Window frames and reveals Defaults

The Defaults Manager: Window frames and reveals panel contains controls to set defaults for calculating heat transfer through window frames and reveals.

Note: The data specified here relates to the frame position and thermal characteristics and the sill and reveal dimensions and characteristics. Data needs to be set up to define typical dimensions for frames and reveals. You should ensure that the windows in rooms are satisfactorily positioned.

Setting	Description
Frame inside projection	Sets the default frame inside projection (see no. 1 in figure above). This can have a significant impact on the total heat transfer characteristics of your windows.
Frame outside projection	Sets the default frame outside projection (see no. 2 in figure above). This can have a significant impact on the total heat transfer characteristics of your windows.
Frame thermal conductance	Sets the default frame thermal conductance factor for your windows to account for energy losses from heat transfer through window frames.
Frame solar absorption coefficient	Sets a default absorption coefficient for window frames. Heat transfer via solar radiation through window frames (both directly transmitted and absorbed) is subsequently released inward. The frame solar absorption coefficient as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits inward.
Frame visible absorption coefficient	Sets a default frame visible absorption coefficient value for determining the decrease in intensity of solar thermal energy as it passes through the window frame.
Frame emissivity	Sets a default frame emissivity factor. Emissivity is a measure of the efficiency in which a surface emits thermal energy. It is defined as the fraction of energy being emitted relative to that emitted by a thermally black surface (a black body). A black body is a material that is a perfect emitter of heat energy and has an emissivity value of 1. A material with an emissivity value of 0 would be considered a perfect thermal mirror.
Outside reveal solar absorptance	Sets a default absorption coefficient for window outside reveal surfaces.
Inside sill depth	Sets the default inside sill depth (see no. 3 in figure above), measured from the inside surface of the glazing to the edge of the sill.
Inside sill solar absorptance	Sets a default absorption coefficient for window sill (inside) reveal surfaces.
Inside reveal depth	Sets the default inside reveal depth (see no. 4 in figure above), measured from the inside surface of the glazing to the inside edge of the wall.
Reveal outside projection	Sets the default reveal outside projection (see no. 5 in figure above), measured from the outside surface of the glazing to the outside edge of the wall.
Window glass fraction	Sets the default fraction of window area occupied by glass. This enables a correction for the frame to be made in energy transfer calculations.
Rooflight glass fraction	Sets the default fraction of rooflight area occupied by glass. This enables a correction for the frame to be made in energy transfer calculations.

Tip: Units Display – Units are displayed using the default system of units that was defined for the project, but can be changed to display using alternative units.