Lights
These library members are created to define the heat gain from internal lighting. They are applied to the zones in the room properties screen. TRACE™ 3D Plus has standard library members that include typical lighting densities and heat gains. Lights Library has two groups created: 90.1 Building Area Method and 90.1 Space Type Method. All other lights libraries are displayed to the right of those groups and more can be added or grouped. The lights library member details screen displays the fields that must be defined for each lights library member standard libraries have information from ASHRAE or from manufacturers:
Power
Defines the design lighting density. It can be defined as a total number of watts in the zone, lighting power per zone floor area (i.e. W/sq. ft.) or lighting power per person (i.e. w/person).
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Default Value: Per ASHRAE HOF 2013 depending on the space type
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Typical Range: 0.5 to 2 W/sq•ft; 5.38 to 21.5 W/m2
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Min & Max: 0 to 100000
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Units: W; W/ft2 ; W/m2; w/person; w/fixture
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Number of Fixtures
This field is only available when the units for the Power is w/fixture. It acts as a direct multiplier of the Power selected on the previous field.
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Default Value: 1
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Typical Range: Depends on the zone
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Min & Max: 1 to 999,999
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Units: N/A
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Lighting Configuration
Defines the luminaire type as defined per Chantrasrisalai, C., and D.E. Fisher. 2007.
Heat into Return Air
The percent of the heat from lights that goes into the zone return air. If the return air flow is zero or the zone has no return air plenum, this load will be put into the zone air. Enter the value as a decimal.*
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Default Value: Depending on the lighting configuration
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Typical Range: 0 to 0.5
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Min & Max: 0 to 1
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Units: %
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Thermal Radiation
The percentage of heat from lights that goes into the zone as long-wave (thermal) radiation. The program will calculate how much of this radiation is absorbed by the inside surfaces. Enter the value as a decimal.*
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Default Value: Depending on the lighting configuration
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Typical Range: 0.01 to 0.22
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Min & Max: 0 to 1
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Units: %
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Visible Radiation
The fraction of heat from lights that goes into the zone as visible (short-wave) radiation. The program calculates how much of this radiation is absorbed by the inside surfaces. Enter the value as a decimal.*
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Default Value: Depending on the lighting configuration
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Typical Range: 0.01 to 0.2
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Min & Max: 0 to 1
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Units: %
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Note: The total sum of the Return Air Fraction From Plenum Temperature, Thermal Radiation, and Visible Radiation percentages must be 100% or less.