Light

Front 1

Electromagnetic radiation that the unaided human eye can perceive,having a wavelength in the range about 370 to 800mm and propagating at the speed of 186,281 mi/sec (299,9272 km/sec)

Back 1

light

Front 2

Unit length equal to one billionth of a meter use esp to expressed the wavelength to the light in or near the visible spectrum

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nanometer

Front 3

A unit of length equal to the ten billionth of a meter,used esp to express wavelength of radiation

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angstrom

Front 4

Pertaining to electromagnetic radiation having wavelength from about 370mm,immediately beyond the violet in the visible cspectrum,to 10mm ,on the border of the X ray region

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ultraviolet

Front 5

Pertaining to electromagnetic radiation having wavelength from about 800mm,contiguous to the red end of the visible spectrum ,to 1mm,on the border of the microwave region

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infrared

Front 6

The luminous flux emitted per unit solid angle by light source ,expressed in candelas

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luminous intensity

Front 7

Luminous intensity expressed in candelas

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Candle power

Front 8

A unit of luminous intensity use prior to 1948,equal to the luminous intensity of wax candle of standard specification

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Candle

Front 9

The basic SI unit of luminous intensity,equal to the luminous intensity of a force that emits monochromatic radiation of frequency by 540x10^12 hertz and has radiant intensity of 1/683 watt per steradian.also called standard candle

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Candela

Front 10

an angle formed by three or more planes intersecting at a common point

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solid angle

Front 11

a solid angle at the center of the sphere subtending an area on a surface equal to the square of the radius of the sphere

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steradian

Front 12

the rate of flow of visible light per unit time expressed iin lumens

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luminous flux

Front 13

the SI unit of luminous flux,equal to the light emitted in a solid angle of one steradian by a uniform point source having intensity of one candela

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lumen

Front 14

the law that the illumination produced on a surface by a point source is proportional to the cosine of the angle of incidense ,also called lumberts law

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cosine law

Front 15

one of the several laws relating two quantities such that one quantity varies inversely as the square of the other,as the law that the illumination produce on the surface by a point of source varies inversely as the square of the distance of the surface from source

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inverse square

Front 16

the sensaqtion by which an observer is able to distinguish between the differences in iluminance

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brightness

Front 17

the intensity of light falling at any given place on the lighted surface,equal to the luminous flux incidents per units area and expressed in lumens per unit of area,also called illuminanco

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illumination

Front 18

the SI unit of illumination equal to one lumen per square meter

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lux

Front 19

a unit of illumination on a surface that is everywhere one foot from a uniform point source of one candela and equal to one lumen incident per square foot

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foot candle

Front 20

the quantitative measure of brightness of a light source or an illuminated surface,equal to the luminous intensity per unit projected area of the source or surface viewed from a given direction

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luminance

Front 21

a unit of luminance or brightness equal to 0.32 candela per square centimeter

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lambert

Front 22

a unit of luminance or brightness equal to 0.32 candela per square foot

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foot lambert

Front 23

the striking of a ray of light or sound wave on a surface

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incidence

Front 24

the return of light ,sound or radiant heat after striking a surface

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reflection

Front 25

the angle that a straight line,such as aray of light falling on asurface ,makes it normal to the surface at the point of incidence

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angle incidence

Front 26

the angle that reflected ray makes with a normal to a reflecting surface at the point of incidence

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angle reflection

Front 27

the principle that when the light and sound is reflected from a smooth surface,the angle of incidence is equal to the angle of reflection,and the incident ray,the reflected ray,and the normal to the surface all lie in the same time

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law of reflection

Front 28

directed from a smooth polished surface

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specular

Front 29

a scattered reflection of light from an irregular surface or an erratic dispersion through a translucent material

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diffusion

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dispersed from an irregular surface

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diffuse

Front 31

the change of direction of a ray of light as it passes obliquely from one medium to another in which it velocity is different

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refraction

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the ratio of the radiation reflected by a surface to the total incident on the surface

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reflectance

Front 33

the ratio of the light or radiation reflected by a surface tp that incident upon it ,measured from zero for no reflecting power of a perfectly black surface to 1 for the perfect reflection of a white surface

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albedo

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the ratio of the radiation absorbed by a surface to the total incident of a surface

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absorptance

Front 35

the ratio of the radiation transmitted through and emerging from a body to the total incident on it,equivalent to one minus the absorptance

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transmittance

Front 36

the modulation of the light or sound waves as they bend around the edges of an obstacle in their path

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diffraction

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the angle that a refracted ray makes with a normal to the interface between two media at the point of incidence

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angle of refraction

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impenetrable to light

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opaque

Front 39

transmitting the diffusing light so that bodies on the opposite side are not clearly visible

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translucent

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cable of transmitting light so that bodies situated beyond or behind can be distinctly seen

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transparent

Front 41

any of various device for producing light .or ,heat ,as bt electricity ,or gas

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lamp

Front 42

a lamp in which a filament gives off light when heated to incandescence by an electric current ,also called light bulb

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incandecent lamp

Front 43

the glass housing of an incandescent lamp ,filled with an inert gas mixture,usually of argon and nitrogen,to retard evaporation of the filament,its shape is designated by better,followed by a number that indicates the lamp

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bulb

Front 44

the maximum diameter of lamp bulb,measured in eights of an inch

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lamp diameter

Front 45

the threadlike conductor of an electric lamp that is heated to incandescence by the passage of electric current

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filament

Front 46

the emission of visible light by a body when heated to a high temperature

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incandescene

Front 47

the dimension in inches from the base of a lamp to the point on the bulb farthest away or the based to base dimension of a lamp having a based at each end

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maximum overall length

Front 48

the distance in inches from the center of the filament of a lamp and reference plane on the lamp base

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light center length

Front 49

the lamp design for reduced energy consumption and a life longer then the conventionally set value for its general class,also called long life lamp

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extended service lamp

Front 50

a measure of effectiveness with which a lamp convert electric power into luminous flux,equal to the ratio of flux emitted to the power input and expressed lumens per watt

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efficacy

Front 51

the average life in hours of a given type of lamp,based on the laboratory test of a representative group under the controlled condition

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rated life

Front 52

an incandescent lamp having two filaments so that it can be switched to three successive degrees of illumination

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three way lamp

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the part of a lamp that connect to a lamp holder

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lamp base

Front 54

a device for mechanically supporting and marking electrical contact with a lamp,also called lamp socket

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lamp holder

Front 55

an incandescent lamp having a tungdten filament

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tungsten lamp

Front 56

a tungsten lamp having a quartz bulb containing a small amount of halogen at the vaporized on heating and redeposits any evaporate tungsten particle back in the filament .also called halogen lamp ,quartz lamp

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tungsten halogen lamp

Front 57

Tungsten halogen lamp having an infrared what dichroic coating for lifting infrared energy back to the filament, raising lamp efficiency and reducing radiant heat in the emitted light beam

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IR lamp

Front 58

candescent lamp having a higher percentage of its Indian power in the infrared region then a standard incandescent lamp, often having a red gas bulb to reduce the radiated visible light

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Infrared lamp

Front 59

quartz bulb for tungsten halogen lamps, similar in shape to the A bulb but having an angular profile

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TB bulb

Front 60

Multifaceted reflector bulb for tungsten halogen lamps, having highly polished reflectors arranged in discrete segments to provide a desired bean spread

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MR bulb

Front 61

Standard rounded shape for the bulbs general service incandescent lamps

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A bulb

Front 62

Flame shape bulb for low wattage, decorative incandescent lamp

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B bulb

Front 63

Cone shape bulb for low wattage decoritive incandescent lamp

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C bulb

Front 64

candle shape bulb for low wattage decorative incandescent lamps

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CA bulb

Front 65

Reflector bulb of blown glass for incandescent in high intensity discharge lamp, having an internal reflective coating in either a clear or frosted glass front to provide the desired beams spread

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R bulb

Front 66

Parabolic aluminized reflector bulb of course. For incandescent in high intensity internal reflector and lense front to provinde Atlantic8 front to provide a desired beam spread

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PAR bulb

Front 67

an ellipsoidal reflector bulb for the incandescent lamps,having the precised form internal reflectors that collects light and redirects it into dispersed pattern at some distance in from of the light source

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ER bulb

Front 68

an A bulb having hemispherereflective silver bowl opposite at the lamp base to decrease glare

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A/SB bulb

Front 69

a globe shape bulb for incandescent lamps,having a low brightnees for exposed use

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G bulb

Front 70

a pear shape bulb for large incandescent lamps

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PS bulb

Front 71

a striaght sided bulb for low wattage decorative incandescent

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S bulb

Front 72

a device for maintaining the current through a flourescent or HID lamp at the desired constant value ,and some times also providing the required starting voltage

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ballast

Front 73

a device use with a ballast to provide the sarting voltage fpr a preheay flourescent lamp

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starter

Front 74

a tabular bulb for flourescent,incandescent ,and high intensity discharge lamps

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T bulb

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a doughnut shape flourescent lamp for circular luminaires

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circline lamp

Front 76

a U shaped flourescent lam for square or rectangular luminaires

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U bent lamp

Front 77

any of various small, improve efficiency,flourescent lamps having a single ,double ,U shape or spiral tube and either an edison screw base or an adapter for fitting an incandescent lampholder ,compact flourescent emit a similar amount of visible light,useless power and have a longer rated life than the incandescent lamps they are designated to replace

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compact flourescent lamp

Front 78

any of a number of substance that emit light when excited by radiaton

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phosphor

Front 79

a phosphor having peaks in three specific color regions ,red ,blue and green used improved the color rendering of a flourescent lamp

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triphosphor

Front 80

a lamp in which light is produced by discharge of electricity between electrodesin a gas filled glass enclosure

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discharge lamp

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the emission of radiation esp of visible light by a substance during exposure to external radiation

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flourescent lamp

Front 82

a flourescent lamp that requires a separate starter to preheat the cathodes before opening the circuit t the starting voltage

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preheat lamp

Front 83

a flourescent lamp designed to operate with a ballast having a high voltage transformer to initiate the arc directly without any preheating of the cathodes

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rapid start lamp

Front 84

a rapid start flourescent lamp designed to operate on current of 800 milliamperes resulting in a corresponding increase in luminous flux per unit length of lamp

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high cutput lamps

Front 85

a rapid start flourescent lamp designed to operate on a current of 1500 milliamperes providing a correseponding increase in luminous flux per unit lenght of lamp

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very high output lamp

Front 86

a measured of the ability of the elctric lamp to render color accurately when compared with a reference light source of similar color temperature,a tungsten lamp operating at a color temperature of 3200°k,noon sunlight havng the color temperature of 4800°k average daylight having the color temperature of 7000°k all have an index of 100 and ae considered to render a color perfectly

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color rendering index

Front 87

the temperature at which black body emits light or a specified spectral distribution used to specify the color of light source

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color temperature

Front 88

a curve plotting the radiant energy in each wavelength of a particular light source

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spectral distribution curve

Front 89

a cold cathode. lamp emitting a glow whe hig voltage is appliec across two electrodes in neon filled glass tube

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neomn lamp

Front 90

a discharge lamp having cathodes that emit electrons without having to be heated

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cold cathodes lamp

Front 91

a bulged tabular bulb for high intensity discharge lamp

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Bt bulb

Front 92

an ellipsoidal bulb for high intensity discharge lamp

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E bulb

Front 93

a discharge lamp in which a significant amount of light is produce by the discharge of electricity through a metallic vapor in a sealed glass enclosure also called HID lamp

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high intensity discharge lamp

Front 94

a high intensity discharge lamp producing light by means of an electric discharge in mercury vapor also called mercury vapor lamp

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mercury lamp

Front 95

high intensity discharge lamp producing light by means of electric discharge in sodium vapor also called sodium vapor lamp

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sodium lamp

Front 96

a sodium lamp producing a yellow glueless light and used esp to illuminate roadways,also called LPS lamp

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low pressure sodium lamp

Front 97

a sodium lamp producing a broader specturm golden white light than alow pressure sodium lamp,also called HPS lamp

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high pressure sodium lamp

Front 98

a high intensity discharge lamp simila in construction to a mercuy lamp but having an arc tube to which various metal halides are added to produce more light and improve color rendering

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netal halide lamp

Front 99

a fully assembled light fixture utilizing LED lamps and equipped with a compact LED drivers for connecting to 110-240v power source

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LED fixture

Front 100

a flexible or rigid linear module with a very low porfile ,surface mounted LEDs used for the edges lghting displays lighting and cove lighting

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LED strip

Front 101

an LED lamp designed to serve as a replacement for traditional T8/T10/T12 flourescent tubes

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LED tube

Front 102

the light provided by lighting diode LED lamps in various form factors,such as light strips,bulbs,tubesand fixgures

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LED lighting

Front 103

semi conductor device consisting of two materials, one having a surplus of positive charge and the other surplus of negative charge that when combined at a junction ,releases light energy as a forward voltage is applied

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light emitting diode

Front 104

a solid state,low voltage electric lamp that uses light emitting diodes LED as the source oc light LED lamps offer low power consumption ,long rated life ,compact sized durability and reliability but because of eir relative low lumen output and low color rendering index,they must be groupec or custer in suitable housing to attaing the equivalent whit light of CFLs and incandescent lamps ,various forms of LED lamps are available to serve as a replacement for incandescent and halogen bulb and for flourescent tubes

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LED lamp

Front 105

an LED lam design t o be interchangeable with incandescent and halogen lamp in existing luminaires ,consisting of a group or cluster of high power LED housed in standard bulb shapes with bases that fit normal sockets,high power LEDs generate heat ,which must be dissipated through the use of heat sink and cooling fins

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LED bulb

Front 106

a power supply designed to deliver a constant current source for LED lamp over a range of load voltage ,sometimes LED drivers also offer thermal protection ,DC voltage and dimming by means of pulse width modulation (pwm)circuits

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LED drivers

Front 107

a surface for reflecting light,heat ,or sound esp the device on a luminaire having such a surface for controlling the distribution of light emmitted by a lamp

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reflector

Front 108

Piece of transparent materials such as glass or plastic having two apposite surface either or both of which are curve, use in luminaires the full course, disperse or collimate the emitted light

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Lens

Front 109

lens having concentric ,prismatic grooves to consentrate light from a small source

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Fresnel lens

Front 110

lens having a multifaceted surface with parallel prism to redirect a rays from the light source

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prismatic lens

Front 111

finned or vaned device for controlling the radiation from a light source

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louver

Front 112

Louvered construction divided into cell like areas and used for redirecting the light emitted by an overhead source

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Egg crate

Front 113

Louvered device for shielding a light source from view at certain angles

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Buffle

Front 114

Angle below with a light source can be seen

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Shielding angle

Front 115

Series of circular Ridge for reducing the brightness of a light source at an aperture

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ridges Buffle

Front 116

the ratio of luminous flux emitted by a luminaire to the Lord to the total flux emitted by the lamps in the luminaire

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Luminaire efficiency

Front 117

The light unit consisting of one or more electric lamps with all of the necessary parts in wiring for positioning in protecting the lamps connecting the land to a power supply in distributing the light. Also called lighting fixture

Back 117

Luminaire

Front 118

Reflector having a parabolic surface to collimate, spread or focus the rays from a light source, depending on the location of the source

Back 118

Parabolic reflector

Front 119

To make rays of light parallel

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collimate

Front 120

Reflector having an elliptical surface to forward the race from a light source

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elliptical reflector

Front 121

Any of variety of translucent material for filtering glare from a light source in distributing the light over an extended area

Back 121

Diffuser

Front 122

Polar plot of the luminous intensity imitated by lamp, luminaire or window in a given direction from the center of the light source,

Back 122

Candle power distribution curve

Front 123

Graphic plot of the pattern of illumination reduce on the surface by a lamp or luminaire

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isochart

Front 124

line through old points on a surface where the level of elimination is the same. Call isofootcandle line if illumination is expressed in foot candles

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isolux line

Front 125

downlight mountain close to the panel of the wall, is equipped with a reflector, buffle Or lens to illuminate of vertical surface

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Wall washer

Front 126

lamp designed to project or diffuse a comparative uniform level of illumination over a large area. Also called flood, flood lamp

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Floodlight

Front 127

Luminaire consisting of lamp set in a metal cylinder, recessed into or mounted on a ceiling the direct a beam of light downward

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Downlight

Front 128

Lamp designed to project a strong, focus beam of light on an object or area. Also called spot

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Spotlight

Front 129

Superflous are useless light rays I just form a spotlight or another focused Light Source . also called spill light

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Spill

Front 130

Lighting provided by adjustable spotlights mounted along in a row, ceiling or wall mounted metal tracks through which current is conducted

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track lighting

Front 131

indirect lighting directed upward from an interior cornice at the edge of a ceiling

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cove of lightning

Front 132

Regent of flexible kid with the exposed low voltage light source of 1 to 10 watts . Also called light tape

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Light strip

Front 133

Light source having one dimension significantly greater than its other dimensions such as fluorescent lamps

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linear source

Front 134

Indirect lighting directed upward or downward from a light source concealed by a horizontal board or band

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Valence lighting

Front 135

Indirect lighting directed downward from an interior cornice at the edge of a ceiling

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Cornice lighting

Front 136

Luminaire having a trough shape reflector holding one or more fluorescent lamps

Back 136

troffer

Front 137

Light source having significant dimension in two directions, such as large window or luminous ceiling

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area source

Front 138

lighting fixture suspended from a ceiling or wall by a flexible cord by which it can be raised or lowered

Back 138

drop light

Front 139

lighting fixture suspended from the ceiling

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Pendant

Front 140

A floor lamp having the light source on the hinge horizontally adjustable arm

Back 140

Brige lamp

Front 141

desk lamp having a flexible shaft resembling the neck of English

Back 141

Gooseneck lamp

Front 142

The floor having its light source within a reflecting bowl that directs the light upward. Also,torchee,torchier

Back 142

torchiere

Front 143

Decorative lighting fixtures suspended from a ceiling usually having branch supports for a number of lamps

Back 143

chandelier

Front 144

Decorative wall bracket for candles or other lights

Back 144

scone

Front 145

Science, theory or method of providing illumination through the use of electric lamps

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Lighting

Front 146

Lighting designed to provide a uniform level of illumination throughout an area

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General lighting

Front 147

Lighting designed to provide a relatively high level of illumination over a small area, with a surrounding area of a lower intensity from spill light

Back 147

Local lighting

Front 148

Lighting. Calls attention to a particular object or feature in the visual field or that forms a decorative pattern on a surface

Back 148

Accent lighting

Front 149

To emphasize by illuminating with a strong light

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highlights

Front 150

To illuminate something from behind in order to enhance depth or to separate the subject from its background

Back 150

Backlight

Front 151

lighting coming or produced from the side

Back 151

Sidelight

Front 152

Diffused light that produce little contrast in poorly defined shadow on the subject

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Softlight

Front 153

Direct light that produces high contrast and distinct shadow on the subject

Back 153

Hardlight

Front 154

Lighting designed to provide strong illumination for visually demanding activity such as reading or sewing

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tasklighting

Front 155

Lighting in which Lumineers distribute 90% to 100% of the emitted light downward on the surface or area to be illuminated

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Direct lighting

Front 156

Lighting in which Lumineers distributed 60% to 90% of the emitted light downward

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semidirect lighting

Front 157

Lighting from luminaires that Emitted an approximately equal distribution of light upward or downward

Back 157

General diffuse lighting

Front 158

General diffuse lighting in which little light is emitted in the horizontal plane of the luminaire

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Direct indirect lighting

Front 159

Lighting in which luminaires distributed 60% to 90% of the emitted light upward

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Semi indirect lighting

Front 160

Lighting in which Lumineers distribute 90% to 100% of the emitted light upward especially to avoid glare or prevent shadow

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Indirect lighting

Front 161

The sensation produced by any brightness within the visual field that is sufficiently greater than the luminance to which the eyes are adapted to cause annoyance , discomfort or loss of visibility

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Glare

Front 162

The regulating by the Pupil if the quantity of light entering the eye, resulting in a change in the sensitivity of the eye photoreceptors to light

Back 162

Adaptation

Front 163

rating of the likelihood . at a lighting system will not caused directly, expressed as a percentage of people who may be expected experience visual comfort when seated in the least favorable visual position

Back 163

Visual comfort probability

Front 164

The ratio between the luminance of an object and its background. Also called contrast ratio

Back 164

Brightness ratio

Front 165

The ratio between the luminance of an object in the office background. Also called contrast ratio

Back 165

Brightness ratio

Front 166

glare so intense that, for an appreciable length of time after it has been removed, visibility is lost

Back 166

Blind glare

Front 167

Glare at the juices visibility or in pairs visual performance, often accompanied by discomfort

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Disability glare

Front 168

Glad that produces discomfort but does not necessarily interfere with disability or visual performance

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Discomfort glare

Front 169

Glare resulting from a high brightness ratio or an insufficiently shielded light source in the visual field

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direct glare

Front 170

Glare resulting from the specular reflection of a light source within the visual field. Also called indirect glare

Back 170

Reflected glare

Front 171

Reflected glare on a task surface that reduces the contrast necessary for seeing details

Back 171

veiling reflectance

Front 172

The angle of a light beam that intersects the candle power distribution curve at points where the luminous intensity equal a stated of the maximum reference intensity

Back 172

Beam spread

Front 173

Formula for determining so far apart Luminaire may be installed for uniform lighting of the surface or area, based on mounting height

Back 173

spacing criteria

Front 174

A procedure for calculating the illumination produced on a surface by a point source for an angle, based on the inverse square and cosine law

Back 174

Pointed method

Front 175

Group of nearly parallel rays of light

Back 175

beam

Front 176

the effective length of a beam of light

Back 176

Throw

Front 177

Cavity formed by the ceiling, a plane of suspended luminaires in the wall surface between these two planes

Back 177

Ceiling cavity

Front 178

Cavity formed by a plane of luminaires , the word plane in the wall surfaces between these two planes

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Room cavity

Front 179

The cavity formed by the word plane, the floor in the wall surfaces between these two planes

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Floor cavity

Front 180

Single number that derived from the dimensions of the room cavity for use in determining the coefficient of utilization

Back 180

room cavity ratio

Front 181

The ratio of the luminous flux reaching a specified work plane to the total lumen output of a luminaire, taking into account the proportions of a room in the reflectances of its surfaces

Back 181

Coefficient utilization

Front 182

Any of several factors in calculating the effective of illumination provided by a lighting system after a given. Of time and under given conditions. Formerly called maintenance Factor

Back 182

light loss factor

Front 183

Weight loss factor that may be recovered by relamping or maintenance such as a lamp lumen depreciation, luminaire dirt depreciation and room surface dirt depreciation

Back 183

recoverable light loss factor

Front 184

Procedure for determining the number and types of lamps, luminaires, or window required to provide the uniform level of illumination on a work plane, taking into account both direct and reflected luminous flux. Also called zonal cavity method

Back 184

Lumen method

Front 185

horizontal plane at which work is done in on which illumination is a specified and measured usually assume to be 30 inches or 762 mm above the floor

Back 185

Work plane

Front 186

light loss factor representing the decrease in luminous output of a lamp during its operating life, expressed as a percentage of initial lamp lumens

Back 186

Lamp lumen depreciation

Front 187

Light loss factor in representing the decrease in luminous output of luminaire resulting from the accumulation of dirt on it sufaces, expressed as a percentage of the illumination from the luminaire when new or clean

Back 187

luminaire dirt depreciation

Front 188

Light loss fact the presenting the decrease in reflected light resulting from the accumulation of dirt and rooms surfaces

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room surface dirt depreciation

Front 189

Any of several permanent light loss factor. Take into account the effect of temperature voltage drops or surge , ballast variation and partition heights

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Non-removable light loss factor

Front 190

Science, theory or method of providing illumination through the use of light of day

Back 190

Daylighting

Front 191

To provide an interior space with delight from both direct and indirect sources

Back 191

Daylight

Front 192

The light from the sky reflected and diffuse by air molecules

Back 192

Skylight

Front 193

Direct light of the Sun

Back 193

Sunlight

Front 194

Sky having less than 30% cloud cover with the solar disk unobstructed. Also, the CIE standard for a reference cloudless sky condition, having the greatest luminance near the Sun and lease luminance 90 degrees from the Sun

Back 194

Clear sky

Front 195

Sunlight or sky light reflected by services below the plane of the horizon

Back 195

Ground light

Front 196

The point of the celestial sphere vertically about the given position or observer

Back 196

zenith

Front 197

Light originating from the source facing each other as from windows in opposite walls

Back 197

Counter light

Front 198

Nitrogen eating from the source not facing each other as from windows in adjacent walls

Back 198

Cross light

Front 199

Method for calculating the performance of the lighting system based on the daylight Factor

Back 199

Daylight Factor metal

Front 200

Measured of daylight illuminance, expressed as the ratio of the light illumination at a point on a given plane to the simultaneously measured illuminance on the horizontal plane from an unobstructed sky of assume or known illuminance distribution

Back 200

Daylight factor

Front 201

Component of the daylight Factor, equal to the ratio of the light illumination at the point of a given plane receive directly from sky of assume or known luminance distribution to the simultaneously measured illuminance on a horizontal plane from and an unobstructed hemisphere of this sky

Back 201

sky component

Front 202

Component of the daylight factor , equal to the ratio of the daylight illummination at a point of a given plane received directly from the exterior reflecting surfaces to the simultaneous measured illuminance on a horizontal plane from in an unobstructed sky assumed or known illuminance distribution

Back 202

External reflected component

Front 203

Component of the light factor , equal to the ratio of the daylight illumination at a point on a given plane receive directly or indirectly from internal reflecting surfaces to the simultaneously measured illuminance on a horizontal plane from an unobstructed sky of assume or known illuminance distribution

Back 203

Internal reflected component

Front 204

Hemispherical dome or similar enclosure illuminated by concealed light sources that simulate the luminance distribution of a clear or overcast sky use for studying in this thing they lighting techniques on architectural models place near its center

Back 204

Artificial sky

Front 205

Device for orienting architectural model to a light source representing the Sun calibrated with respect to latitude, time of day, in season of the year in use for studying the lighting techniques in shadow cast by the Sun

Back 205

heliodon

Front 206

Sky having between 30% and 70% cloud cover with the solar disk obstructed

Back 206

Cloudy sky

Front 207

Sky having 100% cloud cover, also the CIE standard for reference sky having the luminance distribution 3 times brighter near the Zenith then the reason

Back 207

Overcast sky

Front 208

Commission internationale de l'Eclalrage , International Commission developing definitions, standards and procedures for the art, science and technology of lighting

Back 208

CIE

Front 209

Illuminating Engineering Society a professional society in North America devoted to the development and the see me nation of standards and procedures relating to the art, science and the technology of lighting

Back 209

IES

Front 210

Fraction of visible light that is transmitted through a window, door or Skylight assembly, including its frame, expressed as a number between 0 & 1, the higher the vi greater the potential for daylighting

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Visible transmittance

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A pipe of tube lin with highly reflective specular material and design to transport like some distance from a single point source. Some light pipes I love like to be extracted uniformly along the entire length of the pipe. Also called light tube solar tube, sun pipe

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Light pipe

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An instrument containing a computer-controlled mirror that automatically moves to reflect sunlight in a fix direction

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heliostat

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Horizontal overhang that shades glazing from direct sunlight below when reflecting the light through glazing above under the ceiling of a room in more deeply into a space

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Light shelf

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Any of various exterior device for regulating the amount of solar heat in sunlight that enters a window, consisting of movable horizontal or vertical fins controlled manually operated automatically real time or photoelectric controls

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Sun control

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Louvered awning, the metal fins of which are angled to shade a window from direct sunlight and glare while preserving the outside view in admitting soft and diffuse light

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shutter panel

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Manually or electrically controlled exterior venetian blind for protecting a building interior for solar gain and glare

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Shutter blind

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Any of various external device consisting of fixed horizontal or vertical fins angle to shield a window from direct sunlight

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Sunshade

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Screen, usually of the worst place on the outside of a building the shield the windows from direct sunlight

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brise soleil

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Final of miniature external louver for shading a window from direct sunlight in the layer while allowing the high degree of visibility, daylighting , ventilation, visual daytime privacy an insect protection

Back 219

Solar screen

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The ratio of visible transmittance of a window, door or sky light assembly to each solar heat gain coefficient, Express as a dimensionless fraction. if the LSG of product is higher than 10 then it transmit more light than heat

Back 220

light to solar gain ratio

Front 221

Fraction of incident solar radiation that passes through a window, door or skylight assembly including the frame, expressed as a number between 0 & 1. a Prada with the high SHGC rating is more effective in solar heating application, white a product with a lower SHGC rating reduces cooling loads during the summer

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Solar heat gain coefficient

Front 222

Amount of solar heat transmitted through a standard glazing per unit of glazing area. for a given for a given latitude, time of day in year and orientation of exposure, Express i btu/ft^2 (w/m^2) per hour or day. SHG f values at a fixed window orientation very throughout the year as the direction of incident sunlight continually charges

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Solar heat gain factor

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Nonprofit organization that administer an independent grading and certification system for the energy performance of window, door and skylight

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National fenestration rating Council