## 5.7 Prescriptive Compliance Approach for Indoor Lighting – Part 2, Allowed Lighting Power

Following are the three methods permitted for the prescriptive compliance approach for calculating the allowed lighting power:

1. Complete Building Method

2. Area Category Method

3. Tailored Method

### 5.7.1 Complete Building Method (one of the Prescriptive Compliance Approaches)

§140.6(c)1

The Complete Building Method shall only be applied when lighting will be installed throughout the entire building. The building must consist of one type of use for a minimum of 90 percent of the floor area of the entire building.

The allowed indoor lighting power allotment for the entire building shall be calculated as follows:

1. For a conditioned building, multiply the entire conditioned floor area of the building by the applicable lighting power density (LPD, watts per sq. ft.) provided in Table 140.6-B.

2. For an unconditioned building, multiply the entire unconditioned floor area of the building by the applicable LPD provided in Table 140.6-B.

5.7.1.1 Requirements for Using the Complete Building Method

The Complete Building Method shall be used only for building types, as defined in §100.1, that are specifically listed in Table 140.6-B (for example, retail and wholesale stores, hotel/motel, and high-rise residential buildings.)

The Complete Building Method shall be used only on projects involving:

a. Entire buildings with one type of use occupancy.

b. Mixed occupancy buildings where one type of use makes up at least 90 percent of the entire building (in which case, when applying the Complete Building Method, it shall be assumed that the primary use is 100 percent of the building).

c. A tenant space where one type of use makes up at least 90 percent of the entire tenant space (in which case, when applying the Complete Building Method, it shall be assumed that the primary use is 100 percent of the tenant space).

A few more notes as follows:

• Use the Complete Building Method only when the applicant is applying for a lighting permit and submits plans and specifications for the entire building or the entire tenant space.

• Use the Complete Building Method only when the lighting power allotment in Table 140.6-B is available for the entire building. There are no additional lighting power allowances available when using Complete Building Method. Also, there are no mounting height multipliers available when using the Complete Building Method.

• For buildings including a parking garage plus another type of use listed in Table 140.6-B, the parking garage portion of the building and other type of use portion of the building shall each separately use the Complete Building Method.

Example 5-9 Mixed occupancy building – a parking garage building

Question

A building is to be constructed with 95 percent of it consisting of a parking garage, and the remaining 5 percent consisting of offices and support spaces such as an electrical room. What is the assumed building type under the complete building method?

Answer

Since parking garage makes up at least 90 percent of the entire building, the building shall be considered a parking garage when applying the Complete Building Method.

5.7.1.2 Definitions of Complete Building Types

When using the Complete Building Method, qualifying building types are those in which a minimum of 90 percent of the building floor area functions as one of the building types listed in Table 140.6-B, (as defined below), and which do not qualify as any other building occupancy type more specifically defined in §100.1, and which do not have a combined total of more than 10 percent of the area functioning as any nonresidential function areas specifically defined in §100.1:

• Assembly Building is a building with meeting halls in which people gather for civic, social, or recreational activities. These include civic centers, convention centers and auditoriums.

• Commercial and Industrial Storage Building is a building with building floor areas used for storing items

• Financial Institution Building is a building with building floor areas used by an institution which collects funds from the public and places them in financial assets, such as deposits, loans, and bonds.

• Industrial/Manufacturing Facility Building is a building with building floor areas used for performing a craft, assembly or manufacturing operation.

• Grocery Store Building is a building with building floor areas used for the display and sale of food.

• Gymnasium Building is a building with building floor areas used for physical exercises and recreational sport events and activities.

• Library Building is a building with building floor area used for repository of literary materials, and for reading books, periodicals, newspapers, pamphlets and prints.

• Office Building is a building of CBC Group B occupancy with building floor areas in which business, clerical or professional activities are conducted.

• Parking Garage Building is a building with building floor areas, parking vehicles, and consists of at least a roof over the parking area enclosed with walls on all sides. The building includes areas for vehicle maneuvering to reach designated parking spaces. If the roof of a parking structure is also used for parking, the portion without an overhead roof is considered an outdoor parking lot instead of a parking garage.

• Religious Facility Building is a building with building floor areas used for assembly of people to worship.

• Restaurant Building is a building with building floor areas in which food and drink are prepared and served to customers in return for money.

• Retail Store Building is a building with building floor area used for the display and sale of merchandise except food.

• School Building is a building used by an educational institution. The building floor area can include classrooms or educational laboratories, and may include an auditorium, gymnasium, kitchen, library, multi-purpose room, cafeteria, student union, or workroom. A maintenance or storage building is not a school building.

• Sports Arena Building is a building with building floor areas used for public viewing of sporting events and activities. Sports arena are classified according to the number of spectators they are able to accommodate, as follows:

Class I Facility is used for competition play for 5,000 or more spectators.

Class II Facility is used for competition play for up to 5,000 spectators.

Class III Facility is used for competition play for up to 2,000 spectators.

Class IV Facility is normally used for recreational play and there is limited or no provision for spectators.

• Motion Picture Theater Building is a building with building floor areas used for showing motion pictures to audiences.

• Performance Arts Theater Building is a building with building floor areas used for hosting performing arts such as plays, music or dance to audiences.

Example 5-10 Calculating allowed lighting power using the Complete Building Method

Question

A 10,000-ft² healthcare facility building is to be built. What is the allowed lighting power under the complete building method?

Answer

From Table 140.6-B, a healthcare facility building is allowed 0.9 W/ft². The allowed lighting power for the entire building is 10,000 x 0.9 = 9,000 W.

### 5.7.2 Area Category Method (one of the Prescriptive Compliance Approaches)

§140.6(c)2

5.7.2.1 Area Category Method General Lighting Power Allotment

The Area Category Method is more flexible than the Complete Building Method because it can be used for multiple tenants or partially completed buildings. Under the Area Category Method, an "area" is defined as all contiguous spaces that accommodate or are associated with a single primary function as listed in Table 140.6-C. For primary function areas not listed, selection of a reasonably equivalent type shall be permitted. When the lighting in these areas is completed later under a new permit, the applicant may show compliance with any of the lighting options except the Complete Building Method.

The Area Category Method divides a building into primary function areas. Each function area is defined under occupancy type in §100.1. The allowed lighting power is determined by multiplying the area of each function times the lighting power density for that function. Where areas are bounded or separated by interior partitions, the floor space occupied by those interior partitions shall be included in any area. The total allowed watts is the summation of the allowed lighting power for each area covered by the permit application.

When using this method, each function area in the building must be included as a separate area. Boundaries between primary function areas may or may not consist of walls or partitions. For example, kitchen and dining areas within a fast food restaurant may or may not be separated by walls. For purposes of compliance, they must still be separated into two different function areas. However, it is not necessary to separate aisles or entries within primary function areas. When the Area Category Method is used to calculate the allowed total lighting power for an entire building however, the main entry lobbies, corridors, restrooms, and support functions shall each be treated as separate function areas.

A. Requirements for using the Area Category Method include all of the following:

1. The Area Category Method shall be used only for primary function areas, as defined in §100.1, that are listed in Table 140.6-C.

2. Primary Function Areas in Table 140.6-C shall not apply to a complete building. Each primary function area shall be determined as a separate area.

3. For purposes of compliance with §140.6(c)2, an "area" shall be defined as all contiguous areas which accommodate or are associated with a single primary function area listed in Table 146.0-C.

4. Where areas are bounded or separated by interior partitions, the floor area occupied by those interior partitions may be included in a Primary Function Area.

5. If at the time of permitting for a newly constructed building, a tenant is not identified for a multi-tenant area, a maximum of 0.4 watts per sq. ft. shall be allowed for the lighting in each area in which a tenant has not been identified. The area shall be classified as Unleased Tenant Area.

6. Under the Area Category Method, the allowed indoor lighting power for each primary function area is the lighting power density value in Table 140.6-C multiplied by the square footage of the primary function area. The total allowed indoor lighting power for the building is the sum of the allowed indoor lighting power for all areas in the building.

5.7.2.2 Additional Lighting Power - Area Category Method

In addition to the allowed indoor lighting power calculated according to §140.6(c)2A thru F, the building may add additional lighting power allowances for qualifying lighting systems as specified in the Qualifying Lighting Systems column in Table 140.6-C under the following conditions:

1. Only primary function areas having a lighting system as specified in the Qualifying Lighting Systems column in Table 140.6-C and in accordance with the corresponding footnote of the table shall qualify for the additional lighting power allowances.

2. The additional lighting power allowances shall be used only if the plans clearly identify all applicable task areas and the lighting equipment designed to illuminate these tasks.

3. Tasks that are performed less than two hours per day or poor quality tasks that can be improved are not eligible for the additional lighting power allowances.

4. The additional lighting power allowances shall not utilize any type of luminaires that are used for general lighting in the building.

5. The additional lighting power allowances shall not be used when using the Complete Building Method, or when the Tailored Method is used for any area in the building.

6. The additional lighting power allowed is the smaller of:

i. The lighting power density listed in the “Allowed Additional Lighting LPD” column in Table 140.6-C, times the sq. ft. of the primary function, or

ii. the adjusted indoor lighting power of the applicable lighting.

7. In addition to the lighting power allowed under §140.6(c)2G(i through vi), up to 1.0 watts per square foot of additional lighting power shall be allowed in a videoconferencing studio, as defined in §100.1, provided the following conditions are met:

i. Before the Additional Videoconference Studio Lighting power allotment will be allowed for compliance with §140.6 of the Energy Standards, the person who is eligible under Division 3 of the Business and Professions Code to accept responsibility for the construction or installation of features, materials, components, or manufactured devices shall sign and submit the Certificate of Installation.

If any of the requirements in this Certificate of Installation are not met, the Additional Videoconference Studio Lighting installation shall not be eligible for the additional lighting power allotment.

ii. The Videoconferencing Studio is a room with permanently installed videoconferencing cameras, audio equipment, and playback equipment for both audio-based and video-based two-way communication between local and remote sites.

iii. General lighting is controlled in accordance with Table 130.1-A.

iv. Wall wash lighting is separately switched from the general lighting system.

v. All of the lighting in the studio, including general lighting and additional lighting power allowed by §140.6(c)2Gvii is controlled by a multi-scene programmable control system (also known as a scene preset control system).

Example 5-11 Calculating the allowed lighting power using Area Category Method

Question

A 10,000-ft² multi-use building is to be built consisting of:

A) 500 ft² main entry lobby,

B) 1.500 ft² corridors,

C) 3,000 ft² grocery store (Grocery Sales),

D) 2,500 ft² retail store (Retail Merchandise Sales), and

E) 2,000 ft² future development.

F) 500 ft² restrooms

What is the allowed lighting power under the area category method?

Answer

Most of the functional area types can be identified from Table 140.6-C for their designated lighting power density values.

The future development area is unknown and with no built-out plan at the time of permitting and “All other” (with 0.4 W/ft²) is designated as its primary function area type.

Space LPD Area Allowed Lighting Power

A) Main Entry 0.85 W/ft² 500 ft² 425 W

B) Corridors and Restrooms 0.6 W/ft² 1,500 ft² 900 W

C) Grocery Store (Grocery Sales) 1.05 W/ft² 3,000 ft² 3,150 W

D) Retail Store(Merchandise Sales) 1.00 W/ft² 2,500 ft² 2,500 W

E) Restrooms 0.65 W/ft² 500 ft² 325 W

F) Future Development (All other) 0.4 W/ft² 2,000 ft² 800 W

TOTAL 10,000 ft² 8,100 watts

Example 5-12 Calculating allowed lighting power for spaces with display lighting and decorative lighting

Question

What if in the multi-use building (example 5-11), the retail store is planning floor displays and wall displays, as well as decorative chandeliers. How do you determine the allowed lighting power for the retail store with display lighting and decorative lighting?

Answer

A) As in the above example, determine the total area of the retails store (2,500 ft²)

B) As in the above example multiply the allowed LPD (1.0 W/ft²) X 2,500 ft² = 2,500 W (allowed lighting power)

C) Determine the additional allowed lighting power for display and accent lighting by multiplying the retail store size of 2,500 ft²by 0.2 W/ft² (Qualifying Lighting Column of Table 140.6-C) = 500 W

D) Determine the additional allowed lighting power for ornamental lighting (for chandeliers) by multiplying the retail store size of 2,500 ft² by 0.15 W/ft² (Qualifying Lighting Column of Table 140.6-C) = 350 W

E) Add the 2,500 W plus 500 W for display and 350 W for ornamental = 3,375 W

The allowed lighting power for this retail store, under the area category method, is 3,375 W.

Note: The allowed lighting power may be less than the theoretical 3,375 W since the display/accent lighting and ornamental lighting components are “use-it or-lose it”. This means that the lesser of the adjusted additional lighting power for display/ornamental lighting and the calculated additional allowed lighting power (500 W and 375 W) is used. Also for the added power to be allowed, it must be in addition to general lighting and must use the appropriate luminaires for the task as defined in Table 140.6-C.

Example 5-13 Calculating additional lighting power for ornamental lighting

Question

What is the allowed lighting power for an ornamental chandelier with five 50 W lamps in a 300 ft² bank entry lobby?

Answer

The allowed lighting power for ornamental lighting is 0.3 W/ft² x 300 ft² = 90 W (0.3 W/ft² is based on Qualifying Lighting Column of Table 140.6-C.)

The wattage of the chandelier is 5 lamps x 50 W = 250 W.

If there are no applicable PAF or luminaire power reduction for the chandelier, the total wattage of the chandelier is the adjusted indoor lighting power or 90W.

The allowed lighting power for the chandelier is the smaller of the two values, or 90 W.

Example 5-14 Calculating additional lighting power for ornamental LED lighting

Question

What is the allowed lighting power for an LED chandelier with five 10 W LED lamps in a 300 ft² bank entry lobby?

Answer

The allowed lighting power for ornamental lighting is 0.3 W/ft² x 300 ft² = 90 W

The wattage of the chandelier 5 lamps x 10 W = 50 W.

If there are no applicable PAF or luminaire power reduction for the chandelier, the total wattage of the chandelier is the adjusted indoor lighting power or 50W.

The allowed lighting power for the chandelier is the smaller of the two values, or 50 W.

Example 5-15 Tunable-White and Dim-to-Warm Luminaires

Question

Which tunable-white and dim-to-warm luminaires qualify for the allowed additional lighting power for applications in healthcare facilities?

Answer

There are allowed additional lighting power for tunable-white and dim-to-warm luminaires for most of the healthcare/hospital function areas as specified in Table 140.6-C.

The qualified tunable-white luminaires shall be capable of color change ≥ 2000K CCT.

The qualified dim-to-warm luminaires shall be capable of color change ≥ 500K CCT.

A dim-to-warm luminaire product capable of color tune from 2700K to 1800K is acceptable and qualifies for the additional light power.

### 5.7.3 Tailored Method (one of the Prescriptive Compliance Approaches)

§140.6(c)3

5.7.3.1 Tailored Method Application and General Rules

The Tailored Method is a lighting compliance approach which establishes an allowed lighting power budget on a room-by-room or area-by-area basis.

Use of Tailored Method could be helpful when more general lighting power is required for the listed primary function areas1 in Table 140.6-D and for the listed area that has a high room cavity ratio (RCR).

In addition to providing a lighting power budget for general illumination, the tailored method provides additional lighting power budgets for illuminating wall displays, floor displays, task lighting, and ornamental/special effects lighting. These additional layers of lighting power have been informally referred to as “use-it-or-lose-it” lighting power allowances because these additional allowances cannot be traded-off to other areas or applications. If a lighting design does not include these additional layers of lighting power, the total lighting power budget using the Tailored Method may be less than if the Area Category Method or Complete Building Method of compliance is used.

1Definitions of the primary function areas can be found in Section 100.1.

1. There shall be no lighting power allotment trade-offs between the separate conditioned and unconditioned indoor function areas. Indoor conditioned and indoor unconditioned lighting power allotments must each be separately determined on compliance documentation

2. There shall be no lighting power allotment trade-offs between the separate indoor and outdoor function areas. Indoor and outdoor lighting power allotments must each be separately determined on compliance documentation.

3. Some areas of a building may use the Tailored Method, while other areas of the same building may use the Area Category Method. However, no single area in a building shall be allowed to use both the Tailored Method and the Area Category Method.

4. The Tailored Method shall not be used in any building using the Complete Building method for compliance.

5.7.3.2 Determining Allowed General Lighting Power for Tailored Method

§140.6(c)1 3G thru 3H; Table 140.6-D, F, G

A. Tailored Method Trade-Off Allowances

Compliance forms shall be used to document trading-off Tailored Method lighting power allotments. Trade-offs are available only for general lighting, and only under the following circumstances:

1. From one conditioned primary function area using the Tailored Method, to another conditioned primary function area using the Tailored Method.

2. From one conditioned primary function area using the Tailored Method, to another conditioned primary function area using the Area Category Method.

3. From one unconditioned primary function area using the Tailored Method, to another unconditioned primary function area using the Tailored Method.

4. From one unconditioned primary function area using the Tailored Method, to another unconditioned primary function area using the Area Category Method.

B. Determine Lighting Power Allotments for Conditioned and Unconditioned Primary Function Areas

The allowed Tailored Method Indoor Lighting Power allotment for general lighting shall be separately calculated for conditioned and unconditioned primary functions are as follows:

1. For a conditioned primary function area, multiply the conditioned square feet of that area times the applicable allotment of watts per square feet for the area shown in Table 140.6-D.

2. For an unconditioned primary function area, multiply the unconditioned square feet of that area times the applicable allotment of watts per square feet for the area shown in Table 140.6-D.

An "area" is defined as all contiguous areas which accommodate or are associated with a single primary function area, listed in Table 140.6-D. Where areas are bounded or separated by interior partitions, the floor area occupied by those interior partitions may be included in a primary function area.

C. Calculating Tailored Method General Lighting Power Allotments

The Energy Standards define general lighting as installed electric lighting that provides a uniform level of illumination throughout an area, exclusive of any provision for special visual tasks or decorative effect, exclusive of daylighting. To qualify as general lighting for the Tailored Method, the lighting system shall not use narrow beam direction lamps, wall-washers, valance, direct cove or perimeter linear slot types of lighting systems.

§140.6(c)3H shall be used to determine the general lighting power density allotments as follows:

1. Using Table 140.6-D and 140.6-G to Determine General Lighting Power Allotments:

a. Find the appropriate Primary Function Area in column 1 that fits one of the Nonresidential Function Area definitions in §100.1.

b. Find the corresponding General Illumination Level (Lux) in column 2.

c. Determine the room cavity ratio (RCR) for that primary function area, according to the applicable equation in Table 140.6-F. Use the nonresidential certificate of compliance to document the RCR calculation.

d. Refer to Table 140.6-G, using the General Illumination Level (Lux, determined according to item b), and the RCR (determined according to item c), to determine the allowed lighting power density value.

e. Multiply the allowed general lighting power density value by the square footage of the primary function area. The product is the allowed general lighting power for general lighting for that primary function area.

2. How to calculate Room Cavity Ratio (RCR)

• The room cavity ratio must be determined for any primary function area using the Tailored Lighting Method.

• The lighting level in a room is affected in part by the configuration of the room, expressed as the room cavity ratio (RCR). Rooms with relatively high ceilings typically are more difficult to light and have a high RCR. Because luminaires are not as effective in a room with a high RCR, §140.6 allows a greater LPD to compensate for this effect.

• The RCR is based on the entire space bounded by floor-to-ceiling partitions. If a task area within a larger space is not bounded by floor to ceiling partitions, the RCR of the entire space must be used for the task area. The exception to this rule allows for imaginary or virtual walls when the boundaries are established by “high stack” elements (close to the ceiling structure and high storage shelves) or high partial walls defined as “permanent full height partitions” described in §140.6(c)3liv wall display. These permanent full height partitions are only applicable when claiming additional lighting power for wall display lighting.

o Note: For use in calculating the RCR of the space, the walls are not required to be display walls as is required under §140.6(c)3liv.

o The RCR is calculated from one of the following formulas:

Equation 5-3 (Table 140.6-F) Rectangular Shaped Rooms

Where:

RCR = The room cavity ratio

H = The room cavity height, vertical distance measured from the work plane to the center line of the luminaire

L = The room length using interior dimensions

W = The room width using interior dimensions

A = The room area

Equation 5-4 (Table 140.6-F) Non-Rectangular Shaped Rooms

Where:

RCR = The room cavity ratio

H = The room cavity height (see equation above)

A = The room area

P = The room perimeter length

• For rectangular rooms, these two methods yield the same result and the second more general form of calculating RCR may be used in all instances, if desirable.

• It is not necessary to document RCR values for rooms with an RCR less than 2.0. Rooms with a RCR higher than 2.0 are allowed higher LPDs under the Tailored Method. The figure below gives example RCR values calculated for rooms with the task surface at desk height (2.5 ft above the floor). This is useful in assessing whether or not a room is likely to have an RCR greater than 2.0.

• A special situation occurs when illuminating stacks of shelves in libraries, warehouses, and similar spaces. In this situation, the lighting requirements are to illuminate the vertical stack rather than the horizontal floor area. In stack areas the RCR is assumed to be greater than seven. The non-stack areas are treated normally.

Example 5-15 Calculating Room Cavity Ratio (RCR)

Question

A small retail shop “Personal Shopper” room is 14 ft. wide by 20 ft. long by 8 ft. high. The lighting system uses recessed ceiling fixtures. The task surface is at desk height (2.5 ft. above the floor). What is the room cavity ratio?

Answer

The room cavity height is the distance from the ceiling (center line of luminaires) to the task surface (desk height). This is 8 ft. -2.5 ft. = 5.5 ft.

RCR = 5 x H x (L + W) / Area

RCR = 5 x 5.5 (14+20) / (14 x 20) = 3.34

5.7.3.3 Determine Additional Allowed Power for Tailored Method

§140.6(c)3G thru 3J; Table 140.6-D and E

When using the Tailored Method for lighting compliance, the additional allowed lighting power values and adjustment factor values are listed in Table 140.6-D, E, F, and G, for the special applications below:

• Wall display lighting,

• Floor display lighting and task lighting,

• Ornamental/special effects lighting, and

• Very valuable display case lighting.

These additional layers of lighting power are not available when using §140.6(c)3F to determine the general Lighting Power allotment, and are not available for any primary function areas using the Complete Building or Area Category methods of compliance.

All of the additional lighting power allowances are “use-it-or-lose-it” allowances that cannot be traded-off. That is, if the installed watts are less than the allowed watts, the difference in watts is not available to trade off anywhere else in the building.

Use the appropriate compliance form to document the additional lighting power for wall display lighting, floor display lighting and task lighting, ornamental/special effects lighting, and very valuable display case lighting.

A. Additional Wall Display Lighting Power:

9. Wall display lighting is defined as supplementary lighting required to highlight features such as merchandise on a shelf, which is displayed on perimeter walls; and that provides a higher level of illuminance to a specific area than the level of surrounding ambient illuminance.

10. Additional allowed power for wall display lighting is available only for lighting that illuminates walls having wall displays, and only when there is a watt per linear foot allowance in column 3 of Table 140.6-D for the primary function area.

1. The additional allowed power for wall display lighting shall be the smaller of:

i. The wall display lighting power density values (Column 3 of Table 140.6-D) times the wall display length (determined from item #3);

ii. The adjusted lighting power used for the wall display luminaires.

11. Calculate the adjusted lighting power by multiplying the maximum rated wattage of the display luminaires with the appropriate mounting height adjustment factor from Table 140.6-E.

12. Note that mounting height adjustment factor is available for wall display luminaires mounted at height greater than 10 feet 6 inches from the finished floor. Mounting height is the distance from the finished floor to the bottom of the luminaire.

2. To qualify for the additional wall display lighting power:

i. The lighting system shall be a type that is appropriate for creating a higher level of illuminance on the wall display. Lighting systems appropriate for wall display lighting are lighting track adjacent to the wall, wall-washer luminaires, luminaires behind a wall valance or wall cove, or accent light. (Accent luminaires are adjustable or fixed luminaires with PAR, R, MR, AR, or luminaires providing directional display lighting.)

ii. The qualifying wall display lighting shall be mounted within 10 feet of the wall having the wall display.

iii. The lighting system shall not be a general lighting system type.

13. Note: Lighting internal to display cases that are attached to a wall or directly adjacent to a wall are counted as wall display. All other lighting internal to display cases are counted as floor display lighting, or as very valuable display case lighting.

3. The length of display walls shall include the length of the perimeter walls including but not limited to closable openings and permanent full height interior partitions.

14. Permanent full height interior partitions are those that meet the following conditions:

i. Extend from the floor to within two feet of the ceiling or are taller than ten feet; and

ii. Are permanently anchored to the floor.

4. The additional wall display lighting power is not available for the following:

i. For any function areas using the Complete Building or Area Category methods of compliance.

ii. General lighting systems.

15. Note that floor displays shall not qualify for wall display lighting power allowances.

B. Additional Floor Display and Task Lighting Power:

16. Floor display lighting is defined as supplementary lighting required to highlight features, such as merchandise on a clothing rack, which is not displayed against a wall; and provides a higher level of illuminance to this specific area than the level of surrounding ambient illuminance.

17. Task Lighting is defined as lighting that specifically illuminates a location where a task is performed, but not general lighting.

18. Additional allowed power for floor display lighting and additional allowed power for task lighting may be used only for qualifying floor display lighting systems, qualifying task lighting systems, or a combination of both, for the listed primary function areas in Table 140.6-D.

19. Lighting internal to display cases that are not attached to a wall and not directly adjacent to a wall, shall be counted as floor display lighting or very valuable display case lighting.

1. The additional allowed power for the floor display and task lighting shall be the smaller of:

a. The floor display and task lighting power density values (Column 4 of Table 140.6-D) times the square footage of floor display or task area.

b. The adjusted lighting power used for floor display lighting or task lighting.

20. Calculate the adjusted lighting power by multiplying the maximum rated wattage of the floor display or task luminaires with the appropriate mounting height adjustment factor from Table 140.6-E.

21. Note that mounting height adjustment factor is available for floor display luminaires mounted at height greater than 10 feet 6 inches from the finished floor. Mounting height is the distance from the finished floor to the bottom of the luminaire.

2. To qualify for additional floor display lighting power:

a. The floor display lighting system shall be mounted no closer than 2 feet to a wall. When track lighting is used for floor display lighting, and where portions of that lighting track are more than 2 feet from the wall and other portions are within 2 feet of the wall, only those portions of track more than 2 feet from the wall shall qualify for the floor display lighting power allowance.

b. The floor display lighting system consists of only directional lamp types, such as PAR, R, MR, AR; or of luminaires providing directional display light.

c. If track lighting is used, only track heads that are classified as directional lighting types.

3. To qualify for additional task lighting power:

a. The task lighting system shall be located immediately adjacent to and capable of illuminating the task for which it is installed.

b. The lighting system shall be of a type different from the general lighting system.

c. The lighting system shall be separately switched from the general lighting system

4. To qualify for the additional power for floor display and task lighting, the lighting system shall be a type that is appropriate for creating a higher level of illuminance on the floor display or task.

5. The additional power for floor display and task lighting are not available for the following:

a. For any function areas using the Complete Building or Area Category methods of compliance.

b. Displays that are installed against a wall shall not qualify for the floor display lighting power allowances.

c. Any floor area designed to not have floor displays or tasks, such as floor areas designated as a path of egress, shall not be included for the floor display allowance.

6. For floor areas qualifying for both floor display and task lighting power allowances, the additional allowed power shall be used only once for the same floor area so that the allowance shall not be additive.

C. Additional Ornamental/Special Effects Lighting Power:

Special effects lighting is defined as lighting installed to give off luminance instead of providing illuminance.

Qualifying ornamental lighting to include luminaires such as chandeliers, sconces, lanterns, neon and cold cathode, light emitting diodes, theatrical projectors, moving lights, and light color panels when any of those lights are used in a decorative manner that does not serve as display lighting or general lighting.

Additional allowed power for ornamental/special effects lighting may be used only for the listed primary function areas in Table 140.6-D.

1. The additional allowed power for ornamental/special effects lighting shall be the smaller of:

a. The allowed ornamental/special effects lighting power values (Column 5 of Table 140.6-D) times the square footage of the floor areas having ornamental/special effects lighting;

b. The adjusted lighting power used for ornamental/special effects lighting.

2. Additional ornamental and special effects lighting power is not available for any function area using the Complete Building or Area Category methods of compliance.

3. Additional ornamental/special effects lighting power shall be used only in areas having ornamental/special effects lighting.

22. Any floor area not designed to have ornamental or special effects lighting shall not be included for the ornamental/special effects lighting allowance.

D. Additional Very Valuable Display Case Lighting Power:

Case lighting is defined as lighting of small art objects, artifacts, or valuable collections which involves customer inspection of very fine detail from outside of a glass enclosed display case.

Additional allowed lighting power for very valuable display case lighting shall be available only for display cases in retail merchandise sales, museum, and religious worship areas.

1. The additional allowed power for very valuable display case lighting shall be the smallest of:

a. The product of the area of the primary function and 0.55 watt per sq. ft.; or

b. The product of the area of the display case and 8 watts per sq. ft.; or

c. The adjusted lighting power used for very valuable display case lighting.

2. To qualify for additional allowed power for very valuable display case lighting, a case shall contain jewelry, coins, fine china, fine crystal, precious stones, silver, small art objects and artifacts, and/or valuable collections the display of which involves customer inspection of very fine detail from outside of a locked case.

3. The additional very valuable display case lighting is not available for any function areas using the complete building or area Category methods of compliance.

4. Qualifying lighting includes internal display case lighting or external lighting employing highly directional luminaires specifically designed to illuminate the case or inspection area without spill light, and shall not be fluorescent lighting unless installed inside of a display case.

Example 5-17 Ornamental lighting and very valuable display lighting - Tailored Method (Five parts) (Part 1)

Question

A 5,500-ft² retail store has:

5,000 ft² of gross retail sales area (merchandise sales) with a RCR of 2.5

200 ft² of restrooms (with a RCR of 6.0)

300 ft² of corridors (with a RCR of 6.5)

100 ft² of very valuable merchandise case top with 1,200 W of light sources

As part of the retail scheme in the sales floor area, the following lighting is being used.

- Wall display lighting of 300 linear feet of perimeter wall including closeable openings;

- Floor display lighting;

- Ornamental/special effects lighting.

What are the allowed lighting power for general lighting in this store using the Tailored Method?

Answer

The general illumination for merchandise sales and showroom area in retail is 500 Lux per column 3 of Table 140.6-D.

Per Table 140.6-G, the Lighting Power Density (LPD) is 1.05 W/ft² for a 500 Lux space with an RCR of 2.5. Therefore, the allowed general lighting power for the retail store is 1.05 W/ft² X 5,000 ft² = 5,250 W.

Corridors and restrooms are not included in the Tailored Method tables and therefore must comply under the area category method. Look up Table 140.6-C for the allowed LPD for these spaces. Table 140.6-C contains LPD values for primary functional areas and it allows 0.6 W/ft2 of LPD for corridors and 0.65 W/ft2 for restrooms. (RCR is irrelevant in looking up LPD values in Table 140.6-C. This is different from how to look up values from Table 140.6-G)

The allowed power for the restrooms is 200 ft² x 0.65 W/ft² = 130 W.

The allowed power for the corridors is 300 ft² x 0.6 W/ft² = 180 W.

Note that in the Tailored Method, the allowed wattage for each lighting task other than general lighting is of the use-it-or-lose-it variety, which prohibits trade-offs among these wattages and different tasks or areas. Only the General Lighting component of the Tailored Method is tradable between areas using tailored compliance or areas using Area compliance.

Example 5-18 Wall display lighting – Tailored method (Continue – Part 2)

Question

If the adjusted lighting power of the floor display luminaires is 3,000 watts, what is the allowed wall display lighting power for the retail sales area in this store?

Answer

The wall display lighting is computed from the entire wall perimeter, including all closeable openings, times the wall display power allowance. Therefore, the wall display lighting is 300 ft. x 11.8 W/ft. = 3,540 W. The allowed lighting power density value of 11.8 W/ft. is taken from column 3 of Table 140.6-D.

Note that in the Tailored Method, it is a use-it-or-lose-it allowance.

The additional allowed power for wall display lighting is the smaller of:

- The wall display lighting power of 3,540W, as calculated from above;

- The adjusted lighting power used for the wall display lighting, 3,000W.

Since the smaller of 3,540W and 3,000W is 3,000W, the additional allowed power for wall display lighting is 3,000W for the retail sales area in this store.

Example 5-19 Floor display lighting – Tailored method (Continue – Part 3)

Question

If the adjusted lighting power of the floor display luminaires is 4,000 watts, what is the allowed floor display lighting power for this store?

Answer

The floor display allowance is computed from the area of the entire space with floor displays multiplied by the floor display lighting power density. Therefore, the allowed wattage is 5,000 ft² x 0.8 W/ft² = 4,000 W. The allowance is taken from column 4 of Table 140.6-D.

Note that in the Tailored Method, it is a use-it-or-lose-it allowance.

The additional allowed power for floor display lighting is the smaller of:

- the floor display lighting power of 4,000W, as calculated from above;

- the adjusted lighting power used for the floor display lighting, 4,000W.

Since the smaller of 4,000W and 4,000W is 4,000W, the additional allowed power for floor display lighting is 4,000W for the retail sales area in this store.

Example 5-20 Ornamental/special effect lighting – Tailored method (Continue – Part 4)

Question

If the adjusted lighting power of the ornamental/special effect luminaires is 4,000 watts, what is the allowed ornamental/special effect lighting power for this store?

Answer

The ornamental/special effect allowance is computed from the area of the entire space with floor displays times the ornamental/special effect lighting power density. Therefore, the allowed wattage is 5,000 ft² x 0.4 W/ft² = 2,000 W. The allowance is taken from column 5 of Table 140.6-D.

Note that in the Tailored Method, it is a use-it-or-lose-it allowance.

The additional allowed power for ornamental/special effect lighting is the smaller of:

- The ornamental/special effect lighting power of 2,000W, as calculated from above;

- The adjusted lighting power used for the ornamental/special effect lighting, 4,000W.

As the smaller of 2,000W and 4,000W is 2,000W, the additional allowed power for ornamental/special effect lighting is 2,000W for the retail sales area in this store.

The ornamental/special effect luminaires have to be re-selected for a lesser adjusted wattage so that it is no more than 2,000W.

Example 5-21 Very valuable display lighting – Tailored method (Continue – Part 5 of 5)

Question

What are the allowed very valuable display lighting power for this store?

Answer

The allowed wattage for very valuable display case top is smaller of the product of 0.55 W/ft² and the gross sales area (5,000 ft²) or the product of 14 W/ft² and the actual area of the case tops (100 ft²). The allowed lighting power is the smaller of 0.55 W/ft² X 5,000 ft² = 2,750 watts, or 8 W/ft² X 100 ft² = 1,200 watts. Therefore, the maximum allowed power is 1,200 W.

Because the floor display and very valuable display allowances are use-it-or-lose-it allowances, the maximum power allowed is the smallest of primary function area lighting power (2,750 W) and very valuable display case lighting power (800 W) or the adjusted lighting power for very valuable display case lighting (1,200 W). Therefore, the allowed watts for very valuable display lighting is 800 W.

Example 5-22 Retail space – determination on partitions

Question

A large retail store with a sales area that has a 14-foot high ceiling and full height perimeter wall also has several other walls and a high fixture element in the space. Based on the definition of “full-height” partitions (per §140.6(c)3liv), which components qualify for the wall display allocation?

Answer

The sketch below shows full height partitions and non-full height partitions.

Example 5-23 Wall display lighting in a retail store– Tailored Method

Question

In this question, Condition A has 2 x 4 troffers placed 3 feet from a perimeter sales wall as well as fluorescent wall-washers 5 feet from the sales wall. Condition B has fluorescent wall-washers 3 feet from the wall and PAR adjustable accent lights 5 feet from the wall. Which luminaires qualify for the wall display lighting allocation?

Answers

Per §140.6(c)3liia, qualifying lighting must be mounted within 10 feet of the wall and must be an appropriate wall lighting luminaires. (Luminaires with asymmetric distribution toward the wall or adjustable –directed toward the wall).

CONDITION A

While both luminaires are within 10 feet of the wall only the wall-washer qualifies for the wall display allocation. The 2 x 4 troffer is a general lighting luminaire with symmetric distribution and does not qualify for the allocation.

CONDITION B

Both luminaires are within 10 feet of the wall and both qualify for the wall display allocation. The fluorescent wall-washer has an asymmetric distribution and the PAR accent light at 5 feet from the wall provides directional light.

Example 5-24 Display lighting in a museum – Tailored Method

Question

A museum space has directional accent lighting luminaires on a track mounted to the ceiling. The first track is 3 feet from the perimeter wall of the exhibit space and the second track is 9 feet from the wall. There is a third track (not shown) that is 15 feet into the space. To what display category should these luminaires be assigned under §140.6(c) 3I and 3J

Answers

Per §140.6(c)3G & 3H, wall display luminaires must be within 10 feet of the wall and directional, and floor display luminaires must be at least two feet away from the wall and also directional. Using these criteria, the allocations for the two conditions shown are as follows:

CONDITION A

Both sets of luminaires (3 feet and 9 feet away from the wall) shown are at least 2 feet away from the wall and are directed onto a floor exhibit (display) therefore they both qualify for the floor display allocation. The third track (15 feet away from the wall) with directional luminaires also can qualify as floor display.

CONDITION B

Both sets of luminaires shown are closer than 10 feet to the wall and are directed onto a wall exhibit (display) therefore they both, when directed toward the wall qualify for the wall display allocation. The third track with directional luminaire (15 feet from the wall) does not qualify for wall display, only floor display.

Note: Luminaires within a 2 foot to 10 foot zone may be assigned to either wall or floor display depending on the focus direction of the luminaires. However only one classification – either wall or floor – can be used for luminaire compliance, not both.

Example 5-25 Lighting Power Adjustments for luminaire mounting height – Tailored Method

Question

A high ceiling space with allowed display lighting has wall-washers mounted on the ceiling near the wall and accent lights mounted on suspended track in the center of the space. Because of the 14-foot high ceiling, does the display lighting qualify for a mounting height factor adjustment?

Answer

Per §140.6(c) 3Giv and 3Hviii, both the wall-washers and accent lights qualify for the mounting height adjustment as they are mounted at height greater than 10 feet 6 inches and they also provide directional light.

If the track is suspended at 10 feet instead of 11 feet, it is excluded from an adjustment factor and must use the default factor of one with the allowed LPD as shown in column four in Table 140.6-E.