Cooling Minimum Air Flow FractionDesignDay, !- Heating Design Air Flow Method0, !- Heating Design Air Flow Rate {m3/s}, !- Heating Maximum Air Flow Per Zone Area {m3/s-m2}, !- Heating Maximum Air Flow {m3/s}0; !- Heating Maximum Air Flow Fraction


HVACTemplate Example expidf – Unitary Zone (cont’d)ZoneHVAC:EquipmentConnections,

NORTH PERIMETER, !- Zone Name NORTH PERIMETER Equipment, !- Zone Conditioning Equipment List NameNORTH PERIMETER Zone Equip Inlet, !- Zone Air Inlet Node or NodeList Name, !- Zone Air Exhaust Node or NodeList NameNORTH PERIMETER Zone Air Node, !- Zone Air Node NameNORTH PERIMETER Return Outlet; !- Zone Return Air Node Name

ZoneHVAC:EquipmentList,NORTH PERIMETER Equipment, !- NameAirTerminal:SingleDuct:Uncontrolled, !- Zone Equipment 1 Object TypeNORTH PERIMETER Direct Air, !- Zone Equipment 1 Name1, !- Zone Equipment 1 Cooling Sequence1; !- Zone Equipment 1 Heating or No-Load Sequence

AirTerminal:SingleDuct:Uncontrolled,NORTH PERIMETER Direct Air, !- NameHVACTemplate-ALWAYS 1, !- Availability Schedule NameNORTH PERIMETER Zone Equip Inlet, !- Zone Supply Air Node Nameautosize; !- Maximum Air Flow Rate {m3/s}

Part 6 - HVAC Zone Equipment



Oct 2012 Introduction to EnergyPlus - Part 6 - HVAC Zone Equipment 2

Outline

Zone Equipment InputZone Forced Air UnitsRadiative Convective UnitsAir Loop Zone Equipment


Zone Equipment Input

For each controlled zone:ZoneControl:Thermostat

Zone thermostat type and set points or use Operative or Comfort control (more details later)

ZoneHVAC:EquipmentConnections Connects equipment to a zone List of equipment conditioning the zone, 18 max Zone inlet, exhaust, and outlet nodes


ZoneHVAC:EquipmentConnections

Inlet Nodes Supply air to zone from all forced-air equipment types

Exhaust Nodes Extract air from zone to zonal equipment (fan coil, exhaust fan)

Return Node Return to central air loop Only one allowed

Non-forced-air equipment types use none of these nodes e.g. Radiant heater, baseboard heater

ZoneHVAC:EquipmentConnections,

ZONE1, !- Zone Name

ZONE1 Eq, !- Zone Conditioning Equipment List Name

ZONE1 Inlet Node, !- Zone Air Inlet Node or NodeList Name

ZONE1 Exhaust Node, !- Zone Air Exhaust Node or NodeList Name

ZONE1 Node, !- Zone Air Node Name

ZONE1 Out Node; !- Zone Return Air Node Name


ZoneHVAC:EquipmentList

Zone Equipment TypeComponent NameCooling and Heating Sequence

Designates simulation order for multiple systems serving a zone

Repeat for each component serving zone18 components maximum

Only one may be an air loop terminal unit Others must be single-zone self-contained units


ZoneHVAC:EquipmentList –Example

ZoneHVAC:EquipmentList,ZONE1Equipment, !- NameZoneHVAC:AirDistributionUnit, !- Zone Equipment 1 Object TypeZONE1 ATU, !- Zone Equipment 1 Name1, !- Zone Equipment 1 Cooling Sequence1; !- Zone Equipment 1 Heating or No-Load Sequence

ZoneHVAC:EquipmentList,Zone1Equipment Example 2, !- NameZoneHVAC:AirDistributionUnit, !- Zone Equipment 1 Object TypeZone 1 DOAS Terminal Unit, !- Zone Equipment 1 Name1, !- Zone Equipment 1 Cooling Sequence1, !- Zone Equipment 1 Heating or No-Load SequenceZoneHVAC:FourPipeFanCoil, !- Zone Equipment 2 Object TypeZone 1 Fan Coil Unit, !- Zone Equipment 2 Name2, !- Zone Equipment 2 Cooling Sequence2; !- Zone Equipment 2 Heating or No-Load Sequence


Multiple Equipment Serving the Same Zone

Multiple equipment – yes with limits Only one air loop serving a zone Many pieces of zone equipment Pay close attention to sequence

Sizing Each system will autosize to meet the full zone

load requirement If multiple systems share the same load type

(heating or cooling), then must input hard sizes If one system is a dedicated outdoor air system,

providing tempered OA, sizing of other equipment will not be aware of that.


Zone Equipment Types

Zone Forced Air UnitsRadiative Convective UnitsAir Loop Zone Equipment


Zone Forced Air Units

Single-zone self-contained units (no air loop) Ideal Loads Air System Fan Coil Window AC Unit Ventilator Unit Heater PTAC/PTHP Water-to-Air Heat Pump (water loop heat pump) Energy Recovery Ventilator DX Dehumidifier Outdoor Air Unit

Typically zone equipment units are assembled from other components


ZoneHVAC:IdealLoadsAirSystem

Used to compute zone heating/cooling loads without modeling an HVAC system

Unlimited (or limited) capacity at specified temperature and humidity

Controlled by zone thermostatCalculates required flow rate at specified

supply air temperatureDoes not model HVAC ventilation

(outdoor air) load


ZoneHVAC:IdealLoadsAirSystem – Example

ZoneHVAC:IdealLoadsAirSystem,

Zone1Air, !- Name

NODE_1, !- Zone Supply Air Node Name

50, !- Heating Supply Air Temperature {C}

13, !- Cooling Supply Air Temperature {C}

0.009, !- Heating Supply Air Humidity Ratio {kg-H2O/kg-air}

0.009, !- Cooling Supply Air Humidity Ratio {kg-H2O/kg-air}

NoLimit, !- Heating Limit

autosize, !- Maximum Heating Air Flow Rate {m3/s}

NoLimit, !- Cooling Limit

autosize, !- Maximum Cooling Air Flow Rate {m3/s}

NoOutdoorAir, !- Outdoor Air

autosize; !- Outdoor Air Flow Rate {m3/s}


Radiative Convective Units

No forced air – no air inlet/outlet nodesHigh Temperature Alternatives

High Temperature Radiant Heaters

Low Temperature Alternatives Low Temperature Radiant panels

Electric Hydronic – Heating and Cooling

Convective-only Baseboard Radiative-convective Baseboard


Air Loop Zone Equipment

ZoneHVAC:AirDistributionUnitAirTerminal:SingleDuct:Uncontrolled


ZoneHVAC:AirDistributionUnit Attaches zone terminal unit to supply air stream Specific terminal unit type may include

Damper (e.g. VAV or dual-duct) Zone fan (e.g. Powered induction unit PIU) Coils (e.g. Reheat coil) Controls to adjust flow and/or temperature to meet zone

load

Only one central air loop ADU allowed per zone Simplified duct leakage model

Fixed and variable losses to return plenum Requires explicit return plenum zone


ZoneHVAC:AirDistributionUnit

Zone 1

DualDuct

ConstantVolume

(CV)

DualDuctVAV

SingleDuctVAV:

No Reheat

Select One

AirDistribution

UnitOptions

AirDistribution

Unit

SupplyFan

SingleDuct CVReheat

SingleDuctVAV:

Reheat

Not all options shown

Return Plenum Zone (optional)Simplified Duct Leakage Flow to Return Plenum(optional)

Central air loop serving one or more zones


Air Terminal Unit Types

Single Duct Constant Volume ReheatSingle Duct Variable Volume (VAV)

Reheat, No Reheat, Changeover Bypass Heat and Cool, Reheat with Variable Speed fan (UFAD)

Dual Duct Constant VolumeDual Duct Variable Volume (VAV)Powered Induction Units (PIU)

Series and Parallel4-Pipe Induction UnitCooled Beam (active or passive)


ZoneHVAC:AirDistributionUnit- Example

ZoneHVAC:AirDistributionUnit,SPACE1-1 ATU, !- NameSPACE1-1 In Node, !- Air Distribution Unit Outlet Node NameAirTerminal:SingleDuct:VAV:Reheat, !- Air Terminal Object TypeSPACE1-1 VAV Reheat, !- Air Terminal Name0.05, !- Nominal Upstream Leakage Fraction0.07; !- Constant Downstream Leakage Fraction

AirTerminal:SingleDuct:VAV:Reheat,SPACE1-1 VAV Reheat, !- NameReheatCoilAvailSched, !- Availability Schedule NameSPACE1-1 Zone Coil Air In Node, !- Damper Air Outlet Node NameSPACE1-1 ATU In Node, !- Air Inlet Node Nameautosize, !- Maximum Air Flow Rate {m3/s}0.3, !- Zone Minimum Air Flow Fraction, !- Sensor Node NameCoil:Heating:Electric, !- Reheat Coil Object TypeSPACE1-1 Zone Coil, !- Reheat Coil Name, !- Maximum Reheat Water Flow Rate {m3/s}, !- Minimum Reheat Water Flow Rate {m3/s}SPACE1-1 In Node, !- Air Outlet Node Name0.001, !- Convergence ToleranceReverse; !- Damper Heating Action


AirTerminal:SingleDuct: Uncontrolled

Constant volume terminal unitSupply from central air loop supplied directly

to a zone with no further control Furnace, Heat pump, etc.

Central system may be controlled to meet setpoints in a “control zone”

“Slave zones” or “sub-zones” Typically have no individual control May have baseboard heat or other equipment to

allow individual control


AirTerminal:SingleDuct: Uncontrolled - Example

AirTerminal:SingleDuct:Uncontrolled,Zone1 Air Supply, !- Name, !- Availability Schedule NameZone 1 Inlet Node, !- Zone Supply Air Node Name0.47; !- Maximum Air Flow Rate {m3/s}

ZONE1Node

SupplyFan

ZONE1Air Supply

ZONE1

ZONE1Inlet Node

ZONE1Out Node

ZONE2Node

ZONE2Air Supply

ZONE2

ZONE2Inlet Node

ZONE2Out Node

Control Zonew/ Thermostat

Slave Zone (thermostat req’d.if autosizing)

Part 7 - HVAC Air Loops and Water Loops



Outline

Air LoopsOutdoor Air SystemWater LoopsCoilsPlant/Condenser Loop EquipmentCurve and Table Objects

Oct 2012 Introduction to EnergyPlus - Part 7 - HVAC Air Loops and Water Loops 2


Describing a Central Forced Air System

“Air Loop” with 2 “sides” 2 sides are solved iteratively until converged

Supply Side/AirLoopHVAC Main supply duct(s) Central fans, coils, etc. Outdoor air mixer

Demand Side/Zone Equipment Duct splitters and mixers to/from zones Plenums Air terminal units (e.g. VAV box)


Describing a Central Forced Air System (cont’d)

Demand Side/Zone Equipment

North

Zone

EastZone

West

Zone

Ret

urn

Air

Mix

er

Zone Air S

plitter

VAV Box:ReHeat

VAV Box:ReHeat

VAV Box:ReHeat

Supply Side/AirLoopHVAC

Supply Fan

Cooling CoilCC


Relief Air

Outdoor Air

Return Fan


AirLoopHVAC

Controller ListAvailability Manager ListBranch ListConnector ListConnection to Zone Equipment

Supply Side Inlet Node Name Demand Side Outlet Node Name Demand Side Inlet Node Names Supply Side Outlet Node Names


AirLoopHVAC - Example

Supply Fan


Relief Air

Outdoor Air

CoolingCoil

Zone Equip Inlet NodeZone Equip Outlet Node

Air Loop Inlet Node

From Zones To Zones

Air Loop Outlet Node


AirLoopHVAC - Example

AirLoopHVAC,

VAV Sys, !- Name

VAV Sys Controllers, !- Controller List Name

Avail List, !- Availability Manager List Name

autosize, !- Design Primary Air Flow Rate {m3/s}

VAV Sys Branches, !- BranchList Name

, !- ConnectorList Name

Air Loop Inlet Node, !- Supply Side Inlet Node Name

Zone Equip Outlet Node, !- Demand Side Outlet Node Name

Zone Equip Inlet Node, !- Demand Side Inlet Node Names

Air Loop Outlet Node; !- Supply Side Outlet Node Names


Branch

In air loops, a branch defines a supply ductMaximum Flow Rate

Only used for air branches, omit for water side

Component groups Component 1 Object Type Component 1 Name Component 1 Inlet Node Name Component 1 Outlet Node Name Component 1 Branch Control Type Repeat for multiple components


Branch – Example

Branch,VAV Sys Main Branch, !- Nameautosize, !- Maximum Flow Rate {m3/s}

!- Pressure Drop Curve NameFan:VariableVolume, !- Component 1 Object TypeReturn Fan, !- Component 1 NameAir Loop Inlet Node, !- Component 1 Inlet Node NameReturn Fan Outlet Node, !- Component 1 Outlet Node NamePASSIVE, !- Component 1 Branch Control TypeAirLoopHVAC:OutdoorAirSystem, !- Component 2 Object Type

Continued on next slide

Supply Side/AirLoopHVAC

One Branch

Supply Fan

Cooling CoilCC

Mixed OutdoorAir Box

Relief Air

Outdoor Air

Return Fan


Branch – Example (cont’d)

OA Sys, !- Component 2 NameReturn Fan Outlet Node, !- Component 2 Inlet Node NameMixed Air Node, !- Component 2 Outlet Node NamePASSIVE, !- Component 2 Branch Control Type Fan:VariableVolume, !- Component 3 Object TypeSupply Fan, !- Component 3 NameMixed Air Node, !- Component 3 Inlet Node NameSupply Fan Outlet Node, !- Component 3 Outlet Node NameACTIVE, !- Component 3 Branch Control TypeCoil:Cooling:Water:DetailedGeometry, !- Component 4 Object TypeMain Cooling Coil, !- Component 4 NameSupply Fan Outlet Node, !- Component 4 Inlet Node NameAir Loop Outlet Node, !- Component 4 Outlet Node NamePASSIVE; !- Component 4 Branch Control Type

Supply Fan

Cooling CoilCCMixed OutdoorAir Box

Relief Air

Outdoor Air

Return Fan


Air Loop Component –Simple Example

Fan:VariableVolume,Supply Fan, !- NameFanAvailSched, !- Availability Schedule Name0.7, !- Fan Efficiency600.0, !- Pressure Rise {Pa}1.56, !- Maximum Flow Rate {m3/s}0.45, !- Minimum Flow Rate {m3/s}0.9, !- Motor Efficiency1.0, !- Motor In Airstream Fraction0.35071223, !- Fan Coefficient 10.30850535, !- Fan Coefficient 2-0.54137364, !- Fan Coefficient 30.87198823, !- Fan Coefficient 40.000, !- Fan Coefficient 5Mixed Air Node, !- Fan Inlet Node NameSupply Fan Outlet Node; !- Fan Outlet Node Name


Air Volume Flow Rates

Specified in m3/sConverted to mass flow rate using density for

the following “standard conditions”: Dry air 20C drybulb Standard atmospheric pressure for local elevation

p=101325*(1-2.25577E-05*Z)**5.2559where p=pressure in Pa and Z=altitude in m2005 ASHRAE Handbook-Fundamentals, SI edition, p. 6.1

See Input Output Reference, Fan objects


Supply and Return Air Path

PlenumsAirLoopHVAC:SupplyPathAirLoopHVAC:ReturnPath


Plenums

Plenum zone is a separate thermal zoneUse interzone surfaces to link to conditioned

spaceConnected to HVAC system through

AirLoopHVAC:SupplyPlenum AirLoopHVAC:ReturnPlenum

Plenum temp computed like any other zone except there is added flow through the zone when the HVAC system is operating

Outlet temp is from end of previous time step


AirLoopHVAC:SupplyPath

AirLoopHVAC:ZoneSplitter Splits the supply air from the main air

handler to serve individual zones Dual duct systems require splitters for both

the cold and hot air ducts

AirLoopHVAC:SupplyPlenum Allows system air to flow through a zone

before it reaches the zone(s) to be served


AirLoopHVAC:SupplyPath -Example

Zone 3 ATUIn Node

ZONE 3

Zone 2 ATUIn Node

ZONE 2

Zone 1 ATUIn Node

ZONE 1

Zone EqIn Node

Zone Supply Air Splitter 1

Zone Supply Air Path 1

SupplyFan

Plenum Zone(optional)


AirLoopHVAC:SupplyPath -Example (cont’d)

AirLoopHVAC:SupplyPath,

Zone Supply Air Path 1, !- Name

Zone Eq In Node, !- Supply Air Path Inlet Node Name

AirLoopHVAC:ZoneSplitter,!- Component 1 Object Type

Zone Supply Air Splitter 1; !- Component 1 Name

AirLoopHVAC:ZoneSplitter,

Zone Supply Air Splitter 1, !- Name

Zone Eq In Node, !- Inlet Node Name

Zone 1 ATU In Node, !- Outlet 1 Node Name

Zone 2 ATU In Node, !- Outlet 2 Node Name

Zone 3 ATU In Node; !- Outlet 3 Node Name


AirLoopHVAC:ReturnPath

AirLoopHVAC:ZoneMixer Mixes the return air streams returning to the main

air handler from individual zones

AirLoopHVAC:ReturnPlenum Allows system air to flow through a zone before it

reaches the main return duct Allows system air to be mixed from multiple

zones, can eliminate the need for a zone mixer Can mix plenum and ducted returns Plenums may be in series or parallel (series

temperatures lag by a zone time step)


Describing an Outdoor Air System

AirLoopHVAC:OutdoorAirSystemis a subsystem component onmain air loop branch OA System Controller List OA System Equipment List OA System Availability Manager List

AirLoopHVAC:OutdoorAirSystem,

OA Sys, !- Name

OA Sys Controllers, !- Controller List Name

OA Sys Equipment, !- Outdoor Air Equipment List Name

VAV Sys Avail List; !- Availability Manager List Name

Mixed Air Outlet

Supply Fan

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet

Air Loop Inlet (Return Air)

Mixed Air Outlet

Supply Fan

OA Mixing Box

Relief Air OutletAir Loop Inlet (Return Air)


OA System Equipment List

System component type Outdoor air mixer, coil, heat exchanger

System component nameRepeat for each air loop component

AirLoopHVAC:OutdoorAirSystem:EquipmentList,

OA Sys Equipment, !- Name

OutdoorAir:Mixer, !- Component 1 Object Type

OA Mixing Box; !- Component 1 Name


OutdoorAir:Mixer

Specifies the inlet and outlet nodes of the outdoor air mixer

OutdoorAir:Mixer,

OA Mixing Box, !- Name

Mixed Air Outlet, !- Mixed Air Node Name

Outdoor Air Inlet, !- Outdoor Air Stream Node Name

Relief Air Outlet, !- Relief Air Stream Node Name

Air Loop Inlet; !- Return Air Stream Node Name

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet

OA Mixing Box

Relief Air Outlet Air Loop Inlet (Return Air)

Mixed Air Outlet


Outdoor Air System –Controller List

List all controllers which are part of the outdoor air subsystem

AirLoopHVAC:ControllerList,

OA Sys Controllers, !- Name

Controller:OutdoorAir, !- Controller 1 Object Type

OA Controller; !- Controller 1 Name


Controller:OutdoorAir

Economizer optionsMixed Air Node Name – get setpoint temperature Actuator Node Name – set outdoor air flow rateMinimum outdoor air flow rate controls and

scheduleMaximum outdoor air flow rate Simplified demand-controlled ventilation

Based on occupancy and floor area See Controller:MechanicalVentilation


Controller:OutdoorAir -Example

Controller:OutdoorAir,OA Controller, !- NameRelief Air Outlet, !- Relief Air Outlet Node NameAir Loop Inlet, !- Return Air Node NameMixed Air Outlet, !- Sensor Node NameOutdoor Air Inlet, !- Actuator Node Nameautosize, !- Minimum Outdoor Air Flow Rate {m3/s}autosize, !- Maximum Outdoor Air Flow Rate {m3/s}FixedDryBulb, !- Economizer Control TypeModulateFlow, !- Economizer Control Action Type19., !- Economizer Maximum Limit Dry-Bulb Temperature {C}0.0, !- Economizer Maximum Limit Enthaply {J/kg}, !- Economizer Maximum Limit Dew-Point Temperature {C}, !- Electronic Enthalpy Limit Curve Name4., !- Economizer Minimum Limit Dry-Bulb Temperature {C}NoLockout, !- Lockout TypeFixedMinimum, !- Minimum Limit TypeMin OA Sched; !- Minimum Outdoor Air Schedule Name

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet

OA Mixing Box


Mixed Air Outlet

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet

OA Mixing Box


Mixed Air Outlet


Outdoor Air Pretreat Options

Preheat (gas, electric, or hot water)Heat Recovery – sensible and enthalpyEvaporative CoolerDesiccant DehumidifierCooling Coil (DX or chilled water)Transpired Solar Collector


Setpoint Manager Required?

OA Controller needs a setpoint on the mixed air outlet node for continuous fan systems Modulates OA fraction to meet setpoint Scheduled mixed air setpoint simplest Not used for cycling fan –

economizer full on or offSetpointManager:Scheduled,

Mixed Air Temp Manager, !- NameTemperature, !- Control VariableSeasonal Reset Mixed Air Temp Sch, !- Schedule NameMixed Air Outlet; !- Setpoint Node or NodeList Name


Setpoint Manager (cont’d)

Mixed air setpoint adjusted for fan heatSetpointManager:Scheduled,

Supply Air Temp Manager, !- NameTemperature, !- Control VariableSeasonal Reset Supply Air Temp Sch, !- Schedule NameAir Loop Outlet; !- Setpoint Node or NodeList Name

SetpointManager:MixedAir,Mixed Air Temp Manager, !- NameTemperature, !- Control VariableAir Loop Outlet, !- Reference Setpoint Node NameMixed Air Outlet, !- Fan Inlet Node NameSupply Fan Outlet, !- Fan Outlet Node NameMixed Air Outlet; !- Setpoint Node or NodeList Name


Initializing Outdoor Air Nodes

Required for air loops and some zone equipOutdoorAir:NodeList

Assigns weather data temp and humidity to node

OutdoorAir:Node Assigns height-dependent conditions to node Important for tall buildings

Option AOutdoorAir:NodeList,

Outdoor Air Inlet; !- Node or NodeList Name 1

Option BOutdoorAir:Node,

Outdoor Air Inlet, !- Name

50.0; !- Height Above Ground {m}


Defining Water Loops

Two main objects PlantLoop CondenserLoop

Divided into two sub-loops Supply side Demand side


Demand & SupplySub-Loops

Demand-side sub-loop Equipment that creates a load on the plant e.g. Hot water heating coil

Supply-side sub-loop Equipment that meets these loads e.g. Boiler


Demand- & Supply Sub-Loops (cont’d)

Simplest form of a loop with mixers, splitters, and bypasses

Boiler

Boiler Outlet Node

Supply-Side LoopDemand-Side Loop

±HW Circ Pump

Heating Coil

HW Supply inlet Node

HW Supply Outlet Node

HW Demand Inlet Node


Heating CoilInlet Node

HW Pump Outlet Node

Inlet Pipe

Exit Pipe

Heating CoilOutlet Node

HW Supply Outlet Pipe

HW Supply Bypass Pipe

Bypass


Branches for Water-Side Loops

Maximum Branch Flow Rate (Ignored)Pressure Drop Curve NameComponent 1 Object TypeComponent 1 Object NameComponent 1 Inlet Node NameComponent 1 Outlet Node NameComponent 1 Branch Control Type


Branches for Water-Side Loops - ExampleBranch,

Heating Supply Inlet Branch, !- Name, !- Maximum Flow Rate {m3/s}, !- Pressure Drop Curve NamePump:VariableSpeed, !- Component 1 Object TypeHW Circ Pump, !- Component 1 NameHW Supply Inlet Node, !- Component 1 Inlet Node NameHW Pump Outlet Node, !- Component 1 Outlet Node NameACTIVE; !- Component 1 Branch Control Type


Layout for Individual HVAC Sub-Loops

Elements can be defined in series, in parallel, or both with some restrictions

Branches are defined as individual legs within the loop structure

Segment between point A & B is defined as a branch, as is the section between points E and F

1 to mComponents

n Splitter

A

B

1 to iComponents

C1

... 1 to jComponents

Cn

D1 Dn

n Mixer

1 to kComponents

E

F

1 to mComponents

n Splitter

A

B

1 to i

1 to mComponents

n Splitter

A

B

1 to iComponents

C1


Cn

D1 Dn

n Mixer

1 to kComponents

E

F

Supply Sub-Loopor

Demand Sub-Loop


Layout for Individual HVAC Sub-Loops (cont’d)

Can model a single loop pump, or individual branch pumps

For loop pump -The first supply side component between A & B must be the pump, which controls the loop flow.

For branch pumps – pump must be first on the branch

1 to mComponents

n Splitter

A

B

1 to iComponents

C1


Cn

D1 Dn

n Mixer

1 to kComponents

E

F

1 to mComponents

n Splitter

A

B

1 to i

1 to mComponents

n Splitter

A

B

1 to iComponents

C1


Cn

D1 Dn

n Mixer

1 to kComponents

E

F

Supply Sub-Loopor

Demand Sub-Loop


Layout for Individual HVAC Sub-Loops (cont’d)

Each sub-loop may only have one splitter and one mixer.

Equipment may be in parallel between the mixer and splitter,

Within any branch, there can only be elements in series.

1 to mComponents

n Splitter

A

B

1 to iComponents

C1


Cn

D1 Dn

n Mixer

1 to kComponents

E

F

1 to mComponents

n Splitter

A

B

1 to i

1 to mComponents

n Splitter

A

B

1 to iComponents

C1


Cn

D1 Dn

n Mixer

1 to kComponents

E

F

Supply Sub-Loopor

Demand Sub-Loop


Pumping Rules

Supply side must have at least one pump

For primary-secondary, demand-side also has at least one pump

Pumps may be on inlet branch or on parallel component branches

Pumps may be constant flow or variable flow

Pumps may be continuous or intermittent

Splitter

Mixer

Components

Loop Pump

From Demand-Side Sub-Loop

To Demand-Side Sub-Loop

Supply-Side Sub-Loop


Pumping Rules (cont’d)

Bypass may be required on supply and/or demand side Depends on pump type (variable or constant flow) Depends on supply equipment type (variable or

constant flow, series or parallel) Flow from pump must have someplace to go If not sure, include a bypass – it will have no flow if

not needed


Summary of Loop Limitations

Each sub-loop allowed one splitter and one mixer

One bypass on each sub-loop (optional)No other components may be in series with a

bypassEquipment may be in parallel only between

the splitter and mixerEquipment may be in series on each branch


PlantLoop – ExamplePlantLoop,

Hot Water Loop, !- NameWater, !- Fluid TypeHot Loop Operation, !- PlantEquipmentOperationSchemes NameHW Supply Outlet Node, !- Loop Temperature Setpoint Node Name100, !- Maximum Loop Temperature {C}10, !- Minimum Loop Temperature {C}autosize, !- Maximum Loop Flow Rate {m3/s}0.0, !- Minimum Loop Flow Rate {m3/s}autosize, !- Plant Loop Volume {m3}HW Supply Inlet Node, !- Plant Side Inlet Node NameHW Supply Outlet Node, !- Plant Side Outlet Node NameHeating Supply Side Branches, !- Plant Side Branch List NameHeating Supply Side Connectors, !- Plant Side Connector List NameHW Demand Inlet Node, !- Demand Side Inlet Node NameHW Demand Outlet Node, !- Demand Side Outlet Node NameHeating Demand Side Branches, !- Demand Side Branch List NameHeating Demand Side Connectors, !- Demand Side Connector List NameSequential, !- Load Distribution Scheme, !- System Availability Manager ListSingleSetPoint, !- Plant Loop Demand Calculation SchemeNONE; !- Common Pipe Simulation


PlantLoop – Set Point Control

Plant loop supply temperature controlled by a set point manager

SetpointManager:Scheduled,Hot Water Loop Setpoint Manager, !- NameTemperature, !- Control VariableHW Loop Temp Schedule, !- Schedule NameHW Supply Outlet Node; !- Setpoint Node or NodeList Name

SetpointManager:OutdoorAirReset,Hot Water Loop HW Temp Manager, !- NameTemperature, !- Control Variable82.2, !- Setpoint at Outdoor Low Temperature {C}-6.7, !- Outdoor Low Temperature {C}65.6, !- Setpoint at Outdoor High Temperature {C}10, !- Outdoor High Temperature {C}Hot Water Loop HW Supply Outlet; !- Setpoint Node or NodeList Name


Primary-Secondary Loops

Specify in PlantLoop objectCommon Pipe Simulation field options

None –Primary loop, no pump on demand-side

CommonPipe or TwoWayCommonPipe –Primary-Secondary loop, pump on demand side

PlantLoop,Primary-Secondary Chilled Water Loop, !- NameWater, !- Fluid Type. . .

SingleSetPoint, !- Plant Loop Demand Calculation SchemeCommonPipe; !- Common Pipe Simulation


Coils

Heating CoilsCooling Coils


Heating Coils

Coil:Heating:Water Coil:Heating:Electric Coil:Heating:Gas Coil:Heating:Steam Coil:Heating:DX:SingleSpeed Coil:Heating:DX:MultiSpeed Coil:Heating:WaterToAirHeatPump:EquationFit Coil:Heating:WaterToAirHeatPump:ParameterEstimation Coil:Heating:Desuperheater Coil:WaterHeating:AirToWaterHeatPump Coil:WaterHeating:Desuperheater


Cooling Coils

Coil:Cooling:Water Coil:Cooling:Water:DetailedGeometry Coil:Cooling:DX:SingleSpeed Includes the condensing unit

Coil:Cooling:DX:TwoSpeed Coil:Cooling:DX:MultiSpeed Coil:Cooling:DX:TwoStageWithHumidityControlMode CoilSystem:Cooling:Water:HeatExchangerAssisted CoilSystem:Cooling:DX:HeatExchangerAssisted Coil:Cooling:WaterToAirHeatPump:EquationFit Coil:Cooling:WaterToAirHeatPump:ParameterEstimation


DX Cooling Coil – ExampleCoil:Cooling:DX:SingleSpeed,Furnace ACDXCoil 1, !- NameFanAndCoilAvailSched, !- Availability Schedule Name25000, !- Rated Total Cooling Capacity (gross) {W}0.75, !- Rated Sensible Heat Ratio3.0, !- Rated COP1.3, !- Rated Air Flow Rate {m3/s}, !- Rated Evaporator Fan Power Per Volume Flow Rate {W/(m3/s)}DX Cooling Coil Air Inlet Node, !- Air Inlet Node NameAir Loop Outlet Node, !- Air Outlet Node NameWindACCoolCapFT, !- Total Cooling Capacity Function of Temperature Curve NameWindACCoolCapFFF, !- Total Cooling Capacity Function of Flow Fraction CurveWindACEIRFT, !- Energy Input Ratio Function of Temperature Curve NameWindACEIRFFF, !- Energy Input Ratio Function of Flow Fraction Curve NameWindACPLFFPLR, !- Part Load Fraction Correlation Curve Name

continued on next slide


DX Cooling Coil – Example (cont’d)

Coil:Cooling:DX:SingleSpeed,. . . , !- Nominal Time for Condensate Removal to Begin {s}, !- Ratio of Initial Moisture Evaporation Rate and Steady State Latent . . ., !- Maximum Cycling Rate {cycles/hr}, !- Latent Capacity Time Constant {s}DX Coil 1 Condenser Inlet Node, !- Condenser Air Inlet Node NameAirCooled, !- Condenser Type0.9, !- Evaporative Condenser Effectiveness {dimensionless}, !- Evaporative Condenser Air Flow Rate {m3/s}, !- Evaporative Condenser Pump Rated Power Consumption {W}0, !- Crankcase Heater Capacity {W}10, !- Maximum Outdoor Dry-Bulb Temperature for Crankcase Heater Operation {C}, !- Supply Water Storage Tank Name; !- Condensate Collection Water Storage Tank Name


Plant/Condenser Loop Equipment

PumpsBoilersChillersTowersWater-Side EconomizersSolar CollectorsThermal Storage


Pumps

Pump:ConstantSpeedPump:VariableSpeedHeaderedPumps:VariableSpeedHeaderedPumps:ConstantSpeed


Pump – Example

Pump:VariableSpeed,CW Circ Pump, !- NameCW Supply Inlet Node, !- Inlet Node NameCW Pump Outlet Node, !- Outlet Node Name.0013, !- Rated Flow Rate {m3/s}300000, !- Rated Pump Head {Pa}560, !- Rated Power Consumption {W}.87, !- Motor Efficiency0.0, !- Fraction of Motor Inefficiencies to Fluid Stream0, !- Coefficient 1 of the Part Load Performance Curve1, !- Coefficient 2 of the Part Load Performance Curve0, !- Coefficient 3 of the Part Load Performance Curve0, !- Coefficient 4 of the Part Load Performance Curve0, !- Minimum Flow Rate {m3/s}INTERMITTENT, !- Pump Control TypeAlwaysAvailable; !- Pump Flow Rate Schedule Name


Pipes

Pipe:AdiabaticPipe:Adiabatic:SteamPipe:IndoorPipe:OutdoorPipe:Underground


Boilers and Heat Sources

Boiler:HotWaterBoiler:SteamWaterHeater:StratifiedWaterHeater:MixedWaterHeater:HeatPumpDistrictHeating


Boiler – ExampleBoiler:HotWater,

Boiler, !- NameGAS, !- Fuel Type25000, !- Nominal Capacity {W}0.8, !- Nominal Thermal EfficiencyCondensingBoilerEff, !- Normalized Boiler Efficiency Curve Name100, !- Design Water Outlet Temperature {C}0.0021, !- Design Water Flow Rate {m3/s}0.10, !- Minimum Part Load Ratio1.00, !- Maximum Part Load Ratio1.00, !- Optimum Part Load RatioBoiler Inlet Node, !- Boiler Water Inlet Node NameBoiler Outlet Node, !- Boiler Water Outlet Node Name100, !- Water Outlet Upper Temperature Limit {C}ConstantFlow, !- Boiler Flow Mode Type, !- Parasitic Electric Load {W}; !- Sizing Factor

Curve:Biquadratic,CondensingBoilerEff, !- Name1.124970374, !- Coefficient1 Constant0.014963852, !- Coefficient2 x. . .


Chillers

Chiller:Electric:EIR (based on DOE-2)Chiller:Electric:ReformulatedEIRChiller:Electric (based on BLAST)Chiller:ConstantCOP (electric)Chiller:AbsorptionChiller:EngineDrivenChiller:CombustionTurbineChillerHeater:Absorption:DirectFiredDistrictCooling


Chiller – Example

Chiller 1Chiller 1 ChW Inlet

Chiller 1 ChW Outlet

Chiller 1Cnd Outlet

Chiller 1Cnd Inlet

Condenser DemandSide Loop


CW PumpPlant Demand Side

Cooling Loop


Chiller – Example (cont’d)Chiller:Electric:EIR,Chiller 1, !- Nameautosize, !- Reference Capacity {W}3.6, !- Reference COP {W/W}6.67, !- Reference Leaving Chilled Water Temperature {C}29.4, !- Reference Entering Condenser Fluid Temperature {C}autosize, !- Reference Chilled Water Flow Rate {m3/s}autosize, !- Reference Condenser Water Flow Rate {m3/s}Chiller 1 RecipCapFT, !- Cooling Capacity Function of Temperature Curve NameChiller 1 RecipEIRFT, !- Electric Input to Cooling Output Ratio Function . . . Chiller 1 RecipEIRFPLR, !- Electric Input to Cooling Output Ratio Function . . .0, !- Minimum Part Load Ratio1, !- Maximum Part Load Ratio1, !- Optimum Part Load Ratio0.25, !- Minimum Unloading RatioChiller 1 ChW Inlet, !- Chilled Water Inlet Node NameChiller 1 ChW Outlet, !- Chilled Water Outlet Node NameChiller 1 Cnd Inlet, !- Condenser Inlet Node NameChiller 1 Cnd Outlet, !- Condenser Outlet Node NameWaterCooled, !- Condenser Type, !- Condenser Fan Power Ratio {W/W}1, !- Compressor Motor Efficiency5, !- Leaving Chilled Water Lower Temperature Limit {C}ConstantFlow, !- Chiller Flow Mode0; !- Design Heat Recovery Water Flow Rate {m3/s}


Cooling Towers

Condenser TowerInlet Node

Condenser TowerOutlet Node

Tower

Cond DemandSide Loop

Plant Supply SideCondenser Loop


Cooling Towers (cont’d)

CoolingTower:TwoSpeedCoolingTower:SingleSpeedCoolingTower:VariableSpeed

CoolingTower:SingleSpeed,Tower, !- NameCondenser Tower Inlet Node, !- Water Inlet Node NameCondenser Tower Outlet Node, !- Water Outlet Node Name0.0011, !- Design Water Flow Rate {m3/s}16.0, !- Design Air Flow Rate {m3/s}1000, !- Fan Power at Design Air Flow Rate {W}1750.0, !- U-Factor Times Area Value at Design Air Flow Rate {W/K}0.0, !- Air Flow Rate in Free Convection Regime {m3/s}0.0, !- U-Factor Times Area Value at Free Convection Air Flow Rate {W/K}UFactorTimesAreaAndDesignWaterFlowRate, !- Performance Input Method, !- Nominal Capacity {W}; !- Free Convection Capacity {W}


Fluid Coolers

EvaporativeFluidCooler:SingleSpeedEvaporativeFluidCooler:TwoSpeedFluidCooler:SingleSpeedFluidCooler:TwoSpeed


Water-Side Economizers

HeatExchanger:HydronicHeatExchanger:PlateHeatExchanger:WatersideEconomizer


Solar Collectors

SolarCollector:FlatPlate:WaterSolarCollector:FlatPlate:PhotovoltaicThermal

SolarCollector:UnglazedTranspiredSolarCollector:UnglazedTranspired:Multisystem


Thermal Storage

WaterHeater:MixedWaterHeater:StratifiedThermalStorage:Ice:SimpleThermalStorage:Ice:DetailedThermalStorage:ChilledWater:MixedThermalStorage:ChilledWater:Stratified


Curve Objects

Curve:CubicCurve:QuadratricCurve:BiquadraticCurve:Biquadratic,

Sample Curve, !- Name1.000, !- Coefficient1 Constant0.100, !- Coefficient2 x0.001, !- Coefficient3 x**20.200, !- Coefficient4 y0.002, !- Coefficient5 y**20.003, !- Coefficient6 x*y0, !- Minimum Value of x100, !- Maximum Value of x0, !- Minimum Value of y100; !- Maximum Value of y


Curve Object Used in Gas Heating Coil

Coil:Heating:Gas,Furnace Coil, !- NameFanAndCoilAvailSched, !- Availability Schedule Name0.8, !- Gas Burner Efficiency15000, !- Nominal Capacity {W}Heating Coil Air Inlet Node, !- Air Inlet Node NameAir Loop Outlet Node, !- Air Outlet Node Name, !- Temperature Setpoint Node Name100, !- Parasitic Electric Load {W}PLFCurveforGasFurnace, !- Part Load Fraction Correlation Curve Name10; !- Parasitic Gas Load {W}

Curve:Cubic,PLFCurveforGasFurnace, !- Name0.8, !- Coefficient1 Constant0.2, !- Coefficient2 x0.0, !- Coefficient3 x**20.0, !- Coefficient4 x**30, !- Minimum Value of x1; !- Maximum Value of x


Table Objects

Table of valuesAvoid need for user curve fittingTable:OneIndependentVariableTable:TwoIndependentVariablesTable:MultiVariableLookup

Part 8 - HVAC Controlsand Autosizing



June 2012 Introduction to EnergyPlus - Part 8 - HVAC Controls and Autosizing 2

Outline

Zone Controls Thermostat Humidistat

System ControlsHVAC Autosizing


Zone Control

Thermostat controlHumidistat control


Thermostat Control

Controls zone to a specified temperatureControl type schedule

Specifies which type of control is active at any given time0 = Uncontrolled1 = Single heating setpoint2 = Single cooling setpoint3 = Single heating/cooling setpoint4 = Dual setpoint with deadband


Thermostat Control (cont’d)

Control Type and Name Reference other objects which specify the setpoint

schedules for a given control type Repeat for each control type used

in the zoneThree control options

ZoneControl:Thermostat (air temp) ZoneControl:Thermostat:OperativeTemperature

(air temp and mean radiant temp) ZoneControl:Thermostat:ThermalComfort

(Fanger PMV)


Zone Thermostat – ExampleYear-Round Auto

ZoneControl:Thermostat,Space 1-1 Thermostat, !- NameSPACE1-1, !- Zone NameZone Control Type Sched, !- Control Type Schedule NameThermostatSetpoint:DualSetpoint, !- Control 1 Object TypeAll Zones Dual SP Control; !- Control 1 Name

Schedule:Compact, Zone Control Type Sched, Any Number,Through: 12/31, For: AllDays, Until: 24:00, 4; ! Always=4=Dual SP

ThermostatSetpoint:DualSetpoint,All Zones Dual SP Control, !- NameHtg-SetP-Sch, !- Heating Setpoint Temperature Schedule NameClg-SetP-Sch; !- Cooling Setpoint Temperature Schedule Name

Schedule:Compact, Htg-SetP-Sch, Temperature,Through: 12/31, For: WeekDays CustomDay1 CustomDay2,Until: 6:00, 13.0, Until: 7:00, 17.0, Until: 21:00, 21.0, Until: 24:00, 13.0,For: WeekEnds Holiday SummerDesignDay, Until: 24:00, 13.0,For: WinterDesignDay, Until: 24:00, 21.0;

Similar schedule for cooling setpoints . . .


Humidity Control

ZoneControl:Humidistat specifies high and low relative humidity setpoint schedules

ZoneControl:Humidistat has no effect by itself For DX systems, activate humidity control in unitary

system object or equivalent For chilled water systems, also need

SetpointManager:SingleZone:Humidity:Maximum and change control variable in Controller:WaterCoil to TemperatureAndHumidityRatio

For humidification need to add humidifer object and a SetpointManager:SingleZone:Humidity:Maximum


System Controls

High Level Control Similar to an energy management system Setpoint Managers algorithms establish fluid loop setpoints

Availability Managersmake global on/off decisions

Demand ManagersDemand limiting for lights, plug loads,

thermostats


System Controls (cont’d)

Component Control Controllers sense state at one node in system control flow at another node to match setpoint

Integrated control control integrated within component

Control is ideal physical simulation of PI controllers requires

shorter time step


System Controls (cont’d)

Programmable Energy Management System Advanced feature Sensors (e.g. Zone1 humidity ratio) Actuators (e.g. Turn a fan on/off) User defined programs/rules to take action based

on current sensor values For example, turn on a fan when one of several

temperatures > limit

See Application Guides – Energy Management System


System Availability Managers

Global on/off decisions for a systemScheduled

Availability determined by an on/off schedule

Night Cycle Used to cycle an air system on when one or more

zones becomes too hot or too cold

Temperature-Based DifferentialThermostat HighTemperatureTurnOff/On LowTemperatureTurnOff/On


Setpoint Managers

SetpointManager:ScheduledSetpointManager:Scheduled:DualSetpoint Uses a schedule to determine one or more

setpoints

SetpointManager:OutdoorAirReset Sets the supply air temperature according to the

outside air temperature using a reset rule Reset rule determined by the supply air setpoint

temperature at the outside high and low temperature


Setpoint Managers (cont’d)

SetpointManager:SingleZone:ReheatSetpointManager:SingleZone:HeatingSetpointManager:SingleZone:Cooling Calculates a setpoint temperature for the supply air

that will satisfy the load of a controlled zone

SetpointManager:SingleZone:Humidity:MinimumSetpointManager:SingleZone:Humidity:Maximum Calculates the supply air humidity ratio needed to

maintain the zone relative humidity as specified



SetpointManager:MixedAir Adjust supply air setpoint for fan heat Outside air controller operates the outside air damper to

meet this setpoint

SetpointManager:WarmestSetpointManager:WarmestTemperatureFlowSetpointManager:Coldest Supply air temperature reset based on zone demands

SetpointManager:OutdoorAirPretreat Calculate required outdoor air stream conditions which will

produce the reference setpoint condition at the mixed air node



SetpointManager:MultiZone:Heating:Average SetpointManager:MultiZone:Cooling:Average SetpointManager:MultiZone:MinimumHumidity:Average SetpointManager:MultiZone:MaximumHumidity:Average SetpointManager:MultiZone:Humidity:Minimum SetpointManager:MultiZone:Humidity:Maximum SetpointManager:FollowOutdoorAirTemperature SetpointManager:FollowSystemNodeTemperature SetpointManager:FollowGroundTemperature SetpointManager:CondenserEnteringReset SetpointManager:CondenserEnteringReset:Ideal


Controllers

Controller:WaterCoil Controls variable at one node based on the

condition at another node For a cooling coil, the control node might be the

outlet air temperature while the actuated variable is the flow rate through the coil

Controller:OutdoorAir Controls mixed air box outside air flow rate Economizer options, temperature and enthalpy Simple demand controlled ventilation


Controller:WaterCoilSensor Node Name is the sensed nodeActuator Node Name is the water inlet to coilConvergence tolerance usually autosizedAction: Reverse (cooling) or Normal (heating)

Controller:WaterCoil,

VAV Sys 1 Central Cooling Coil Controller, !- Name

Temperature, !- Control Variable

Reverse, !- Action

FLOW, !- Actuator Variable

VAV Sys 1 Outlet Node, !- Sensor Node Name

VAV Sys 1 Central Cooling Coil Water Inlet Node, !- Actuator Node Name

autosize, !- Controller Convergence Tolerance {deltaC}

autosize, !- Maximum Actuated Flow {m3/s}

0.0; !- Minimum Actuated Flow {m3/s}


HVAC Autosizing

Sizing:ZoneDesignSpecification:OutdoorAir

DesignSpecification:ZoneAirDistributionSizing:SystemSizing:Plant

Component SizingSizing Outputs

Mixing Autosize with Specified Values


HVAC Autosizing Overview

Uses all sizing periods and selects max size Typically a winter and summer design day Zone and system airflow rates Component sizes Water loop flow rates and capacities

Outside air options “Size and go” runs with computed sizesSizing report files (.zsz, .ssz)Component sizing reported in .eio output file


Autosizing Input

SimulationControlAt least 2 sizing periodsSpecial day schedules for sizing (optional)Global sizing parametersZone, System and Plant Sizing objects “Autosize” indicates which inputs to be

autosized


SimulationControl

Activate sizing calculationsActivate sizing period simulationsExample below performs sizing calculations

using the sizing periods, but then simulates and reports results for only the weather file run period

SimulationControl,

Yes, !- Do Zone Sizing Calculation

Yes, !- Do System Sizing Calculation

Yes, !- Do Plant Sizing Calculation

No, !- Run Simulation for Sizing Periods

Yes; !- Run Simulation for Weather File Run Periods


Sizing:Parameters

Global sizing factor applied to zone design loads and air flow rates, >=1.0

Averaging window – critical if using setback Size on the average load over several time steps Ideal loads sizing simulation will recover from

setback in a single time step To avoid gross oversizing, increase averaging

window or use design day thermostat schedules with no setback

Sizing:Parameters,1.2, !- Heating Sizing Factor1.2, !- Cooling Sizing Factor; !- Time Steps in Averaging Window

Blank above defaults to 1 hour averaging window


Zone Sizing Calculations

Computes maximum cooling load, heating load and design supply air flow rates

Computes zone OA requirements per user inputs, used to sum system OA requirement

Slave zones or sub-zone need a thermostat to be included in zone sizing calculations (even though thermostat may not be active during the simulations)


Zone Sizing Calculations (cont’d)

An ideal loads air simulation is performed for each zone for each sizing period Hot or cold air supplied directly to a zone

at a fixed temperature and with infinitely variable air flow.

This determines zone design air flow rates for heating and cooling.


Sizing:Zone Inputs

Design heating and cooling supply air temperatures and humidity ratios

Reference outdoor air requirementsZone sizing factors

Overrides global sizing factors

Design flow rate limitsOptional - specify hard supply flow rate to

feed into other sizing calculationsReference ventilation effectiveness specs


DesignSpecification:OutdoorAir Inputs

Referenced by other objects Sizing:Zone ZoneHVAC:IdealLoadsAirSystem AirTerminal:*:VAV:* Controller:MechanicalVentilation (DCV)

Outdoor air requirements per person, per area, per zone, ACH, sum or max OA flow rate schedule (used by some objects) OA flow per person may be based on design occupancy (sizing) current number of occupants (DCV)


DesignSpecification:ZoneAirDistribution Inputs

Referenced by other objects Sizing:Zone Controller:MechanicalVentilation (DCV)

Air distribution effectiveness Heating/Cooling Schedule

Secondary recirculation fractionUsed for ventilation rate procedure

(VRP) for sizing and DCV


Sizing:Zone - ExampleSizing:Zone,SPACE1-1, !- Zone or ZoneList Name

SupplyAirTemperature, !- Zone Cooling Design Supply Air Temperature Input Method14., !- Zone Cooling Design Supply Air Temperature {C}, !- Zone Cooling Design Supply Air Temperature Difference {delta C}SupplyAirTemperature, !- Zone Heating Design Supply Air Temperature Input Method50., !- Zone Heating Design Supply Air Temperature {C}, !- Zone Heating Design Supply Air Temperature Difference {deltaC}0.009, !- Zone Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}0.004, !- Zone Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}SZ DSOA SPACE1-1, !- Design Specification Outdoor Air Object Name0.0, !- Zone Heating Sizing Factor0.0, !- Zone Cooling Sizing FactorDesignDayWithLimit, !- Cooling Design Air Flow Method, !- Cooling Design Air Flow Rate {m3/s}, !- Cooling Minimum Air Flow per Zone Floor Area {m3/s-m2}, !- Cooling Minimum Air Flow {m3/s}, !- Cooling Minimum Air Flow FractionDesignDay, !- Heating Design Air Flow Method, !- Heating Design Air Flow Rate {m3/s}, !- Heating Maximum Air Flow per Zone Floor Area {m3/s-m2}, !- Heating Maximum Air Flow {m3/s}, !- Heating Maximum Air Flow FractionSZ DZAD SPACE1-1; !- Design Specification Zone Air Distribution Object Name


DesignSpecification:OutdoorAir Example

DesignSpecification:OutdoorAir,ZoneMinOARequirements, !- NameSum, !- Outdoor Air Method0.00472, !- Outdoor Air Flow per Person {m3/s-person}0.000508, !- Outdoor Air Flow per Zone Floor Area {m3/s-m2}, !- Outdoor Air Flow per Zone {m3/s}, !- Outdoor Air Flow Air Changes per Hour {1/hr}Min OARequirements Sched;!- Outdoor Air Flow Rate Fraction Schedule Name


DesignSpecification:ZoneAirDistribution Example

DesignSpecification:ZoneAirDistribution,ZoneAirDistribution, !- Name1.2, !- Zone Air Distribution Effectiveness in Cooling Mode {dimensionless}0.8, !- Zone Air Distribution Effectiveness in Heating Mode {dimensionless}

, !- Zone Air Distribution Effectiveness Schedule Name0.1; !- Zone Secondary Recirculation Fraction {dimensionless}


System Sizing Calculations

Calculates design air flow rates and heating and cooling capacities based zone sizing results, specified supply air conditions, and design weather conditions.

Must use zone sizing objects to force hard flow rates (will not read component sizes)

Only controlled zones are included in system sizing calculations


Sizing:System Inputs

“System” is an AirLoopHVACType of load to size on

Sensible (latent and total will be future options) VentilationRequirement (for DOAS) Coincident or non-coincident

Design supply and preheat temperaturesDesign minimum outside air flow rateMinimum system air flow ratioOptional - specify hard supply flow rate – this

will scale zone flows to match system flow


Sizing:System - ExampleSizing:System,

VAV Sys 1, !- AirLoop Namesensible, !- Type of Load to Size Onautosize, !- Design Outdoor Air Flow Rate {m3/s}0.3, !- Minimum System Air Flow Ratio7.0, !- Preheat Design Temperature {C}.008, !- Preheat Design Humidity Ratio {kg-H2O/kg-Air}11.0, !- Precool Design Temperature {C}.008, !- Precool Design Humidity Ratio {kg-H2O/kg-Air}12.8, !- Central Cooling Design Supply Air Temperature {C}16.7, !- Central Heating Design Supply Air Temperature {C}noncoincident, !- Sizing Optionno, !- 100% Outdoor Air in Coolingno, !- 100% Outdoor Air in Heating0.008, !- Central Cooling Design Supply Air Humidity Ratio

{kg-H2O/kg-Air}0.008, !- Central Heating Design Supply Air Humidity Ratio

{kg-H2O/kg-Air}DesignDay, !- Cooling Design Air Flow Method0, !- Cooling Design Air Flow Rate {m3/s}DesignDay, !- Heating Design Air Flow Method0; !- Heating Design Air Flow Rate {m3/s}


Plant Sizing

Calculates heating, cooling & condenser loop flow rates

Used to calculate maximum water flow rates for heating and cooling components

Component flow rates summed to calculate plant loop flow rates – even if components are not autosized


Sizing:Plant Inputs

Plant loop or Condenser loopLoop type – heat, cool, condenserDesign loop exit temperatureDesign loop delta T

Sizing:Plant,

Hot Water Loop, !- Plant or Condenser Loop Name

heating, !- Loop Type

82., !- Design Loop Exit Temperature {C}

11; !- Loop Design Temperature Difference {deltaC}


What Component Inputs Can Be Autosized?

Indicated in IDD file

Fan:VariableVolume,…..N3 , \field Maximum Flow Rate

\units m3/s\Autosizeable

…..


In the IDF file:

Fan:VariableVolume,Supply Fan 1, !- NameFanAvailSched, !- Availability Schedule Name0.7, !- Fan Efficiency600.0, !- Pressure Rise {Pa}autosize, !- Maximum Flow Rate {m3/s}autosize, !- Minimum Flow Rate {m3/s}0.9, !- Motor Efficiency1.0, !- Motor In Airstream Fraction0.0015302446, !- Fan Coefficient 10.0052080574, !- Fan Coefficient 21.1086242, !- Fan Coefficient 3-0.11635563, !- Fan Coefficient 40.000, !- Fan Coefficient 5Main Heating Coil 1 Outlet Node, !- Fan Inlet Node NameVAV Sys 1 Outlet Node; !- Fan Outlet Node Name

Component Input Autosizing


Sizing Outputs

*.zsz file – hourly zone loads for heating and cooling

*.ssz file – hourly system loads for heating and cooling

*.eio file – component sizes! <Component Sizing Information>, Component Type, Component Name, Input

Field Description, Value

! Component Sizing, SINGLE DUCT:VAV:REHEAT, SPACE1-1 VAV REHEAT, Maximum air flow rate [m3/s], 0.46114

! Component Sizing, COIL:GAS:HEATING, SPACE1-1 ZONE COIL, Nominal Capacity of the Coil [W], 7423.7


Sizing Outputs (cont’d)

Output:Table:SummaryReports EquipmentSummary HVACSizingSummary


Mixing Autosize with Specified Values

Values for flow rates or equipment sizes may be specified in Sizing:Zone object – Zone supply and OA flow rates Sizing:System object – System supply and OA flow rates Specific component objects – e.g. Fan flow BAD IDEA!

Autosize calculations primarily use only the information from Sizing objects Sizing:System specified flow rate overrides zone flow rates

Autosize calculations generally know nothing about specified values in component objects e.g. – Value specified for supply fan flow rate will only be

used in that specific fan object, other components will size based on Sizing object results

But there are exceptions . . .


Exception for Plant Loops

Plant loop total flow rate Autosized flow rate for plant loop and

pump objects will sum all demand-side equipment flow rates

This works if the demand-side components are autosized or have specified sizes

Specified size in PlantLoop object does notimpact autosized pump flow rate –pump will autosize based on demand-side flow total


Mixed Sizing Inputs in the Same Component

Many components have multiple capacity and/or flow rate inputs DX coil – capacity and airflow rate Chiller – capacity, evaporator flow rate, condenser

flow rateEach component currently computes

Autosized values in a specific order or priorityOften not intuitiveMay be documented in Engineering ReferenceCan end up with inconsistent values

with mixed inputs


Chiller with Mixed Sizing Inputs

Capacity Autosized based on plant loop design flow rate and delta T

Evaporator flow rate Autosized based on plant loop design flow rate Currently ignores a specified capacity value

Condenser flow rate Autosized base on capacity

(whether capacity is specified or autosized) BEST PRACTICE

Treat all 3 inputs the same All 3 “Autosize” or all 3 specified values

Chiller:Electric:EIR, Chiller 1, !- Name70000, !- Reference Capacity {W}. . .autosize, !- Reference Chilled Water Flow Rate {m3/s}autosize, !- Reference Condenser Water Flow Rate {m3/s}


Autosizing Review and Cautions

ZoneControl:Thermostat rules the peak load calculations Uses an internal ideal loads simulation – so peak zone load

calcs know nothing of the actual HVAC equipment Be careful with setback – recovery could set the peak

Sizing:* objects rule everything else Information in component objects is generally not known to

sizing calculations SetpointManager:* and other control inputs must be

consistent with the Sizing:* object inputs Hot water heating loops generally tend to be

significantly oversized (still an issue as of v6.0) Confirm peak hot water loop loads on design days Use hard values to right-size the loop and boilers

Part 8b - HVAC for Light Commercial and

Residential Applications



Oct 2012 Introduction to EnergyPlus - Part 8b - HVAC for Light Commercial and Residential 2

Outline

HVACTemplate System TypesDX System InputsPost-Template CustomizationSizing Considerations

HVACTemplate Zonal Units

Constant volumeCycling or continuous fan –

mode can be scheduledHVACTemplate:Zone:PTAC

DX cooling Electric, Hot Water,

or Gas heat


HVACTemplate Zonal UnitsHVACTemplate:Zone:PTHP

DX cooling Air-to-air heat pump heating Electric or gas supplemental heat

HVACTemplate:ZoneWaterToAirHeatPump DX cooling – Water loop condenser Water-to-air heat pump heating Electric supplemental heat Can be ground-source


HVACTemplate Constant-Volume Central Systems

Rooftop Units or Split SystemsCycling or Continuous Fan –

mode can be scheduledSingle-Zone or Multi-Zone


HVACTemplate Constant-Volume Central Systems

Furnace with DX Cooling HVACTemplate:System:Unitary HVACTemplate:Zone:Unitary DX Cooling Electric or Gas Heating Humidity control with reheat option (including desuperheat)

Air-to-Air Heat Pump HVACTemplate:System:UnitaryHeatPump:AirToAir HVACTemplate:Zone:Unitary DX cooling Air-to-air heat pump heating Electric or gas supplemental heat


HVACTemplate VAV Central Systems

Rooftop Units or Split Systems Continuous Fan with night-cycle mode Single-Zone or Multi-Zone

HVACTemplate:Zone:VAV:FanPowered HVACTemplate:Zone:VAV

HVACTemplate:System:VAV ChW cooling with HW, Electric or Gas Heat

HVACTemplate:System:PackagedVAV DX cooling with HW, Electric or Gas Heat


DX System InputsRated Performance

At ARI conditions 26.7°C drybulb/19.4°C wetbulb outdoor 35.0°C drybulb/23.9°C wetbulb entering

coilCapacity – Gross, totalSHR – Gross, sensible divided by totalCOP – Gross, total cooling cap divided by

power input to compressor + outdoor fanGross = no supply fan heat or electricity



EER – not a direct inputCOP = Gross Cap/(Compressor+OutdoorFan Power)EER = Net Cap/(Compr.+ODFan+SupplyFan Power)COP = [EER*(Compr.+ODFan+SupplyFan Power) +SupplyFanHeat]/(Compressor+OutdoorFan Power)

Catalog data varies Net, gross, sometimes not labeled clearly



Rated Evaporator Fan Power Per Volume Flow Rate Be careful! In Coil:Cooling:DX:SingleSpeed Used to calculate rated peformance

outputs (EER, SEER, IEER, Net Capacity) Does not impact energy simulation – other

fan inputs dictate simulation fan power HVACTemplate leaves this blank which

results in default of 773.3 W/(m3/s) or 365 W/1000 cfm


DX System OutputsRated Performance

EnergyPlus outputs in eio and table file EER – Energy Efficiency Ratio SEER - Seasonal Energy Efficiency Ratio IEER – Integrated Energy Efficiency Ratio Net Capacity - Standard Rating (Net) Cooling

Capacity

Computed based on rated inputs and standard rating calculations

Coil:Cooling:DX:SingleSpeed onlySimulation results may vary


Post-Template Customization

HVACTemplate objects have a limited set of direct inputs

*.expidf – expanded idf contains many more detailed inputs

Following slides list key items that you may need to customize

Copy and rename *.expidf to <newname>.idf then edit


Post-Template CustomizationPerformance Curves

VAV Fan power vs flowGas heating coil PLR curveDX cooling and heating coils

Capacity and EIR vs temperature and flow Part-load curve

DX heating coil defrost curveOthers?


Post-Template CustomizationOther Parameters

DX cooling coils Crankcase heater Moisture (re-)evaporation with continous

fan and cycling compressor Rated Evaporator Fan Power Per Volume

Flow Rate (mentioned earlier) Evaporative condenser


Post-Template CustomizationOther Parameters

DX heating coils Defrost controls

Maximum supply air temperature Furnace Heat pump supplemental heat


Sizing Considerations

Cooling vs Heating Capacity In cold climates, if heating sets supply airflow,

cooling capacity will likely be oversized Separate heating/cooling sizing factors only apply

to supply air flow rate – currently do not function as expected

DX Coil Cooling Capacity Based on design airflow and supply temp Built-in CFM/ton limits may constrain capacity

Heat Pump Heating Coil Capacity based on Cooling Coil Capacity


Part 9 - HVAC VAV System Example

with Hot Water Boiler and Water-Cooled Chiller



Oct 2012 Introduction to EnergyPlus - Part 9 - HVAC VAV System Example 2

Outline

3-Zone VAV with Reheat Air LoopHot Water LoopChilled Water LoopCondenser Loop


3-Zone VAV System ExampleWe are going to look at this system input Loop by Loop

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass


3-Zone VAV Reheat Air Loop

Air Loop contains the Mixed Air System, Supply Fan and the Cooling Coil

Outdoor Air System contains an Outdoor Air Mixing Box and Controller

Zone Equipment Loop contains the Splitter, VAV Air Distribution Unit, the zones, and the Return Air Path with the Mixer.

Remaining slides walk through all input to describe the air side of this system

Mixed Air Outlet

CCSupply FanCooling Coil

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet

Air Loop Inlet (Return Air) Air Loop Outlet(Supply Air)

North

Zone

EastZone

West

Zone

Ret

urn

A irM

ixer

North

Zone

East

Zone

West

Zone

Ret

urn

A irM

ixer

Zone Supply A

ir Splitter

Zone 3 VAV Reheat

Zone Equipment Inlet

Zone 2 VAV Reheat

Zone 1 VAV Reheat

Supply Fan Outlet


VAV Reheat Air Loop

AirLoopHVAC,

VAV System, !- Name

VAV System Controllers, !- Controller List Name

VAV System Avail List, !- Availability Manager List Name

1.3, !- Design Primary Air Flow Rate {m3/s}

VAV System Branches, !- BranchList Name

, !- ConnectorList Name

Air Loop Inlet, !- Supply Side Inlet Node Name

Zone Equipment Outlet, !- Demand Side Outlet Node Name

Zone Equipment Inlet, !- Demand Side Inlet Node Names

Air Loop Outlet; !- Supply Side Outlet Node Names

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Cooling Coil ChW Outlet

Supply Fan Outlet

Cooling Coil ChW Inlet


VAV Reheat Controller and Branch Lists


VAV System Controllers, !- Name

Controller:WaterCoil, !- Controller 1 Object Type

Cooling Coil Controller; !- Controller 1 Name

BranchList,

VAV System Branches, !- Name

VAV System Main Branch; !- Branch 1 Name

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



VAV Reheat Availability Manager

AvailabilityManagerAssignmentList,

VAV System Avail List, !- Name

AvailabilityManager:Scheduled, !- Availability Manager 1 Object Type

VAV System Avail; !- Availability Manager 1 Name

AvailabilityManager:Scheduled,

VAV System Avail, !- Name

FanAndCoilAvailSched; !- Schedule Name

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



VAV Reheat Main Branch

Branch,VAV System Main Branch, !- Name1.3, !- Maximum Flow Rate {m3/s}, !- Pressure Drop Curve NameAirLoopHVAC:OutdoorAirSystem, !- Component 1 Object TypeOA Sys, !- Component 1 NameAir Loop Inlet, !- Component 1 Inlet Node NameMixed Air Outlet, !- Component 1 Outlet Node NamePASSIVE, !- Component 1 Branch Control Type

< continued on next slide >

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



VAV Reheat Main Branch (cont’d)

<BRANCH object continued from previous slide>

Fan:VariableVolume, !- Component 2 Object Type

Supply Fan, !- Component 2 Name

Mixed Air Outlet, !- Component 2 Inlet Node Name

Supply Fan Outlet, !- Component 2 Outlet Node Name

ACTIVE, !- Component 2 Branch Control Type

Coil:Cooling:Water, !- Component 3 Object Type

Cooling Coil, !- Component 3 Name

Supply Fan Outlet, !- Component 3 Inlet Node Name

Air Loop Outlet, !- Component 3 Outlet Node Name

PASSIVE; !- Component 3 Branch Control Type

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



VAV Reheat Outdoor Air System

AirLoopHVAC:OutdoorAirSystem,

OA Sys, !- Name

OA Sys Controllers, !- Controller List Name

OA Sys Equipment, !- Outdoor Air Equipment List Name

VAV System Avail List; !- Availability Manager List Name

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet


VAV Reheat Outdoor Air Equipment List

AirLoopHVAC:OutdoorAirSystem:EquipmentList,

OA Sys Equipment, !- Name

OutdoorAir:Mixer, !- Component 1 Object Type

OA Mixing Box; !- Component 1 Name

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet


VAV Reheat Outdoor Air Mixer

OutdoorAir:Mixer,

OA Mixing Box, !- Name

Mixed Air Outlet, !- Mixed Air Node Name

Outdoor Air Inlet, !- Outdoor Air Stream Node Name

Relief Air Outlet, !- Relief Air Stream Node Name

Air Loop Inlet; !- Return Air Stream Node Name

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet


VAV Reheat Outdoor Air Controller List


OA Sys Controllers, !- Name

Controller:OutdoorAir, !- Controller 1 Object Type

OA Controller; !- Controller 1 Name

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet


VAV Reheat Outdoor Air Controller

Controller:OutdoorAir,

OA Controller, !- Name

Relief Air Outlet, !- Relief Air Outlet Node Name

Air Loop Inlet, !- Return Air Node Name

Mixed Air Outlet, !- Sensor Node Name

Outdoor Air Inlet, !- Actuator Node Name

0.468, !- Minimum Outdoor Air Flow Rate {m3/s}

1.56, !- Maximum Outdoor Air Flow Rate {m3/s}

FixedDryBulb, !- Economizer Control Type

ModulateFlow, !- Economizer Control Action Type

19., !- Economizer Maximum Limit Dry-Bulb Temperature {C}

, !- Economizer Maximum Limit Enthaply {J/kg}

, !- Economizer Maximum Limit Dew-Point Temperature {C}

, !- Electronic Enthalpy Limit Curve Name

4., !- Economizer Minimum Limit Dry-Bulb Temperature {C}

NoLockout, !- Lockout Type

FixedMinimum, !- Minimum Limit Type

Min OA Sched; !- Minimum Outdoor Air Schedule Name


VAV Reheat Outdoor Air Node List

OutdoorAir:NodeList,

Outdoor Air Inlet; !- Node or NodeList Name 1

OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet


Mixed Air Outlet


VAV Reheat Supply Fan

Fan:VariableVolume,Supply Fan, !- NameFanAndCoilAvailSched, !- Availability Schedule Name0.7, !- Fan Efficiency600.0, !- Pressure Rise {Pa}1.3, !- Maximum Flow Rate {m3/s}0.20, !- Minimum Flow Rate {m3/s}0.9, !- Motor Efficiency1.0, !- Motor In Airstream Fraction0.35071223, !- Fan Coefficient 10.30850535, !- Fan Coefficient 2-0.54137364, !- Fan Coefficient 30.87198823, !- Fan Coefficient 40.000, !- Fan Coefficient 5Mixed Air Outlet, !- Fan Inlet Node NameSupply Fan Outlet; !- Fan Outlet Node Name

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



Coil:Cooling:Water,Cooling Coil, !- NameCoolingCoilAvailSched, !- Availability Schedule Nameautosize, !- Design Water Flow Rate {m3/s}autosize, !- Design Air Flow Rate {m3/s}autosize, !- Design Inlet Water Temperature {C}autosize, !- Design Inlet Air Temperature {C}autosize, !- Design Outlet Air Temperature {C}autosize, !- Design Inlet Air Humidity Ratio {kg-H2O/kg-air}autosize, !- Design Outlet Air Humidity Ratio {kg-H2O/kg-air}Cooling Coil ChW Inlet, !- Water Inlet Node NameCooling Coil ChW Outlet, !- Water Outlet Node NameSupply Fan Outlet, !- Air Inlet Node NameAir Loop Outlet, !- Air Outlet Node NameSimpleAnalysis, !- Type of AnalysisCrossFlow; !- Heat Exchanger Configuration

VAV Reheat Cooling Coil – Air Side

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



VAV Reheat Cooling Coil Controller

Controller:WaterCoil,

Cooling Coil Controller, !- Name


Reverse, !- Action

FLOW, !- Actuator Variable

Air Loop Outlet, !- Sensor Node Name

Cooling Coil ChW Inlet, !- Actuator Node Name

0.001, !- Controller Convergence Tolerance {deltaC}

0.0011, !- Maximum Actuated Flow {m3/s}

0.0; !- Minimum Actuated Flow {m3/s}

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



VAV Reheat Cooling Coil Setpoint Manager

SetpointManager:Scheduled,

Cooling Supply Air Temp Manager, !- Name


Always 12.8, !- Schedule Name

Air Loop Outlet; !- Setpoint Node or NodeList Name

Mixed Air Outlet


OA Mixing Box

Relief Air Outlet

Outdoor Air Inlet



Supply Fan Outlet



VAV Reheat Zone Supply Air Path

AirLoopHVAC:SupplyPath,

VAV System Supply Path, !- Name

Zone Equipment Inlet, !- Supply Air Path Inlet Node Name

AirLoopHVAC:ZoneSplitter,!- Component 1 Object Type

Zone Supply Air Splitter;!- Component 1 Name

NorthZone

EastZone

WestZone

Retu

r nA i

rMixe

r

North

Zone

EastZone

West

Zone

Retu

r nA i

rMixe

r

Zone Supply A

ir Splitter

Zone 3 VAV Reheat

Zone 2 VAV Reheat

Zone 1 VAV Reheat

Zone 1 VAV Inlet


Zone 3 VAV Inlet

Zone 2 VAV Inlet


VAV Reheat Zone Splitter

AirLoopHVAC:ZoneSplitter,

Zone Supply Air Splitter,!- Name

Zone Equipment Inlet, !- Inlet Node Name

Zone 1 VAV Inlet, !- Outlet 1 Node Name

Zone 2 VAV Inlet, !- Outlet 2 Node Name

Zone 3 VAV Inlet; !- Outlet 3 Node Name

NorthZone

EastZone

WestZone

Retu

r nA i

rMixe

r

North

Zone

EastZone

West

Zone

Retu

r nA i

rMixe

r

Zone Supply A

ir Splitter

Zone 3 VAV Reheat

Zone 2 VAV Reheat

Zone 1 VAV Reheat

Zone 1 VAV Inlet


Zone 3 VAV Inlet

Zone 2 VAV Inlet


VAV Reheat Zone Thermostat

ZoneControl:Thermostat,Zone 1 Thermostat, !- NameWest Zone, !- Zone NameZone Control Type Sched, !- Control Type Schedule NameThermostatSetpoint:DualSetpoint, !- Control 1 Object TypeDual Setpoints with Setback; !- Control 1 Name

ThermostatSetpoint:DualSetpoint,Dual Setpoints with Setback, !- NameHtg-SetP-Sch, !- Heating Setpoint Temperature Schedule NameClg-SetP-Sch; !- Cooling Setpoint Temperature Schedule Name

NorthZone

EastZone

WestZone

Retu

r nAi

r Mixe

r

North

Zone

EastZone

WestZone

Retu

r nAi

r Mixe

r

Zone Supply A

ir Splitter

Zone 3 VAV Reheat

Zone 2 VAV Reheat

Zone 1 VAV Reheat


VAV Reheat Zone Equipment Connections

ZoneHVAC:EquipmentConnections,

West Zone, !- Zone Name

Zone 1 Equipment, !- Zone Conditioning Equipment List Name

Zone 1 Inlet, !- Zone Air Inlet Node or NodeList Name

, !- Zone Air Exhaust Node or NodeList Name

Zone 1 Node, !- Zone Air Node Name

Zone 1 Outlet; !- Zone Return Air Node Name

West

Zone

West Zone

Zone 1 VAV Reheat

Zone 1Outlet

Zone 1Inlet

Zone 1Node

Zone 1 VAV Damper Outlet

Zone 1 VAV Inlet

Zone 1 Reheat HW Inlet

Zone 1 Reheat HW Outlet

Zone 1Reheat Coil


VAV Reheat Zone Equipment List

ZoneHVAC:EquipmentList,

Zone 1 Equipment, !- Name

ZoneHVAC:AirDistributionUnit, !- Zone Equipment 1 Object Type

Zone 1 ADU, !- Zone Equipment 1 Name

1, !- Zone Equipment 1 Cooling Priority

1; !- Zone Equipment 1 Heating Priority

West

Zone

West Zone

Zone 1 VAV Reheat

Zone 1Outlet

Zone 1Inlet

Zone 1Node


Zone 1 VAV Inlet



Zone 1Reheat Coil


VAV Reheat Air Distribution Unit

ZoneHVAC:AirDistributionUnit,

Zone 1 ADU, !- Name

Zone 1 Inlet, !- Air Distribution Unit Outlet Node Name

AirTerminal:SingleDuct:VAV:Reheat, !- Air Terminal Object Type

Zone 1 VAV Reheat; !- Air Terminal Name

West

Zone

West Zone

Zone 1 VAV Reheat

Zone 1Outlet

Zone 1Inlet

Zone 1Node


Zone 1 VAV Inlet



Zone 1Reheat Coil


VAV Reheat VAV Terminal Unit

AirTerminal:SingleDuct:VAV:Reheat,

Zone 1 VAV Reheat, !- Name

ReheatCoilAvailSched, !- Availability Schedule Name

Zone 1 VAV Damper Outlet,!- Damper Air Outlet Node Name

Zone 1 VAV Inlet, !- Air Inlet Node Name

0.33, !- Maximum Air Flow Rate {m3/s}

0.3, !- Zone Minimum Air Flow Fraction

Zone 1 Reheat HW Inlet, !- Sensor Node Name

Coil:Heating:Water, !- Reheat Coil Object Type

Zone 1 Reheat Coil, !- Reheat Coil Name

0.0003, !- Maximum Reheat Water Flow Rate {m3/s}

0.0, !- Minimum Reheat Water Flow Rate {m3/s}

Zone 1 Inlet, !- Air Outlet Node Name

0.001, !- Convergence Tolerance

Reverse; !- Damper Heating Action

<Refer to schematic on previous slide>


VAV Reheat Reheat Coil – Air Side

Coil:Heating:Water,

Zone 1 Reheat Coil, !- Name

ReheatCoilAvailSched, !- Availability Schedule Name

300., !- U-Factor Times Area Value {W/K}

0.0003, !- Maximum Water Flow Rate {m3/s}

Zone 1 Reheat HW Inlet, !- Water Inlet Node Name

Zone 1 Reheat HW Outlet, !- Water Outlet Node Name

Zone 1 VAV Damper Outlet,!- Air Inlet Node Name

Zone 1 Inlet, !- Air Outlet Node Name

UFactorTimesAreaAndDesignWaterFlowRate, !- Performance Input Method

autosize, !- Nominal Capacity {W}

82.2, !- Design Inlet Water Temperature {C}

16.6, !- Design Inlet Air Temperature {C}

71.1, !- Design Outlet Water Temperature {C}

32.2; !- Design Outlet Air Temperature {C}

West

ZoneWest Zone

Zone 1 VAV Reheat

Zone 1Outlet

Zone 1Inlet

Zone 1Node


Zone 1 VAV Inlet



Zone 1Reheat Coil


VAV Reheat Zone Return Air Path

AirLoopHVAC:ReturnPath,

VAV System Return Path, !- Name

Zone Equipment Outlet, !- Return Air Path Outlet Node Name

AirLoopHVAC:ZoneMixer, !- Component 1 Object Type

Return Air Mixer; !- Component 1 Name

NorthZone

EastZone

WestZone

Retu

r nA i

rMixe

r

North

Zone

EastZone

West

Zone

Retu

r nA i

rMixe

rZone S

upply Air S

plitter

Zone 3 VAV Reheat

Zone 2 VAV Reheat

Zone 1 VAV Reheat


VAV Reheat Zone Mixer

AirLoopHVAC:ZoneMixer,

Zone Return Air Mixer, !- Name

Zone Equipment Outlet, !- Outlet Node Name

Zone 1 Outlet, !- Inlet 1 Node Name

Zone 2 Outlet, !- Inlet 2 Node Name

Zone 3 Outlet; !- Inlet 3 Node Name

NorthZone

EastZone

WestZone

North

Zone

EastZone

West

Zone

Ret

urn

Air

Mix

er

Zone Supply A

ir Splitter

Zone 3 VAV Reheat

Zone 2 VAV Reheat

Zone 1 VAV Reheat

Zone 1Outlet

Zone EquipmentOutlet

Zone 2Outlet

Zone 3Outlet


Hot Water Demand Side

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass


Hot Water Coils & Hot Water Demand Side

Objects required: BranchList ConnectorList Connector:Splitter Connector:Mixer Branch,Zone X Reheat Branch

(3) COIL:Water:SimpleHeating(3)

Branch, HW Outlet Branch Pipe:Adiabatic

Branch, HW Inlet Branch Pipe:Adiabatic

Branch, HW Bypass Branch Pipe:Adiabatic

Zone Air S

plitter

Plant Dem

and SideH

eating Loop

Return H

W M

ixer

Bypass

HW

Splitter

VAV Box:Reheat

VAV Box:Reheat

VAV Box:Reheat

Zone 1 Reheat Coil HW Outlet

Zone 1 Reheat Coil HW Inlet

HW Demand Entrance Pipe Outlet Node

HW DemandInlet Node


HW Exit Pipe Inlet

HW Bypass Outlet

HW

Bypass Inlet


Hot Water Supply Side

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass


Hot Water Loop Supply SideHot Water Supply Side

Objects required: PlantLoop BranchList ConnectorList Connector:Splitter Connector:Mixer

(cont’d on next slide)

Boiler

Pla

nt D

eman

d S

ide

Hea

ting

Loop

Boiler Outlet Node

HW Pump

HW PumpOutlet Node

Byp

ass

BoilerInlet Node

HW SupplyInlet Node

HW SupplyOutlet Node

HW Exit Pipe Inlet NodeHW BypassOutlet Node

HW BypassInlet Node


Objects required: Branch, Supply Inlet Branch

Pump:VariableSpeed Branch, Boiler Branch

Boiler:HotWater Branch, Supply Bypass Branch

Pipe:Adiabatic Branch, Supply Outlet Branch

Pipe:Adiabatic (or Pipe:Indoor or other) PlantEquipmentOperationScheme

PlantEquipmentOperation:HeatingLoad PlantEquipmentList

SetpointManager:* (for HW supply temp)

Hot Water Loop Supply SideHot Water Supply Side (cont’d)

Boiler

Pla

nt D

eman

d S

ide

Hea

ting

Loop

Boiler Outlet Node

HW Pump

HW PumpOutlet Node

Byp

ass

BoilerInlet Node

HW SupplyInlet Node



HW BypassInlet Node

Boiler

Pla

nt D

eman

d S

ide

Hea

ting

Loop

Boiler Outlet Node

HW Pump

HW PumpOutlet Node

Byp

ass

BoilerInlet Node

HW SupplyInlet Node



HW BypassInlet Node


Cooling Coil & Chilled Water Demand Side

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass


Cooling Coil & Chilled Water Demand Side

Objects required: BranchList ConnectorList Connector:Splitter Connector:Mixer

BypassChilled Water Demand-Side Outlet Node

Chilled Water Demand-Side Inlet Node

CCCooling Coil

Cooling Coil ChW Outlet Node

Cooling Coil ChW Inlet Node

ChW Bypass Outlet Node

ChW Bypass Inlet Node

ChW Demand Exit Pipe Inlet Node

ChW Demand Entrance Pipe Outlet Node


Cooling Coil & Chilled Water Demand Side (cont’d)

Objects required (cont’d): Branch, VAV Sys 1 ChW-Branch

Coil:Cooling:Water:DetailedGeometry, VAV SYS 1 Cooling Coil Branch, Chilled Water Loop 1 ChW Inlet Branch

Pipe:Adiabatic Branch, Chilled Water Loop 1 ChW Outlet Branch

Pipe:Adiabatic Branch, Chilled Water Loop 1 ChW Bypass Branch

Pipe:Adiabatic

BypassChilled Water Demand-Side Outlet Node

Chilled Water Demand-Side Inlet Node

CCCooling Coil

Cooling Coil ChW Outlet Node

Cooling Coil ChW Inlet Node

ChW Bypass Outlet Node

ChW Bypass Inlet Node

ChW Demand Exit Pipe Inlet Node

ChW Demand Entrance Pipe Outlet Node


Chilled Water Supply Side

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass


Objects required: PlantLoop, Chiller Plant Chilled Water Loop BranchList ConnectorList Connector:Splitter Connector:Mixer

Chilled Water Supply SidePlant Supply Side

Cooling Loop

ChW Pump

Chiller

Bypass

Pla

nt D

eman

d S

ide

Coo

ling

Loop

ChW Supply Inlet Node

ChW Supply Outlet Node

Chiller Inlet NodeChW Bypass

Inlet Node

Chiller Outlet NodeChW BypassOutlet Node

ChW Exit Pipe Inlet Node

ChW Supply Mixer

ChW Supply SplitterChW Pump Outlet Node


Objects required (cont’d): Branch, Chiller Plant Cooling Supply Inlet Branch

Pump:VariableSpeed Branch, Chiller Plant Chiller Branch

Chiller:Electric Branch, Chiller Plant Cooling Supply Bypass Branch

Pipe:Adiabatic Branch, Chiller Plant Cooling Supply Outlet Branch

Pipe:Adiabatic (or Pipe:Indoor or other type)

Chilled Water Supply Side (cont’d)


ChW Pump

Chiller

Bypass

Pla

nt D

eman

d S

ide

Coo

ling

Loop




Inlet Node



ChW Supply Mixer



Objects required (cont’d): PlantEquipmentOperationSchemes

PlantEquipmentOperation:CoolingLoad PlantEquipmentList

SetpointManager:* (for ChW supply temp)

Chilled Water Supply Side (cont’d)


ChW Pump

Chiller

Bypass

Pla

nt D

eman

d S

ide

Coo

ling

Loop




Inlet Node



ChW Supply Mixer



Condenser Demand Side

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass


Objects required: BranchList ConnectorList Connector:Splitter Connector:Mixer Branch, Condenser Demand Inlet Branch

Pipe:Adiabatic Branch, Chiller Condenser Branch

Chiller:Electric Branch, Cond. Demand Bypass Branch

Pipe:Adiabatic Branch, Cond. Demand Outlet Branch

Pipe:Adiabatic

Condenser Demand Side


Chiller

Condenser SupplySide Loop

Condenser DemandBypass

ChillerCondenser Outlet Node

Chiller CondenserInlet Node

Condenser Demand Inlet Node

Condenser Demand Bypass Inlet Node

Condenser DemandOutlet Node

CondenserDemand

Splitter

Condenser Demand Mixer

Condenser Demand Bypass Outlet Node

Condenser Demand Exit Pipe Inlet Node

Condenser Demand Entrance PipeInlet Node


Condenser Supply Side

NorthZone

EastZone

WestZone


ChW Pump

CoolingTower

Cond. Pump


Bypass

Supply Fan

Ret

urn

Air

Mix

er

Zone Air S

plitter


Plant Dem

and SideH

eating Loop

CC

Bypass

CondenserBypass

VAV Box:ReHeat

VAV Box:ReHeat


CondenserBypass


Relief Air

Outdoor Air



HW Pump

Chiller

Byp

ass

Bypass



Objects required: CondenserLoop BranchList ConnectorList Connector:Splitter Connector:Mixer


CoolingTower

CondenserPump

CondenserBypass Inlet


Condenser Supply Outlet Condenser Supply Inlet

CondenserBypass Outlet

CondenserTower Inlet

CondenserTower Outlet

CondenserSupply

Mixer

CondenserSupply SplitterCondenser

Supply Exit Pipe Inlet Node Condenser

Pump Outlet



Objects required (cont’d): Branch, Supply Inlet Branch

Pump:VariableSpeed Branch, Condenser Branch

CoolingTower:Single Speed Branch, Cond. Supply Bypass Branch

Pipe:Adiabatic Branch, Supply Outlet Branch

Pipe:Adiabatic (or Pipe:Outdoor) CondenserEquipmentOperationSchemes

PlantEquipmentOperation: CoolingLoad

CondenserEquipmentList SetpointManager:*

(for CndW supply temp)

Condenser Supply Side (cont’d)

CondenserSupply Exit

Pipe Inlet Node

CoolingTower

CondenserPump

CondenserBypass Inlet


Condenser Supply Outlet Condenser Supply Inlet

CondenserBypass Outlet

CondenserTower Inlet

CondenserTower Outlet

CondenserSupply

Mixer

CondenserSupply Splitter

CondenserPump Outlet

Part 10 – Infiltration, Natural Ventilation, and

Multizone Airflow



Oct 2012 Introduction to EnergyPlus - Part 10 - Infiltration, Natural Ventilation and Multizone Airflow 2

Outline

Simple Airflow ModelsSpecial Zone Outdoor Airflow ModelAirflow Network OverviewMultizone AirflowHVAC Distribution AirflowHybrid Ventilation


Simple Airflow Models Infiltration

Zone-level infiltrationDriven by wind speed and deltaTThree Models

ZoneInfiltration:DesignFlowRate ZoneInfiltration:EffectiveLeakageArea ZoneInfiltration:FlowCoefficient


Simple Airflow ModelsInterzone Airflow

ZoneMixing Airflow from one zone to the next Scheduled Can specify min deltaT Assumes equal amount leaves receiving zone User must balance air to source zone with other

mixing, infiltration, or HVACZoneCrossMixing

Airflow exchange between two zones Scheduled Can specify min deltaT


Simple Airflow ModelsVentilation

Zone-level simplified ventilation Simple natural ventilation model Flow driven by wind speed and deltaT Temperature controls and other limits Optional fan power consumption

Two Models ZoneVentilation:DesignFlowRate ZoneVentilation:WindandStackOpenArea


Combining Infiltration, Ventilation, and Duct Leakage

ZoneAirBalance:OutdoorAirComputes combined outdoor air flow into

zone ZoneInfiltration ZoneVentilation ZoneHVAC:EnergyRecoveryVentilator Simplified duct leakage specification

Balanced flows are summedUnbalanced flows added in quadrature


Airflow Network Overview

Simulate airflows for Envelope leakage Operable windows and doors Leakage and openings between zones HVAC distribution system

Currently limited to constant volume systems

Drivers Wind Buoyancy HVAC distribution system Zone exhaust fan


Airflow Network Overview

Based on AIRNET tool from NISTObject classes are Airflownetwork:*Disables the simple airflow objectsGood overview in the Input Output

Reference Extensive list of what this model can and

cannot do


Airflow Network Control Objects

AirflowNetwork:SimulationControl AirflowNetwork:MultiZone:ExternalNode AirflowNetwork:MultiZone:WindPressureCoefficientArray AirflowNetwork:MultiZone:WindPressureCoefficientValues


Multizone Airflow

Surface leakageLarge vertical

openings (windows and doors)

Large horizontalopenings

Zone-to-zone airflow

Zone-1

Window-2

Zone-2

Zone-3

Window-1

Window-3

Door-12

Door-23

ExternalNode-1

ExternalNode-2


Ventilation Controls

Open or close windows and doorsZone or surface level controlsControl types

Temperature Enthalpy Scheduled


Multizone Airflow Objects

AirflowNetwork:Multizone:Zone AirflowNetwork:Multizone:Surface AirflowNetwork:MultiZone:ReferenceCrackConditions AirflowNetwork:MultiZone:Surface:Crack AirflowNetwork:MultiZone:Surface:EffectiveLeakageArea AirflowNetwork:MultiZone:Component:DetailedOpening AirflowNetwork:MultiZone:Component:SimpleOpening AirflowNetwork:MultiZone:Component:HorizontalOpening AirflowNetwork:MultiZone:Component:ZoneExhaustFan


HVAC Distribution Airflow

Simulate distribution system airflows Supply leaks Return leaks Ductwork conduction losses

Interact with multizone airflows Pressures from leaks, supplies, returns,

and exhaust fans Impacts envelope and zone-to-zone airflow


Distribution Airflow Objects

AirflowNetwork:Distribution:Node AirflowNetwork:Distribution:Component:Leak AirflowNetwork:Distribution:Component:LeakageRatio AirflowNetwork:Distribution:Component:Duct AirflowNetwork:Distribution:Component:ConstantVolumeFan AirflowNetwork:Distribution:Component:Coil AirflowNetwork:Distribution:Component:HeatExchanger AirflowNetwork:Distribution:Component:TerminalUnit AirflowNetwork:Distribution:Component:ConstantPressureDrop AirflowNetwork:Distribution:Linkage


Hybrid Ventilation Control

AvailabilityManager:HybridVentilationWhen zone and outdoor conditions are

favorable for natural ventilation Override window/door opening controls to

maximize natural ventilation Turn off an HVAC system

Works with simple or detailed ventilation model


Airflow Network Examples

AirflowNetwork3zVent AirflowNetwork3zVentAutoWPC AirflowNetwork_Multizone_HorizontalOpening AirflowNetwork_MultiZone_House AirflowNetwork_MULTIZONE_House_TwoSpeed AirflowNetwork_MultiZone_SmallOffice AirflowNetwork_MultiZone_SmallOffice_HeatRecoveryHXSL AirflowNetwork_Simple_House AirflowNetwork_Simple_SmallOffice HybridVentilationControl HybridVentilationControlGlobalSimple

Part 11 – Weather Converter, Miscellaneous

Features, Testing & Support Resources



Oct 2012 Introduction to EnergyPlus - Part 11 - Weather Converer and Miscellaneous 2

Outline

Weather Converter ReadvarsESO Postprocessor Input Data Dictionary Allowable Ranges and Defaults Additional Features Testing Support


Weather Converter

Convert weather data formats

Generate statistics report

Create design day data


Weather Converter Input

Input formats TMY3/TMY2/TMY IWEC WYEC2/WYEC FMT (DOE-2 ascii format) CLM (ESP-r ascii format) CSV (special epw CSV format) BLAST (separate conversion utility) SAMSON (source data for TMY2) Custom (user described format) and others . . .


Weather Converter Output

Output formats EPW EnergyPlus weather file (ascii text) CSV User-readable and editable form STAT Statistical report DDY Location and design day objects

Holidays and Daylight Savings By design, EPW files have no holidays or daylight

savings time specified You can add it in a text editor or edit csv format

or specify in your IDF (easiest)


Available EPW Weather Files

Several included in standard installDownload other locations from web site

http://www.energyplus.gov/cfm/weather_data.cfm USA locations

TMY3 & CTZ, with a few TMY2 and TMY Over 1000 sites

Canadian locations CWEC 72 sites

International locations TMY2, TMY, ASHRAE IWEC, CIBSE*, CSWD, CTYW, ETMY, IGDG,

INETI, ISHRAE, KISR, RMY, SWEC, SWERA & Technion Over 1000 sites worldwide *available only from CIBSE


Site Variations in Weather Data

EnergyPlus varies external conditions Wind speed increases significantly with height

Ground level zones by default see approximately 50% lower wind speed than weather data

Temperature decreases slightly with height Surfaces, infiltration, ventilation, HVAC (option)

User controls Building object, Terrain field Site:HeightVariation Site:WeatherStation

Wind speed default is 10m above ground, open field Temperature is 1.5m above ground


ReadVarsESO PostProcessor

Converts eso output file to desired format csv (comma-delimited, spreadsheet) tab (tab-delimited) txt (space-delimited)

Filter report and meter variables By name By reporting frequency (hourly, daily, etc.)

Separate input command files rvi and mvi In EP-Launch Edit Postprocessor Command Specify which variables to include Control the order of variables in the spreadsheet file


Example rvi Input File

eplusout.esoeplusout.csvOutdoor Dry BulbZone/Sys Air TemperatureZone/Sys Sensible Cooling RateZone/Sys Sensible Heating RateTotal Water Heating Coil RateTotal Water Cooling Coil RateSensible Water Cooling Coil RatePlant Loop Cooling DemandPlant Loop Heating DemandPump Mass Flow RatePump Outlet Temp0

Required—ESO name and output name

Required—terminator

List of output variables


Optional Simulation Parameters

TimestepSub-hourly timesteps, default=6 per hour

ShadowCalculation Shadowing Calculation Frequency, default=20 days

SurfaceConvectionAlgorithm:InsideSurfaceConvectionAlgorithm:OutsideHeatBalanceAlgorithmRoomAirModelType

See Input Output Reference – Simulation Parameters


Other Construction Types

Construction:InternalSource Radiant heating and cooling Specify where the source term is located

Construction:WindowDataFile Use Window5 software to describe window details

and do a thermal and optical analysis of a window under different design conditions

Save EnergyPlus export file from Window5 Use this command to import window, frame, and

divider descriptions for EnergyPlus Material:RoofVegetation

Plants, soil, irrigation


Water Use Manager

WaterUse:*Control and report water useGeneralized water end-use objects

hot and cold water mixing at the tap, zone latent gains drainwater heat recovery stand-alone or plant loop hot water supply


Water Use Manager (cont’d)

HVAC components calculate and report water consumption or

condensate productionRainwater collectors to harvest

precipitationGroundwater wells with pumpingWater storage tanks for storing and

reusing reclaimed water


Additional Features Electric power generators (fuel and photovoltaic) Building integrated photovoltaics DX cooling coil moisture re-evaporation Duct losses (simple and detailed) Economics (utility rates and life cycle cost) And more . . .

Comparison of 20 programs in Crawley et al, “Contrasting the Capabilities of Building Energy Performance Simulation Programs”, July 2005

http://apps1.eere.energy.gov/buildings/tools_directory/pdfs/contrasting_the_capabilities_of_building_energy_performance_simulation_programs_v1.0.pdf


Sources of Input DataUser interfaces and other utilitiesCADD programs

Trace over DXF in some EnergyPlus interfaces OpenStudio Plugin for Google SketchUp Green Building Studio (gbxml) supports older version EnergyPlugged (AutoCAD plug-in to create and edit

EnergyPlus input files). Graphisoft ArchiCad direct export in ? Bentley Hevacomp, AECOsim Energy Simulator

Window5/6 Window thermal and optical data

windows.lbl.gov/software/window/window.html

Private Sector User Interfaces

EP-Quick

Easy Energyplus(Chinese)

COMFENEnergyGaugeTREAT PlusESP‐r EPlusInterfaceHVAC EnergySolarShoeBoxxEsoViewothers….EFEN

ECOTECT


Private Sector Interfaces Web Sites

http://www.designbuilder.co.uk/

http://www.bentley.com/en-US/Products/Hevacomp+Dynamic+Simulation/

http://www.bentley.com/en-US/Products/AECOsim+Energy+Simulator/

http://www.simeb.ca/

http://www.smartenergysoftware.com/



Model Maker

Web forms to create generic buildingsSelect from 6 Standards or Guidelines

ASHRAE 90.1-2007, 2004, 2001, 1999 Low Energy Advanced Energy Design Guide (30% savings)

Submit and run remotely Input and output sent via e-mail

Model Maker


Model Maker


Model Maker andExample File Generator

Model Maker EnergyPlus v5.0 and v6.0 (as of Oct 2012) https://modelmaker.nrel.gov/

EnergyPlus Example File Generator EnergyPlus v7.0 and v7.1 (as of Oct 2012) Very similar to Model Maker http://www.energyplus.gov/file_generator_

about.cfm



Input Data Dictionary IDD File

Energy+.iddLocated in

EnergyPlus folderField Types

A (alpha) or N (Numeric)

ZoneHVAC:Baseboard:Convective:Water,

A1 , \field Name

\required-field

A2 , \field Availability Schedule Name

\required-field

\type object-list

\object-list ScheduleNames

. . .

N1 , \field U-Factor Times Area Value

\required-field

\autosizable

\units W/K

. . .

N3 ; \field Convergence Tolerance

\type real

\minimum> 0.0

\default 0.001


IDD File (cont’d)

Lists every available input object If it is not in the IDD, then it is not available IDD version must be consistent with exe

version IDD can be edited by user to extend certain

objects e.g. AirLoopHVAC:ZoneSplitter

extend for more than 500 zones


Allowable Ranges and Defaults

Allowable ranges Some max/min declared in IDD

Fatal error if outside of range

Some max/min hidden in source code May reset value and issue warning, may be fatal

Defaults Some defaults declared in IDD Some defaults hidden in source code Some values have no defaults

Alphas become blank Numerics become zero


EnergyPlus Test Suites

Regression test suites run for every build Over 400 files checked for changes in results

Standardized test suites run before every major release ASHRAE

Standard 140 (envelope loads BESTEST) 1052-RP (building fabric analytical load calculations) Standard 140 HVAC CE100/200 (unitary space cooling

equipment) Standard 140 HVAC CE300/400/500 (unitary cooling with

outside air) Standard 140 HVAC HE100/200 (fuel-fired furnaces)


IEA BESTEST Multi-Zone Non-Airflow (heat transfer between

zones) Airflow Tests Including Multi-Zone Airflow (airflow

through external openings and between zones due to thermal and wind forces)

Ground-Coupling (heat transfer from slab-on- grade) Mechanical Equipment Control Strategies (water

heating and water cooling coils)




Developed for EnergyPlusHVAC Equipment Component Tests (water

chiller and hot water boiler) Global Energy Balance Test (window air

conditioner and hydronic heating/cooling system)


ASHRAE Standard 140 Envelope Test Results


ASHRAE 1052-RP Test Results


ASHRAE Standard 140HVAC Test Results


EnergyPlus Testing Reports Reports available at www.energyplus.gov

Building Thermal Envelope and Fabric Load Tests (ASHRAE Std 140-2007) HVAC Tests CE100 to CE545 (ASHRAE Std 140-2007) HVAC Tests HE100 to HE230 (ASHRAE Std 140-2007) ASHRAE 1052-RP Toolkit – Building Fabric Analytical Tests HVAC Component Comparative Tests Global Energy Balance Tests IEA BESTEST Multi-Zone Non-Airflow IEA BESTEST Mechanical Equipment & Control Strategies for a Chilled

Water and a Hot Water System IEA BESTEST In-Depth Ground Coupled Heat Transfer Tests

Contrasting the Capabilities of Building Energy Performance Simulation Programs, Report comparing the features and capabilities of twenty simulation

programs including EnergyPlus, July 2005.

Additional reports in progress


Support Resources

EnergyPlus Website (www.energyplus.gov) Free program download Documentation Weather data Testing and validation reports Developer & commercial distribution licenses

Building Energy Software Tools DirectoryInformation about more than 300 building energy

software tools from around the world: buildingtools.energy.gov


Support Resources (cont’d)

User Support Helpdesk energyplus.helpserve.com Knowledgebase Downloads Submit questions via web: energyplus.helpserve.com via e-mail: [email protected] Attach input files as needed


Support Resources (cont’d)

EnergyPlus “Yahoo” Group User-to-user forum Join EnergyPlus-Support Yahoo Group

http://groups.yahoo.com/group/EnergyPlus_Support

Subscribe by sending e-mail [email protected]

Post messages by sending e-mail [email protected]

Part 12 – Residential Application Highlights



Oct 2012 Introduction to EnergyPlus - Part 12 - Residential Application Highlights 2

Part 12 Outline

Water SystemsAppliances and Misc. Electric LoadsWindow Shades and BlindsHydronic SystemsRadiant SystemsPhotovoltaics


Water Systems

DHW/SHW hot water useCold water useWater collection and storage

Rainwater HVAC Condensate Well

Drain water heat recovery


WaterUse:Equipment

End-use for hot and cold waterCan be used standalone or connected

to a plant loopMix hot and cold waterSensible and latent gains to zone


WaterUse:Equipment

WaterUse:Equipment,

ZN5 Showers, !- Name

SHOWERS, !- End-Use Subcategory

5E-5, !- Peak Flow Rate {m3/s}

Shower flow sched, !- Flow Rate Fraction Schedule Name

ZN5 SHOWERS Temp Sched, !- Target Temp Schedule Name

ZN5 SHOWERS Hot Supply Temp Sched, !- Hot Water Supply Temp Sched Name

, !- Cold Water Supply Temperature Schedule Name


ZN5 SHOWERS Sensible Gain Sched; !- Sensible Fraction Schedule Name

ZN5 SHOWERS Latent Gain Sched; !- Latent Fraction Schedule Name


WaterUse:Connections

Subsystem to connect water components

Can be used standalone or connected to a plant loop

Connects WaterUser:Equipment to plant loop, to storage, etc.



WaterUse:Connections

WaterUse:Connections,

ZN5 SHOWERS, !- Name

ZN5 SHOWERS Water Inlet Node, !- Inlet Node Name

ZN5 SHOWERS Water Outlet Node, !- Outlet Node Name

, !- Supply Water Storage Tank Name

, !- Reclamation Water Storage Tank Name

, !- Hot Water Supply Temperature Schedule Name

, !- Cold Water Supply Temperature Schedule Name

, !- Drain Water Heat Exchanger Type

, !- Drain Water Heat Exchanger Destination

, !- Drain Water Heat Exchanger U-Factor Times Area {W/K}

ZN5 SHOWERS; !- Water Use Equipment 1 Name


DHW Plant Loop

Supply pump Zero pump head if driven by mains

pressure (i.e. no electric power for pump)Supply side branch w/ water heater

Mixed or stratified Direct or indirect

Demand side branches WaterUse:Connections


5ZoneWaterSystems ExampleSupply Side of Plant Loop


5ZoneWaterSystems ExampleDemand Side of Plant Loop


Other WaterUse Objects

WaterUse:StorageWaterUse:WellWaterUse:RainCollector


Appliances and Electric Loads

ElectricEquipmentGasEquipmentElectricEquipment,

SPACE1-1 ElecEq 1, !- Name


EQUIP-1, !- Schedule Name

EquipmentLevel, !- Design Level Calculation Method

1056, !- Design Level {W}

, !- Watts per Zone Area {W/m2}

, !- Watts per Person {W/person}

0, !- Fraction Latent

0.3, !- Fraction Radiant

0, !- Fraction Lost

Computers; !- End-Use Subcategory


Exterior Loads

Exterior:LightsExterior:FuelEquipmentExterior:WaterEquipment

Exterior:FuelEquipment,

Gas Grill, !- Name

NaturalGas, !- Fuel Use Type

BBQ Cooking Schedule, !- Schedule Name

12000, !- Design Level {W}

Cooking; !- End-Use Subcategory


Window Shades and Blinds

Window materials WindowMaterial:Shade WindowMaterial:Blind

Define primary window construction without the shade layer

WindowProperty:ShadingControl Control shade on/off Control blinds on/off and slat angle Interior, exterior, and between glass options


Window Shading Controls

AlwaysOn AlwaysOff OnIfScheduleAllows OnIfHighSolarOnWindow OnIfHighHorizontalSolar OnIfHighOutdoorAirTemperature OnIfHighZoneAirTemperature OnIfHighZoneCooling OnIfHighGlare MeetDaylightIlluminanceSetpoint

Cont’d . . .


Window Shading Controls

OnNightIfLowOutdoorTempAndOffDay OnNightIfLowInsideTempAndOffDay OnNightIfHeatingAndOffDay OnNightIfLowOutdoorTempAndOnDayIfCooling OnNightIfHeatingAndOnDayIfCooling OffNightAndOnDayIfCoolingAndHighSolarOnWindow OnNightAndOnDayIfCoolingAndHighSolarOnWindow OnIfHighOutdoorAirTempAndHighSolarOnWindow OnIfHighOutdoorAirTempAndHighHorizontalSolar OnIfHighZoneAirTempAndHighSolarOnWindow OnIfHighZoneAirTempAndHighHorizontalSolar


Hydronic Systems

Hot water baseboard heat ZoneHVAC:Baseboard:RadiantConvective:

Water ZoneHVAC:Baseboard:Convective:Water

older model – use first one

Hot water plant loopServed by boiler or other heat source


Radiant Heating and Cooling

Embedded in a zone surface ZoneHVAC:LowTemperatureRadiant:VariableFlow

ZoneHVAC:LowTemperatureRadiant:ConstantFlowAbove types are hydronic – connect to plant loop(s)

ZoneHVAC:LowTemperatureRadiant:Electric

Construction:InternalSource Specifies location of heat source/sink

ZoneHVAC:EquipmentList List equipment Note these types of equipment have no air inlet/exhaust

nodes in the ZoneHVAC:EquipmentConnections object


Photovoltaics

ElectricLoadCenter:DistributionElectricLoadCenter:Inverter:SimpleElectricLoadCenter:GeneratorsGenerator:Photovoltaic

PhotovoltaicPerformance:Simple PhotovoltaicPerformance:EquivalentOne-Diode PhotovoltaicPerformance:Sandia

SolarCollector:FlatPlate:PhotovoltaicThermalSee example files GeneratorsWithPV,

ShopWithPVandStorage, ShopWithSimplePVT,


Photovoltaics

PV arrays are attached to a surface Building surface for BIPV SurfaceProperty:OtherSideConditionsModel SurfaceProperty:ExteriorNaturalVentedCavity

Shading surface for freestanding Surface defines orientation Normal shading algorithms apply

PV array can be shadedPV array can cast shadows