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6.4.3 Interior Lighting

The building descriptors in this section are provided for each lighting system. Typically a space will have only one lighting system, but in some cases, it could have two or more. Examples include a general and task lighting system in offices or hotel multi-purpose rooms that have lighting systems for different functions.

Regulated Interior Lighting Power
Applicability All projects
Definition Total connected lighting power for all regulated interior lighting power. This includes the loads for lamps and ballasts.
Units W/ft²
Input Restrictions As designed. The connected power should be cross-referenced to a space type and to the construction documents
Baseline Rules

With the building classification method, use the product of the lighting power density for the building classification from Appendix B and the floor area of the space.

With the space-by-space method, use the product of the lighting power densities for the space-by-space from Appendix B and the floor areas for the corresponding spaces.
Non-Regulated Interior Lighting Power
Applicability All projects
Definition

Power for the following lighting equipment and applications are exempt from the baseline standards, provided they are controlled by an independent control device:

  1. Display or accent lighting that is an essential element for the function performed in galleries, museums, and monuments.
  2. Lighting that is integral to equipment or instrumentation and is installed by its manufacturer.
  3. Lighting specifically designed for medical or dental procedures and lighting integral to medical equipment.
  4. Lighting integral to both open and glass enclosed refrigerator and freezer cases.
  5. Lighting integral to food warming and food preparation equipment.
  6. Lighting for plant growth or maintenance.
  7. Lighting in spaces specifically designed for use by the visually impaired.
  8. Lighting in retail display windows, provided the display area is enclosed by ceiling-height partitions.
  9. Lighting in interior spaces that have been specifically designated as registered historic landmark interiors.
  10. Lighting that is an integral part of advertising or directional signage.
  11. Exit signs
  12. Lighting that is for sale or lighting educational demonstration systems.
  13. Lighting for theatrical purposes including performance, stage, motion picture or television production.
  14. Lighting for television broadcasting in sporting activity areas.
  15. Casino gaming areas.
  16. Furniture mounted supplemental task lighting that is controlled by automatic shut-off and local control (added in ASHRAE 90.1-2007).

In addition, lighting is exempt that is specifically designated as required by a health or life safety statute, ordinance, or regulation for reasons of safety or security.

Emergency lighting that is automatically off during normal building operation is not considered.
Units W/ft²
Input Restrictions As designed. The non-regulated lighting power should be cross-referenced to the type of exception and to the construction documents. The default for non-regulated lighting power is zero.
Baseline Rules The non-regulated interior lighting in the baseline building shall be the same as the proposed design.
Lighting Schedules
Applicability All projects
Definition Schedule of operation for interior lighting power used to adjust the energy use of lighting systems on an hourly basis to reflect time-dependent patterns of lighting usage. Different schedules may be defined for different lighting circuits, depending on the capabilities of the software.
Units Data structure: schedule, fractional
Input Restrictions The lighting schedule is prescribed for tax deductions. The lighting schedule is a default for green building ratings and Design to Earn ENERGY STAR. For tax deductions, an appropriate schedule from Appendix C Tables 12-16 for the California 2005 ACM shall be used. For green building ratings and Design to Earn ENERGY STAR, the default schedules are presented in Appendix C.
Baseline Rules The baseline building shall use the same lighting schedules as the proposed design. The only exception to this rule is when the proposed design has a task/ambient lighting system. In this case the proposed design task lighting system may be controlled on a different schedule and the proposed design schedule proposed for the ambient lighting system is used for all the lighting in the baseline building.
Retail Display Lighting Power
Applicability Display lighting in retail display and other space-by-space classifications
Definition

Display lighting is special lighting to highlight merchandise. Its purpose is to enhance the visual appearance of the merchandise and not to provide lighting for a visual task. Display lighting is treated as use-it-or-lose-it in ASHRAE Standard 90.1. To qualify for display lighting, the lighting must be separately controlled from the general lighting.

 

ASHRAE Standard 90.1-2007 defines four categories of display lighting:

  • Retail Area 1 (all other)
  • Retail Area 2 (vehicles, sporting goods)
  • Retail area 3 (furniture clothing cosmetics)
  • Retail area 4 (jewelry, crystal, china).
    		•
    Units W or W/ft²
    Input Restrictions As designed. The default for lighting power for retail display wattage is 0.0 watts. When display lighting is entered in the software, its purpose shall be defined (see the categories above in the definitions section).
    Baseline Rules Baseline building lighting power is the lesser of proposed design power or the allowed power. The allowed lighting power is defined as the floor area  of the retail display times the allowances in Table 6.4.3-1.

    Table 6.4.3-1: "Lighting Power Allowances for Retail Display Lighting"


    		 ASHRAE Standard 90.1-2007
    Category Allowed Power (W/ft²)

    		Retail Area 1 1.0

    		Retail Area 2
    		 1.7

    		Retail Area 3
    		 2.6

    		Retail Area 4
    		 4.2
    Decorative Lighting Power
    Applicability All projects that have decorative lighting and are rated using the space-by-space method
    Definition

    Decorative lighting includes wall sconces, chandeliers and other decorative lighting that is provided for purposes other than illuminating visual tasks. The baseline standards treat this lighting as use-it-or-lose-it.
    Units W or W/ft2
    Input Restrictions As designed. The default for decorative lighting power is 0.0 watts/ft2. When using the space-by-space method, the user may input the power for qualifying decorative lighting using the decorative lighting power descriptor and cross-referencing the construction documents.
    Baseline Rules For the space-by-space method, decorative lighting power in the baseline building is equal to the lesser of the actual wattage of decorative lighting specified for the proposed design or 1.0 W/ft2.
    Lighting Power for VDT Viewing
    Applicability Tax deductions only (ASHRAE Standard 90.1-2001 baseline)
    Definition

    ASHRAE Standard 90.1-2001 provided additional lighting in spaces that are intended for use with video display terminals (VDT). This special allowance was eliminated with ASHRAE Standard 90.1-2007 and only applies for the purpose of calculating tax deductions.

    In order for a space to qualify for the special allowance, the specified luminaires must have special optical characteristics that direct most of the light down and minimize light cast to the sides. Specifically, a qualifying luminaire must serve a VDT viewing task and provide a maximum luminance measured from the vertical of 80 candelas/ft2 at 65 degrees, 33 candelas/ft2 75 degrees and 17 candelas/ft2 at 85 degrees or greater.
    Units W/ft2
    Input Restrictions As designed. The default for lighting power for VDT viewing is 0.0 watts/ft2 . The user may input qualifying lighting power for qualifying areas with cross-references to lighting schedules and spaces on the construction documents. A cut-sheet tabulating the candela distribution of the luminaires shall be provided.
    Baseline Rules The allowed lighting power for qualifying spaces is increased by 0.35 W/ft2 from the allowed values in Appendix B.

    Light Heat Gain Distribution
    Applicability All projects
    Definition

    The distribution of the heat generated by the lighting system that is directed to the space, the plenum, the HVAC return air, or to other locations. This input is a function of the luminaire type and location. Luminaires recessed into a return air plenum contribute more of their heat to the plenum or the return air stream if the plenum is used for return air; while pendant mounted fixtures hanging in the space contribute more of their heat to the space. Common luminaire type/space configurations are listed in Table 3, Chapter 18, 2009 ASHRAE Handbook – Fundamentals, summarized in Table 6.4.3-1 below. Typically the data will be linked to list of common luminaire configurations similar to Table 6.4.3-1 so that the user chooses a luminaire type category and heat gain is automatically distributed to the appropriate locations.

    This input may also be used to approximate the benefit of displacement ventilation (see Chapter 7).
    Units List (of luminaire types) or data structure consisting of a series of decimal fractions that assign heat gain to various locations.
    Input Restrictions Default values listed in Table 6.4.3-1 shall be used as a default when the luminaire categories apply. Values within the ranges of Table 6.4.3-1 may be used when following the rules in the 2009 HOF. Other values may be used when manufacturers’ literature and/or testing data is available, and adequate documentation is provided to the rating authority.
    Where lighting fixtures having different heat venting characteristics are used within a single space, the wattage weighted average heat-to-return-air fraction shall be used.
    Baseline Rules The baseline building shall use the above referenced defaults.

    Table 6.4.3-2: "Light Heat Gain Parameters for Typical Operating Conditions"

    Source: 3, Table 3, Chapter 18, 2009 ASHRAE Handbook – Fundamentals

    Luminaire Category Space Fraction Radiative Fraction
    Recessed fluorescent luminaire without lens 0.64 to 0.74 (default 0.69) 0.48 to 0.68 (default 0.58)
    Recessed fluorescent luminaire with lens 0.40 to 0.50 (default 0.45) 0.61 to 0.73 (default 0.67)
    Downlight compact fluorescent luminaire 0.12 to 0.24 (default 0.18) 0.95 to 1.00 (default 0.97)
    Downlight incandescent luminaire 0.70 to 0.80 (default 0.75) 0.95 to 1.00 (default 0.97)
    Non-in-ceiling fluorescent luminaire 1.0 (default 1.0) 0.50 to 0.57 (default 0.53)
    Power Adjustment Factors (PAF)
    Applicability All projects
    Definition Automatic controls that are not already required by the baseline standard and which reduce lighting power more or less uniformly over the day can be modeled as power adjustment factors. Power adjustment factors represent the percent reduction in lighting power that will approximate the effect of the control. Models account for such controls by adjusting the installed power by (1 – PAF). 
    The types of controls that are recognized for credit are listed in ASHRAE Standard 90.1-2007, Appendix G, Table G3.2 and shown below in Table 6.4.3-3.
    Units List: control types (see above) linked to PAFs
    Input Restrictions As designed
    Baseline Rules PAF is zero

    Table 6.4.3-3: "Power Adjustment Factors"

    Automatic Control Device Non-24-hour occupied buildings that are less than 5,000 ft² Other buildings
    Programmable timing control 10% 0%
    Occupant sensor 15% 10%
    Occupant sensor and programmable timing controls 15% 10%
    Bi-level parking garage controls1 30% 30%
    Bi-level controls in hotel corridors 20% 20%
    Scene controller with timeclock 20% 20%
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