The Built Environment CONS5C08. >>FACULTY OF TECHNOLOGY AND BUILT ENVIRONMENT Learning resources NZBC G7 Natural lighting NZBC G8 Artificial lighting

The Built EnvironmentCONS5C08

>>FACULTY OF TECHNOLOGY AND BUILT ENVIRONMENT

Learning resources

NZBC G7 Natural lighting

NZBC G8 Artificial lighting

NZS 6703 Interior Lighting Design

AS/NZS 1680 Industrial lighting tasks and processes

BBC - Rules of LightingUnitec FTBE - CONS 5C08

https://www.youtube.com/watch?v=lHk7yRu7_K4

https://www.youtube.com/watch?v=lHk7yRu7_K4


Definitions

Unitec FTBE - CONS 5C08


Natural lighting



Natural lighting



G7 / AS1



Figure 1



Figure 2


G7 / AS1


G7 / AS1


Figure 3


Table 1

Resene LRV valuesUnitec FTBE - CONS 5C08

http://www.resene.co.nz/swatches/index.php



Table 2


G7 / AS1


Figure 4



Photometry

Photometry - Study of radiation emitted from a source that is visible to the human eye

Radiometry - Study of all radiation emitted from a

source


Photometry

http://www.skepticalartist.com


Photometry

• Light is not measured in watts

• Watts is a measurement of electrical work, Volts x Amps

• Light is measured in Luminous Flux (Lumens)

• Different kinds of light bulbs use different amounts energy to produce the same amount of lumens


Luminous Flux

• Basic measurement of the perceived power of a light, adjusted for the human eye

9W LED =60W incandescent

650 Lumens


Luminous FluxSource Luminous flux (lumens)

37 mW "Superbright" white LED 0.20

15 mW green laser (532 nm wavelength) 8.4

1 W high-output white LED 25–120

Kerosene lantern 100

40 W incandescent lamp 325

7 W high-output white LED 450

18 W fluorescent lamp 1250

100 W incandescent lamp 1750


35 W xenon bulb 2200–3200


127 W low pressure sodium vapor lamp 25000

400 W metal-halide lamp 40000

https://en.wikipedia.org


Luminous Flux / Luminous Intensity

Luminous FluxRadiation emitted in all directions

Luminous IntensityRadiation emitted in one direction – Measured in Candela

1 Candela = lm/sr


Illuminance

Is the total luminous flux falling on a surface per unit area

Illuminance is the primary measurement the building code uses to regulate the amount of light required at

floor level.

Illuminance is measured in Lux = lm/m2


Luminance

Is the total luminous flux emitted from a surface

Luminance is measured in cd/m2

Typically used as a specification for monitors /TV’s/etc..

Artificial lighting

NZBC G8


Artificial lighting

Lux = 1 Lumen per m2


About 1/12th of a candle

So… 1 candle for every 12m2.Not much…



Lux Levels Different Scenarios



Light Temperature is measured in degree Kelvin.

Pure white light like that of the noon day sun is 5000K while cool temperatures are over 5000 and warm temperatures are lower than 5000.


G8 / AS1


Table 1


Table 1


Visibility of stair treads

ecoglo


http://www.youtube.com/watch?feature=player_embedded&v=WEKjZ1WFZrc#t=19

Lighting for Stairways


How much lighting?

The amount of lighting or the illumination level recommended for homes depends on the type of rooms and what activity goes on in those rooms.• The illumination level for seeing properly also depends

on age.• Most younger people can see as well with less light.• Most older people (60yrs +) may need up to twice the

usual recommended illumination level.


How much lighting?

The amount of lighting or the illumination level (illuminance) recommended for homes also depends on preferences.

• Some people may be happier with duller lighting in a living room.

• Or accept a lower illumination level for the sake of saving costs.

• Others may prefer more brightly lit rooms to create a feeling of warmth or attractive sparkling effects.

• Care to not over light which will result in glare.• Dimmers are useful for changing atmosphere in a room.


Recommended Illuminance

Living room General/overall lighting

50 lux

Reading 150 lux At/on the surface of the page

Sewing 300 lux At/on the surface of the page

If older than 60, or read or sew a lot

Double above values

Study General /overall lighting

150 lux

At desk 500 lux At the desk top

Kitchen General/overall lightingWork surface

300 lux

500 lux At the work surface


Reflectance levels

The amount of lighting also depends on the reflectance levels of the walls, floor and ceiling. The lighter the colours the higher the reflectance levels.

• Typical average room reflectance levels:• Ceiling - 70%• Walls - 30%• Floor - 15%


NZS 6703

• This standards gives recommended standard illuminance levels for all types of buildings and activities.

Resene Paint Tone LRV%

All Black Cool black 4

Aubergine Ultra deep 5

Blue Charcoal Ultra deep 6

GrasslandsNon-Skid ultra

deep 8

Scarlett Magenta 10

Half Tuna Light 18

Azure Light 22

Lemon Ginger Yellow 2 31

Quarter Sandstone White 39

Pristine Lavender White 44

Ash White 55

Haystack White 64

White Pointer White 74

White White 92Unitec FTBE - CONS 5C08

Natural Lighting

The amount of day lighting available on any given day depends on:

• Time of day• Season of year• Weather conditions• Latitude• Atmospheric composition


Light entering a room

The light entering a room depends on:

• Orientation of a building to the north sun• Size and location of windows• Transmittance levels of the glazing• Internal curtains/blinds used in the room• External shading controls used above the windows• Reflectance of the floor• Proximity of neighbouring buildings /trees


Sky illuminance

The luminance of the sky is 3 times brighter at the zenith than at the horizon.• Direct sunlight can give illumination levels as

high as 60,000 lux on the working plane inside buildings through windows.

• We need only 300 to 500 lux for good lighting.• Our eyes can adapt to the bright sunlight over

time but produces intolerable glare.


Daylight factor

The daylight factor is the percentage of illuminance at a point indoors of the illuminance received simultaneously by an unobstructed point outside under an overcast sky.

For example, if there were 25,000 lux available outdoors and 400 lux available at any given point indoors, then the DF for that point would be calculated as follows DF = 400/20,000 *100 or DF=1.6.

LEED – Require 2 for at least 75% of the work spacesBS 8206-2 requires 2 - 5


Unitec FTBE - CONS 5C08http://patternguide.advancedbuildings.net

Daylight factor

The interior daylight factor can be obstructed and thereby reduced by neighbouring buildings, trees, natural features…

The interior daylight factor is composed of 3 factors:

Sky component (SC)Externally reflected component (IRC)Internally reflected component (IRC)


Overcast days

Illuminance received from the sky varies greatly according to the sun and clouds.• However, the International Commission on

Illumination (CIE) has established a standard overcast sky as being 5000 lux.

• This assumes that a heavily overcast sky gives a total unobstructed illuminance at ground level of 5000 lux.

• Measurements show that between 8am and 5pm, the illuminance from the sky is 5000 lux for at least 85% of the day.


Glare

Glare is excessive contrast of brightness.• Excessive glare can make an area or activity unsafe as

people have reduced vision when partly closing their eyes to reduce glare.

• While we can adapt to glare it also reduces the environment’s colours and reduces aesthetic appeal.

• A good designer aims to balance light levels between being able to see to work efficiently and having a comfortable/non-glare environment.

• The glare index indicates the degree of discomfort.• NZS 6703 gives glare index tables.


Views

Most people prefer rooms giving views of:• scenery, • activity outside (esp. street from kitchens,

children play area), • weather change.

• It is unhealthy to live in a room without windows with views of the exterior on a long term basis. Cf. solitary confinement


Glass / glazing

Glazed windows don’t reflect all of the light arriving at their surfaces.• About 89% is transmitted through clean, clear

glass, with 8% being reflected and 3% lost in transmission.

• If glass is dirty or otherwise obstructed as diffused glass, tinted, heat reducing, double or triple glazed, the light transmitted is further reduced.


Glass –points to consider


Orientation aided by performance


Performance of different glass


Low-E glass


Soft Coat Low-E Glass


Hard Coat Low-E Glass


Transmittance values

Glazing type Transmitted Reflected/Absorbed

Plain clear glass 85% 15%

Tinted or heat absorbing 60% 40%

Diffusing 25% 75%

Clear double glazing 70% 30%



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The Built Environment CONS5C08. >>FACULTY OF TECHNOLOGY AND BUILT ENVIRONMENT Learning resources NZBC G7 Natural lighting NZBC G8 Artificial lighting