Partition Properties

Contains controls used to view and define properties for partition surface types. Partition surfaces are wall sections that are exposed to adjacent rooms inside the building. The partition contains properties that all surface sub-types share as well as properties specific to the partition sub-type.

The Properties For: Partition dialog opens when the Partition Project Tree object´s pop-up menu is activated in the OpenBuildings Energy Simulator Project Tree dialog box and the Properties menu item is selected.

Note: The Partition Construction details properties panels under the Construction details heading contain controls used to view the selected partition construction details. The properties displayed here are saved in the OpenBuildings Energy Simulator materials database’s constructions definitions. Constructions can be viewed, manipulated and created using controls and settings found on the Materials Manager dialog.

Property heading	Properties
Category	Displays the surface category. Category is a read only property.
Sub type	Used to view or change the surface Sub type from Partition to another wall sub-type. The Sub type drop-down list is filtered and contains only partition and wall sub types.
Name	Used to enter a name for the partition. The name entered here appears appended to the partition object on the OpenBuildings Energy Simulator Project Tree dialog box.
Construction	Used to view of change the partition material construction definition.
Dimensions	Displays overall dimensions of the selected partition. Length — Displays the length (horizontal distance) of the partition shape element when viewed from a point normal to it. Width — Disabled for the partition sub-type. Height — Displays the height (vertical distance) of the partition shape element when viewed from a point normal to it. Area — Displays the total area of the selected partition. Volume — Disabled for the partition sub-type. Orientation — Displays the orientation of the partition relative to the building orientation. Building orientation is defined in the Properties For: Building dialog.
Heatflow	Contains controls used to view and set Heatflow data for the partition. Heatflow refers to the energy transfer occurring through a surface’s material construction. Heatflow is established automatically as rooms are created. OpenBuildings Energy Simulator determines if the adjacent space to the room wall is in contact with another room. If an adjacent room is found next the wall, the surface is defined as being of the surface sub-type partition. Type — Used to display and modify the nature of the heatflow occurring through the partition. None – When selected, the surface is considered to have no energy transferred through it. For instance, when the surface is a virtual wall. This is almost never selected for an partition sub-type. Specified Temperature – When selected, heatflow through the partition will be calculated based on the values entered for winter and summer temperatures in the two available temperature options. The temperature options are only visible when the heatflow type is set to Specified Temperature. Winter temperature – Specifies the winter temperature in the room adjacent to the partition. Summer temperature – Specifies the summer temperature in the room adjacent to the partition. Room Type – When selected, heatflow through the partition is calculated based on the standard room type of its parent room. Room type – Lists the room types available for the project. Adjacent Room – When selected, the heatflow through the surface is calculated by the conditions in the Adjacent Room. Adjacent room – Adjacent room is the default heatflow type for exposed walls. When selected, the heatflow through the surface is calculated by the conditions in the Adjacent Room. Ground – This option is not selectable due to the exposed wall being of the surface sub-type partition. Heatflow can not be calculated using this option. External – This option is not selectable due to the exposed wall being of the surface sub-type partition. Heatflow can not be calculated using this option.
Common	Displays common construction details for all surface sub-types. Common construction details are read only properties. Category — Displays the construction category associated with the surface. Total thickness — Displays the surface total thickness which included all the material layers (solids and air gaps) that make up the construction. Decrement factor (internal) — Displays a Decrement factor associated with the construction’s inside surface. The Decrement factor is used to calculated the amount a thermal wave is decreased in intensity during its propagation process from the outside to the inside of the surface construction. Decrement factor (external) — Displays a Decrement factor associated with the construction’s exterior surface. The Decrement factor is used to calculated the amount a thermal wave is decreased in intensity during its propagation process from the outside to the inside of the surface construction. Fixed thermal properties — Used to display the surface construction setting related to its thermal properties which are defined in the Materials Manager dialog box. When on, calculated surface emissivity and absorption coefficients are overridden, enabling you to define your own thermal properties (in the Materials Manager dialog box). When off, the calculated transmission values are used. Admittance (internal) — Displays the amount of heat that passes through a unit area of the constructions’s inside surface, when its external face is subject to a unit temperature change. Admittance (external) — Displays the amount of heat that passes through a unit area of the constructions’s external surface, when its inside face is subject to a unit temperature change. Time lag (internal) — Displays the time it takes for heat generated by the sun to transfer from the outside, through the construction, to the inside surface of the construction into the building envelope, and affect the internal conditions. Time lag (external) — Displays the time it takes for heat lost to transfer from the inside, through the construction, to the external surface of the construction from the building envelope. Weight (internal) — Displays the construction inside surface’s weight per unit area. Weight (external) — Displays the construction external surface’s weight per unit area.
Internal surface	Contains controls used to display thermal transfer properties for internal surface types such as the partition. Internal surface construction details are read only properties. Internal surface construction details are defined using the controls in Materials Manager . Surface emissivity — Displays the construction surface emissivity factor. Surface 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. Absorption coefficient — Displays the absorption coefficient for the construction's external surface. The absorption coefficient is a number between 0 and 1. The lower a construction's external surface solar absorption coefficient, the less solar heat it transmits. Upward-U-Value — Displays the calculated outside surface U-value or thermal transmittance of energy traveling upward through the selected construction. Downward-U-Value — Displays the calculated outside surface U-value or thermal transmittance of energy traveling downward through the selected construction. Horizontal-U-Value — Displays the calculated outside surface U-value or thermal transmittance of energy traveling horizontally through the selected construction.
Layers	Contains controls used to display the surface’s construction material layers in a read only table. The table displays thermal properties for each layer such as the thickness, density, conductivity, specific heat and vapor resistivity.