Set Outside Thermal Design

Overview

Describes the setting of values of outside design conditions required for the analysis of energy demand and consumption.
Outside design conditions or criteria may be provided as an extension of the specification of a building by an energy analyst or be obtained from an external data source such as a meteorological data provider.
Outside design criteria are defined for a building. A prior requirement to the execution of this functional part is that a building has already been modelled using the functional part fp_model_building.

Concept: Set outside thermal design [heating]

Sets the outside design conditions prevailing during a winter season when heating is required.

Concept: Set outside thermal design [cooling]

Sets the outside design conditions prevailing during a summer season when cooling is required.

Concept: Set outside thermal design [weather]

Sets the weather criteria to be applied at the point of design

Results

Outside design conditions for winter heating are defined
Outside design conditions for summer cooling are defined
Weather data are defined

Description	Entity/Pset/Functional Part	MAN	REC	OPT
It is assumed that the building has already been modeled using the functional part fp_model_building.
Concept: Set outside thermal design [heating]
Set the outside dry bulb temperature for heating design calculations.	Pset_OutsideDesignCriteria.HeatingDryBulb::IfcPropertySingleValue::IfcThermodynamicTemperatureMeasure
Set the outside wet bulb temperature for heating design calculations.	Pset_OutsideDesignCriteria.HeatingWetBulb::IfcPropertySingleValue::IfcThermodynamicTemperatureMeasure
Set the month, day and time that has been selected for the heating design calculations. This property references an entity which is declared separately within an IFC data population.	Pset_OutsideDesignCriteria.HeatingDesignDay::IfcCalendarDate
Set the year value Note that a year component is a mandatory requirement of a calendar date and therefore must be set even though it is not a requirement in this context.	IfcCalendarDate.YearComponent::IfcYearNumber
Set the month value	IfcCalendarDate.MonthComponent::IfcMonthInYearNumber
Set the day value	IfcCalendarDate.DayComponent::IfcDayInMonthNumber
Concept: Set outside thermal design [cooling]
Set the outside dry bulb temperature for cooling design calculations.	Pset_OutsideDesignCriteria.CoolingDryBulb::IfcPropertySingleValue::IfcThermodynamicTemperatureMeasure
Set the outside wet bulb temperature for cooling design calculations.	Pset_OutsideDesignCriteria. CoolingWetBulb::IfcPropertySingleValue::IfcThermodynamicTemperatureMeasure
Set the month, day and time that has been selected for the cooling design calculations. This property references an entity which is declared separately within an IFC data population.	Pset_OutsideDesignCriteria. CoolingDesignDay::IfcCalendarDate
Set the year value Note that a year component is a mandatory requirement of a calendar date and therefore must be set even though it is not a requirement in this context.	IfcCalendarDate.YearComponent::IfcYearNumber
Set the month value	IfcCalendarDate.MonthComponent::IfcMonthInYearNumber
Set the day value	IfcCalendarDate.DayComponent::IfcDayInMonthNumber
Concept: Set outside thermal design [weather]
Identify the weather data station description or reference to the data source from which weather data was obtained for use in calculations.	Pset_ OutsideDesignCriteria.WeatherDataStation ::IfcPropertySingleValue::IfcText
Set the thermal exposure expected by the building based on surrounding site conditions. Exposure values enabled by the enumeration include: LIGHT MEDIUM HEAVY NOTKNOWN UNSET	_Pset_OutsideDesignCriteria.BuildingThermalExposure::IfcPropertyEnumeratedValue::PEnum_BuildingThermalExposure
Set the prevailing wind angle direction. Wind angle direction is measured from True North (0 degrees) in a clockwise direction.	Pset_ OutsideDesignCriteria.PrevailingWindDirection::IfcPropertySingleValue::IfcPlaneAngleMeasure
Set the design wind velocity. This is the wind velocity coming from the direction specified by the PrevailingWindDirection property above.	Pset_ OutsideDesignCriteria.PrevailingWindVelocity::IfcPropertySingleValue::IfcLinearVelocityMeasure
Set the date for which the weather data was gathered. This property references an entity which is declared separately within an IFC data population.	Pset_OutsideDesignCriteria.WeatherDataDate::IfcCalendarDate
Set the year value	IfcCalendarDate.YearComponent::IfcYearNumber
Set the month value	IfcCalendarDate.MonthComponent::IfcMonthInYearNumber
Set the day value	IfcCalendarDate.DayComponent::IfcDayInMonthNumber

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 functional part fp_model_building.

Examples of Setting Outside Thermal Design Conditions

In this example, all of the concepts associated with setting outside design criteria are indicated in the same sample file code below.

#2=IFCOWNERHISTORY(...);

/* defining the building */
#902=IFCBUILDING(...);

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

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

/* definition of outside design criteria properties */
#931=IFCPROPERTYSINGLEVALUE('HeatingDryBulb',$,-4.0,$);
#932=IFCPROPERTYSINGLEVALUE('HeatingWetBulb',$,-4.0,$);
#933=IFCPROPERTYREFERENCEVALUE('HeatingDesignDay',$,$,#4001);
#934=IFCPROPERTYSINGLEVALUE('CoolingDryBulb',$,32.0,$);
#935=IFCPROPERTYSINGLEVALUE('CoolingWetBulb',$,25.0,$);
#936=IFCPROPERTYREFERENCEVALUE('CoolingDesignDay',$,$,#4002);
#937=IFCPROPERTYSINGLEVALUE('WeatherDataStation',$,'Bucklebury',$);
#938=IFCPROPERTYREFERENCEVALUE('WeatherDataDate',$,$,#4003);
#939=IFCPROPERTYENUMERATEDVALUE('BuildingThermalExposure',$,(MEDIUM),$);
#940=IFCPROPERTYSINGLEVALUE('PrevailingWindDirection',$,45,$);
#941=IFCPROPERTYSINGLEVALUE('PrevailingWindVelocity',$,15,$);

/* specify the design dates */
#4001=IFCCALENDARDATE(21,12,2005);
#4002=IFCCALENDARDATE(21,6,2005);
#4003=IFCCALENDARDATE(30,3,2001);

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