Libraries - Windows

Location = Libraries/Materials and Assemblies/Windows

 

Type and Sub Type Mapping

The Type and Sub Type options that can be selected from the drop down lists in that area of the workspace, which filter the Source Library to display the variables the user can select to include, along with a value, in a Library Entry.

Note: The links within the table are to the EnergyPlus Input Output Reference providing additional detailed explanation of the EnergyPlus objects.

 

Type Options Sub Type Options EnergyPlus Objects (IO Reference links)

Skylight

Default

 

Window

Default

 

 

Window (Type)

 

Default (Sub Type)

Property Set - Fenestration Surface : Detailed

This surface class is used for subsurfaces, which can be of five different types: Windows, Doors, GlassDoors, TubularDaylightDomes, and TubularDaylightDiffusers. A subsurface (such as a window) of a base surface (such as a wall) inherits several of the properties (such as Outside Boundary Condition, Sun Exposure, etc.) of the base surface. Windows, GlassDoors, TubularDaylightDomes, and TubularDaylightDiffusers are considered to have one or more glass layers and so transmit solar radiation. Doors are considered to be opaque.

 

Construction Name

This is the name of the subsurface’s construction (ref: Construction [for Window, GlassDoor and Door]  and Construction:WindowDataFile [for Window and GlassDoor]).

For windows, if Construction Name is not found among the constructions on the input (.idf) file, the Window5 Data File (Window5DataFile.dat) will be searched for that Construction Name (see “Importing Windows from WINDOW 5”). If that file is not present or if the Construction Name does not match the name of an entry on the file, an error will result. If there is a match, a window construction and its corresponding glass and gas materials will be created from the information read from the file.

 

Shading Control Name

This field, if not blank, is the name of the window shading control (ref: WindowProperty:ShadingControl) for this subsurface. It is used for Surface Type = Window and GlassDoor. To assign a shade to a window or glass door, see WindowMaterial: Shade. To assign a screen, see WindowMaterial:Screen. To assign a blind, see WindowMaterial:Blind. To assign switchable glazing, such as electrochromic glazing, see WindowProperty:ShadingControl.

 

Frame and Divider Name

This field, if not blank, can be used to specify window frame, divider and reveal-surface data (ref: WindowProperty:FrameAndDivider). It is used only for exterior GlassDoors and rectangular exterior Windows, i.e., those with OutsideFaceEnvironment = Outdoors.

This field should be blank for triangular windows.

 

Property Set - AirflowNetwork:MultiZone:Component:DetailedOpening

 

Air Mass Flow Coefficient when Opening is Closed

 

Air Mass Flow Exponent when Opening is Closed

 

Type of Rectangular Large Vertical Opening (LVO)

 

Extra Crack Length or Height of Pivoting Axis

 

Number of Sets of Opening Factor Data

 

Opening Factor [1-4]

 

Discharge Coefficient for Opening Factor [1-4]

 

Width Factor for Opening Factor [1-4]

 

Height Factor for Opening Factor [1-4]

 

Start Height Factor for Opening Factor [1-4]

 

 

Property Set - AirflowNetwork:MultiZone:Component:Simple Opening

 

Air Mass Flow Coefficient when Opening is Closed

 

Air Mass Flow Exponent when Opening is Closed

 

Minimum Density Difference for Two-Way Flow

 

Discharge Coefficient

 

Property Set - Complex Fenestration Property: Solar Absorbed Layers

 

Construction Name

 

Layer [1-5] Solar Radiation Absorbed Schedule Name

 

Property Set - WindowProperty:Airflow Control

This object is used to specify the control mechanism for windows in which forced air flows in the gap between adjacent layers of glass. Such windows are called “airflow windows.” They are also known as “heat-extract windows” or “climate windows.”

A common application is to reduce the zone load by exhausting indoor air through the window. In the cooling season this picks up and expels some of the solar heat absorbed by the window glass (and by the between-glass shade or blind, if present). In the heating season this warms the window, reducing the heat loss from the window. A side benefit is increased thermal comfort. This is because the inside surface of the window will generally be cooler in summer and warmer in winter.

Airflow Source

The source of the gap airflow. The choices are:

IndoorAir: Indoor air from the window’s zone is passed through the window.

OutdoorAir: Outdoor air is passed through the window.

Airflow Destination

This is where the gap air goes after passing through the window. The choices are:

IndoorAir: The gap air goes to the indoor air of the window’s zone.

OutdoorAir: The gap air goes to the outside air.

ReturnAir. The gap air goes to the return air for the window’s zone. This choice is allowed only if Airflow Source = InsideAir. If the return air flow is zero, the gap air goes to the indoor air of the window’s zone. If the sum of the gap airflow for all of the windows in a zone with Airflow Destination = ReturnAir exceeds the return airflow, then the difference between this sum and the return airflow goes to the indoor air.

The allowed combinations of Airflow Source and Airflow Destination as shown in the diagram below are:

IndoorAir à OutdoorAir

IndoorAir à IndoorAir

IndoorAir à ReturnAir

OutdoorAir à IndoorAir

OutdoorAir à OutdoorAir

 

Source: EnergyPlus Input Output Reference  

 

Maximum Flow Rate

The maximum value of the airflow, in m3/s per m of glazing width. The value is typically 0.006 to 0.009 m3/s-m (4 to 6 cfm/ft).

The airflow can be modulated by specifying Airflow Has Multiplier Schedule = Yes and giving the name of the Airflow Multiplier Schedule (see below).

The fan energy used to move the air through the gap is generally very small and so is ignored.

Airflow Control Type

Specifies how the airflow is controlled. The choices are:

AlwaysOnAtMaximumFlow. The airflow is always equal to Maximum Airflow.

AlwaysOff. The airflow is always zero.

ScheduledOnly. The airflow in a particular timestep equals Maximum Airflow times the value of the Airflow Multiplier Schedule for that timestep.

Airflow Is Scheduled

Specifies if the airflow is scheduled. The choices are:

Yes. The airflow is scheduled.

No. The airflow is not scheduled.

If Yes, Airflow Multiplier Schedule Name is required.

Airflow Multiplier Schedule Name

The name of a schedule with values between 0.0 and 1.0. The timestep value of the airflow is Maximum Airflow times the schedule value. Required if Airflow Is Scheduled = Yes. Unused if Airflow Is Scheduled = No. This schedule should have a ScheduleType with Numeric Type = Continuous and Range = 0.0 : 1.0
 
 

Property Set - WindowProperty:StormWindow

This object allows you to assign a movable exterior glass layer (“storm window” or “storm glass”) that is usually applied to a window in the winter to reduce heat loss and removed in the summer. A WindowProperty:StormWindow object is required for each window that has an associated storm window. It is assumed that:

With the addition of a storm window, single glazing effectively becomes double glazing, double glazing becomes triple glazing, etc.

Storm Glass Layer Name

This is the name of a window glass material. Storm windows are assumed to consist of a single layer of glass. A storm window frame, if present, is ignored.

Distance Between Storm Glass Layer and Adjacent Glass

The separation between the storm glass and the rest of the window. It is measured from the inside of the storm glass layer to the outside of the adjacent glass layer.

Month that Storm Glass Layer Is Put On

The number of the month (January = 1, February = 2, etc.) during which the storm window is put in place.

Day of Month that Storm Glass Layer Is Put On

The day of the month that the storm window is put in place. It is assumed that the storm window is put in place at the beginning of this day, i.e., during the first simulation timestep of the day, and remains in place until that month and day given by the following two fields.

Month that Storm Glass Layer Is Taken Off

The number of the month (January = 1, February = 2, etc.) during which the storm window is removed.

Day of Month that Storm Glass Layer Is Taken Off

The day of the month that the storm window is removed. It is assumed that the storm window is removed at the beginning of this day, i.e., during the first simulation timestep of the day, and stays off until the month and day given by Month that Storm Glass Layer Is Put On, Day of Month that Storm Glass Layer Is Put On.

In the northern hemisphere, the month the storm window is put on is generally greater than the month it is taken off (for example put on in month 10, when it starts to get cold, and taken off in month 5, when it starts to warm up). In the southern hemisphere this is reversed: month on is less than month off.

 

 

Property Set - Daylighting:DELight:Complex

The DElight daylighting analysis method can be applied to daylighting zones that contain only simple fenestration systems such as windows and skylights that are standard EnergyPlus sub-surfaces. In this situation, no Daylighting:DElight: Complex Fenestration object would be input.

 

In addition to analyzing simple fenestration systems, DElight includes the capability of analyzing complex fenestration systems such as geometrically complicated static shading systems (e.g., roof monitors) and/or optically complicated glazings (e.g., prismatic or holographic glass). This capability is based on characterizing these complex fenestration systems (CFS) using bidirectional transmittance distribution functions (BTDF). In general, BTDF data for a specific CFS must be either measured or simulated (e.g., using ray-tracing techniques) prior to employing DElight to analyze it within EnergyPlus. The current implementation of DElight CFS calculations within EnergyPlus supports two approaches to the input of BTDF, an analytical approach and a file-based approach. The details of inputting these two approaches are described below under the User Complex Fenestration Type field.

 

Two analytical CFS BTDF types are currently supported, window and light shelf. The file-based approach requires that a user has access to a data file containing raw BTDF data that DElight reads as additional input during its analysis calculations. BTDF data files are described separately since it is anticipated that individual EnergyPlus users will not create these data files themselves.

The methods related to characterizing and analyzing CFS using BTDF are still evolving. DElight is an early implementation of CFS analysis methods. These methods, and the input associated with them here, will likely change in the future.

Complex Fenestration Type

Type name of the DElight daylighting Complex Fenestration system to be analyzed. This type name must take one of the following two forms.

BTDF^GEN^Analytical Type^Normal Visible Transmittance^Dispersion Angle

BTDF^FILE^Filename

The first form above is for supported analytical CFS types which currently include WINDOW and LIGHTSHELF. While these analytical types are relatively simple, they represent flexible ways to explore diffusing CFS systems and the impact of light shelves in redirecting light through an aperture. Each of these types also requires the visible transmittance of the CFS at normal incidence angle, and a dispersion angle (in degrees) that represents the “spread” of transmitted light. A small dispersion angle of 10 corresponds to clear glazing while a large angle of 90 corresponds to perfectly diffusing glazing. The “^” symbol must be used as a delimiter between sub-fields within this Complex Fenestration type name string as shown in the IDF example for WINDOW below, and in the DElight sample input data files.

 

The second form above is for CFS types for which there is pre-measured or pre-simulated BTDF data. In this case the Filename sub-field must be a valid data file name that is associated with an existing BTDF dataset that DElight can use in its calculations.

Fenestration Rotation

The in-plane counter-clockwise rotation angle between the Complex Fenestration optical reference direction and the base edge of the Doppelganger Surface geometry. The Complex Fenestration optical reference direction is the direction of the zero azimuth angle for the BDTF dataset. This Rotation angle will typically be zero when the Doppelganger surface is rectangular and its width edge is aligned with the Complex Fenestration optical reference direction.

 

 

Skylight (Type)

Default (Sub Type)

 

Property Set - Fenestration Surface : Detailed

This surface class is used for subsurfaces, which can be of five different types: Windows, Doors, GlassDoors, TubularDaylightDomes, and TubularDaylightDiffusers. A subsurface (such as a window) of a base surface (such as a wall) inherits several of the properties (such as Outside Boundary Condition, Sun Exposure, etc.) of the base surface. Windows, GlassDoors, TubularDaylightDomes, and TubularDaylightDiffusers are considered to have one or more glass layers and so transmit solar radiation. Doors are considered to be opaque.

 

Construction Name

This is the name of the subsurface’s construction (ref: Construction [for Window, GlassDoor and Door]  and Construction:WindowDataFile [for Window and GlassDoor]).

For windows, if Construction Name is not found among the constructions on the input (.idf) file, the Window5 Data File (Window5DataFile.dat) will be searched for that Construction Name (see “Importing Windows from WINDOW 5”). If that file is not present or if the Construction Name does not match the name of an entry on the file, an error will result. If there is a match, a window construction and its corresponding glass and gas materials will be created from the information read from the file.

 

Shading Control Name

This field, if not blank, is the name of the window shading control (ref: WindowProperty:ShadingControl) for this subsurface. It is used for Surface Type = Window and GlassDoor. To assign a shade to a window or glass door, see WindowMaterial: Shade. To assign a screen, see WindowMaterial:Screen. To assign a blind, see WindowMaterial:Blind. To assign switchable glazing, such as electrochromic glazing, see WindowProperty:ShadingControl.

 

Frame and Divider Name

This field, if not blank, can be used to specify window frame, divider and reveal-surface data (ref: WindowProperty:FrameAndDivider). It is used only for exterior GlassDoors and rectangular exterior Windows, i.e., those with OutsideFaceEnvironment = Outdoors.

This field should be blank for triangular windows.

 

Property Set - AirFlowNetwork:MultiZone:Component:Horizontal Opening

 

Air Mass Flow Coefficient when Opening is Closed

 

Air Mass Flow Exponent when Opening is Closed

 

Sloping Plane Angle

 

Discharge Coefficient

 

 

Property Set - Complex Fenestration Property: Solar Absorbed Layers

 

Construction Name

 

Layer [1-5] Solar Radiation Absorbed Schedule Name

 

 

 

Exterior (Sub Type)

Property Set - AirflowNetwork:MultiZone:Component:DetailedOpening

Property Set - AirflowNetwork:MultiZone:Component:Simple Opening

Property Set - Window

The Window object is used to place windows on surfaces that can have windows, including exterior walls, interior walls, interzone walls, roofs, floors that are exposed to outdoor conditions, interzone ceiling/floors. These, of course, can be entered using the simple rectangular objects or the more detailed vertex entry objects.

Shading Control Name

This field, if not blank, is the name of the window shading control (ref: WindowProperty:ShadingControl) for this subsurface. It is used for Surface Type = Window and GlassDoor. To assign a shade to a window or glass door, see WindowMaterial: Shade. To assign a screen, see WindowMaterial:Screen. To assign a blind, see WindowMaterial:Blind. To assign switchable glazing, such as electrochromic glazing, see WindowProperty:ShadingControl

Simergy source for  drop down list = Libraries/Controllers/ShadingControl/<collection from Sub Types>

Frame and Divider Name

This field, if not blank, can be used to specify window frame, divider and reveal-surface data (ref: WindowProperty:FrameAndDivider). It is used only for exterior GlassDoors and rectangular exterior Windows, i.e., those with OutsideFaceEnvironment = Outdoors.

This field should be blank for triangular windows.

Simergy source for  drop down list = Libraries/Windows/TypicalWindow/FrameAndDivider

 

Interior (Sub Type)

Property Set - AirflowNetwork:MultiZone:Component:DetailedOpening

Property Set - AirflowNetwork:MultiZone:Component:Simple Opening

Property Set - Window Interzone

The Window:Interzone object is used to place windows on surfaces that can have windows, including interzone walls, interzone ceiling/floors. These, of course, can be entered using the simple rectangular objects or the more detailed vertex entry objects.

Construction Name

This is the name of the subsurface’s construction (ref: Construction and Construction:WindowDataFile).

For windows, if Construction Name is not found among the constructions on the input (.idf) file, the Window5 Data File (default Window5DataFile.dat) will be searched for that Construction Name (see “Importing Windows from WINDOW 5”). If that file is not present or if the Construction Name does not match the name of an entry on the file, an error will result. If there is a match, a window construction and its corresponding glass and gas materials will be created from the information read from the file.

Note:The source for the drop down list is - Libraries/Material/<collection of entries from Types>/<collection of entries across possible sub types>

Outside Boundary Condition Object

The Outside Boundary Condition Object field is the name of a window in an adjacent zone or the name of the adjacent zone.  If the adjacent zone option is used, the adjacent ceiling is automatically generated in the adjacent zone.  If the surface name is used, it must be in the adjacent zone.

Note:The source for the drop down list is - Libraries/Windows or Doors/<collection of entries from Types>/<collection of entries across possible sub types>

 

Frame and Divider (Sub Type)

 

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