Set Thermal Properties

Overview

Describes the setting of values required for the thermal properties of a building element to be used in energy analysis calculations. Thermal properties may be provided as part of the specification of building elements by the building designer or from catalogue sources of building element types.
Thermal properties may be applied to building element type entities or to building element occurrence entities.
A prior requirement to the execution of this functional part is that a building element has already been modelled using the appropriate functional part. Functional parts that are relevant as preconditions for the setting of thermal properties include:

fp_model_door
fp_model_slab
fp_model_wall
fp_model_window

Concept: Set thermal properties [door]

Sets the thermal properties of a door. Takes into account whether a door is external or internal. Takes into account the proportion of glazing within a door that has a glazing panel (or panels)

Concept: Set thermal properties [slab]

Sets the thermal properties for a slab that is acting either as the floor element or as part of the roof of a space

Concept: Set thermal properties [wall]

Sets the thermal properties of a wall. Takes into account whether a wall is external or internal.

Concept: Set thermal properties [window]

Sets the thermal properties of a window. For the purposes of this functional part, a window is considered to include a skylight and glazing within doors. Takes into account whether a window is external or internal.

Results

Thermal properties are specified for a door
Thermal properties are specified for slab
Thermal properties are specified for a wall
Thermal properties are specified for a window

Description	Entity/Pset/Functional Part	MAN	REC	OPT
It is assumed that the building element for the thermal properties to be set has already been modeled using the appropriate functional part and that a relevant common property set exists which contains mandatory naming information required by the functional part has been defined for the building element. Values of thermal information are set by this functional part within the already defined common property set occurrences.
Concept: Set thermal properties [door] Reference is to the functional part fp_model_door Note that thermal properties may be defined for a door style or an occurrence of a door.
Indication of whether the door is located within an exterior element of the building and therefore provides access to outside. The value of this property must be set to TRUE for an exterior door and FALSE for an interior door.	Pset_DoorCommon.IsExternal::IfcPropertySingleValue::IfcBoolean
If the door contains glazing, and if the glazing area is not given separately for all panels within the door, then set the fraction of the glazing area relative to the total area of the door. This value is given as a positive ratio measure and not as a %. That is, if the glazing area is half of the total door area then the value shall be given as 0.5	Pset_DoorCommon.GlazingAreaFraction::IfcPropertySingleValue::IfcPositiveRatioMeasure
Set the thermal transmittance coefficient (U-Value) of the door. Note that for simple calculation purposes, the thermal transmittance coefficient may be given to apply to the whole door including the glazing panel. For more detailed calculations, the thermal transmittance of the glazing should be dealt with as under door/window glazing below.	Pset_DoorCommon.ThermalTransmittance::IfcPropertySingleValue::IfcThermalTransmittanceMeasure
Concept: Set thermal properties [slab] Reference is to the functional part fp_model_slab Note that thermal properties may be defined for a slab type or an occurrence of a slab.
Indication of whether the slab forms an exterior element of the building or not. The value of this property must be set to TRUE for a slab forming an exterior element and FALSE for a slab forming an interior element .	Pset_SlabCommon.IsExternal::IfcPropertySingleValue::IfcBoolean
Set the thermal transmittance coefficient (U-Value) of the slab.	Pset_SlabCommon.ThermalTransmittance::IfcPropertySingleValue::IfcThermalTransmittanceMeasure
Concept: Set thermal properties [wall] Reference is to the functional part fp_model_wall Note that thermal properties may be defined for a wall type or an occurrence of a wall.
Indication of whether the wall forms an exterior element of the building or not. The value of this property must be set to TRUE for a wall forming an exterior element and FALSE for a wall forming an interior element .	Pset_WallCommon.IsExternal::IfcPropertySingleValue::IfcBoolean
Set the thermal transmittance coefficient (U-Value) of the wall.	Pset_WallCommon.ThermalTransmittance::IfcPropertySingleValue::IfcThermalTransmittanceMeasure
Concept: Set thermal properties [window] Reference is to the functional part fp_model_window Note that thermal properties may be defined for a window style or an occurrence of a window.
Indication of whether the window is located within an exterior element of the building. The value of this property must be set to TRUE for an exterior window and FALSE for an interior window.	Pset_WindowCommon.IsExternal::IfcPropertySingleValue::IfcBoolean
Set the fraction of the glazing area relative to the total area of the window. This value is given as a positive ratio measure and not as a %. That is, if the glazing area is 90% of the total window area then the value shall be given as 0.9	Pset_WindowCommon.GlazingAreaFraction::IfcPropertySingleValue::IfcPositiveRatioMeasure
Set the thermal transmittance coefficient (U-Value) of the window. Note that for simple calculation purposes, the thermal transmittance coefficient may be given to apply to the whole window including the glazing. For more detailed calculations, this value is the thermal transmittance of the material surrounding the glazing. The thermal transmittance of the glazing should be dealt with as under door/window glazing below.	Pset_WindowCommon.ThermalTransmittance::IfcPropertySingleValue::IfcThermalTransmittanceMeasure
Concept: Set thermal properties [glazing] Reference is to the functional part fp_model_door or fp_model_wall depending on whether the glazing is within a door or window.
THIS CONCEPT IS NOT YET DEVELOPED

For the purposes of this functional part, the IFC subset schema and all requirements for entities, datatypes, functions property sets and functional parts are considered to be exactly the same as for the relevant functional parts identified above.

Refer to the functional parts fp_model_door, fp_model_slab, fp_model_wall, fp_model_window for further information.

Examples of Setting Thermal Properties

Example 1: Setting thermal properties of a door occurrence

In this example, thermal properties are defined for an occurrence of a door. In the example, whilst the door occurrence is referenced, its attributes are not fully shown.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#902=IFCDOOR(...);

/* relating the door and the property set */
#912=IFCRELDEFINESBYPROPERTIES('abcdefghijklmnopqrst912',#2,$,$,(#902),#921);

/* definition of occurrence property set */
#921=IFCPROPERTYSET('abcdefghijklmnopqrst921',#2,'Pset_DoorCommon',$,(#931,#932,#933,#934,#935,#936,#937,#938,#939,#940,#941,#942));

/* definition of common properties for a door */
/* note that the optional values given in #938 and #940 relate to IFC 2x3 */
/* - a value must be asserted for prior IFC releases - */
#931=IFCPROPERTYSINGLEVALUE('Reference',$,'X23',$);
#932=IFCPROPERTYSINGLEVALUE('FireRating',$,'FR60',$);
#933=IFCPROPERTYSINGLEVALUE('AcousticRating',$,$,$);
#934=IFCPROPERTYSINGLEVALUE('SecurityRating',$,$,$);
#935=IFCPROPERTYSINGLEVALUE('IsExternal',$,.TRUE.,$);
#936=IFCPROPERTYSINGLEVALUE('Infiltration',$,$,$);
#937=IFCPROPERTYSINGLEVALUE('ThermalTransmittance',$,2.0,$);
#938=IFCPROPERTYSINGLEVALUE('GlazingAreaFraction',$,$,$);
#939=IFCPROPERTYSINGLEVALUE('HandicapAccessible',$,.TRUE.,$);
#940=IFCPROPERTYSINGLEVALUE('FireExit',$,.TRUE.,$);
#941=IFCPROPERTYSINGLEVALUE('SelfClosing',$,.TRUE.,$);
#942=IFCPROPERTYSINGLEVALUE('SmokeStop',$,.TRUE.,$);

Example 2: Setting thermal properties of a door style

In this example, thermal properties are defined for a style (or type) of door. The properties within the property set are as in example 1 above.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#902=IFCDOOR(...);

/* relating the door style and the door */
#912=IFCRELDEFINESBYTYPE('abcdefghijklmnopqrst912',#2,$,$,(#902),#1011);

/* definition of property set */
#921=IFCPROPERTYSET('abcdefghijklmnopqrst921',#2,'Pset_DoorCommon',$,(#931,#932,#933,#934,#935,#936,#937,#938,#939,#940,#941,#942));

/* defining the door style or type including property set reference */
#1011= IFCDOORSTYLE ('abcdefghijklmnopqrst1011',#2,$,$,$,(#921),$,$,.SINGLE_SWING_RIGHT.,.PLASTIC.,.TRUE.,.TRUE.);

Example 3: Setting thermal properties of a slab occurrence
In this example, thermal properties are defined for an occurrence of a slab.
 In the example, whilst the slab occurrence is referenced, its attributes are not fully shown.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#903=IFCSLAB(...);

/* relating the door and the property set */
#913=IFCRELDEFINESBYPROPERTIES('abcdefghijklmnopqrst913',#2,$,$,(#903),#922);

/* definition of occurrence property set */
#922=IFCPROPERTYSET('abcdefghijklmnopqrst922',#2,'Pset_SlabCommon',$,(#951,#952,#953,#954,#955,#956,#957,#958,#959,#960));

/* definition of common properties for a slab */
/* note that the optional values shown relate to IFC 2x3 */
/* - a value must be asserted for prior IFC releases - */
#951=IFCPROPERTYSINGLEVALUE('Reference',$,'X25',$);
#952=IFCPROPERTYSINGLEVALUE('AcousticRating',$,$,$);
#953=IFCPROPERTYSINGLEVALUE('FireRating',$,'FR60',$);
#954=IFCPROPERTYSINGLEVALUE('Combustible',$,.FALSE.,$);
#955=IFCPROPERTYSINGLEVALUE('SurfaceSpreadOfFlame',$,3,$);
#956=IFCPROPERTYSINGLEVALUE('ThermalTransmittance',$,1.6,$);
#957=IFCPROPERTYSINGLEVALUE('IsExternal',$,.TRUE.,$);
#958=IFCPROPERTYSINGLEVALUE('LoadBearing',$,.TRUE.,$);
#959=IFCPROPERTYSINGLEVALUE('Compartmentation',$,.TRUE.,$);
#960=IFCPROPERTYSINGLEVALUE('PitchAngle',$,30.0,$);

Example 4: Setting thermal properties of a slab type

In this example, thermal properties are defined for a type of slab acting as a floor slab. The properties within the property set are as in example 3 above.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#903=IFCSLAB(...);

/* relating the door style and the door */
#913=IFCRELDEFINESBYTYPE('abcdefghijklmnopqrst913',#2,$,$,(#903),#1012);

/* definition of property set */
#922=IFCPROPERTYSET('abcdefghijklmnopqrst922',#2,'Pset_SlabCommon',$,(#951,#952,#953,#954,#955,#956,#957,#958,#959,#960));

/* defining the slab type including property set reference */
#1012= IFCSLABTYPE('abcdefghijklmnopqrst1012',#2,$,$,$,(#922),$,$,$,.FLOOR.);

Example 5: Setting thermal properties of a wall occurrence

In this example, thermal properties are defined for an occurrence of a wall. In the example, whilst the wall occurrence is referenced, its attributes are not fully shown.
Note also that an occurrence of IfcWallStandardCase could be used in place of the occurrence of IfcWall shown.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#904=IFCWALL(...);

/* relating the door and the property set */
#914=IFCRELDEFINESBYPROPERTIES('abcdefghijklmnopqrst914',#2,$,$,(#904),#923);

/* definition of occurrence property set */
#923=IFCPROPERTYSET('abcdefghijklmnopqrst923',#2,'Pset_WallCommon',$,(#961,#962,#963,#964,#965,#966,#967,#968,#969,#970));

/* definition of common properties for a slab */
/* note that the optional values shown relate to IFC 2x3 */
/* - a value must be asserted for prior IFC releases - */
#961=IFCPROPERTYSINGLEVALUE('Reference',$,'X27',$);
#962=IFCPROPERTYSINGLEVALUE('AcousticRating',$,$,$);
#963=IFCPROPERTYSINGLEVALUE('FireRating',$,'FR60',$);
#964=IFCPROPERTYSINGLEVALUE('Combustible',$,.FALSE.,$);
#965=IFCPROPERTYSINGLEVALUE('SurfaceSpreadOfFlame',$,3,$);
#966=IFCPROPERTYSINGLEVALUE('ThermalTransmittance',$,1.6,$);
#967=IFCPROPERTYSINGLEVALUE('IsExternal',$,.TRUE.,$);
#968=IFCPROPERTYSINGLEVALUE('ExtendToStructure',$,.TRUE.,$);
#969=IFCPROPERTYSINGLEVALUE('LoadBearing',$,.TRUE.,$);
#970=IFCPROPERTYSINGLEVALUE('Compartmentation',$,.TRUE.,$);

Example 6: Setting thermal properties of a wall type

In this example, thermal properties are defined for a type of wall. The properties within the property set are as in example 5 above.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#904=IFCWALL(...);

/* relating the door style and the door */
#914=IFCRELDEFINESBYTYPE('abcdefghijklmnopqrst914',#2,$,$,(#904),#1013);

/* definition of property set */
#923=IFCPROPERTYSET('abcdefghijklmnopqrst923',#2,'Pset_WallCommon',$,(#961,#962,#963,#964,#965,#966,#967,#968,#969,#970));

/* defining the wall type including property set reference */
#1013= IFCWALLTYPE ('abcdefghijklmnopqrst1013',#2,$,$,$,(#923),$,$,$,.STANDARD.);

Example 7: Setting thermal properties of a window occurrence

In this example, thermal properties are defined for an occurrence of a window. In the example, whilst the window occurrence is referenced, its attributes are not fully shown.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#902=IFCDOOR(...);

/* relating the door and the property set */
#912=IFCRELDEFINESBYPROPERTIES('abcdefghijklmnopqrst912',#2,$,$,(#902),#921);

/* definition of occurrence property set */
#921=IFCPROPERTYSET('abcdefghijklmnopqrst921',#2,'Pset_DoorCommon',$,(#931,#932,#933,#934,#935,#936,#937,#938,#939,#940,#941,#942));

/* definition of common properties for a door */
/* note that the optional values given in #938 and #940 relate to IFC 2x3 */
/* - a value must be asserted for prior IFC releases - */
#971=IFCPROPERTYSINGLEVALUE('Reference',$,'X29',$);
#972=IFCPROPERTYSINGLEVALUE('FireRating',$,'FR60',$);
#973=IFCPROPERTYSINGLEVALUE('AcousticRating',$,$,$);
#974=IFCPROPERTYSINGLEVALUE('SecurityRating',$,$,$);
#975=IFCPROPERTYSINGLEVALUE('IsExternal',$,.TRUE.,$);
#976=IFCPROPERTYSINGLEVALUE('Infiltration',$,$,$);
#977=IFCPROPERTYSINGLEVALUE('ThermalTransmittance',$,2.0,$);
#978=IFCPROPERTYSINGLEVALUE('GlazingAreaFraction',$,0.9,$);
#979=IFCPROPERTYSINGLEVALUE('SmokeStop',$,.TRUE.,$);

Example 8: Setting thermal properties of a window style
In this example, thermal properties are defined for a style (or type) of window. 
The properties within the property set are as in example 7 above.

#2=IFCOWNERHISTORY(...);

/* defining the door */
#902=IFCDOOR(...);

/* relating the door style and the door */
#912=IFCRELDEFINESBYTYPE('abcdefghijklmnopqrst912',#2,$,$,(#902),#1011);

/* definition of property set */
#921=IFCPROPERTYSET('abcdefghijklmnopqrst921',#2,'Pset_DoorCommon',$,(#931,#932,#933,#934,#935,#936,#937,#938,#939,#940,#941,#942));

/* defining the door style or type including property set reference */
#1011= IFCDOORSTYLE ('abcdefghijklmnopqrst1011',#2,$,$,$,(#921),$,$,.SINGLE_SWING_RIGHT.,.PLASTIC.,.TRUE.,.TRUE.);

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