Shading Devices

The fields in the Window Type Definition area define the parameters that will be used for the various windows in your SPOT project. The input fields are shown to the right and discussed below.

Window Type # – This pulldown menu selects the current window type # (1-10). SPOT allows you to define the following information for up to 10 different types of windows. This is useful when there are multiple types of windows and/or skylights on your project with different base parameters. All the types will default to the same default, so if no additional types (beyond 1) are defined, SPOT will use this type for all windows. If more than 1 type is defined differently then the defaults, you will have the option to assign a window type to each window defined in your model in the Apertures and Objects input section.

Blind Slat Rotation – This field sets the rotation angle of any blinds used in this window type. Open slats, perpendicular to your window, would have a 0° rotation and a positive number rotates the inside slat edge down.

Blind Slat Width – This field sets the width, and spacing, of any blinds used in this window type. Typically, blinds are between 1 and 2” wide, but a larger 9” or 12” louver can also be defined.

Mullion Thickness – This defines the thickness of the window frame in this window type. This is the distance that the actual glass will be offset from the window opening in the wall.

Mullion Depth – This defines the depth of the window frame in this window type. Many typical store front systems will be 4.5” – 6” but they can vary, particularly with larger curtain wall systems. Caution, if this is defined deeper than the window thickness or offset enough, it will stick out of the edge of the wall.

Interior Mullions – Width – This defines the number of interior mullions across the width of the window. A value of 0 would have no intermediate mullions, a value of 1 would model one vertical mullion, centered along the width of the window, and so on.

Interior Mullions – Height – This defines the number of interior mullions across the height of the window. A value of 0 would have no intermediate mullions, a value of 1 would model one horizontal mullion, centered along the height of the window, and so on.

Window Mounting Location – This defines where the glass is mounted relative to the window frame. Three mounting options are available: ‘i’ for interior mounting, ‘c’ for a centered mounting, and ‘e’ for an exterior mounting. Interior will place the glass flush with the interior edge of the window frame. Center will center the glass in the window frame. Exterior will place the glass flush with the exterior edge of the window frame.

Window Offset – This defines the distance between the pane of glass and the interior wall surface. The window frame will be moved and placed accordingly. This must be less than the wall thickness.

Window Treatment Offset – This defines the distance between the glass and any interior or exterior shading devices. For blinds, it defines the plane that contains the exterior edge of the blinds. A positive values defines interior treatment, while a negative value can define an exterior blind or shade.

Selecting the Check Mark button displays the illustration to the right that diagrams what each window and shading parameter controls.

The Miscellaneous Simulation Settings area defines the manual control setting for all window types and the energy modeling schedule type.

Manual Shade Control Delay – This defines how many hours past a window glare incident in which a user would reopen manual shades or blinds. 4 hours might be the most typical occupant. 3 hours represents a fairly aware occupant. A more active occupant might readjust blinds after 2 hours. Even the most conscious occupant, rarely readjusts blinds every hour.

Manual Shade Glare Trigger – This defines the exitance threshold of a window before it represents a potential source of glare. An exitance of 500fc gives a reasonable approximation.

Energy Model Schedule Type – This defines the method to use when writing out Lighting Power Density modifier schedules for either DOE-2 or EnergyPlus.