TheLightingHandbook ZumTobel

8/3/2019 TheLightingHandbook ZumTobel

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TThhee LLiigghhttiinngg HHaannddbbooookk



1st edition, July 2004

T h e L i g h t i n g H a n d b o o

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Chapter 1

Lighting fundamentals

Chapter 2

Recommended values for indoor and outdoor lightingNEW: Based on the new European standards

Chapter 3

Luminaires

Chapter 4

Lamps and ballasts

Chapter 6

Quickplan – Calculating luminaire quantities

Chapter 8Economic efficiency calculation

Chapter 5

Lighting and room management,

Emergency lighting

Chapter 9

Technical information

Chapter 10

Notes

Chapter 7

Lighting refurbishment


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What is light? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Basic parameters used in lighting . . . . . . . . . . . . . . . . 4 – 5

Luminous flux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Luminous intensity . . . . . . . . . . . . . . . . . . . . . . . . . 5

Illuminance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Luminance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

General quality criteria for lighting . . . . . . . . . . . . . . . . 6 – 7

The right light – traditional and new quality criteria . . 6

Illuminance – definition of terminology . . . . . . . . . . . 6 – 7

Glare – glare limitation . . . . . . . . . . . . . . . . . . . . . . 7

Lighting technology . . . . . . . . . . . . . . . . . . . . . . . . . . 8 – 9

Light colour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Colour rendition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Chapter 1

Lighting fundamentals



What is light?

Light is that part of the electromagnetic spectrum that is perceived

by our eyes.

By day we see in colour, while at night we can only see in shades

of grey.

Chapter 1 / 3

What is light? What does the human eye see?

105

100

10-5

10-10

Wavelength [m] Relative spectralbrightness perception

Television, VSW

Visible light

Medium waves

Radio waves

Microwaves

Infrared

Ultraviolet

X-rays

Gamma rays

1.0

0.8

0.6

0.4

0.2

350 450 550Wavelength [nm]

650 750

Wavelength [m]

Night Day


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Luminous fluxThe luminous flux describes

the quantity of light emitted

by a light source.

The luminous efficiency

is the ratio of the luminous

flux to the electrical power

consumed (lm/W).

It is a measure of a lamp’s

economic efficiency.

4 / Chapter 1

Basic parameters used in lighting

Luminous flux – Luminous intensity – Illuminance – Luminance

Luminous flux

Lumen [lm]

Luminance L

[lm/(sr*m2 )]=[cd/m2]

Illuminance E

Lux [lm/m2]=[lx]

Luminous intensity I

φ

Candela [lm/sr]=[cd]

I =φΩ

ΩL =

EL =

I

A

E =φ

A

Abbreviation: φ phi

Unit: lm lumen


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Luminous intensity

The luminous intensity

describes the quantity of light

that is radiated in a particulardirection.

This is a useful measurement

for directive lighting elements

such as reflectors. It is repre-

sented by the luminous inten-

sity distribution curve (LDC).

Abbreviation: Ι

Unit: cd candela

IlluminanceIlluminance describes the

quantity of luminous flux falling

on a surface. It decreases by

the square of the distance

(inverse square law). Relevant

standards specify the required

illuminance (e.g. EN 12464

“Lighting of indoor work-places” ).

Illuminance:

E(lx) = luminous flux (lm)

area (m2 )

Abbreviation: EUnit: lx lux

Luminance

The luminance is the only

basic lighting parameter that

is perceived by the eye.

It specifies the brightness of

a surface and is essentially

dependent on its reflectance

(finish and colour).

Abbreviation: LUnit: cd/m2


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General quality criteria for lighting

The right light – traditional and new

quality criteria

NEW

NEW

Quality criteriaQuality criteria

Sufficientillumination level

Appropriatecolour rendition

Harmoniousbrightness distribution

Glarelimitation

Avoidanceof reflections

Good modelling

Correct light colour

Personalcontrol

Light as an interiordesign element

Changinglighting situations

Daylight integration

Energy efficiency

TRADITIONAL

TRADITIONAL

Illuminance – definition of terminology

Each term corresponds to the new European standards

(see Chapter 2 / 2).

Illuminance maintenance value Em: Value that the illuminance

level must not fall below in the visual task area.

Visual task area: Illuminance levels are specified for specific

visual tasks and are designed for the area in which these may

take place. If the precise location is not known, then the whole

room or a specific working area is used to define it. The visual

task area may be a horizontal, vertical or inclined plane.

Area immediately surrounding the visual task area: Here

the illuminance may be one level lower than in the visual task area (e.g. 300 lx to 500 lx).

Maintenance factor: The initial value multiplied by the mainten-

ance factor gives the illuminance maintenance value. The main-

tenance factor accounts for the reduction in luminous flux from

lamps, luminaires and room surfaces in the installation, and can

be determined on a case-by-case basis.

The maintenance schedule (the cleaning and maintenance

intervals for the lamps and installation) must be documented.See also the chapter on “Economic efficiency calculation”.


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e f f e c t

r e m e d y

Chapter 1 / 7

Glare – glare limitationDirect glare Reflected glare

c a u s e• luminaires without glare

control

• very bright surfaces

• loss of concentration• more frequent mistakes

• fatigue

• luminaires with limitedluminance levels

• blinds

• reflective surfaces• incorrect luminaire arrangement

• incorrect workstation position

• loss of concentration• more frequent mistakes

• fatigue

• matching luminaire toworkstation (layout)

• indirect lighting• matt surfaces

relative illuminance (%)

operating time

150

125

100

75

50

25

initial

value

mainten-

ance

value

Maintenance value = maintenance factor x initial value


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Lighting technology

Under the new European standard for interior workplace lighting

EN 12464, (psychological) glare is assessed by the unified glare

rating method (UGR), which is based on a formula for glare.It takes account of all the luminaires in a system contributing to

the sensation of glare. UGR tables derived from this formula are

provided by the manufacturers for glare rating.

The Quickplan tables in Chapter 6 and the lighting catalogues

contain reference values for specific room sizes.

The UGR method takes account of all the luminaires in the

system that contribute to the glare sensation (2) as well as the brightness of walls and ceilings (1). It produces a UGR index.

The two methods – the one set out in DIN 5035 and the one

defined in EN 12464 – produce comparable results.

UGR limits (UGRL), that must not be exceeded:

≤ 16 Technical drawing≤ 19 Reading, writing, training, meetings,

computer-based work ≤ 22 Craft and light industries≤ 25 Heavy industry≤ 28 Railway platforms, foyers

UGR = 8 log 0,25Lb

L2

P2

(1) (2)

( )


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The previously used luminance limiting curve method defined in

DIN 5035 assesses the mean luminance of the luminaires over

a beam angle of 45° to 85°. The new European standard sets

UGR = 19 as the maximum permissible value for offices, which

is equivalent to the luminance limiting curve for 500 lx in Quality

class 1.

8 5 °

7 5 °

6 5 °

5 5 °

4 5 °

A

= 4

5 °

= 8

5 °

a h s

8 6 4 3 2 1

8

1 0

3

1 0

4

2

3

4

4

5

6

8

2

3

L u m i n a n c e

L i n c d / m 2

Q u a l i t y c l a s s

A 1 2 3

1 0 0 0

2 0 0 0

7 5 0

1 5 0 0

5 0 0

1 0 0 0

7 5 0

< 3 0 0

5 0 0

< 3 0 0

2 0 0 0

1 0 0 0

5 0 0

< 3

0 0

2 0 0 0

1 0 0 0

5

0 0

< 3 0 0

f o r n o m i n a l i l l u m i n a n c e ( l x )

U G R L

1 3

1 6

1 9

2 2

2 5

2 8


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Colour renditionColour rendition index Ra

Daylight

Incandescent lamp

Sodium vapour high-pressure lamp

≥ 90 80–89 70–79 60–69 40–59 20–39

Compact fluorescent lamp

Fluorescent lamp

Mercury vapour high-pressure lamp

Metal halide lamp

Light colour

The light colour describes the colour appearance of the light.

Colour temperature Appearance Associationww up to 3,300 K reddish warm

nw 3,300 K – 5,300 K white intermediate

tw above 5,300 K blue-ish cool

The light colour sets the underlying mood of the room!

Application examples:

Ra ≥ 90: colour inspection

Ra 80–89: offices

Ra 70–79: electronics industry

Ra 60–69: assembly work

Ra 40–59: fabrication shop

Ra 20–39: warehouses

8 40

Ra ≥ 80

Colour temperature 4,000 K (nw)

Display format on fluorescent lamps

Example 840:

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