6 Lighting

LIGHTING

5.0

3. High-Intensity Discharge

Lamps

are members of the electric

discharge family of light sources (as

are fluorescent lamps). Light is

produced when a high-pressure

electric arc is passed through a gas

vapor, rather than by a low-pressure

arc as in fluorescent lamps.

a) Mercury Vapor Lamps

b) Metal Halide Lamps

c) High Pressure Sodium Lamps

6.1 General

6.1.1 Types of Lamps

1. Filament Lamps

a) Incandescent Lamps

b) R and PAR

c) Tungsten - Halogen

2. Gaseous Discharge Lamps

a) Fluorescent Lamps

b) Energy Savings Lamps

c) Neon Vapor Lamps

d) PL lamps

5.0 LIGHTING

6.1 General

6.2 Incandescent Lamps

6.3 R and PAR Lamps

6.4 Tungsten Halogen Lamps

6.5 Fluorescent Lamps

6.6 Mercury Vapor Lamps

6.7 Metal Halide Lamps

6.8 High-Pressure Sodium

Lamps

6.9 Ballasts

6.10 Luminaires

6.11 Classification of

Luminaires

6.12 Lighting Systems

6.13 Lighting Methods

6.14 Factors which will

Achieve Desirable Seeing

Conditions

6.15 Lighting Terms

6.1.2 Units of Light

1. Unit of Light or Luminous Flux

Lumens

2. Unit of Density of Light

a) Footcandle

is the amount of lumens falling on

an area one square foot one foot

away

b) Lux

is the amount of lumens falling on

an area one square meter one

meter away. One (1) footcandle is

equivalent to 10.76 lux.

3. Unit of Light Intensity

candlepower (cp)

4. Unit of Brightness

footlambert (FL)

5.0 LIGHTING

=

=

=

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

6.2 Incandescent

Lamps

composed basically of a sealed

glass containing a filament

connected at its ends to the contact

area in the base thereby completing

an electric circuit.

The glass envelope comes in a

variety of shapes and sizes; bulb

designations consist of a letter to

indicate its shape, and a number to

indicate the diameter in eights of an

inch.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

The various shapes are:

Standard - A

Globular - G

Straight - S

Tubular - T

Pear-shape - PS

Flame - F

PAR - Parabolic

Aluminized

Reflector

A PS 30 Lamp therefore is a pear-

shaped bulb 30/8 or 3-3/4 in

diameter

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

5.0 LIGHTING

6.4 Tungsten Halogen

Lamps

The tungsten-halogen (also called

quartz or quartz-iodine) lamps use a

halogen gas cycle to prevent rapid

depreciation of the lamp filament

and darkening of the transparent

envelop.

6.3 R and PAR Lamps

Are complete optical systems in a

single bulb. The bulb contains a

filament, reflector and lens.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

For the operation of some

fluorescent tubes, an automatic

switch known as a starter is

required, in addition to the normal

wall switch. The starter is self

contained in a small tubular jacket

which is inserted in the fixture body

and is a replaceable part.


comprises a cylindrical glass tube,

sealed at both ends and containing

an inert gas usually argon and

mercury vapors. Built into each end

is a cathode which supplies the

electrons to start an maintain the

mercury arc or gaseous discharge.

This light is absorbed by the

phosphors in which the inside of the

tube is coated and is re-radiated in

the visible light range.

All fluorescent light sources, require

a control device or an auxiliary,

called a ballast, located in the metal

base.

The ballast serves the following

functions: Supplying the high voltage necessary

to start the arc;

Limiting the current in the arc after it

is formed.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

using a device called a trigger-start

ballast. This ballast provides both a

current-limiting function and an

appropriate automatic starting system.

Instant Start When the lamp is first switched on, a

sufficient voltage is applied between the

electrodes to strike the arc without

preheating them. Instant-start lamps start

as soon as current is turned on and

eliminates the need for external starters.

They have single-pin bases which are

called slim-line lamps.

Rapid Start are the most recent developments and

the one that is most widely used. Rapid-

start lamps use low-resistance electrodes

which can be heated continuously with

low current loses. These are the only

fluorescent lamps that can be electrically

dimmed or flashed. They start as quickly

as the instant-start lamps; require no

external starters; and the ballasts are

smaller and more efficient.

Fluorescent lamps are classified as:

1. According to shape

Standard

Slim-line does not require a starter, have single-pin

bases, come in diameters 3/4, 1, and 1-

1/2 ; and come in lengths from 42 (4 ft)

to 96 (8 ft).

Circline

2. According to method of tube

operation

Pre-heat requires a starter which preheats the

cathodes so that less voltage is required

to strike an arc. There is a 2-5 seconds

delay in the start of lamp after switch is

on. This class is also called a switch-

start or starter-start lamp. In certain

cases, the starter can be eliminated by

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

5.0 LIGHTING

6.6 Mercury Vapor

Lamps

contains mercury vapor in a clear

quartz arc tube, which when

electrically excited, produces visible

light of characteristically blue-green

color. It is suitable only for limited

industrial areas, general outdoor

applications and street lighting.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms


a modification of the mercury vapor

with an arc of improved color. In

addition to mercury, the arc tube

contains metallic vapors such as

indium iodide, thallium iodide, or

sodium iodide. It possesses

therefore increased light output,

improved color rendition without the

use of phosphors, and small source

size.

6.9 Ballasts

are auxiliary equipment for

fluorescent and HID lamps which

limits the amount of current in the

lamp and provides the proper

starting voltages. A power factor is

frequently listed with each ballast

description. The low power factor

ballast is cheap and inefficient; while

the high power factor ballast has a

capacitor* which improves its

efficiency. *CAPACITOR An electric component which

consists of conducting plates insulated from

each other by a layer of dielectric material;

introduces capacitance into a circuit.

Capacitance is the quantitative measure of the

electric-energy storage capability of a capacitor;

usually measured in farads or microfarads.

6.8 High-Pressure

Sodium Lamps

are the newest addition to the HID

field. Its arc tube is made of high-

density polycrystalline alumina an

contains a mixture of primarily

sodium.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

6.10 Luminaires

(Or Lighting Fixtures)

is the device which supports the

source or sources of electric light

and redirects or helps to control the

light rays from the source. Control of

the rays is necessary to secure even

distribution, to avoid glare, to cut-off

direct rays to the eyes, and

eliminates disturbing reflection of the

rays from polished surfaces.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

Ceiling-Mounted Downlights

Spotlights

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

Pendants

Wall Lights

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

Task and Table Lights

Floor Lights

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

Fluorescent Fittings

Oddities

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

Exterior Lights

6.11 Classifications of

Luminaires

5.0 LIGHTING

1. Indirect

90% to 100% of the light

output is directed towards

the ceiling and upper

walls of the room.

2. Semi-indirect

60% to 90% of the light is

directed upwards; 40% to

10% downwards.

3. General diffuse or

direct-indirect

provides approximately

equal distribution of light

upwards and downwards.

4. Semi-direct

60% to 90% of light is

directed downwards;

while 40% to 10% is

directed upwards.

5. Direct

90% - 100% of the light

output is directed

downwards

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms


1. Cornice Lighting

a system where light sources are

shielded by a panel parallel to the

wall and attached to the ceiling to

distribute light downwards over the

wall. This is considered as direct

lighting.

2. Cove Lighting


shielded by a ledge to distribute light

upwards over the ceiling and upper

wall. It is a form of indirect lighting.

3. Valance Lighting


shielded by a panel parallel to the

wall usually across the top of a

window. This provides light both

upwards and downwards over the

wall.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

3. Combined Local and General

Lighting (sometimes called

Localized Lighting)

provides sufficient general lighting to

illuminate various objects in the

room and at the same time furnishes

additional local lamps at desks,

reading tables, showcases and other

equipment needing additional

illumination


1. Local Lighting

method which employs lamps at

definite points where light is

specially needed producing pools of

light mingled with areas of shadows.

It is the very opposite of uniform

illumination. The location of lamps in

this method usually depends upon

the position of furniture or the

position of activity areas.

2. General Lighting

this method strives for diffused light

and uniform intensity over an entire

area. The lamps are evenly spaced

without regard to furniture location

and are provided with reflectors,

baffles or diffusing prisms to prevent

glare, harsh shadows and uneven

illumination.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

2. Quality of Light

Light Distribution depends upon:

Uniformity

freedom from variations of illumination in a

room or space. Absolute uniformity signifies

same intensity throughout and it is not

always practicable to attain. A deviation of

25% from the average intensity cannot be

detected by the eye, and is considered an

acceptable maximum.

Diffusion

refers to the number of directions and angles

from which illuminating rays proceed. Good

diffusion is obtained when light falls upon a

matte or satin surface from a variety of

directions thus eliminating shadows and

streaks of brilliancy. Poor diffusion results

from illumination from one direction only thus

causing visual confusion because of

distorted highlights and shadows


Achieve Desirable

Seeing Conditions

1. Intensity of Illumination

intensity of light required will depend

upon the tasks involved as follows

a) for casual work, as in conferencing,

interviewing and inactive filing 10 to 30 fc

b) for moderate work, as in intermittent filing

and general clerical work 30 to 50 fc

c) for prolonged work, as in active filing,

index referencing and mail sorting 50 to

100 fc

d) for precision work, as in accounting,

auditing, tabulating, bookkeeping, business

machine operation, reading poor

reproductions and rough layout drafting

100 to 150 fc

e) for fine precision work, as in cartography,

designing and detail drafting 150 to 200 fc

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

Absence of Glare

Glare is defined as the effect of brightness in

the field of vision which causes annoyance

or discomfort, or in worse cases, interferes

with seeing. When the glare is caused by

light sources in the field of vision, it is known

as direct glare or disability glare. When

glare is caused by the reflection of a light

source in a viewed surface, it is known as

reflected glare or discomfort glare.

Bare lamps or brilliant fixture globes should

never be in the line of sight from any point in

the room. An angle of 45 deg. between the

horizontal and the line of sight (line from the

lamp to the eye) is generally accepted as the

greatest permissible angle.

Color of Light

depends upon the type of lamp chosen.

Incandescent lamps provide yellow light;

although there are many other colors

depending upon the color of their glass

bulbs. Fluorescent lamps have the greatest

variety of colors ranging from daylight to

bluish white and even pinkish white. Color is

also used to enhance certain qualities. For

example, de luxe FL lamps are used to

enhance food in restaurants.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

4. Reflectance

also called reflection factor; it is the

ratio of light reflected by a surface to

the light falling upon it.

5. Transmission

is the passage of light through a

medium when light falls upon a

transparent material. It is refracted

(bent) as it passes through the

material but emerges at the same

angle that it entered. When passing

through a translucent material, such

as plastic, and the emerging rays

are spread in all directions, it is

called diffused transmission.

6. Transmittance

also called transmission factor; it is

the ratio of light transmitted to light

striking the surface.

6.15 Lighting Terms

1. Absorption

Loss of light when light rays strikes

or traverses any medium. The ratio

of light absorbed by a material to the

light falling upon it is called the

absorption factor or absorptance.

2. Diffuse Reflection

a beam of light is reflected diffusely,

that is, its ray is scattered in all

directions, if it strikes a rough or

matte surface.

3. Specular Reflection

a beam of light is specularly

reflected when a light ray striking a

shiny or glossy surface at an angle

of incidence is reflected as the same

beam with equal angle of reflection.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

12. Luminance Ceiling

a false ceiling of diffusing material

with light sources mounted above

13. Filter

device which changes either amount

or color, or both. of light passing

through it.

14. Dimmer

a device to control the amount of

light by reducing the voltage or the

current; also called a rayostat.

15. Capacitor

An electric component which

consists of conducting plates

insulated from each other by a layer

of dielectric material; introduces

capacitance into a circuit.

Capacitance is the quantitative

measure of the electric-energy

storage capability of a capacitor;

usually measured in farads or

microfarads.

7. Accent Lighting

directional lighting to emphasize a

space or an object.

8. Down Light

a fixture producing concentrated

direct lighting from a single bulb. It

may be recessed in or mounted on

the ceiling

9. High Hat

a term often applied to a can-type of

recessed incandescent downlight.

10. Eye Ball

recessed or semi-recessed lighting

unit with a rotating spherical element

that may be turned to project light in

any direction.

11. Lumiline

a tubular fluorescent lamp with a

disc base at each end.

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

5.0 LIGHTING

6.1 General


6.3 R and PAR Lamps






Lamps

6.9 Ballasts

6.10 Luminaires


Luminaires





Conditions

6.15 Lighting Terms

Lighting Symbols

END

LIGHTING

6 Lighting

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