PRESCRIPTIVE APPROACH - California Lighting …cltc.ucdavis.edu/.../files/publication/...prescriptive-approach_1.pdf7/29/2013 SLIDE 95 PRESCRIPTIVE APPROACH (Page 4-5 of T24 EnergyPro

PRESCRIPTIVE APPROACH

1. Actual and allowed LPD

2. Complete Building Method

3. Area Category Method

4. Tailored Method

SECTION 5

ACTUAL VS. ALLOWED LIGHTING POWER DENSITY

A building complies with under the prescriptive method if the actual

lighting power density is less than the allowed indoor lighting power.

The allowed indoor lighting power density for each building type

or primary function area is calculated using the Complete Building,

Area Category, or Tailored methods.

7/29/2013 PRESCRIPTIVE APPROACH SLIDE 76

SECTION 5

ACTUAL VS. ALLOWED LIGHTING POWER DENSITY

The actual indoor lighting power of the proposed building area is the

total watts of all planned, permanent and portable lighting systems,

adjusted by the following:

1. Multiple interlocked lighting systems

2. Reduction of wattage through controls

3. Lighting wattage exclusions

4. Indoor lighting power trade-offs


Photo Credit: Color Kinetics

SECTION 5

ACTUAL LPD: INTERLOCKED LIGHTING SYSTEMS

When multiple interlocked lighting systems serve a single space, the watts

of all systems except the system with the highest wattage may be excluded if

the lighting systems are interlocked with a non-programmable double-throw

switch to prevent simultaneous operation.

Spaces included:

• Auditorium

• Convention center

• Conference room

• Multipurpose room

• Theatre


SECTION 5

ALLOWED LPD: LIGHTING POWER TRADE-OFFS

Complete Building Method: Within a single building.

Allowed lighting power may not be traded between two

or more buildings.

Area Category Method: Between the primary function

areas. Conditioned and unconditioned spaces must be

separate allotments, met separately without trade - offs.

Tailored Method: Within the primary function areas for

general illumination. Wall display, floor display and

ornamental / special effects lighting must be separate

allotments without trade - offs.


SECTION 5

ALLOWED LPD: COMPLETE BUILDING METHOD

The Complete Building Method may only be used on projects

involving entire buildings with one primary type of use occupancy.

• May only be used when the applicant is applying for a lighting permit

• Must submit plans and specifications for the entire building

• (TABLE 146-E ) X (floor area of entire building ) = Allowed LPD


Retail and wholesale stores, hotel / motel, and high - rise

residential buildings may not use this method.

SECTION 5

TABLE 146-E


Can be found:

(Page 120) 2008 Building

Energy Efficiency Standards

SECTION 5

ALLOWED LPD: AREA CATEGORY METHOD

The total allowed lighting power for the building is the sum of all

allowed lighting powers for all areas in the building.

An “area” is all adjacent spaces which accommodate or are associated

with a single one of the primary functions listed in TABLE 146-F.


Photo Credit:

Philips

Photo Credit:

Philips Photo Credit:

Philips

SECTION 5

TABLE 146-F


Can be found:



SECTION 5

ALLOWED LPD: AREA CATEGORY METHOD

When the Area Category Method is used to calculate the allowed total

lighting power for an entire building, main entry lobbies, corridors,

restrooms, and support functions are treated as separate areas.


Photo Credit:

Philips

SECTION 5

TABLE 146-F FOOTNOTES

1. The smallest of the following values may be added to the allowed lighting power for ornamental chandeliers and

sconces that are in addition to and switched or dimmed on circuits different from the circuits for general lighting:

• One watt per square foot times the area of the task space that the chandelier or sconce is in; or

• The actual design wattage of the chandelier or sconce.

2. The smallest of the following values may be added to the allowed lighting power for specialized task work:

• 0.5 watt per square foot times the area of the task space required for an art, craft assembly or manufacturing operation; or

• The actual design wattage of the luminaire(s) providing illuminance to the specialized task area. For spaces employing this

allowance, the plans shall clearly identify all task spaces using these tasks and the lighting equipment designed to illuminate

these tasks. Tasks that are performed less than two hours per day or poor quality tasks that can be improved are not eligible

for this specialized task work allowance.

3. The smallest of the following values may be added to the allowed power for precision commercial and industrial work:

• One watt per square foot times the area of the task space required for the precision work; or

• The actual design wattage of the luminaire(s) providing the illuminance to the precision task area. For spaces employing this

allowance, the plans shall clearly identify all task spaces using these tasks and the lighting equipment designed to illuminate

these tasks. Tasks that are performed less than two hours per day or poor quality tasks that can be improved are not eligible

for this precision task work allowance.

4. The smallest of the following values may be added to the allowed lighting power for specialized task work:

• 0.2 watt per square foot times the area of the task space required for a lab in a school; or

• The actual design wattage of the luminaire(s) providing illuminance to the specialized task area.


SECTION 5

ACTUAL LPD: REDUCTION THROUGH CONTROLS

( Controlled W ) X ( PAF from the table 146-C ) = LPD reduction


Creative Commons, Photo Credit: Noway

SECTION 5

TABLE 146-C: LIGHTING POWER ADJUSTMENT FACTORS


Can be found:



SECTION 5

ACTUAL LPD: REDUCTION THROUGH CONTROLS

In order to use the LPD reductions from TABLE 146-C,

the following requirements must be met:

• The control must comply with mandatory requirements

• At least 50% of the light output must be within the applicable

space listed in TABLE 146-C

• Only one Power Adjustment Factor is used for the luminaire

(except where noted otherwise in TABLE 146-C)

• The multi-level occupancy sensor must meet all multi-level

and uniformity requirements.


SECTION 5

ACTUAL LPD: LIGHTING WATTAGE EXCLUDED

Wattage of many lighting applications may be excluded:

• Theme Parks: Lighting for themes and special effects

• Studio lighting for film or photography and for a videoconferencing studio

• Lighting for dance floors, theatrical and other live performances

• Equipment that is for sale and for demonstration

• Temporary exhibits in civic facilities, transportation facilities, convention

centers and hotel function areas

• Lighting installed by the manufacturer in refrigerated cases, walk-in

freezers, vending machines, food preparation equipment and scientific

and industrial equipment


Photo Credit: Philips Photo Credit: Philips Photo Credit: Philips

SECTION 5

ACTUAL LPD: LIGHTING WATTAGE EXCLUDED

Also, lighting for:

• Plant growth or maintenance

• Required exit signs

• Guestrooms in hotel / motel

• Temporary lighting systems

• Parking garages for 7 or less vehicles


Photo Credit: Martin Pettitt

EXERCISE:

CHARMED BOUTIQUE

AREA CATEGORY: RETAIL MOCKUP

1. Calculate installed lighting wattage

2. Calculate control credit watts

3. Calculate the allowed general lighting power

4. Verify installed lighting wattage is within allowed parameters

SECTION 5

AREA CATEGORY: RETAIL MOCKUP


SECTION 5 7/29/2013 PRESCRIPTIVE APPROACH SLIDE 93

TOTAL: 1,021 INSTALLED WATTS

(Page 2 of T24 EnergyPro printout)

INSTALLED LIGHTING WATTAGE

SECTION 5



Can be found:

(Page 119) 2008 Building Energy

Efficiency Standards

SECTION 5

CONTROL CREDIT

Storage area: 2 controlled luminaires

Wattage of control lighting X PAF (Table 146-C) = W, control credit

124 W of Control Lighting X [0.15 PAF] = 19 W, control credit


(Page 4-5 of T24 EnergyPro printout)

SECTION 5

TABLE 146-F: DETERMINING ILLUMINANCE CATEGORY


Can be found:



SECTION 5

DETERMINING ILLUMINANCE CATEGORY


Retail Sales, Wholesale:

1.60 W / ft2

Commercial,

Industrial

Storage:

0.60 W / ft2


SECTION 5

CALCULATING ROOM SIZE


Sales Floor:

595 ft2

Storage:

170 ft2


SECTION 5

CALCULATING ALLOWED LIGHTING POWER


595 ft2 x 1.60 = 952 W allowed

170 ft2 x 0.60

= 102 W allowed

TOTAL: 1,054 W ALLOWED


SECTION 5

DOES IT COMPLY?

Installed Lighting: 1,021 W

– Lighting Control Credit: 19 W

= Adjusted Installed Lighting Power: 1,002 W

Allowed Lighting Power: 1,054 W


Complies!

SECTION 5

ALLOWED LPD: TAILORED METHOD

The Tailored Method is calculated

according to primary function

type as permitted in column 1 of

TABLE 146-G. (Please refer to the handout.)


Can be found:



SECTION 5

ALLOWED LPD: TAILORED METHOD, STEP 1

If a specific IESNA Illuminance Category is listed in Column 2 of TABLE 146-G,

then that category must be used.

Otherwise, determine the illuminance category for each lighting primary function

type according to categories specified in the IESNA Lighting Handbook using the

“Design Guide” for illuminance.

1. Determine the area of each primary function

2. Determine the room cavity ratio (RCR) for each primary function area

3. Multiply the area of each primary function by the allowed lighting power density for the

illuminance category and RCR for each primary function area according to TABLE 146-I.

4. The product or the actual installed lighting power for the primary function, whichever is

less, is the allowed general lighting power for the space.


Note: The general allowed lighting change when using the Tailored Method, from the

average lighting requirement for a retail sales space (AC allowance), to an allotment

based on specific spacial requirements (actual RCR) and IES illuminance categories.

SECTION 5

ALLOWED LPD: TAILORED METHOD, STEP 2

Four types of Tailored Method allowances: wall, floor, very valuable

merchandise, and ornamental displays

Determine additional allowed power for display and decorative lighting

(columns 3-5 of TABLE 146-G)

• Displays installed against a wall do not qualify for floor display lighting power allowances.

• Floor displays do not qualify for the wall display allowances.

In retail merchandise sales, museum, and religious worship,

the smallest of the following separate lighting power for display cases

presenting very valuable display items is permitted:

• The product of the area of the primary function and 1.0 W / ft2; or

• The product of the area of the display case and 16 W / ft2, or

• The actual power of lighting for very valuable displays.

Only the general portion of the lighting power may be used for tradeoffs.

Display and decorative lighting power allowances are “use it or lose it.”


EXERCISE:

CHARMED BOUTIQUE TAILORED METHOD: RETAIL MOCKUP

Very valuable merchandise displays: business is changing

center merchandise tables to jewelry cases

SECTION 5

FLOOR PLAN CHANGES


SECTION 5

LUMINAIRE CHANGES


SECTION 5



Can be found:



SECTION 5

TABLE 146-F DETERMINING ILLUMINANCE CATEGORY


Can be found:



SECTION 5

TABLE 146-G


Can be found:



SECTION 5

TABLE 146-G Continued


SECTION 5

TABLE 146-I


Can be found:


Energy Efficiency

Standards

SECTION 5

GENERAL SALES FLOOR

• Primary Function Type (Table 146-G, col 1)

• Illuminance Category (Table 146-G, col 2)

• Floor Area for Primary Function =

(Length) x (Width)

• Room Cavity Ratio =

5 x (H) x (Length + Width) / (Length x Width)

• Allowed LPD (Table 146-I)

• Allowed W = Area x Allowed LPD


Primary Function Type

F GC D EB

Illuminance

Category

Room

Cavity

Ratio

Retail Sales, Wholesale D 4.15 595 1.20 714

Floor Area for

Primary FuntionAllowed LPD

Allowed W (E x F)

Retail Sales, Wholesale

D

35 ft x 17 ft = 595 ft

5 x 9.5 x (52) / (595) = 4.15

1.2 W

714 W

SECTION 5

• In retail merchandise sales, museum, and religious worship, the smallest of the

following is permitted for display cases presenting very valuable merchandise :

(See §146(c)3B(iv)(a))

1. The product of the area of the primary function and 1.0 W / ft2; or

2. The product of the area of the display case and 16 W / ft2, or

3. The actual power of lighting for very valuable displays.

• Area Wattage = (Floor Area) x (Valuable Display Power)

595 x 1.00 = 595

• Display Case Wattage = (Display Case Area) x (W / ft2)

24 x 16 = 384

• Design Wattage = (# of lm) x (W/lm)

6 x 54 = 324

HIGH VALUE DISPLAYS


SECTION 5

CALCULATING ALLOWED LIGHTING POWER


General Sales: 714 W allowed

Very Valuable Displays: 324 W allowed

Total: 1038 W allowed

Storage Area

170 ft2 x 0.60

= 102 W allowed

TOTAL: 1,140W ALLOWED

SECTION 5

PUTTING IT ALL TOGETHER

Allowed lighting power

• General sales floor lighting: 714 W

• High value merchandise displays: 324 W

• Storage area: 102 W

(same as area category method calculation)

TOTAL: 1,140 W

Installed lighting power

• Installed lighting: 1093 W

• Lighting control credit:19 W

(same as area category method calculation)

TOTAL: 1,074 W


Complies!

Documents

PRESCRIPTIVE APPROACH - California Lighting …cltc.ucdavis.edu/.../files/publication/...prescriptive-approach_1.pdf7/29/2013 SLIDE 95 PRESCRIPTIVE APPROACH (Page 4-5 of T24 EnergyPro