Transcript EnergyPlus Training Part 1

Lecture 6: Building Envelope
Description (Part II)
Material prepared by GARD Analytics, Inc. and University of Illinois
at Urbana-Champaign under contract to the National Renewable Energy
Laboratory. All material Copyright 2002-2003 U.S.D.O.E. - All rights reserved
Importance of this Lecture to the
Simulation of Buildings
 Every building is different in many ways:
 Location/exterior environment
 Construction/building envelope
 HVAC system
 Building envelope/construction determines how a
building will respond to the exterior environment
 Thermal simulation requires information about the
physical make-up of the building, where various
constructions are located and how they are oriented,
how the building is subdivided into zones, etc.
 Thermal simulation requires information on the
building envelope to properly analyze the building
from an energy perspective
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Purpose of this Lecture
Gain an understanding of how to specify
the building construction



Groups of Surfaces (Zones) and Overall
Building Characteristics
Walls, Roofs, Ceilings, Floors, Partitions,
etc.
Materials and Groups of Materials
(Constructions)
3
Keywords Covered in this Lecture
Zone
SurfaceGeometry
Surface (all types)
Construction
Material:Regular
Material:Regular-R
Material:Air
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Review of Envelope Hierarchy
Building
Surface
Zone
Zone
Zone
Surface
Surface
Surface
Material
… more surfaces
only one construction per surface
Construction
Material
… more zones
Material
Material
… more materials
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Keyword: Zone
 IDD Description (shortened)
ZONE,
A1 ,
N1 ,
N2 ,
N3 ,
N4 ,
N5 ,
N6 ,
N7 ,
N8 ,
A2 ;
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
Zone Name
Relative North (to building)
X Origin
Y Origin
Z Origin
Type
Multiplier
Ceiling Height
Volume
Zone Inside Convection Algorithm
 Purpose: to define basic properties about a
thermal zone
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Keyword: Zone
IDD Description (detailed)
Keyword
ZONE,
\required-object
A1 , \field Zone Name
User defined zone name
\required-field
\type alpha
\reference ZoneNames
N1 , \field Relative North (to building)
\units deg
\type real
Allows rotation of the zone
\default 0
with respect to the building;
see north axis for building
description
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Keyword: Zone
IDD Description (detailed, continued)
N2 , \field X Origin
\units m
\type real
\default 0
N3 , \field Y Origin
\units m
\type real
\default 0
N4 , \field Z Origin
\units m
\type real
\default 0
Origin for the “lower
southwest corner” of the
zone in Cartesian
coordinates
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Keyword: Zone
IDD Description (detailed, continued)
N5 , \field Type
\maximum 1
\minimum 1
\default 1
N6 , \field Multiplier
\type integer
\minimum 1
\default 1
N7 , \field Ceiling Height
\units m
\type real
\default 0
N8 , \field Volume
\units m3
\type real
\default 0
This is a placeholder for a
future feature of the program
Used to represent
similar zone without
having to input all of the
data multiple times
Volume is used to calculate
the amount of thermal
capacitance in the zone air
and has an impact on how
quickly the zone air
temperature changes
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Keyword: Zone
IDD Description (detailed, continued)
A2 ; \field Zone Inside Convection Algorithm
\type choice
Determines the interior
\key Simple
convection correlation used
\key Detailed
by the program; optional
\key CeilingDiffuser
parameter
\key TrombeWall
\note Simple = constant natural convection (ASHRAE)
\note Detailed = variable natural convection based
\note on temperature difference (ASHRAE)
\note CeilingDiffuser = ACH based forced and mixed
\note convection correlations for ceiling diffuser
\note configuration with simple natural convection
\note limit
\note TrombeWall = variable natural convection in an
\note enclosed rectangular cavity
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Keyword Example: Zone
IDF Example
ZONE,ZONE ONE, 0.0, 6.096, 0.0, 0.0, 1, 1, 0.0, 0.0, Detailed;
or
ZONE,
ZONE ONE,
0.0,
6.096,
0.0,
0.0,
1,
1,
0.0,
0.0,
Detailed;
!!!!!!!!!!-
Zone Name
Relative North (to building) {deg}
X Origin {m}
Y Origin {m}
Z Origin {m}
Type
Multiplier
Ceiling Height {m}
Volume {m3}
Zone Inside Convection Algorithm
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Keyword: SurfaceGeometry
 Three dimensional
(3D) Cartesian
coordinate system
 Right hand
coordinate system



X-axis points east
Y-axis points north
Z-axis points up
Building and/or Zone North Axis
Z Axis
Y Axis
X Axis
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Keyword: SurfaceGeometry
(cont’d)
 Vertex-based
 Specify 3D coordinates of each corner of a surface
 World Coordinates
 All coordinates refer to global origin
 Building and Zone north axes ignored
 Zone origins ignored (except for daylighting)
 Relative Coordinates
 Zones relative to building
 Surfaces relative to zones
 Subsurfaces relative to zones
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Keyword: SurfaceGeometry
(cont’d)
 Surface starting position, looking from outside
 UpperLeft, UpperRight, LowerLeft, LowerRight
 Order of vertex entry
 Clockwise, Counterclockwise
 Coordinate system
 WorldCoordinateSystem, RelativeCoordinateSystem
 IDF Example:
SurfaceGeometry,
UpperLeftCorner,
CounterClockWise,
WorldCoordinateSystem;
!- SurfaceStartingPosition
!- VertexEntry
!- SurfaceGeometryKey
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Relative Coordinate Options
 Building North Axis
 Relative to true north
 Rotates about bldg origin
True
North
Building North Axis
+30 degrees
 Zone North Axis
 Relative to building north
 Rotates about zone origin
Zone
North
Axis
 Zone Origin
 Relative to building origin
(0,0,0)
(0,0,0)
 Surface vertices in zone Building Origin
coordinates
Zone Origin (x, y, z)
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Types of Surfaces
Surface:HeatTransfer

Surface:HeatTransfer:Sub

Surface:HeatTransfer:InternalMass
Surface:Shading:Detached

Surface:Shading:Detached:Fixed

Surface:Shading:Detached:Building
Surface:Shading:Attached
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Heat Transfer Surface
 Surface:HeatTransfer
 Walls, Roofs, Floors, Ceilings
 Inside environment is always a zone
 Outside environment
 Exterior with or without wind and sun
 Another zone surface (interzone heat transfer)
 Adiabatic (internal mass with geometry)
 Other Side Coefficients (user control of exterior
surface temperature, ignores solar and sky
radiant)
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Heat Transfer Surface
(cont’d)
 Exterior surfaces cast
shadows


Shadows only cast in the
direction of the outward
facing normal
A roof extended beyond
the walls will not cast
shadows downward
 Interior surfaces do not
cast shadows
 All surfaces reflect solar
as diffuse inside zone
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Heat Transfer Surface
(cont’d)
IDD Description (shortened)
Surface:HeatTransfer,
A1 , \field User Supplied Surface Name
A2 , \field Surface Type (FLOOR|WALL|CEILING|ROOF)
A3 , \field Construction Name of the Surface
A4 , \field InsideFaceEnvironment
A5 , \field OutsideFaceEnvironment
\note (OtherZoneSurface|ExteriorEnvironment|Ground|
\note OtherSideCoeff)
A6, \field OutsideFaceEnvironment Object
\note Used only if OutsideFaceEnvironment is
\note OtherZoneSurface or OtherSideCoeff
\note If OtherZoneSurface, specify name of
\note corresponding surface in adjacent zone or
\note specify current surface name for internal
\note partition separating like zones
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Heat Transfer Surface
(cont’d)
IDD Description (shortened, continued)
A7 ,
A8,
N1,
N2 ,
N3,
N4 ,
N5 ,
N6,
N7,
N8,
N9,
N10,
N11,
N12,
N13,
N14;
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
Sun Exposure (SunExposed|NoSun)
Wind Exposure (WindExposed|NoWind)
View Factor to Ground
Number of Surface Vertex Groups
Vertex 1 X-coordinate
Vertex 1 Y-coordinate
Vertex 1 Z-coordinate
Vertex 2 X-coordinate
Vertex 2 Y-coordinate
Vertex 2 Z-coordinate
Vertex 3 X-coordinate
Vertex 3 Y-coordinate
Vertex 3 Z-coordinate
Vertex 4 X-coordinate
Vertex 4 Y-coordinate
Vertex 4 Z-coordinate
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Heat Transfer Subsurface
Surface:HeatTransfer:Sub
Windows, Doors, Glass Doors


Only windows and glass doors transmit
sunlight
Can have interior windows
Must be placed on a base surface
Cannot completely cover base surface
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Door and Window Details
(a)
 Outside reveal
defined by
window
vertices
 WindowFrame
AndDivider
specifies
details of
frame, sill,
inside reveal,
etc.
(b)
Wall
Outside
Reveal
Surface
Outside
Reveal
Depth
Inside
Reveal
Surface
Inside
Reveal
Depth
Outside
Reveal
Depth
Inside
Reveal
Depth
Glazing
Glazing
Frame
Wall
Inside Sill
Depth
Sill
Inside Sill
Depth
Wall
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Heat Transfer Subsurface
(cont’d)
IDD Description (shortened)
Surface:HeatTransfer:Sub,
A1 , \field User Supplied Surface Name
A2 , \field Surface Type (WINDOW|DOOR|GLASSDOOR)
A3 , \field Construction Name of the Surface
\note To be matched with a construction
\object-list ConstructionNames
A4 , \field Base Surface Name (that subsurface attached to)
A5, \field OutsideFaceEnvironment Object
\note Used only if Base OutsideFaceEnvironment is
\note OtherZone or OtherSideCoeff
\note If OtherZone, specify name of corresponding
\note subsurface in adjacent zone or specify current
\note subsurface name for internal partition
\note separating like zones
N1, \field View Factor to Ground
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Heat Transfer Subsurface
(cont’d)
IDD Description (shortened, continued)
A6,
\field Name of shading control
\note used for windows and glass doors only
\note If not specified, window or glass door has
\note no shading (blind, roller shade, etc.)
A7, \field WindowFrameAndDivider Name
\note Used only for exterior windows (rectangular)
\note and glass doors.
\note Unused for triangular windows.
\note If not specified (blank), window or glass door
\note has no frame or divider and no beam solar
\note reflection from reveal surfaces.
N2 , \field Multiplier
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Heat Transfer Subsurface
(cont’d)
IDD Description (shortened, continued)
N3 ,
N4,
N5 ,
N6 ,
N7,
N8,
N9,
N10,
N11,
N12,
N13,
N14,
N15;
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
\field
Number
Vertex
Vertex
Vertex
Vertex
Vertex
Vertex
Vertex
Vertex
Vertex
Vertex
Vertex
Vertex
of Surface Vertex Groups
1 X-coordinate
1 Y-coordinate
1 Z-coordinate
2 X-coordinate
2 Y-coordinate
2 Z-coordinate
3 X-coordinate
3 Y-coordinate
3 Z-coordinate
4 X-coordinate
4 Y-coordinate
4 Z-coordinate
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Shading Surface
 Three types
Upper Left Corner Vertex for
Overhang
 Transmittance
schedule
(default is
always opaque)
 Automatically
mirrored to cast
shadows in
both directions
 Must specify
vertices
D
A
C
B
(0,0,0)
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Shading Surface (cont’d)
IDD Description (shortened)

Similar for all three shading surface types:
 Surface:Shading:Detached:Fixed
 Surface:Shading:Detached:Building
 Surface:Shading:Attached
Detached shading
surfaces are not
associated with a
base surface
Surface:Shading:Attached,
A1 , \field User Supplied Surface Name
A2 , \field Base Surface Name
A3 , \field Transmittance schedule for shading device
N1 , \field Number of Surface Vertex Groups
N2 , N3 , N4 , \field Vertex 1 X, Y, Z-coordinates
N5 , N6 , N7 , \field Vertex 2 X, Y, Z-coordinates
N8 , N9 , N10, \field Vertex 3 X, Y, Z-coordinates
N11, N12, N13; \field Vertex 4 X, Y, Z-coordinates
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Construction
List material layers from outside to
inside
Convection coefficients (film layers) are
added automatically
IDF Example:
CONSTRUCTION,
CEILING39,
C5 - 4 IN HW CONCRETE,
E4 - CEILING AIRSPACE,
E5 - ACOUSTIC TILE;
!!!!-
User Defined Name
Outside Layer
Layer #2
Inside Layer
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Materials for Opaque Surfaces
 Material:Regular
 Has thermal mass
 Thickness, conductivity, density, and specific heat
 Material:Regular-R
 Has no thermal mass
 Specify only thermal resistance
 Material:Air
 Also no thermal mass, just resistance
 Cannot be an outside layer, no absorptances
 Otherwise, modeled same as Material:Regular-R
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Material Example
MATERIAL:REGULAR,
PLASTERBOARD-2,
Rough,
0.01,
0.16,
950.0,
840.0,
0.9,
0.6,
0.6;
!!!!!!!!!-
Options: VeryRough,
MediumRough, Rough,
Name
Smooth, MediumSmooth,
Roughness
Thickness {m} VerySmooth
Conductivity {W/m-K}
Density {kg/m3}
Specific Heat {J/kg-K}
Thermal Absorptance
Solar Absorptance
Visible Absorptance
 Parameters Affecting:



Convection—Roughness
Conduction—Thickness, Conductivity, Density, Specific Heat
Radiation—Absorptances
 Material:Regular-R and Material:Air contain a subset
of the above information (see IDD for more details)
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DataSets for Materials and
Constructions
EnergyPlus\DataSets\
 BLASTMaterials.idf BLASTConstructs.idf
 DOE-2Materials.idf DOE-2Constructs.idf
 WindowGlassMaterials.idf
 WindowGasMaterials.idf
 WindowShadeMaterials.idf
 WindowConstructs.idf
 WindowBlindMaterials.idf
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Materials for Moisture
Transfer
MaterialProperty:Moisture:MTF

Moisture Transfer Function model
MaterialProperty:Moisture:EMPD

Effective Mean Penetration Depth model
\DataSets\MoistureMaterials.idf
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Summary
 In EnergyPlus…
 Buildings are made up of one or more Zones
 Zones are made up of one or more Surfaces
 Zones are “thermal zones”—basis of the heat
balance solution
 Surfaces are defined by a Construction
 Constructions are made up of one or more
Material layers
 Accuracy of simulation results directly related
to accuracy of input data
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