Category
|
Displays the surface category. Category is a read
only property.
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Sub type
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Used to view or change the surface Sub type from
Exposed roof to another roof or ceiling sub-type. The Sub type drop-down list
is filtered and contains only floor and ceiling sub types.
|
Name
|
Used to enter a name for the exposed roof. The name
entered here appears appended to the exposed roof object on the OpenBuildings Energy Simulator Project
Tree dialog box.
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Construction
|
Used to view of change the exposed roof
material construction
definition.
|
Dimensions
|
Displays overall dimensions of the selected exposed
roof.
- Length — Disabled
for the exposed roof sub-type.
- Width — Disabled for
the exposed roof sub-type.
- Height — Disabled
for the exposed roof sub-type.
- Area — Displays the
total area of the selected exposed roof.
- Volume — Disabled
for the exposed roof sub-type.
- Orientation —
Displays the orientation of the exposed roof relative to the building
orientation. Building orientation is defined in the
Properties
For: Building
dialog.
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Heatflow
|
Contains controls used to view and set Heatflow data
for the exposed roof. 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
above the room ceiling is in contact with another room. If no adjacent room is
found above the ceiling, the surface is defined as being of the surface
sub-type exposed roof.
- Type — Used to
display and modify the nature of the heatflow occurring through the exposed
roof.
|
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.
|
External surface
|
Contains controls used to display thermal transfer
properties for external surface types such as the exposed roof. External
surface construction details are read only properties. External 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.
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