14
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:218
(RAY)
218-223_30056.indd 218 3/4/13 7:51 PM
218
THE INTERIOR DESIGN REFERENCE + SPECIFICATION BOOK
Text
Chapter 14: Artificial Light
Consider a strongly evocative interior space, one where the mood is immediately
striking, and chances are high that lighting played a central role in its design. In a
restaurant that is both cozy and contemporary, for instance, articial lighting will
inform the design features and the character of the space. Simple surfaces and
colors will have been selected to take best advantage of the light: Walls might be
a warm, buttery yellow, and mirrors and other reective surfaces used to throw the
focal glow of candles and soft light around the room.
Lighting design that creates a mood is based on an approach that is at odds with
lighting design that seeks evenly distributed and specic lighting levels. This kind
of “perfect” all-over task lighting may be appropriate for exible ofce space, but it
fails to produce an imaginative setting for most other human activities. By under-
standing the specic tasks intended for a space, however, the designer can readily
determine the appropriate lighting strategies that will integrate function and inspira-
tion into a design.
TYPES OF LIGHTING
Articial lighting is best examined according to the function it performs, typically described
as
space. Ideally, the ambient light source comes from different xtures that can be individually
controlled and dimmed depending on the time of day or amount of natural light available.
Accent lighting acts as a spotlight to illuminate a specic artwork, architectural detail, or piece
of furniture. Accent lights are typically low-voltage xtures that can be manually adjusted to
focus on a particular object. To avoid glare, the light source should be at a
the object.
Unlike ambient or accent lighting sources, chandeliers, wall scones, and lamps draw the eye
to themselves. These glowing objects serve as focal points in a room and, in fact, are often
referred to as
focal glow.
Task lighting provides light for a specic activity. In a typical ofce space, the light levels are
evenly distributed by a grid of uorescent xtures, but are usually supplemented with a task
light over each desktop. Different tasks require different lighting levels, for which there are
general recommendations. Lighting levels can be described in
how much light a lit candle would throw on a surface that is a foot away. The metric equivalent
is the lux.
RECOMMENDED LIGHT LEVELS
Task Area Foot-candles Lux
Kitchen
Reading or Writing
Classroom
Demonstration Lab
Computer Lab
Auditorium
Conference Room
Enclosed Ofce
Ofce Landscape
Corridor and Stairway
Arai Jackson Ellison Murakami, Veil Resaurant, Seattle; Studio Lumen, lighting design.
Photo by Richard Spry.
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:218
(RAY)
218-223_30056.indd 218 3/4/13 7:52 PM
14
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:219
(RAY)
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:218
218-223_30056.indd 219 3/4/13 7:51 PM
219
Text
a warm, buttery yellow, and mirrors and other reective surfaces used to throw the
of “perfect” all-over task lighting may be appropriate for exible ofce space, but it
standing the specic tasks intended for a space, however, the designer can readily
determine the appropriate lighting strategies that will integrate function and inspira
-
TYPES OF LIGHTING
Articial lighting is best examined according to the function it performs, typically described
as ambient, accent, focal, or task lighting. Ambient lighting is the general-purpose light in a
space. Ideally, the ambient light source comes from different xtures that can be individually
controlled and dimmed depending on the time of day or amount of natural light available.
Accent lighting acts as a spotlight to illuminate a specic artwork, architectural detail, or piece
of furniture. Accent lights are typically low-voltage xtures that can be manually adjusted to
focus on a particular object. To avoid glare, the light source should be at a 30-degree angle to
the object.
Unlike ambient or accent lighting sources, chandeliers, wall scones, and lamps draw the eye
to themselves. These glowing objects serve as focal points in a room and, in fact, are often
referred to as focal glow. Most successful lighting design solutions balance ambient light with
focal glow.
Task lighting provides light for a specic activity. In a typical ofce space, the light levels are
evenly distributed by a grid of uorescent xtures, but are usually supplemented with a task
light over each desktop. Different tasks require different lighting levels, for which there are
general recommendations. Lighting levels can be described in foot-candles, which measure
how much light a lit candle would throw on a surface that is a foot away. The metric equivalent
is the lux.
RECOMMENDED LIGHT LEVELS
Task Area Foot-candles Lux
Kitchen
20 215
Reading or Writing
25 270
Classroom
50 540
Demonstration Lab
100 1076
Computer Lab
30 323
Auditorium
10 108
Conference Room
30–50 323–540
Enclosed Ofce
50 540
Ofce Landscape
75 807
Corridor and Stairway
10 108
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:219
(RAY)
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:218
218-223_30056.indd 219 3/4/13 7:52 PM
14
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:220
(RAY)
218-223_30056.indd 220 3/4/13 7:51 PM
22 0
THE INTERIOR DESIGN REFERENCE + SPECIFICATION BOOK
Text
LIGHTING BASICS
Lighting is measured by the amount of luminous ux on a surface, called illuminance. It is ex-
pressed either in foot-candles (illuminance in a square foot) or in lux (illuminance in a square
meter). An articial light source is referred to as a lamp. Although lamps are commonly identi-
ed by their wattage, this does not describe the output of light. A watt is the measurement of
energy consumption from a particular light source. So an incandescent lamp and a uores-
cent lamp can have the same light output of foot-candles or lux, while ranging dramatically in
wattage. As an example, a 60-watt incandescent lamp has the same light output of a 15-watt
uorescent lamp.
Light coming from a single point source can, like direct sunlight, create dark areas of shadow
around the pool of light it provides. A point source calls attention to the surface it is illuminat-
ing and highlights its inherent characteristics. Diffuse light, like that on a cloudy day, distrib-
utes light evenly and is not strong enough to create shadows. While this even distribution of
light may be good in a working environment because it is easy on the eyes, it can seem a bit
dull and lifeless over time.
An unshaded lamp or poorly positioned xture with an exposed lamp can cause extreme
brightness from a light source called glare. While not measurable, glare is easily recognizable.
It can impair vision and induce discomfort as the eye usually squints to reduce the impact of
its harshness. Veiling reflection is another type of glare that is caused by the brightness of
a light source reecting off a shiny surface such as glass. A familiar example might be the
reection of a bright window on a computer screen. The well-thought-out distribution and loca-
tion of light xtures can reduce glare signicantly.
TYPES OF LAMPS
Many types of lamps are available, each with specic characteristics for color rendition, size,
energy consumption, and lamp life. Juggling all the variables can be complex. To specify
lamps correctly, designers should know their efcacy rating (1 = low/poor, 5 = high/excellent)
as well as their correlated color temperature and color rendering index.
warm neutral cool
1900–3450K 3500–3800K 4000–6500K
Correlated Color Temperature
Color Rendering Index (CRI)
poor good excellent
0 10 20 30 40 50 60 70 80 90 100
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:220
(RAY)
218-223_30056.indd 220 3/4/13 7:52 PM
14
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:221
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:220
(RAY)
218-223_30056.indd 221 3/4/13 7:51 PM
221
Articial Light
Text
. It is ex-
pressed either in foot-candles (illuminance in a square foot) or in lux (illuminance in a square
meter). An articial light source is referred to as a lamp. Although lamps are commonly identi-
ed by their wattage, this does not describe the output of light. A watt is the measurement of
cent lamp can have the same light output of foot-candles or lux, while ranging dramatically in
Light coming from a single point source can, like direct sunlight, create dark areas of shadow
around the pool of light it provides. A point source calls attention to the surface it is illuminat-
brightness from a light source called glare. While not measurable, glare is easily recognizable.
It can impair vision and induce discomfort as the eye usually squints to reduce the impact of
reection of a bright window on a computer screen. The well-thought-out distribution and loca-
Many types of lamps are available, each with specic characteristics for color rendition, size,
lamps correctly, designers should know their efcacy rating (1 = low/poor, 5 = high/excellent)
Efficacy: 1
Lamp Life:
750–1,000 hours
Ballast/Transformer: no
Start-to-Full Output: instant
Incandescent
Tungsten Halogen
Low-Voltage Halogen
Fluorescent Tube
Metal Halide
High-Pressure Sodium
Efficacy: 2
Lamp Life:
2,000–3,000 hours
Ballast/Transformer: no
Start-to-Full Output: instant
Efficacy: 2
Lamp Life: 2,000–4,000 hours
Ballast/Transformer: yes
Start-to-Full Output: instant
Efficacy: 5
Lamp Life: 18,000–24,000 hours
Ballast/Transformer: yes
Start-to-Full Output: nearly instant
Efficacy: 5
Lamp Life: 10,000–20,000 hours
Ballast/Transformer: yes
Start-to-Full Output: nearly instant
Efficacy: 5
Lamp Life: 10,000–20,000 hours
Ballast/Transformer: yes
Start-to-Full Output: 5–10 minutes
Efficacy: 5
Lamp Life: 24,000 hours
Ballast/Transformer: yes
Start-to-Full Output: 3–5 minutes
Compact Fluorescent
2600–3100K
100
3000K
95
3000K
95
3000–6000K
75–85
3000–5000K
75–85
6000K
65
2100K
65
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:221
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:220
(RAY)
218-223_30056.indd 221 3/4/13 7:52 PM
14
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:222
(RAY)
218-223_30056.indd 222 3/4/13 7:51 PM
22 2
THE INTERIOR DESIGN REFERENCE + SPECIFICATION BOOK
Text
yields white light. Varying combinations of the three colors can produce a full spectrum of
color options. LEDs have the additional advantage of producing no heat. Currently, LEDs are
used in interior design to create desired effects such as accenting a reveal or washing a wall
with colored light. As the technology advances, it will become more affordable and eventually
be applied to general purpose lighting.
LIGHTING TERMINOLOGY
Ballast:
and then reducing the current during operation.
Correlated Color Temperature (CCT):
Kelvins (K). The lower the temperature, the warmer the (yellow/red) tones; the higher the
temperature, the cooler the (blue) tones. Sunlight at dawn has a color temperature of
while a uniform overcast sky is
Color Rendering Index (CRI):
an object or surface. The higher the index, the more natural and vibrant the object appears.
Dimming Ballast:
dimmer control.
Efcacy, or Luminous Efcacy:
measures the number of lumens emitted per watts consumed (lm/W).
Low-voltage Lamp:
Luminance:
Transformer:
NEW LIGHTING TECHNOLOGIES
Although fiber-optic and LED lighting technologies have been around for a while, they are now
becoming more readily available to designers. Both lighting types are more energy efficient
than fluorescent lighting, but also much more cost prohibitive. As the market continues to
focus on energy efficiency, however, designers will see these technologies advance further
and become more affordable.
Fiber-Optic Lighting
This technology relies on strands of acrylic cables to transmit light from the light source,
called the illuminator, to the ends of the cables. The illuminator is simply a box with either a
tungsten halogen lamp or a metal halide lamp of varying wattages. Tungsten halogen lamps
are more common, while metal halide lamps are typically used for large installations. The
ends of the acrylic cable are gathered in a bundle and placed in an aperture directly in front
of the lamp. The illuminators should be conveniently located for easy access to relamp the
fixtures. It is also important to note that the illuminators need ventilation to release the heat
that is generated by the lamp.
Depending on the lighting design, there can be less than a handful of acrylic cables or hun-
dreds of cables. The length of the cables can vary per installation, but as a general rule they
should not exceed 50 feet (15 meters) or light transmission will be compromised. The advan-
tage of this system is that multiple lights can be located in difficult-to-access places, con-
trolled by a single lamp inside the illuminator.
LED Lighting
Although light-emitting diodes (LEDs) use a fraction of the electricity and last up to ten times
as long as uorescent lamps, they are too costly for use in general lighting. LEDs are available
in high intensities of red, green, and blue light, and the combination of all three colored lights
Incandescent Tungsten Halogen Low-Voltage Halogen Fluorescent Tube–cool
Comparative Correlated Color Temperature
Fluorescent Tube–warm
Job:02-30056 Title: RP-Interior Design Reference and Specification
#175 Dtp:216 Page:222
(RAY)
218-223_30056.indd 222 3/4/13 7:52 PM
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.