Chapter 4 Flashcards
1
Q
- Lighting accounts for _________ of the electricity consumed in the _________ and ______and almost ___of total global electricity consumption.
A
20 to 25%, United States, Canada, 20%
2
Q
The fundamental reasons for providing light in a space are to make the objects in the space visible and to conduct activities that must take place in the space.
A
T
3
Q
- ______________provides the right quantity of ______, with excellent color ______ and minimal _______. ____________ has been shown to improve productivity and enhance worker satisfaction.
A
Good architectural lighting, light, rendition, glare, Quality lighting
4
Q
______ has played an important role in human activity throughout history. Up until the early part of the 20th century, people have relied on _________ and __________ such as wood, candle wax, whale oil, coal oil, coal gas, and kerosene but with the advent of _____ and ______________ communities started switching to the safer, cost-effective electricity powered lighting.
A
Light, natural lighting, flame sources, electricity, incandescent lamps
5
Q
the earliest known unit of illumination still used today.
A
Foot-candle
6
Q
a German chemist invented a more efficient _________ in _____ which was critical to the development of _______________.
A
Herman Sprengel, vacuum pump, 1865, incandescent light bulb
7
Q
first developed a working __________ using ___________ in ____________.
A
Joseph Swan, incandescent light bulb, carbon-filament lamp, February 5, 1879.
8
Q
- First announced the successful development of an
_____________ with a baked __________________ in _____________.
A
Thomas Alva Edison, incandescent lamp, carbonized cotton thread filament, Dec. 21, 1879.
9
Q
- First to develop a commercially feasible _________, a low cost lamp that could remain lit for a long period of time.
A
Thomas Alva Edison, electric light
10
Q
- _______, ___________ later known as ______________ powered incandescent streetlights and lamps in parts of London and later in New York which served as a model for future utilities.
A
Thomas Alva Edison, 1882, Edison Electric Light Company, Consolidated Edison Company
11
Q
- On __________, the ____________ became the first commercial utility to produce and transmit hydroelectric power.
A
August 26, 1895, Niagara Falls Power Company
12
Q
- In ______, ___________ introduced ___________, an electric light source that is more efficient than the ______________.
A
1939, General Electric, fluorescent lighting, incandescent lamp
13
Q
- Developed ________, ___________, and _________ that govern the design and construction of building lighting and electrical systems.
A
Professional Organization, technical standards, specifications and design techniques
14
Q
IESNA
A
Illuminating Engineering Society of North America
15
Q
LALD
A
International Association of Lighting Designers
16
Q
NEMA
A
National Electrical Manufactures Association
17
Q
ALA
A
The American Lighting Association
18
Q
- model code that specifies the minimum provision necessary for protecting people and property from the use of electricity and electrical equipment.
A
National Electrical Code (NEC)
19
Q
- applies to both the ________ and installation of ________________.
A
National Electrical Code (NEC), manufacture, electrical equipment
20
Q
Most municipalities and countries require that _______ and __________ electrical wiring conform to the ____. In some jurisdiction, certain NEC requirements are superseded by local requirements.
A
residential, commercial, NEC
21
Q
- Addresses energy consumption in commercial and high rise residential buildings.
A
ASHRAE/IESNA 90.1 (American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc./Illuminating Engineering Society of North America, Inc., Standard 90.1)
22
Q
- Sets minimum performance standards for building systems and components that have an impact on building energy consumption, including the building envelope, heating, ventilation and air-conditioning (HVAC) systems, and lighting.
A
ASHRAE/IESNA 90.1 (American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc./Illuminating Engineering Society of North America, Inc., Standard 90.1)
23
Q
- Design of a _____________ involves application of a blend between scientific principles, artistic skill, and design experience.
A
Elements of seeing; good lighting system
24
Q
- ______ is that branch of physics that relates to the properties of _____and the function of _____. It involves a study of the __________ and how it interacts with light.
A
Optics, light , vision, human visual system
25
The _________ of a human is composed of the ____, ________, and certain parts of the _______.
visual system, eye, optic nerve, brain
26
- The____ is the organ that allows human to sense light and produce electrical impulses that will be sent through the optic nerve to the brain.
eye
27
- The _____ is that part of the visual system where the impulses are processed.
brain
28
- The ____ functions much like a simple, very crude camera. Rays of light pass through the transparent ____ of the eye and through an opening called the _____.
eye, cornea, pupil
29
- The ____ surrounds the ____ and adjusts for the amount of light available. It opens and closes to control the quantity of light the ________ receives, much like the _______ on a camera opens and closes to limit the light to which the film is exposed.
iris, pupil, interior of the eye, aperture
30
- The _____ is a transparent ellipsoidal medium that changes _______, allowing it to bend and focus the rays of light entering the interior of the eye. The _____ thickens to focus rays of light from objects nearby and narrows to focus light from distant objects. The lens concentrates the rays of light on the ______, a membrane on the back of the eye.
lens, thickness, retina
31
The _______ is composed of nerve cells with photoreceptors that are shaped like rods and cones.
retina
32
- These ___________ do not discern color well, so dimly lit objects are perceived as being uncolored- that is, seen in shades of ____. The _______ that are shaped like _____ provide color vision and respond best to bright light.
photoreceptors, gray, photoreceptors, cones
33
- There are three different types of cone-shaped photoreceptors in the retina. Each type responds to one of the primary colors of light: ______, ______, and _______. In individuals with normal vision, the electrical impulses from each cone blend together to create the sensation of other colors. However, about 5% of the population, mostly males has defective color vision.
red, green, and blue
34
- _________ is the inability to distinguish colors. The most common form of color blindness is found on those individuals who have difficulty distinguishing red from green. Individuals who are completely red green color blind see yellows and blues normally, but have trouble differentiating reds and greens. They tend to see reds and greens as yellow. Individuals who are totally color blind see only black, white, and shades of gray.
Color blindness
35
Fundamental reasons for providing light in a space
To make the objects in the space visible and to conduct activities that must take place in the space
36
_ provides the right quantity of _, with excellent _ _ and _ _ . _____ has been shown to improve productivity and enhance worker satisfaction
Good architectural lighting provides the right quantity of light, with excellent color rendition and minimal glare. Quality lighting has been shown to improve productivity and enhance worker satisfaction.
37
This chapter introduces basic lighting terminology and the procedures of _ This presentation highlights material that acquaints the technician with basic design principles
simple lighting design
38
A Chronicle of Artificial Lighting
1. Light has played an important role in human activity throughout history
2. Up until the early part of the 20th century, people have relied on natural lighting and flame sources such as wood, candle wax, whale oil, coal oil, coal gas and kerosene
3. With the advent of electricity and incandescent lamps, communities started switching to the safer, cost-effective electricity powered lighting
39
The earliest known unit of illumination still used today
Foot-candle
40
______________- A German chemist who invented a more efficient __________ in ______which was critical to the development of incandescent light bulb
Herman Sprengel, vacuum pump, 1865
41
_________- First developed a working ______________ using ______________ in _________.
Joseph Swan, incandescent light bulb, carbon-filament lamp, February 5, 1879
42
____________- First announced the successful development of an incandescent lamp with a baked carbonized cotton thread filament in ___________
First to develop a commercially feasible ___________, a low-cost lamp that could remain lit for a long period of time
Thomas Alva Edison, December 21, 1879, electric light
43
(year) - ________________ later known as ______________ powered incandescent streetlights and lamps in parts of London and later in New York which served as a model for future utilities
1882, Edison Electric Light Company, Consolidated Edison Company
44
(date) - The ______________ became the first commercial utility to produce and transmit hydroelectric power
August 26, 1895, Niagara Falls Power Company
45
)year) -__________ introduced __________, an electric light source that is more efficient than the incandescent lamp
1939, General Electric , fluorescent lighting
46
Professional organizations related to building lighting and electrical systems
Illuminating Engineering Society of North America (IESNA)
International Association of Lighting Designers (LALD)
National Electrical Manufacturers Association (NEMA)
American Lighting Association (ALA)
47
Model code that specifies the minimum provisions necessary for protecting people and property from the use of electricity and electrical equipment
Applies to both the manufacture and installation of electrical equipment
Most municipalities and counties require that residential and commercial electrical wiring conform to the NEC
In some jurisdictions, certain NEC requirements are superseded by local requirements
Lighting installations powered by electricity must comply with this code
National Electrical Code (NEC)
48
Addresses energy consumption in commercial and high-rise residential buildings
Sets minimum performance standards for building systems and components that have an impact on building energy consumption, including the building envelope, heating, ventilation and air-conditioning (HVAC) systems, and lighting
ASHRAE/IESNA 90.1
49
Design of a good lighting system involves application of a blend between scientific principles, artistic skill, and design experience
Elements of Seeing
50
Branch of physics that relates to the properties of light and the function of vision
Involves a study of the human visual system and how it interacts with light
optics
51
Composed of the eye, optic nerve, and certain parts of the brain
Visual system
52
Organ that allows a human to sense light and produce electrical impulses that will be sent through the optic nerve to the brain
Eye
53
Number of ______ cycles per second
Expressed in units of _______.
Frequency, wave, hertz (Hz)
54
Most light sources emit _ composed of different wavelengths of light
electromagnetic radiation
55
Sunlight striking the earth's outer atmosphere is made up of _ (about 5%), __ (about 45%), and __ (about 50%) radiation
ultraviolet, visible light, infrared
56
Classifications of electromagnetic radiation spectrum
Cosmic rays
Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
TV waves
Radio waves
57
Visible light spectrum by color
Violet (380-450 nm)
Blue (450-495 nm)
Green (495-570 nm)
Yellow (570-590 nm)
Orange (590-620 nm)
Red (620-750 nm)
58
Part of the electromagnetic radiation spectrum that is capable of exciting the retina and ultimately producing a visual sensation
The wavelengths of electromagnetic radiation to which the human eye is sensitive
Visible light
59
The amount of light incident on (striking) a surface
Illuminance
60
How bright an object appears
The eye sees luminance as the light leaving an object, but the eye cannot see it without visible light reflecting off the object in the direction of the viewer
Luminance
61
The ratio of reflected light versus the light striking the surface
___________ occurs when light is reflected off a polished or mirror-like surface
Reflectance, Specular reflection
62
The ratio of light transmitted through a body to the light illuminating the surface
A _______________ transmits light without distorting the image
___________ is a type of translucent medium
_______________ is an example of a transparent medium
Transmittance, transparent body, Frosted glass, Ordinary window glass
63
Pigment colors
Magenta (purplish red), cyan (greenish blue), and yellow
64
Produces visible light in a very small range of wavelengths
Monochromatic light
65
Emits a fairly even distribution of all wavelengths of light
Chromatic light
66
Renders all colors evenly on a multicolored surface
White light
67
Renders different colors unevenly
Poor color quality light
68
Methods to rate color quality
Color Temperature
Color Rendering Index
69
Ability to distinguish fine details, necessary for tasks like reading, writing, etc.
Visual acuity
70
_ text on white background is easy to see due to high contrast in reflectance
Black
71
Light gray text on dark _ background is hard to see due to similar reflectance
gray
72
Device that generates light
Lamp
73
Categories of lamps
Incandescent
Gaseous Discharge
74
Provide light through ____________, the emission of light caused by heating the filament
Incandescent lamps, incandescence
75
Low-pressure
High-intensity discharge (HID)
Gaseous discharge lamps
76
Low-pressure discharge lamps
Fluorescent
Mercury vapor
Low-pressure sodium
77
High-intensity discharge lamps
Metal halide
High-pressure sodium
78
Complete lighting unit consisting of lamps, lamp sockets, lenses, refractors, louvers, ballasts, and housing
Luminaire
79
Luminaire without lamps
Light fixture
80
Generally used to describe a luminaire
Lantern
81
Measure of the perceived power of light, expressed in lumens
Luminous flux
82
SI unit of luminous intensity, the power emitted by a light source in a particular direction
Candela
83
Incandescent filament temperature
Ranges from 4600-6000°F (2300-3000 K)
84
Emit visible light by heating a filament to incandescence
Advantages: low cost, reliability, familiarity, good color rendition
Disadvantages: short life, poor efficacy
Incandescent lamps
85
Sodium (HPS)
Pressure
86
Internal
External
Lamp Types
87
Emit visible light as a result of heating; they incandesce
Incandescent Lamps
88
Also known as "Light Bulb" by the lay consumer
Incandescent Lamps
89
(year) -___________ introduced a commercially successful lamp and the basic design of incandescent lamp remained unchanged
1890s, Thomas Edison
90
Advantages of Incandescent Lamps
low lamp cost
reliability
familiarity
good color rendition
91
The ability to distinguish and interpret different wavelengths of visible light
Artificial and natural (daylight) light sources are composed of many wavelengths having varying magnitudes
An _____________ will selectively absorb different proportions of each of these wavelengths and reflect the remainder toward the viewer
Color perception, opaque object
92
A light source producing a blend of wavelengths that are evenly distributed across the light spectrum is perceived by the human eye as _ or normal light
white
93
Part of the visual system where the impulses are processed
Brain
94
The eye functions much like a _, very crude camera
simple
95
Surrounds the pupil and adjusts for the amount of light available
Opens and closes to control the quantity of light the interior of the eye receives, much like the aperture on a camera opens and closes to limit the light to which the film is exposed
Iris
96
Transparent ellipsoidal medium that changes thickness, allowing it to bend and focus the rays of light entering the interior of the eye
_________ to focus rays of light from objects nearby and _______ to focus light from distant objects
Concentrates the rays of light on the _______
Lens, Thickens, narrows, retina
97
Composed of nerve cells with photoreceptors that are shaped like rods and cones
_____________ do not discern color well, so dimly lit objects are perceived as being uncolored-that is, seen in shades of gray
Photoreceptors that are shaped like ________ provide color vision and respond best to bright light
Retina, Photoreceptors, cones
98
Three different types in the retina, each responding to one of the primary colors of light: red, green, and blue
In individuals with normal vision, the electrical impulses from each cone blend together to create the sensation of other colors
Cone-shaped photoreceptors, electrical impulses
99
Inability to distinguish colors
Most common form is found in those individuals who have difficulty distinguishing red from green
Individuals who are completely red-green color-blind see yellows and blues normally, but have trouble differentiating reds and greens
Individuals who are totally color-blind see only black, white, and shades of gray
Color blindness
100
-________
Form of energy known as __________
Travels as an ____________
Travels through the vacuum of space - unlike sound
Travels at _________
Light, electromagnetic radiation, electromagnetic wave, 300 000 km/s
101
Energy radiated in the form of a wave caused by an electric field interacting with a magnetic field
Result of the acceleration of charged particles
Categorized by wavelength and frequency
Electromagnetic radiation
102
Measured as the distance from one peak of one wave to the next wave
Expressed in meters or nanometers (1 nm = 0.000 000 001 meter or one billionth of a meter)
Wavelength
103
Most light sources emit _ composed of different wavelengths of light
electromagnetic radiation
104
Part of the electromagnetic radiation spectrum that is capable of exciting the retina and ultimately producing a visual sensation
The wavelengths of electromagnetic radiation to which the human eye is sensitive
Visible light
105
Red, green, and blue
Can be used in various combinations to produce any other color by adding color
When they are combined together, they produce white
Primary colors of light
106
Magenta (purplish red), cyan (greenish blue), and yellow
They are opposite to the primary colors of light
Primary colors of pigments
107
Composed of many wavelengths having varying magnitudes
Light sources
108
Selectively absorbs different proportions of each wavelength and reflects the remainder toward the viewer
Opaque object
109
Colors of objects
Violet or blue (absorbs all longer wavelengths, reflects shorter)
Magenta
Red
White
Violet
Cyan
Yellow
Green
110
Blend of wavelengths that are evenly distributed across the light spectrum
White light
111
Primary colors of light
Red, green, and blue wavelengths that can be combined to produce any other color
112
Pigment colors
Magenta (purplish red), cyan (greenish blue), and yellow
113
Produces visible light in a very small range of wavelengths
Monochromatic light
114
Emits a fairly even distribution of all wavelengths of light
Chromatic light
115
Renders all colors evenly on a multicolored surface
White light
116
Provide light through incandescence, the emission of light caused by heating the filament
Incandescent lamps
117
Low-pressure
High-intensity discharge (HID)
Gaseous discharge lamps
118
Complete lighting unit consisting of lamps, lamp sockets, lenses, refractors, louvers, ballasts, and housing
Luminaire
119
Luminaire without lamps
Light fixture
120
Generally used to describe a luminaire
Lantern
121
Measure of the perceived power of light, expressed in lumens
Luminous flux
122
SI unit of luminous intensity, the power emitted by a light source in a particular direction
Candela
123
Incandescent
Gaseous Discharge
Categories of lamps
124
Provide light through incandescence, the emission of light caused by heating the filament
Incandescent lamps
125
Emit visible light as a result of heating; they incandesce
Incandescent Lamps
126
Also known as "Light Bulb" by the lay consumer
Incandescent Lamps
127
Advantages of Incandescent Lamps
low lamp cost
reliability
familiarity
good color rendition
128
Emit visible light by heating a filament to incandescence
Advantages: low cost, reliability, familiarity, good color rendition
Disadvantages: short life, poor efficacy
Incandescent lamps
129
Threaded or pinned bases
Medium Base
Candelabra Base
Mogul Base
130
- familiar threaded base found with ordinary lamp up to 300 W.
Medium Base
131
- smaller threaded base used in ornamental lighting such as chandeliers.
Candelabra Base
132
- larger threaded base found on lamps that are 300 W or greater/
Mogul Base
133
Special use incandescent lamps
Long-life lamps
Rough service lamps
Plastic-coated lamps
Low-voltage lamps
134
Frequently called halogen lamps, a smaller, brighter, and more expensive version of incandescent lamp
Tungsten-Halogen Lamps
135
Contain high-pressure halogen gases such as iodine or bromine allow the tungsten filaments to be operated at higher temperatures and efficacies; higher advantages of better color rendition, more light output, and a longer life
Tungsten-Halogen Lamps
136
Generate intense heat and require adequate clearance and good ventilation for heat dissipation
Tungsten-Halogen Lamps
137
It cannot be touched by hand without depositing residual skin oils that substantially reduce the life of the quartz glass bulb
Tungsten-Halogen Lamps
138
Electricity passing through a gas such that it causes the gas to arc, it produces continuous light by passing electricity through a gas contained within the lamp, unlike incandescent lamps that produce light by getting a filament hot
Gaseous Discharge Lamps
139
are miniaturized fluorescent lamps, manufactured with integral ballast and a standard screw base that can be installed in a standard light fixture in place of incandescent lamps, designed as a substitute for standard size incandescent lamp
Compact Fluorescent Lamps (CFL)
140
comes in a variety of shapes, wattages, and Voltages, Straight-, circular-, and U-shaped tubes available, with the 48-in straight tube the most common
Fluorescent light fixture
141
are available in wattages of between 20 to 125 W and lengths of 6 to 96 inches
Fluorescent Lamps
142
have a variety of colors or temperatures such as Daylight, Cool White, Soft White, Warm White, and Deluxe Warm White that cover the color temperature range from 3000 to 6500 K, the ______ blend in a fluorescent lamp determines the color temperature and color rendering of the light emitted by the lamp
Fluorescent Lamps, phosphor
143
__________- ________ are the most popular, least expensive, and lowest quality phosphors
Fluorescent Lamps, Halo phosphors
144
are designed to operate at a specific air temperature, usually a surrounding air temperature of 77°F (25°C)
Fluorescent Lamps
145
is the ratio of light (the luminous flux, in lumens) emitted by a fluorescent luminaire to the total electrical power (in watts) required to operate the luminaire
Luminaire Efficacy Rating (LER)
146
Luminaire Efficacy Rating (LER) is the ratio of light (the luminous flux, in lumens) emitted by a fluorescent luminaire to the electrical energy consumed, including the _
ballast
147
_______ produce a very bright light by __________ when electrical current passes through a metal gas contained under high pressure in a glass bulb
HID lamps, discharging an arc
148
The gas is under higher pressure compared to fluorescent lamps
The lamp is physically smaller compared than that of the fluorescent lamp
The light emitted from HID lamps are more concentrated
HID Lamps
149
Common Types of HID Lamps
Mercury Vapor (MV) Lamps
Metal Halide (MH) Lamps
High-Pressure Sodium (HPS) Lamps
Low-Pressure Sodium (LPS) Lamps
150
The first commercially available HID lamps
High pressure MV lamps without color correction produce a blue-white light directly from their discharge arc
Constructed of an internal quartz tube enclosed in an outer glass envelope
A small amount of liquid mercury is sealed in an argon gas fill inside the quartz tube
After the warm-up period, the arc emits both visible and ultraviolet (UV) light
Phosphor coatings can be added to improve color rendition
Available in wattages ranging from 50 to 1000 W
Mercury Vapor Lamps
151
Constructed similar to MV lamps except that it has various metal halides added to mercury and argon in the glass fill
Offers much better efficacy and color rendition compared to MV lamps
Available in wattages ranging from 32 to 1000 W
Produce high levels of UV radiation that must be shielded by glass in the lamp or fixture
Use of metal halides increases luminous efficiency and improves color rendition
No phosphor is needed to produce a cool white color, but some may be added to improve rendering of oranges and reds
Metal Halide Lamps
152
Contain an internal arc tube made of a translucent ceramic material rather than quartz glass because of the high temperature (2350 °F/1300 °C)
Available in wattages ranging from 18 to 1000 W and vary more widely than other HID lamps in their efficacy and color quality
The arc tube is enclosed in an outer glass envelope like other HID lamps
A small amount of solid metallic sodium and mercury is sealed in a xenon gas fill inside the ceramic arc tube
High-Pressure Sodium Lamps
153
Produce a monochromatic yellow light consisting almost entirely of orange-yellow wavelengths
Constructed of a large sodium-resistant glass tube containing sodium and a neon-argon gas mixture
Excess sodium is contained in the arc tube because the glass may absorb or react with some of the sodium
The inner surface of the outer bulb is coated with a material that reflects infrared radiation but passes visible light
Full light output does not occur immediately when power is applied, there is a start-up time delay called _______ before the lamp reaches it peak output
A restart delay called the _______ time of one to several minutes is needed before the lamp reaches its peak output
Unlike fluorescent lamps, these generate full light output at low air temperatures, although a special ballast may be needed
Low-Pressure Sodium Lamps, strike time, restrike
154
Combine the luminous efficiency of an HID lamp with the good color rendering capability of an incandescent lamp
Have no start time and thus total luminous flux is available immediately
Color rendition is fair to good
Blended Lamps
155
Advantage: They are directly interchangeable with incandescent lamps and have a longer lamp life
Disadvantage: They cannot be dimmed
Mercury-Tungsten Blended Lamps
156
A blue or near-UV chip is coated with phosphor(s) to emit white light
Phosphor conversion
157
Light from multiple monochromatic LEDs (red, green, and blue) is mixed, resulting in white light
RGB systems
158
_ and HID lamps have some mercury content
Fluorescent
159
Vibration and shock resistant
No moving parts, no fragile glass, no mercury, no toxic gasses, and no filament
Not subject to sudden failure or burnout and have an exceptionally long life (50 000+ to 100 000 hours)
Gradually degrade in performance over time
Low voltage and cool to touch
Emit light in a specific focused direction, reducing the need for reflectors and diffusers that can trap light
Well suited for decorative and accent lighting such as that found in retail stores, theaters, and restaurants
LEDs
160
Illuminated signage used to provide clear directions for an emergency exit of building occupants
Exit Lighting
161
_________- A luminaire that is hang with a cord, chain, or tube that enables it to be suspended from a _____ or other support, _________ light over the entire space
Pendent
ceiling, broadcasts
162
__________- A luminaire where a _________ source directs its light to the ceiling, where it is reflected back to the space
Uplight
shielded light
163
_________- A luminaire that is usually attached to or recessed in the ceiling and emits a concentrated light ________
Downlight
downward
164
__________A type of downlight that is a recessed, canister-shaped luminaire with a shielded lamp that emits light downward
High Hat
165
_________Mounted above the ceiling or behind a wall or other surface so that any visible projection of light is insignificant
Recessed Luminaires
166
_________- Decorative, wall-mounted luminaires that provide ambient illumination, can direct light upward, downward, or in all directions
Scones
167
___________- Used in high-ceiling areas, 20 ft (6 m) or higher, that require uniform illumination, high wattage (200 W or more) to deliver light over long distances, fixture size is fairly large, about 2 ft (0.6 m)
High Bay Luminaires
168
__________- More compact, designed for use in low- to medium-ceiling areas, 12 to 20 ft (3 to 6 m), typically used for general illumination in offices, retail spaces, and loading dock areas
Low Bay Luminaires
169
___________- A luminaire that is designed to emit an intense, concentrated beam of light with usually no more than a 20° divergence (spread) from where it is directed
Spotlight
170
____________- A luminaire that emits an intense light that is broader than a spotlight and that is capable of being pointed in any direction
Floodlight
171
__________- Illumination where light received at the work plane or light illuminating an object is incident predominantly from a particular direction, spot, flood, and track lighting are common types
Directional Lighting
172
_____________- A directional lighting installation where luminaires are attached to and are moveable along a metal track
Track Lighting
173
____________- Lighting installation in which the light on the working plane or on an object is not incident predominantly from a particular direction, light is cast and disbursed over a large area
Diffused Lighting
174
___________- A lighting component such as a translucent glass refractor that redirects or scatters the light from a source
Diffuser
175
___________- Lighting installation where the light source is shielded by a panel that is parallel to the wall and attached to the ceiling, distributes light over the wall
Cornice Lighting
176
_______________- Uplighting installation where the light source is shielded by a ledge or recess with light dispersed over the ceiling and upper wall
Cove Lighting
177
__________- Lighting installation where the light source is shielded by a panel that is parallel to the wall at the top of a window
Valance Lighting
178
__________- Widely used for general lighting installations in buildings, __________________ are available in recessed, surface-mounted, or pendent style fixture designs, produce a diffuse light that is relatively glare free and visually comfortable
Fluorescent Lighting, fluorescent luminaires
179
Types of Fluorescent Luminaires
Lensed
Parabolic Louvered
Wraparound
180
Have a flat lens to diffuse the light
Lensed
181
Have parabolic-shaped reflectors and open louvers to direct the light downward
Parabolic Louvered
182
Have a lens that wraps around the lamps to diffuse and direct the light outward
Wraparound
183
_______ A linear luminaire constructed of an inverted metal trough that serves as a fixture for fluorescent lighting lamps, usually installed with the opening flush with the ceiling
Troffer
184
______________ can be incorporated in a luminous ceiling that is constructed of open fluorescent luminaires mounted above a translucent suspended ceiling, or used in a strip installation consisting of rows of bare-bone fixtures with exposed lamps
Fluorescent luminaires
185
- have a flat lens to diffuse the light.
Lensed
186
New Lamp and Luminaire Designs
Halogen and Compact fluorescent lamps
Metal Halide Lamp
High Pressure Sodium (HPS) Lamps
Low Pressure Sodium (LPS) Lamps
Incandescent, Halogen, and High-intensity Discharge (HID) lamps
187
- offer excellent lighting and solution to specific lighting problems
New Lamp and luminaire designs
188
Small, offer low maintenance, and have excellent light and color qualities
Halogen and Compact fluorescent lamps
189
Good color rendering qualities and work well in spaces with high ceiling
Metal Halide Lamp
190
Used when color rendition is not important such as factories and warehouse
High Pressure Sodium (HPS) Lamps
191
Rarely used in building interiors because they produce a monochromatic yellow light that renders even the most vibrant colors in the shade of yellow
Low Pressure Sodium (LPS) Lamps
192
Produce a very intense light, a direct view of the lamp can be extremely irritating, even with diffusion globes or lenses the light can be very intense
Incandescent, Halogen, and High-intensity Discharge (HID) lamps
193
Specific type of luminaries approved for areas such as paint spray booths, flammable chemical areas, refinement plants and corrosive areas, tested and listed by agencies like Underwriters Laboratory, Inc. (UL)
Hazardous Locations
194
Incandescent, compact fluorescent or HID lamps with a built-in reflecting surface, HID and Incandescent versions are made from a single piece of bowl-molded soft or hard glass, compact fluorescent versions may be one piece or designed so that the inner lamp can be replaced
Reflector Lamps
195
Incandescent lamp with an elliptically shaped reflector, particularly effective at increasing efficiency of baffled-down lights
Elliptical Reflector (ER) Lamp
196
May use an incandescent filament, halogen filament tube, or HID arc tube, is a pressed-glass reflector lamp that relies on both internal reflector and prisms in the lens for the control of the light beam
Parabolic Aluminized Reflector (PAR) Lamp
197
An advanced lighting technology that transports light from a single source over a distance to one or more light outlets, emits light evenly along the way, more costly than traditional lighting installations, used in decorations and gives healthy and safety benefits as it releases less ultraviolet energy and infrared, but is less energy efficient
Remote-Source Lighting Installations
198
Made from a single piece of bowl-molded soft or hard glass. Compact fluorescent versions may be one piece or designed so that the inner lamp can be replaced.
Reflector Lamp
199
Types of Reflector Lamp
Elliptical Reflector (ER) Lamp
Parabolic Aluminized Reflector (PAR) Lamp
200
Incandescent lamp with an elliptically shaped reflector. Particularly effective at increasing efficiency of baffled-down lights.
Elliptical Reflector (ER) Lamp
201
May use an incandescent filament, halogen filament tube, or HID arc tube, is a pressed-glass reflector lamp. Rely on both internal reflector and prisms in the lens for the control of the light beam.
Parabolic Aluminized Reflector (PAR) Lamp
202
An advanced lighting technology that transports light from a single source over a distance to one or more light outlets. Emits light evenly along the way. More costly than traditional lighting installations. Provides health and safety benefits by releasing less ultraviolet energy and infrared. Less energy efficient than conventional systems.
Remote-Source Lighting (RSL) Installations
203
Systems of Remote-Source Lighting (RSL)
Fiber optic RSL systems
Light pipe RSL systems
204
A set of reflectors, filters, and lenses to feed the light of fiber optic cables and a fixture to distribute the light at the point of illumination. The number of fixtures depends on the intensity of the light source.
Fiber optic RSL systems
205
A hollow tube with a reflective inner surface that directs light through the tube. The most common linings are __________ films and _________.
Light pipe RSL systems, prismatic films and mirrored surface
206
A graphical representation that illustrates the luminous intensity around the cross-section of a lamp or luminaire. It is a curve on a polar graph that shows the relative luminous intensity, in candela, around the lamp or luminaire. A cross-sectional map of intensity (candelas) measured at many different angles. It is a two-dimensional representation and therefore shows data for one plane only.
Candlepower (Candela) Distribution Curve
207
If the distribution of the unit is symmetric, the ______ in one plane is sufficient for all calculations. If the distribution of the unit is asymmetric, such as with ______ and fluorescent units, three or more planes are required.
curve, street lighting
208
Categories of Light Distribution Produced By Luminaires
Direct
Indirect
Semidirect
General diffuse/ direct-indirect
Highlighting
209
- 90 to 100% of the light is directed downward for maximum use
Direct
210
- 90 to 100% of the light is directed to the ceilings and upper walls and is reflected to all parts of a room or 90 to 100% of the light is directed downward for maximum use.
Indirect
211
- 60 to 90% of the light is directed downward with the remainder directed upward
Semidirect
212
- equal portions of the light are directed upward and downward
General diffuse/ direct- indirect
213
- beam projection distance and focusing ability to characterize this luminaire
Highlighting
214
- is excessive brightness in the field of vision that causes discomfort or, in extreme cases, produces a _______ from a temporary loss of vision. A _________ caused by luminance that is sufficiently greater than the luminance to which the eyes are adapted. ______ can be an irritant of or impediment to vision.
Glare
disability,
visual sensation, Glare
215
A rating of a lighting installation expressed as a percentage of individuals who, when viewing from a specified location and in a specified direction, will be expected to find it acceptable in terms of discomfort glare. In most spaces, the VCP should exceed 70%.
Visual Comfort Probability (VCP)
216
Types of Glare
Discomfort glare
Disability glare
Direct glare
Reflected glare
217
- causes visual discomfort without necessarily impairing vision.
Discomfort glare
218
- occurs when visibility is impaired from excessive brightness.
Disability glare
219
- occurs when excessive light enters the eye directly from a light source
Direct glare
220
- the result of light entering the eye after reflecting off a glossy surface. A common type is ______________: the reflection on a computer screen or on a glossy sheet in a magazine.
Reflected glare, veiling reflection
221
A zone above a 45° angle from the fixture's vertical axis. When light is emitted into the glare zone, direct glare and reflected glare are likely, so light emitted in the glare zone can cause visual discomfort.
Glare Zone
222
Positioning and selecting light fixtures that do not throw light in the ________ is a good way to reduce problems with ______.
glare zone, glare
223
In small spaces, _____ lighting techniques consisting of cornice, cove, and valance lighting installations diffuse light well and prevent _______.
indirect, glare
224
Uplights direct their light to the ______, where it is reflected back to the space, preventing ______.
ceiling, glare.
225
Properly designed _____ use ______ to prevent light from being thrown into the glare zone.
downlights, baffles
226
Most linear fluorescent fixtures use either a ___ or a louver to prevent direct viewing of the _______ so direct glare is prevented.
lens, lamps
227
Typically made from clear UV-stabilized plastics. ________ types include prismatic, batwing, linear batwing, and polarized lenses. White translucent diffusers are much less efficient than clear lenses, and they result in relatively low visual comfort probability. New low-glare lens materials are available for retrofit and provide high visual comfort (a VCP of 80 or more) and high efficiency.
Lenses,Clear lens
228
-Slats in a light fixture that create openings for emitting light. ________ provide superior glare control and high visual comfort compared with lens-diffuser systems. The most common application of ________ is to eliminate the fixture glare reflected on computer screens. ______________ (with 5 to 7 in cell apertures and depths of 2 to 4 in) provide a good balance between visual comfort and luminaire efficiency, reducing it to about 40%. A disadvantage of the deep-cell louver is that it adds 2 to 4 in to the overall depth of a luminaire.
Louvers, Deep-cell parabolic louvers,
229
Opaque or translucent elements that shield a light source from direct view. They are typically part of the light fixture. ______prevent the light source from throwing light beyond a 30° angle from the fixture's vertical axis, keeping the light from being broadcast into the glare zone.
Baffles
230
The amount of light incident on (striking) a surface.
Illuminance
231
The amount of light leaving an object, thus relating to how bright an object appears to the human eye. An object may be illuminated, but the eye cannot see it without visible light leaving (reflecting off) the object in the direction of the viewer. The ________ of a surface is equal to the reflected ___________.
Luminance,
luminance, illuminance
232
A unit of luminance, the luminous intensity of a surface in a given direction per unit of projected area of the surface.
Candela per square inch (cd/in²)
233
A unit of luminance, the luminance of a surface emitting one lumen per square foot.
Foot lambert (ft-L)
234
A unit of luminance, the luminance of a surface emitting one lumen per square cm.
Lambert (L)
235
1 cd/in² = ____ foot lamberts, 1 lambert = _____ foot lamberts = 2.054 cd/in²
452, 929
236
A unit of illuminance, the intensity of light falling on a surface. It is equal to one lumen of light uniformly illuminating a surface over an area of one square foot.
Foot-candle (fc)
237
The SI (metric) unit for illuminance, which is one lumen of light uniformly illuminating a one square meter surface (lm/m²).
Lux (lx)
238
One foot-candle is roughly equal to ___ lux: 1 fc = _______lx, 1 lx = 0.0929 fc
10, 10.764
239
Natural sunlight illuminates a surface _______ times more than light cast by a full moon on a ______.
100,000, clear night.
240
Typical Values of Illuminance for Selected Conditions
Light cast by full moon on clear night (0.1 fc, 1 lx)
Street lighting (1 fc, 10 lx)
Work space lighting (10 to 100 fc, 100 to 1000 lx)
Lighting for surgery (1000 fc, 10,000 lx)
Natural sun light on clear day (10,000 fc, 60,000 lx)
241
Large lighting installations that consume a lot of energy (electricity and cooling) or too much lighting that is not necessary in a building interior should be avoided as it is wasteful due to _________, maintenance, and ________.
higher investment, energy costs
242
Measured in foot-candles or in terms of lumens per square meter or lux.
Light Intensity
243
Measured in lumens.
Light Output
244
The recommended lighting level will be near the ______ level of the range when the size and/or contrast of the visual task is large and will be near the upper level of the range when the size and/or contrast of the visual task is ___.
lower, small
245
In general, recommended lighting levels ______ as the size and contrast of the visual task ________.
increase, decrease
246
Proper design of a lighting installation requires use of ___ calculating procedures: __________ from a point source and ________ illuminance levels
two, computing illuminance, computing average
247
The density of luminous flux, the intensity of light on a surface
Illuminance (E)
248
The intensity of light traveling away from a source
Decreases as it gets farther from the source
249
Spreads over a larger area as the plane (surface) being illuminated is held farther away from the light source
A beam of light
250
The illuminance of a surface
Decreases as the surface gets farther from the light source
251
States that the illuminance at a point on a plane perpendicular to the line joining the point and a source is inversely proportional to the square of the distance between the source and the plane
Inverse square law
252
States that illuminance (E) at a point on a plane is proportional to the cosine of the angle of light incidence, where the angle of light incidence is measured between the direction of the incident light and the normal to the plane of the surface
Cosine law of incidence
253
Average illuminance at a reference work plane
Target illumination
254
Usually horizontally positioned, at which work is performed and on which the illuminance is specified and measured
Work plane
255
The ______________ is the currently accepted method for calculating average illuminance levels for indoor areas unless the light distribution is extremely __________.
zonal cavity method, asymmetric
256
A room is made up of three spaces called_________. The space between the __________ and the work plane is referred to as the _______; the space between the work plane and
the floor is called the _________; and the space between the ceiling and the luminaires
(if they are suspended) is defined as the ____________.
cavities, luminairs, room
cavity, floor cavity, ceiling cavity
257
Once the number of ______ (#) required for uniform illumination has been
determined, the ________ must be arranged. Incandescent and HID ________
generally cast light evenly in all directions, which permits uniform spacing in even
rows and columns, although even rows and offset columns may be used. _________ generally require spacing that is __________ to
the _____ of the lamps versus ____ with the lamps. To ensure uniform
illumination of the work plane, luminaires cannot be spaced too far apart.
luminaires (3). Tubular
fluorescent luminaires, greater perpendicular, axis, parallel
258
An approximate maximum spacing-to-mounting
height ratio required to ensure uniform illumination on the work plane. It is used as
a conservative guide to determine maximum center-to-center luminaire spacing.
Spacing criterion (CS) ratio
259
- refers to a type of lighting that uses light emitting diodes LEDs, organic LEDs or polymer light emitting diodes PLEDs
Solid state lighting
260
-semiconductor that consists of a chip of semiconducting material treated to create a structure with two electron charged electros
Light Emitting Diodes
261
are based on aluminum gallium arsenide
Red LED
262
are from indium gallium phosphide
Blue LED
263
are from aluminum phosphide
Green LED
264
- sometimes called general lighting}
- provides uniform illumination throughout the space.
-Illumination for color and texture
Ambient Lighting
265
- sometimes called task lighting
- Illumination provided for specific visual function
- can influence the effectiveness of the individual performing the task
Local Lighting
266
-Is directional lighting used to emphasize a particular object or area
- emphasizing a particular architectural feature, piece of artwork, photograph, or plant
Accent Lighting
267
- light source that adds a quality of interest to the space
- combines with other types of lighting to give an overall "feel" to a room that serves little purpose other than to look attractive.
Decorative Lighting
268
Is a secondary lighting system that provides back up illumination when the power supply to the normal lighting system is interrupted.
Emergency and safety lighting
269
- required in the critical care and emergency spaces found in hospitals, police, fire protections and crisis management areas.
Emergency Lighting
270
- enables normal activities to continue substantially unchanged
-powered by an emergency generator or battery backup
Stand-by Lighting-
271
- ensures the safety of people involved in a potentially hazardous process
Safety lighting
272
- to ensure that an escape route can be effectively identified and used in case of failure of normal lighting system
Escape lighting
273
- illuminated signage used to provide clear directions for an emergency exit of building occupants.
Exit Lighting
274
If one assumes that one-quarter of the sunlight entering a daylighting system can effectively be used for daylighting, then an aperture of sunlight of about ___ is required - roughly __ of window or skylight area for every 100 of floor area
4% , 4
275
An area one hundred times greater than the area of captured sunlight will give an illuminance of 60 fc, an acceptable intensity for general lighting tasks
T
276
Illuminance of outdoor sunlight is _________
6000 fc
277
For most incandescent and HID luminaires, _ (S) is the center-to-center luminaire spacing
Spacing
278
_______________ is the distance between the plane of the luminaires and reference work plane
Mounting height (MH)
279
Power consumed for illumination (W) divided by the area (ft^2 or m^2) served by the lighting installation, expressed in W/ft^2 or W/m^2
Unit power density (UPD)
280
Limit on the unit power density for lighting installations in various space and function types, adjusted for lighting controls and daylighting
Power allowance
281
The _ standard stimulates use of more efficient lighting and reduces a building's cooling load by reducing waste heat
Power allowance
282
Electricity required for lighting would be cut by at least 50% with _ lighting
energy effecient
283
Energy efficient lighting _ annual carbon dioxide, sulfur dioxide, nitrogen oxide emissions and other forms of pollution
reduces
284
Both a science and an art, with no single correct lighting solution for all situations
The creative side helps make the space aesthetically interesting and psychologically comfortable
Architectural lighting design
285
A _ is uninteresting and wasteful compared to a classroom space lit with uplights, which provides a more comfortable seeing environment with less glare
conventionally lit classroom space
286
Main goals in designing aesthetically pleasing architectural lighting systems
Provide sufficient quantity of light to meet occupants' seeing needs without being excessive
Provide the appropriate quality (color rendition) of light
Provide a balance and variety to add interest to the space being illuminated
287
A non-uniform, balanced use of all types of architectural lighting, creating a composition quality that best suits good atmosphere within most spaces by blending color rendering and other properties of the different light sources
Layered light
288
The most essential form of lighting, providing the basic background of light for almost every room, often desirable to have the major ambient light source dimmable
Ambient lighting
289
Illuminates a specific visual function and can influence the effectiveness of the individual performing a task, focuses light in a particular direction or area without casting any glare
Task/local lighting
290
aesthetically adds interest to the space by blending with other types of lighting
Decorative lighting
291
The major light source in a space
Ambient light
292
Illuminates a specific visual function and can influence the effectiveness of the individual performing task
Task/ local lighting
293
Focuses light in a particular direction or area, without casting any glare
Task lighting
294
_ makes work easier
Good task lighting
295
Provided by wall-mounted fixtures
Used with permission or ABC
Ambient lighting
296
Used as task lighting over a conference table
Used with permission of ABC
Halogen accent lighting
297
Accent lighting used to add drama and emphasize a particular object or area
Accent lighting
298
Low voltage halogen are excellent applications
Picture lights focus attention on wall paintings of interest, up-lights, or cans of light on the floor shining upward, illuminate plants and sculptures
Aesthetically adds interest to the space by blending with other types of lighting to give an overall "feel" to a space
Decorative lighting may provide some ambient lighting, it serves principally as an eye-catching attraction
Use decorative lighting sparingly
Decorative lighting
299
Low voltage halogen are excellent applications
Picture lights focus attention on wall paintings of interest, up-lights, or cans of light on the floor shining upward, illuminate plants and sculptures
Accent Lighting
300
The____________ is the transitional space from public to private and exterior to interior
entrance or foyer
301
Lighting in _ should draw attention to the building entry
homes and commercial establishments
302
_ illumination is also important to make guests/occupants feel welcome and comfortable
Ambient
303
Reading and writing require quality lighting that limits eye fatigue caused from _
glare
304
This space can take advantage of a beautiful vista out the window and good natural ambient light daylight
jojowain
305
At night, an _________ light source should be provided to compensate for daylight
ambient
306
_ require special attention, soft indirect lighting is enough illumination and should be properly located so as not cause patterns on the screen
Computers
307
In restrooms and bathrooms, the best light washes the face from all directions, _ shadows
softening
308
There should be sufficient light to see detail for _ but not so much to cause glare and discomfort
grooming
309
Quality lighting can be accomplished within any design style because there is great _ in well engineered fixtures
variety
310
_ should make the food, the table setting, and the people look attractive, so excellent color rendition is a must
Lighting
311
Ambient lighting should be low to make the occupants sitting at the dining tables feel _
isolated
312
A center-pendent luminaire works well if not too obtrusive, a _ is very appropriate in formal dining, particularly in residences
chandelier
313
The light level from the center-pendent luminaire or _ should be indirect so it does not draw attention from other, more important views
chandelier
314
Ambient lighting should be _ to draw attention away from the occupants sitting at dining tables
low
315
A balance of accent lighting showing off artwork, a special sideboard, and the _ is very effective and desirable
table centerpiece
316
In the home, _ has become very important because this space has become a central focal point
kitchen lighting
317
As a gathering point and a place of special work, lighting must be a well-conceived part of the overall _
design
318
Inappropriate _ can make rich materials look dark and cause glare on shiny counters
lighting
319
_ and well-placed task lighting are the successful solution and the ability to control light levels is essential in the open-plan house
Ambient
320
In _, adequate, diffused lighting with good color rendition is a must
commercial kitchens
321
Building codes generally require that building exits be illuminated any time that the building is occupied, with light having an intensity of not less than _ at the floor/walking surface level
one foot-candle
322
_____ signage should safely mark exits or direct occupants to an exit where the route is not directly apparent
Exit
323
When two or more exits from a story are required by code (most commercial buildings), exit signs are required at stair enclosure doors, horizontal exits, and other required exits from the story
True
324
Each exit sign must have the word "EXIT" in plainly legible letters not less than __ in high nor less than ___ in wide
6, 3/4
325
Any door, passage, or stairway that is neither an exit nor a means of exit and that may be mistaken for an exit shall be identified by a sign reading, "NOT AN EXIT," or a _
a similar phrase
326
An exit sign shall be distinctive in color and decorations, interior finish, or other signs in must offer contrast with the space
T
327
Decorations, furnishings, _, or equipment cannot impair visibility of an exit sign
protrusions
328
_ sign guide occupants to an exit where the route is not directly apparent
Directional exit
329
A sign reading "EXIT" or a similar phrase, with an arrow indicating the direction, must be located at locations where the route to the _ exit is not apparent
nearest
330
A variety of switches and controls used to manage operation of lighting installations
Lighting system controls
331
An electrical device that opens an electrical circuit, thereby shutting the lights off or closing the circuit to energize the lighting installation
Switch
332
A simple on/off switch that controls a lighting installation from one location
Single-pole, single throw (SPST) switches
333
Can be circuited to control a lighting installation from two or more locations
Three-way switches (S3) and four-way switches (S4)
334
Deactivate the lighting circuit after a preset time period has lapsed
Automatic switches
335
Can be used to vary the luminous flux (lumen output) from lamps in a lighting installation
Dimmer switches
336
Limit access to switches for lights and equipment to authorized personnel
Keyed switches
337
Can activate a lighting circuit when a door is open or closed (e.g., similar to a refrigerator light)
Door switches
338
Automatically control operation of a lighting installation with electronic components wired into the circuitry
electronic timers
339
Sense light and can be used to control night lighting in lieu of a time clock or timer
Photocell controls
340
Control a lighting installation by sensing occupants in a space and usually mounted on the wall or ceiling
Occupancy sensors
341
Offers building operators full control of multiple lighting installations from a single location
Central lighting control system
342
Untitled
A central lighting control system controls the lighting installations in a building along with controlling _ equipment, fire protection and security systems, and other devices
HVAC
343
The advantage of a central lighting control system is that light circuits can be controlled in a _ that, on some systems, can be controlled remotely
remote location
344
Multiple switches that are connected together and controlled by a single switch
Ganged (multiple) key switched
345
Can activate a lighting circuit when a door is open or closed (e.g., similar to a refrigerator light)
Door switches
346
Automatically control operation of a lighting installation with electronic components wired into the circuitry. They allow great flexibility as they can easily be set for daily and weekly cycles
Electronic timers
347
_ timers require relay switching on larger lighting loads
Electronic
348
Common types of switches used in lighting installations
Photocell controls
Occupancy sensors
349
Sense light and can be used to control night lighting in lieu of a time clock or timer
Photocell controls
350
Control a lighting installation by sensing occupants in a space and usually mounted on the wall or ceiling. Works well in interior spaces such as classrooms and offices
Occupancy sensors
351
Offers building operators full control of multiple lighting installations from a single location. It controls the lighting installations in a building along with controlling HVAC equipment, fire protection and security systems, and other devices
Central Lighting Control system
352
Light circuits can be controlled in a remote location that, on some systems, can be controlled remotely off-site
Central Lighting Control System
353
_ is the efficient and effective use of direct, diffuse, or reflected sunlight to provide full or supplemental illumination for building interiors during hours of sunlight
Daylighting
354
_______ has excellent color rendition and brilliance, _ the need for artificial light in buildings and thus saves lighting costs up to 80% (in some buildings)
Sunlight, diminishes
355
Daylighting in buildings also typically decreases _ and cooling costs
space heating
356
Daylighting generally improves occupant comfort by providing a more pleasant, _
naturally lit indoor environment
357
Advantages of daylighting for the human eye
It tends to adapt more easily to daylight
The glazed surfaces needed for daylighting give the occupants a sense of contact with the outdoors
358
_ increases worker and student productivity, and reduces absenteeism
Daylighting
359
Daylighting has also been shown to contribute to______ in retail stores
higher sales
360
In factories, daylighting can reduce the loss of worker productivity during _
power failures
361
Travels in a straight path from the sun - more intense than diffuse and reflected sunlight
Direct light
362
Strikes a surface and reflects off the surface in another direction - the receiving surface absorbs some sunlight before reflecting the light
Reflected light
363
Is light that has been reflected or refracted by clouds, glazing, or other objects - less intense than direct and reflected light and typically results in less glare
Diffuse light
364
A measure of how easily heat travels through an assembly of materials. A higher R factor indicates better insulating performance
Overall Coefficient of Heat Transfer (U)
365
The fraction of solar heat that is transmitted through the glazing and ultimately becomes heat. The lower the SHGC, the less solar heat is transmitted through the glazing and the greater its shading ability
Solar Heat Gain Coefficient (SHGC)
366
The percentage of visible light (light in the 380 to 720 nm range) that is transmitted through the glazing. Low VT glazing such as bronze, gray, or reflective-film windows are more logical for office buildings or where reducing interior glare is desirable
Visible Transmittance (VT)
367
The ratio between SHGC and VT of a single glazing. It provides a gauge of the relative efficiency of different glazing types in transmitting daylight while blocking heat gains. The higher the LSG ratio the brighter the room is without adding unnecessary amounts of solar heat
Light-to-Solar Gain Ratio (LSG)
368
Types of glazing materials
Glass
Plastic
Glass and plastic combined
369
Ordinary window glass strongly absorbs the _ portion of sunlight, so a plastic material will survive longer if it is installed inside glass
damaging UV
370
Daylighting strategies
Increase the number and size of glazed areas in the walls or ceilings of a building, but simply using large glazed openings does not ensure good daylighting
Daylighting strategies
371
The main functions are to bring in daylight and fresh air (if windows are operable) and introduce a view of the outdoors
Windows
372
Describes window size, arrangement, and glazing type (the glass and coatings used in the window). It affects daylighting, passive solar heating, space cooling, and natural ventilation
Fenestration
373
A fenestration arrangement in an upper story wall that extends above one roof surface; it introduces daylight into the ceiling area of the space
Clerestory Window System
374
An interior courtyard covered with glazing. Rooms and spaces adjoining the atrium receive daylight entering through the glazed roof
Atrium
375
Clerestories and atriums are effective _ strategies
daylighting
376
The use of natural light to illuminate a building's interior
Daylighting
377
Bring in daylight and fresh air (if operable)
Introduce a view of the outdoors
Windows
378
Design term that describes window size, arrangement, and glazing type (the glass and coatings used in the window)
Fenestration
379
Elective daylighting strategies because they introduce daylighting deep into a structure
Clerestories and atriums
380
Fenestration arrangement of several smaller windows
Can provide uniform daylight illumination if properly distributed in the space being illuminated
381
Good distribution of daylight is difficult to achieve in _ rooms or in interior spaces without outside walls
large deep
382
In cold climates in the northern hemisphere, the low position of the sun
Produces a shallow angle and a heat gain that contributes to space heating
383
South-facing windows in the summer
Limit solar gains because the steep angle of the summer sun generally results in a net energy gain over the winter season in all but severe climates
384
A slanted south-facing window surface should be avoided because it gains heat all year long and is particularly poor at _ in the summer
limiting solar heat gains
385
Provide good quality daylighting, but excessive heat loss and resultant low temperature in the winter is a concern in cold climates
North-facing windows in the northern hemisphere
386
Transparent panels located in a roof opening that allow direct and diffuse sunlight into the building
Skylights
387
Commonly made from glass, glass composites, plastics, and plastic composites
Skylights
388
A type of skylight system that is a raised, typically triangular shaped, extension of a roof and that has at least one glazed surface
Roof Monitor
389
Installations with large skylights commonly suffer from excess brightness directly _ the skylight, accompanied by gloomy dark areas surrounding the skylight
below
390
Repetitive layout of small skylights provides uniform illumination within the space and requires _ alteration of the roof structure
less
391
_ design should include gutters to capture condensation that flows off the interior surface of the glazing
Skylight
392
Stepped windows and light shelves throw natural light deep into the building
Side lights and a roof monitor in the center of the ceiling throw natural light evenly
Naturally lit high school corridor area
393
Effective for many industrialized operations and warehousing applications
Can be used to provide a sense of natural ambience, which is valuable in applications such as restaurants, transportation centers, and other public areas
Can be effective for retailing because sunlight has excellent color rendition and brilliance
Skylights
394
Passive (non-mechanical) architectural elements or mechanisms that allow sunlight to enter deep into a building, located on the interior or exterior of the building envelope
Reflective Light Shelves
395
Properly designed light shelves allow daylight to penetrate the interior of the space up to _ times the distance between the floor and the top of the window
2.5
396
Examples of light shelves
Light shelves suspended by stainless steel cables
Fabric light shelves stretched over metal tubes
Assemblies of commercially available components created by ceiling manufacturers
397
Consist of an exterior, roof-mounted transparent dome, a reflecting metal pipe, and a diffuser for installation at the ceiling level of the space
Light Pipes
398
Can pass through attic spaces more easily
Flexible pipes are easier to install but suffer more light loss from increased light absorption from reflection and scatter on the inside surface of the pipe wall
Light Pipes
399
A type of light pipe that has a movable mirror or light-refracting system to align the incoming sunlight with the axis of the light pipe, minimizing reflection losses
Sun tracking light pipe
400
_ light reflecting apparatus of a sun tracking light pipe gets in the way of the whole sky when the sun is obscured, and there is a need for occasional maintenance
THE
401
Translucent fabric roof membranes that can be used to introduce daylight through the roof itself
Fabric Roof Membranes
402
Main uses for fabric structures
Sports stadiums
Shopping malls
Harbors
Airports (Denver International Airport)
403
May be divided into tension and air-supported membrane structures
Fabric structures
404
Commercially available fabric roof membranes
Polyvinyl chloride-polyester
Teflon-coated woven fiberglass
405
A second inner fabric liner is needed for _, sound control, and protection against condensation
insulation
406
Illuminance of outdoor sunlight is _ fc
6000
407
_ area one hundred times greater than the area of captured sunlight will give an illuminance of 60 fc, an acceptable intensity for general lighting tasks
:)
408
If one assumes that one-quarter of the sunlight entering a daylighting system can effectively be used for daylighting, then an aperture of sunlight of about 4% is required - roughly _ of window or skylight area for every 100 of floor area
4
409
- can be used to control the time period that a lighting installation operates.
Time clocks
410
- historically, only glass was used as a glazing material
-long life, high light transmission, hardness and stiffness.
Glass
411
- plastic glazings have become an alternative to glass
- much lighter in weight and are resistant to shattering, so they pose less of a safety hazard
Plastic
412
combined in a composite to minimize the limitations of each
Glass and plastic combined
