BBBD 2011 Efficient Lighting Fundamentals...Color Rendering A scale of the effect of a light source on the color appearance of an object compared to its color appearance under a reference

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Efficiency Vermont is a Registered Provider with The American

Institute of Architects Continuing Education Systems

(AIA/CES). Credit(s) earned on completion of this program will

be reported to AIA/CES for AIA members. Certificates of

Completion for both AIA members and non-AIA members are

available upon request.

This program is registered with AIA/CES for continuing

professional education. As such, it does not include content that

may be deemed or construed to be an approval or endorsement

by the AIA of any material of construction or any method or

manner of handling, using, distributing, or dealing in any material

or product.

Questions related to specific materials, methods, and services

will be addressed at the conclusion of this presentation.

Learning ObjectivesLearning Objectives

By the end of this program, participants will be able to:

• Understand key techniques & common terminology of energy-efficient lighting

• Gain knowledge that can strengthen your communications with lighting

designers, suppliers, and manufacturers

• Increase your understanding of lighting decisions on your projects

• Understand basic lighting terminology such as lumens, footcandles, color

temperature, color rendering, etc.

• Understand how to apply lighting terminology to the selection of new light

sources and fixtures.

• Understand how lighting terminology is critical to the evaluation of new energy

efficient lighting sources and fixtures.

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In order to maintain high-quality learning experiences, please

access the evaluation for this course by logging into CES

Discovery and clicking on the Course Evaluation link on the

left side of the page.

Course EvaluationsCourse Evaluations

Lighting TerminologyLighting Terminology

� Lumens

� Footcandles

� Illuminance

� Luminance

� Efficacy

� Color Temperature

� Color Rendering

Quantity of Light Appearance of Light

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Lighting TerminologyLighting Terminology

Lumen

A unit of light flow, or luminous flux. The lumen

rating of a lamp is a measure of the total light

output of the lamp.

The amount of light generated by a light source, at

the source.

Glossary definitions as defined by Architectural Lighting Magazine 2008.

Lighting TerminologyLighting Terminology

Footcandle (FC)

The English measurement of the illuminance (or

light level) on a surface. One footcandle is equal to

one lumen per square foot.

The amount of illumination measured (with a light

meter) on a vertical or horizontal surface…

We do not “see” footcandles…

Glossary definitions as defined by Architectural Lighting Magazine 2008.

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Lighting TerminologyLighting Terminology

Illuminance

A photometric term that quantifies light incident on

a surface or plane. Illuminance is commonly called

light level. It is expressed as lumens per square

foot (footcandles) or lumens per square meter (lux).

The term for the quantity of illumination that a light

meter measures (footcandles).

Glossary definitions as defined by Architectural Lighting Magazine 2008.

Lighting TerminologyLighting Terminology

Luminance

A photometric term that quantifies brightness of a

light source or of an illuminated surface that reflects

light. It is expressed as footlamberts (English units)

or candelas per square meter (Metric units).

The term for what we actually see, which is

reflected illumination off of a surface.

Glossary definitions as defined by Architectural Lighting Magazine 2008.

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LUMENSLUMENSLUMENSLUMENS

ILLUMINANCEILLUMINANCEILLUMINANCEILLUMINANCE(FOOTCANDLES)(FOOTCANDLES)(FOOTCANDLES)(FOOTCANDLES)

LUMINANCELUMINANCELUMINANCELUMINANCE(REFLECTED LIGHT)(REFLECTED LIGHT)(REFLECTED LIGHT)(REFLECTED LIGHT)

Lighting TerminologyLighting Terminology

Efficacy

A metric used to compare light output to energy

consumption. Efficacy is measured in lumens per

watt. Efficacy is similar to efficiency, but expressed

in dissimilar units. For example, if a 100 watt light

source produces 9000 lumens, then the efficacy is

90 lumens per watt.

Lumens per watt.

Glossary definitions as defined by Architectural Lighting Magazine 2008.

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Lighting TerminologyLighting Terminology

Color Temperature

The color temperature is a specification of the color

appearance of a light source, relating to the color of

a reference source heated to a particular

temperature, measured by the thermal unit Kelvin.

The measurement can also be described as the

“warmth” or coolness” of a light source.

The outward appearance of the color of a light

source (i.e. warm or cool).

Glossary definitions as defined by Architectural Lighting Magazine 2008.

2700 K

2900 K

3000 K

3500 K

4100 K

6000 K

4200 K

INCANDESCENT

3000K FLUORESCENT

3500K FLUORESCENT

4100K FLUORESCENT

COOL WHITE

NOON DAYLIGHT

LOW VOLT HALOGEN

WARM

COOL

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Lighting TerminologyLighting Terminology

Color Rendering

A scale of the effect of a light source on the color

appearance of an object compared to its color

appearance under a reference light source.

Expressed on a scale of 1 to 100, where 100

indicates no color shift. A low CRI rating suggests

that the colors of objects will appear unnatural

under that particular light source.

The ability of a light source to render colors in

comparison to other light sources of a similar color

temperature.

Glossary definitions as defined by Architectural Lighting Magazine 2008.

Spectral Power DistributionSpectral Power Distribution

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Determining FactorsDetermining Factors

•Color Temperature

•Color Rendering

•Color Changing

•Light Output

(actual)

•Lumen Output

•Efficacy

•Distribution

•Dimmability

•Heat Production

•Fixture Compatibility

•UV Transmittance

•Code Compliance

•Energy Efficiency

•Accessorization

•Soft / Hard Edge

•Effect on People

•Initial Cost

•Operating Cost

•Replacement Cost

•Ease of

Maintenance

•Availability

•Lamp Life

•Physical Size

•Physical

Appearance

Other Factors…Other Factors…

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Other Factors…Other Factors…

Other Factors…Other Factors…

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Other Factors…Other Factors…

Naming a Light Source Naming a Light Source

(incandescent)(incandescent)

WATTS

100

40

60

50

75

50

SHAPE

A

A

G

PAR

PAR

MR

SIZE

19

15

30

20

30

16

ATTRIBUTES

IF

CL

WH

NFL25

NSP15

FL35

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Naming a Light Source Naming a Light Source

(fluorescent)(fluorescent)

WATTS

F017

F17

F032

F32

CF32

PL-T32

SHAPE

T

T

DT

SIZE

8

8

ATTRIBUTES

830

SPX30

835

SPX35

E/IN/827

827/X/4P

Lamp Data ComparisonLamp Data Comparison

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Lamp Data ComparisonLamp Data Comparison

Inverse Square Law

FC = CBCP / Distance Squared

50PAR30/HAL/NFL25

FC = 2300 / 36

FC = 63.8

50PAR30/CAP/IR/NFL25

FC = 2900 / 36

FC = 80.5

50PAR30/HAL/FL40

FC = 1300 / 36

FC = 36.1

50PAR30/CAP/IR/FL40

FC = 1600 / 36

FC = 44.4

Lamp Data ComparisonLamp Data Comparison

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Lamp Data ComparisonLamp Data Comparison

Light Source DistributionLight Source Distribution

DirectDirectDirectDirect IndirectIndirectIndirectIndirect Indirect / Indirect / Indirect / Indirect /

DirectDirectDirectDirect

DiffuseDiffuseDiffuseDiffuse

(general)(general)(general)(general)

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Layers of LightLayers of Light

� General (ambient)

� Task

� Accent

� Sparkle