Workspace: Libraries/Materials and Assemblies/Windows
Workspace Areas: Libraries Controls - Property Values Table
Related Examples - Creating an Operable Window - "Simple" Library Entry
What to do if you want to create an Operable Window, Window Type using the Detailed Opening capabilities for the Air Flow Network within EnergyPlus:
Type = Window and Sub Type = Default
Expand the property categories of Window and AirflowNetwork:MultiZone:Component:DetailedOpening by selecting the check boxes in the Property Values Table.
Note: For a Detailed Operable Window library entry the AirflowNetwork:MultiZone:Component:SimpleOpening should not have property values specified. It will lead to Validation errors and potential simulation problems.
Make Construction, Shading Control and Frame and Divider selections from the drop down lists as applicable. See table below to identify sources for drop down lists.
| Property Category | Property Name | Value Sources |
Window |
Construction Name |
|
Shading Control Name |
||
| Frame and Divider Name | Windows/Typical
Window/FrameAndDivider
Doors/Glazed Door/FrameAndDivider |
Note: If there is not a desirable option in the drop down list and the user wants to create a new one or review in more detail the ones that are there, they will need to go to the source within libraries, which are the links included above.
Enter Values for the first four Detailed Opening Properties. See image below for typical values.
Crack flow is assumed when the window or door is closed. There is no default but the entered value must be greater than zero (recommend entering .001). EnergyPlus will automatically generate four cracks around the perimeter of the window or door--one along the bottom, one along the top, and one on each side.
Crack flow is assumed when the window or door is closed. In this case, the value of this field is the exponent, n, in the crack air flow equation. The valid range for this exponent is 0.5 to 1.0, with the default value being 0.65.
This alpha field specifies the type of rectangular window or door. (Open windows or doors are also called Large Vertical Openings (LVOs). The choices for the opening type are NonPivoted (LVO Type 1) and HorizontallyPivoted (LVO Type 2) with the default being NonPivoted. The NonPivoted type represents a regular window or door. The HorizontallyPivoted type represents a window with a horizontal axis ((i.e., a horizontally-pivoting window) and cannot be used for a door.
Specifies window or door characteristics that depend on the LVO type.
For LVO Type 1 (rectangular non-pivoted windows and doors) this field is the extra crack length in meters due to multiple openable parts, if present. “Extra” here means in addition to the length, calculated by the program, of the cracks on the top, bottom and sides of the window/door.
For LVO Type 2 (rectangular horizontally-pivoted windows) this field gives the height of the pivoting axis measured from the bottom of the glazed part of the window.
This is the number of the following sets of data for opening factor, discharge coefficient, width factor, height factor, and start height factor.
An “opening factor” refers to the amount that a window or door is opened. The program linearly interpolates each timestep between the values of discharge coefficient, width factor, etc., in these sets using the opening factor for the window or door for the timestep.
The allowable entries are 2 to 4, which determine the number of "opening states" that input values are being provided for.
The next five property inputs are dependent on the number that was entered in the previous step. If "2" was entered, then two sets of input values are required for each value (image below). If "4" was entered, then four sets of input values are required.
The first opening factor of a window or door. This value must be 0.0. The default value is also 0.0.
For LVO Type 1 (rectangular non-pivoted window or door), the Opening Factor corresponds to the fraction of window or door that is opened.
For LVO Type 2 (rectangular horizontally-pivoted windows), the Opening Factor is determined by the window opening angle. For example, an opening angle of 45° corresponds to an Opening Factor of 0.50 since the maximum opening angle is 90°.
The discharge coefficient of the window or door for Opening Factor. The range is greater than 0.0 to less than or equal to 1.0. The default value is 0.001. The Discharge Coefficient indicates the fractional effectiveness for air flow through a window or door at that Opening Factor.
Note: "Width" and "Height" are glazing dimensions; they do not include the frame, if there is one present.
The Width Factor of the rectangular window or door for Opening Factor 1. The Width Factor is the opening width divided by the window or door width (see Figure 83). The range is 0.0 to 1.0. The default value is 0.0. Note that the width factor applies to rectangular windows or doors where the width is assumed constant along the entire height of the opening.
The Height Factor of the rectangular window or door for Opening Factor 1. The Height Factor is the opening height divided by the window or door height (see Figure 83). The range is 0.0 to 1.0. The default value is 0.0. Note that the height factor applies to rectangular windows or doors where the height is assumed constant along the entire width of the opening.
The Start Height Factor of the window or door for Opening Factor 1. The Start Height Factor is the Start Height divided by the window or door height (see Figure 83). The range is 0.0 to 1.0. The default is 0. Start Height is the distance between the bottom of the window or door and the bottom of the window or door opening. The sum of the Height Factor and the Start Height Factor must be less than 1.0 in order to have the opening within the window or door dimensions.
Figure 83 - Source EnergyPlus Input Output Reference
When all the desired input values have been entered, hit Save, and now the Library Entry has been stored in the Source Library that the user has active. The Operable Window type is ready to be specified in the user's Natural Ventilation BEM!
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