E2-E3 ELECRICAL Technical

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E2-E3 ELECRICAL

Technical

Energy Efficient Lighting System


WELCOME

• This is a presentation for the E2-E3 Electrical, Technical

Module for the Topic: Energy Efficient Lighting System

• Eligibility: Those who have got the Upgradation to from

E2 to E3.

• This presentation is last updated on 15-3-2011.

• You can also visit the Digital library of BSNL to see this

topic.


AGENDA

• Understand, design philosophy and concepts of energy

efficient lighting system

• Features of energy efficient lighting system


DESIGN PHILOSOPHY AND CONCEPTS

• Primary Objective of the lighting system design is to

realise the end objectives of

– Cost effectiveness – life cycle cost

– Energy Conservation

– Electrical and Fire Safety

– Aesthetics, Appearance, Lighting impact and users’ comfort

– Flexible switching lighting system.

– Introduction of New Concepts, Designs and New Technologies

and

– Ease of Maintenance


Concepts in Lighting

1. Interior decor and scientific lighting design

2. Right light at Right place

3. Energy efficient light source

4. Luminaires with glare free, uniform and optimum light

distribution

5. Low loss accessories

6. Flexible switching lighting


7. Life cycle cost

8. Energy intensity

9. Ease of maintenance & fire safety


Concept 1: Interior decor and scientific lighting

design

• Lighting system in modern office buildings shall be as

per modern trends, international practices and standards

to provide a stimulating and motivating environment to

occupants and visitors.

• Need to provide quality and quantity of light for

performing various tasks efficiently with visual comfort

and visual satisfaction.


Interior decor and scientific lighting design-

Contd.

• Proposed to treat different areas such as Executive

cabins, Conference Hall, Workstations, Entrance Lobby,

corridors differently, so as to achieve aesthetic

appearance and lighting impact. Decorative plants and

wall paintings shall be exclusively lit with spotlights/ wall

washers.


• Walls and the ceilings are to be treated and finished in

light colours, preferably off-white, whereas the floor,

working tables are proposed to be finished in light brown

colours.


Contd.


• For these finishes, we can consider 70% reflections from

walls and ceilings and about 30% from the floor.

• In the design for worst-case, reflections from ceiling,

walls and working surface are taken as 50%, 30% and

10% respectively, to take care of the changes in surface

finishes by the Architect/ Occupants at the finishing

stage or even at some later date.

• For lumen depreciation and luminaire surface

depreciation, a maintenance factor of 0.8 is considered.


Contd.


Concept 2: Right light at Right place

Area ISI-3646

(Lux)

Selected

(Lux)

Work Stations, Executive

Cabins/Conference Room/Board

Room

300-500-750 500

Library, Control Room, Public

Places

200-300-500 300

Lift Lobby, Canteen Service Area 150-200-300 200

Passage, Staircase, Toilet, Lobbies 50-100-150 100


Concept 3: Energy efficient light source

• Energy efficiency (i.e lumens/watt) of 28 W T5 lamp is

104, 36W T8 is 68, 36W high-lumen T8+ is 90, 36W CFL

is 80 and that of 40W T12 is 64.

• T-5 lamp is the most energy efficient light source and

also has maximum life. Further, the light distribution of

T5 lamp as compared with other light sources is better

and uniform.

• The Compact fluorescent lamp (CFL) has better life than

T8 and T12 and the energy efficiency is also

comparable.


Energy efficient light source- Contd.

• Compact fluorescent lamps are available in various

ratings and their luminaires are also available in various

shapes.

• To achieve the prime objective of energy efficient lighting

and aesthetic appearance, CFL and T-5 lamps to be

used.


Concept 4: Luminaires with glare free, uniform and

optimum light distribution

• Modern office is designed on a Open Office Concept

basis with large population of Personnel Computers.

• Lluminaires to be conforming to stringent CAT – 2

Guidelines, to create a visual stress-free and glare-free

ambience for working with Video Display Units (VDUs).

• For VDUs, the high luminance of light source has to be

eliminated by positioning them beneath the parabolic

cross louver reflectors.


• For the cabins of Board of Directors, Senior Officers,

Conference Halls and Committee Rooms, the light on

the working table, shall be with CAT-2 Mirror optic

luminaires with 2 x 28watts T5 Lamps and on the

periphery with 2 x 13watt / 2 x 18watt CFL down lighters

to give lighting impact and aesthetic appearance with

various designs and geometric shapes.

Luminaires with glare free, uniform and

optimum light distribution- Contd.


• In order to avoid glare, the CFL down lighters shall also

have inbuilt parabolic cross louvers. The walkways, lift

lobby, stairways, corridors and toilets shall be illuminated

by means of compact fluorescent down lighters to

provide aesthetic lighting impact.

• Service areas i.e. Air Handling Unit, Electrical

Distribution and Lift Machine rooms shall be provided

with sleek Box type fitting with T5 lamps.

Luminaires with glare free, uniform and

optimum light distribution- Contd.


Concept 5: Low loss accessories

• High Frequency Electronic Ballasts are ideal for

increasing system efficiency with T5, as power loss with

these Ballasts is only around 2 watts, when compared

with at least 9 watts of best quality copper Ballasts.

• As these Ballasts operate above 20KHZ; there is no

tiring effect on workers due to absence of stroboscopic

effect. The electronic Ballast further gives instant and

soft start. The power factor is more than 0.95.


Low loss accessories- Contd.

• These Ballasts have better life and more tolerance of

voltage fluctuations. Though the initial investment on

these Ballasts is high, yet they pay back as they are

most energy efficient.

• Care to be taken to provide only quality products, which

can avoid electromagnetic interference and give a short

pay back period with guaranteed life.


Concept 6: Flexible switching lighting

• Proper Switching ‘OFF and ON’ of lighting system,

based on day light, occupancy, week days or holidays is

the key in optimising energy demand of the lighting

system without causing any occupant dissatisfaction.


Flexible switching lighting- Contd.

Daylighting

– The Building design should be such that we get

daylight only from the windows fixed at one of the

outer walls in the working area.



– In order to get the advantage of natural day light at

lower expense, it is proposed to provide simple

control through separate lighting circuits in the areas

adjacent to the windows so that these lighting circuits

can be connected with dimmers and natural light

sensors so as to switch ‘OFF and ON’ these circuits

or dim the lighting level, as per available natural light.



– Natural light sensor measures the level of free day

light and if the natural light level rises, luminaires

close to the windows are dimmed down and after a

delayed period, they are switched off.

– As the daylight entering the room falls, the artificial

lighting is increased, thus, day light dimming involves

continuous variation of electrical lighting to maintain a

constant target level of illumination.



Zoning

• Lighting system in a typical floor shall be divided into

various areas/ zones.

• Lighting fixtures shall be wired so that they can be

switched ‘OFF and ON’ through Intelligent Building

Management System command in stages of 25%, 50%,

75% or 100%.

• Each zone shall also be provided with one switch which

can be switched ‘OFF and ON’, by the occupants

manually. The corridoors, service areas, the working

area, Executive cabins, Conference Rooms, Meeting

Rooms shall be in different Zones so that they can be

separately switched ‘OFF and ON’.



Scheduling

• The switch ‘OFF and ON’ the lights in a programmed

manner, should be scheduled, based on the occupancy,

daytime and holidays. The IBMS control with

programmed Switching ‘OFF and ON’ of lighting system

definitely results into energy saving.



Occupancy Sensors

• These sensors have an adjustable inbuilt time delay to

prevent the lights from switching ‘OFF and ON’ even

when the space is occupied but there is little activity.

The occupancy sensors are basically motion detectors

and their settings have to be carefully done so as to

avoid occupant dissatisfaction .The occupancy sensors,

thus, minimize the energy wastage in unoccupied areas.


Concept 7: Life cycle cost

Concept 7: Life cycle cost

• The life cycle cost for 500 lux level at typical floor of a

Building with different alternatives is given at Table –2 in

Handout.


Concept 8: Energy intensity

• Energy intensity for a typical floor with different

alternatives is given at Table-3 in Handout


Concept 9: Ease of maintenance & fire safety

– Wiring with Fire Retardant Low Smoke (FRLS) wires

and should be run in steel conduits fixed on suitable

MS trays above the false ceiling.

– The luminaires to be supported / fixed on these cable

trays. The use of electronic Ballasts will reduce the

fire risk. Further the life of these Ballasts is also very

high as compared to copper Ballasts and thus

maintenance efforts shall be reduced.

– Similarly less maintenance efforts shall be required

for replacement of CFL & T-5 lamps as they have

much longer life as compared to T-8 or T-12 lamps.


Ease of maintenance & fire safety- Contd.

– The Electronic Ballasts also provide electrical safety

as it has internal separation transformer.

– When the amount of energy supply is limited, we

would like to see and feel the same emotions, warmth

and colour variations inside the building as what is

given by the nature to the outside.

– The energy efficiency of the scheme is much higher

as electrical intensity for the main office areas is only

2 Watt per sqmt per 100 lux. There will be further

energy saving on account of scheduling based on

natural daylight, occupancy, holidays and zoning.


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