design energy efficient lighting in all new … guidelines/pdfs/ene bg 4.pdfan energy efficient...

Phase 2 - Environmental Building Initiative for Greater Hyderabad—by TERI and TVPL

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Energy Ene Bg 4

Environmental Building Guidelines for Greater Hyderabad — Ver. 1.2(2010)

The following design guidelines should be considered at the design

and installation stage of all new residential and commercial buildings:

1. Ensure that the illuminance levels on working plane conforms

the level recommended by NBC (BIS 2005) in Table 4 (clauses

4.1.3, 4.1.3.2, 4.3.2 and 4.3.2.1) [Part 8 Building services -

Section 1 lighting and ventilation]

2. Ensure that the uniformity ratio (minimum illuminance

divided by average illuminance levels) of an area, which is

entirely being utilized as work place, should not be less than

0.7 as per recommended in NBC (BIS2005).

3. Select lamps with high Colour rendering index.

4. Do not exceed the LPD (light power density) as

recommended by Energy Conservation Building Code 2007

5. Apply lighting controls as recommended by ECBC 2007

6. Integrate daylight control strategies for perimeter areas with

access to day lighting

7. Retrofit external and common area lighting with efficient

fixtures and apply lighting controls in existing residential

complexes/buildings.

8. All the spaces should use of efficient lighting equipment e.g.

lamps, luminaries and control gears.

An energy efficient lighting design must meet with minimum

illuminance level for specified task as specified by NBC. Illumination

level for specified task should be maintained at all times as

recommended by National building code 2005. The National Building

Code recommends a range of illumination levels for a activity as

circumstances may be significantly different for different interiors

used for the same application or for different conditions for the same kind of activity. Each range consists of three successive steps of

recommended scale of illuminance. For working interiors, the middle

value of each range represents the recommended service illuminance

that should be used. It should be ensured that the required

illumination level is provided by use of efficient lamp and luminaire

combination. Suitable control strategies should be simultaneously

applied to switch off or dim lights during unoccupied or day lit hours.

All these measures ensure efficient lighting.

Design energy efficient lighting in

all new residential and commercial buildings

Checklist

New build

Des

O & M

Con

1. Maintain

recommended

illumination

levels

2. Maintain

uniformity

ratio

3. Maintain

lighting power

4. Apply contols

5. Retrofit

suitably


Good lighting aims at illuminating the task effectively and the general surroundings

appropriately.

Good lighting design enhances architecture but energy-efficient lighting design enhances

both the design and the performance of building.

Energy-efficient lighting design focuses on methods and materials that improve both quality

and efficiency of lighting.

A good lighting design should be able to provide desired quantity and quality of light at

minimum energy consumption.

Lighting contributes to significant energy consumption in buildings. In air conditioned

buildings lighting energy consumption may be as high as as 20-25% of total energy

consumed, whereas in non air conditioned buildings, share of lighting energy consumption

may be as high as 60% of its net energy consumption.

Hence it is important to design and operate lighting systems efficiently.

Use of efficient lighting serves the purpose of visibility and safety– Maintaining the ade-

quate lighting level as per the task and use of efficient lamps with provides sufficient light for

performing required task without wasting any energy.

Use of Controls– Reducing the connected load of the lighting system represents partly the

potential for maximizing energy savings. Lighting controls play a major role in reducing en-

ergy consumption by avoiding wastages. There are numerous choices available today from

simple light switches to fully automated systems. Automatic controls switch off or dim the

lights based on the time, occupancy, illumination requirements, or a combination of all three.

Please refer guidance note for more details.

Retrofit– The existing building campuses get advantage of saving in electricity bills by retrofit

options.

Saves operating costs: Energy efficient lighting have minimal incremental cost (sometimes

the cost is lower due to reduction in total number of luminaries and lamps required to pro-

vide requisite illumination) and the payback period is usually within six to eight months

Energy efficient lighting is very cost effective as an ECM (energy conservation measure). The

incremental cost usually gets paid back within a year’s time. A sample study has been en-

closed at the end of the guidance notes.

How is it Beneficial?

1. Detailed listing of connected load for lighting, and details like luminous efficacy (Lumen

Output/wattage) etc. for all the types of lamps should be submitted in following Table 1

format.

2. Calculation of connected load for indoor lighting and energy requirement for the same in the

format given in Table 2.

Submittals

Why is it required?


Table 1: Detailed listing of connected load for lighting, and details like luminous Efficacy

(Lumen Output/wattage) etc. for all the types of lamps

Table 2 Calculation of connected load for indoor lighting and energy requirement

List out the control strategies applied to reduce wastage.

Floor Level Room/

Area

Room Dimensions (Length X Width)

Calculated average Lighting (Lux) levels

Recommended lighting levels as per NBC

Code Luminaire

Lamps Ballast Luminaire

wattage

Luminous Efficacy

Make Description Type Make Lumen

output

Wattage Type Make Power

loss

(W)

(Lamp+

Ballast)

Achieved Minimum

recom-

mended

A-1 Philips TBC-22 CFL Phil-

ips

600 10 Elec-

tronic

Phil-

ips

2 12 50 50

An energy efficient approach to design for energy efficient lighting aims to cover the following

aspects.

Illuminance level for specified task

Use of efficient lighting equipment e.g. lamps, luminaries and control gears

Use of appropriate controls.

Explore possibilities of daylight integration

Ensure effective maintenance

Additionally the following parameters are also critical to a good lighting design

Room surface brightness

Glare reduction

Uniform light distribution

Good lamp coloration

Design for specified illumination level as recommended by the National

Building Code 2005

The basic intent in an efficient lighting design to achieve the desired illumination level and light

quality at minimum energy use. For the purpose of achieving the desired objectives, the following

procedure should be followed to ensure efficient lighting

Illumination level for specified task should be maintained at all times as recommended by

National building code 2005.

The National Building Code recommends a range of illumination levels for a activity as

Guidance Notes


circumstances may be significantly different for different interiors used for the same application

or for different conditions for the same kind of activity. Each range consists of three successive

steps of recommended scale of illuminance. For working interiors, the middle value of each range

represents the recommended service illuminance that should be used unless one or more of the

factors mentioned below apply.

The higher value of the range should be used when:

Unusually low reflectance or contrasts are present in the task;

Errors are costly to rectify

Visual work is critical

Accuracy or high productivity is of great importance; and

The visual capacity of the worker makes it necessary.

The lower value of the range may be used when:

Reflectance or contrast are unusually high;

Speed and accuracy is not important; and

The task is executed only occasionally.

Where a visual task is required to be carried out through an interior, general illumination level

meeting the recommended value on the working plane is necessary; where the precise height and

location of the task are not known or cannot be easily specified, the recommended value is that

on horizontal 850 mm above floor level.

Where the task is localised, the recommended value is that for the task only; it need not, and

sometimes should not, be the general level of illumination used throughout the interior. Some

processes, such as industrial inspection process, call for lighting of specialized design, in which

case the level of illumination is only one of the several factors to be taken into account.

Lighting Design

Lighting systems and equipment shall comply with the provisions of Energy Conservation

Building Code as outlined below:

Interior spaces of buildings, Exterior building features, including facades, illuminated roofs,

architectural features, entrances, exits, loading docks, and illuminated canopies, and,Exterior

building grounds lighting that is provided through the building's electrical service.

Exceptions:

The following lighting equipment and applications shall not be considered when determining the

interior lighting power allowance, nor shall the wattage for such lighting be included in the

installed interior lighting power. However, any such lighting shall not be exempt unless it is an

addition to general lighting and is controlled by an independent control device.

1. Display or accent lighting that is an essential element for the function performed in

galleries, museums, and monuments,

2. Lighting that is integral to equipment or instrumentation and is installed by its

manufacturer,

3. Lighting specifically designed for medical or dental procedures and lighting integral to

medical equipment,

4. Lighting integral to food warming and food preparation equipment,

5. Lighting for plant growth or maintenance,

6. Lighting in spaces specifically designed for use by the visually impaired,

7. Lighting in retail display windows, provided the display area is enclosed by ceiling height

partitions,

8. Lighting in interior spaces that have been specifically designated as a registered interior

historic landmark

9. Lighting that is an integral part of advertising or directional signage,

10. Exit signs


11. Lighting that is for sale or lighting educational demonstration systems,

12. Lighting for theatrical purposes, including performance, stage, and film or video

production

13. Athletic playing areas with permanent facilities for television broadcasting.

Interior Lighting Power and Design

The installed interior lighting power for a building shall not exceed the interior lighting power

allowance determined in accordance with either Table 3 or 4.

Building area method

Determination of interior lighting power allowance (watts) by the building area method

shall be in accordance with the following:

Determine the allowed lighting power density from Table 3 for each appropriate building

area type.

Calculate the gross lighted floor area for each building area type.

The interior lighting power allowance is the sum of the products of the gross lighted floor

area of each building area times the allowed lighting power density for that building area

types.

Space Function Method

Determination of interior lighting power allowance (watts) by the space function method

shall be in accordance with the following:

Determine the appropriate building type as per the proposed use and the allowed lighting

power density.

For each space enclosed by partitions 80% or greater than ceiling height, determine the

gross interior floor area by measuring to the center of the partition wall. Include the floor

area of balconies or other projections. Retail spaces do not have to comply with the 80%

partition height requirements.

The interior lighting power allowance is the sum of the lighting power allowances for all

spaces. The lighting power allowance for a space is the product of the gross lighted floor

area of the space times the allowed lighting power density for that space.

Table 3 Interior Lighting Power - Building Area Method

In cases where both a general building area type and a specific building area type are listed, the

specific building area type shall apply.

Building Area Type LPD (W/m2) Building Area Type LPD (W/m2)

Automotive Facility 9.7 Multifamily Residential 7.5

Convention Center 12.9 Museum 11.8

Dining: Bar Lounge/Leisure 14.0 Office 10.8

Dining: Cafeteria/Fast Food 15.1 Parking Garage 3.2

Dining: Family 17.2 Performing Arts Theater 17.2

Dormitory/Hostel 10.8 Police/Fire Station 10.8

Gymnasium 11.8 Post Office/Town Hall/ 11.8

Healthcare-Clinic 10.8 Religious Building 14.0

Hospital/Health Care 12.9 Retail/Mall 16.1

Hotel 10.8 School/University 12.9

Library 14.0 Sports Arena 11.8

Manufacturing Facility 14.0 Transportation 10.8

Motel 10.8 Warehouse 8.6

Motion Picture Theater 12.9 Workshop 15.1


Table 4: Interior Lighting Power –Space Function Method

Space Function LPD (W/m2) Space Function LPD (W/m2)

Office-enclosed 11.8 Library

Office-open plan 11.8 Card File & Cataloging 11.8

Conference/Meeting/Multipurpose 14.0 Stacks 18.3

Classroom/Lecture/Training 15.1 Reading Area 12.9

Lobby 14.0 Hospital

For Hotel 11.8 Emergency 29.1

For Performing Arts Theater 35.5 Recovery 8.6

For Motion Picture Theater 11.8 Nurse Station 10.8

Audience/Seating Area 9.7 Exam Treatment 16.1

For Gymnasium 4.3 Pharmacy 12.9

Patient Room 7.5

For Convention Center 7.5 Operating Room 23.7

For Religious Buildings 18.3 Nursery 6.5

For Sports Arena 4.3 Medical Supply 15.1

For Performing Arts Theater 28.0 Physical Therapy 9.7

For Motion Picture Theater 12.9 Radiology 4.3

For Transportation 5.4 Laundry – Washing 6.5

Atrium-first three floors 6.5 Automotive – Service Repair 7.5

Atrium-each additional floor 2.2 Manufacturing

Lounge/Recreation 12.9 Low Bay (<8m ceiling) 12.9

For Hospital 8.6 High Bay (>8m ceiling) 18.3

Dining Area 9.7 Detailed Manufacturing 22.6

For Hotel 14.0 Equipment Room 12.9

For Motel 12.9 Control Room 5.4

For Bar Lounge/Leisure Dining 15.1 Hotel/Motel Guest Rooms 11.8

For Family Dining 22.6 Dormitory – Living Quarters 11.8

Food Preparation 12.9 Museum

Laboratory 15.1 General Exhibition 10.8

Restrooms 9.7 Restoration 18.3

Dressing/Locker/Fitting Room 6.5 Bank Office – Banking Activity Area 16.1

Corridor/Transition 5.4 Retail

For Hospital 10.8 Sales Area 18.3

For Manufacturing Facility 5.4 Mall Concourse 18.3

Stairs-active 6.5 Sports Arena

Active Storage 8.6 Ring Sports Area 29.1

For Hospital 9.7 Court Sports Area 24.8


Installed Interior Lighting Power

The installed interior lighting power calculated for all power used by the luminaires, including

lamps, ballasts, current regulators, and control devices except as specifically exempted in the

previous paragraph. If two or more independently operating lighting systems in a space are

controlled to prevent simultaneous user operation, the installed interior lighting power shall be

based solely on the lighting system with the highest power.

Luminaire Wattage

Luminaire wattage incorporated into the installed interior lighting power shall be determined in

accordance with the following:

a. The wattage of incandescent luminaires with medium base sockets and not containing

permanently installed ballasts shall be the maximum labeled wattage of the luminaires.

b. The wattage of luminaires containing permanently installed ballasts shall be the operating

input wattage of the specified lamp/ballast combination based on values from

manufacturers’ catalogs or values from independent testing laboratory reports.

c. The wattage of all other miscellaneous luminaire types not described in (a) or (b) shall be

the specified wattage of the luminaires.

d. The wattage of lighting track, plug-in busway, and flexible-lighting systems that allow the

addition and/or relocation of luminaires without altering the wiring of the system shall be

the larger of the specified wattage of the luminaires included in the system or 135 W/m (45

W/ft). Systems with integral overload protection, such as fuses or circuit breakers, shall be

rated at 100% of the maximum rated load of the limiting device.

Luminiare efficiency

The efficiency of a luminare is the percentage of lamp lumens produced that exit the fixture. Use

of louvers improve visual comfort, reduce glare but reduces efficiency. It is thus important to

determine the best compromise between efficiency and visual comfort probability while choosing

luminaries. A lighting simulation is necessary to determine the type of luminaire and lamp

combination for a specific application. Efficient luminare also plays an important role for energy

conservation in lighting. The choice of a luminare should be such that it is efficient not only

initially but also throughout its life.

Following luminaries are recommended by the NBC 2005 for different locations:

a. For offices semi-direct of luminaries are recommended so that both the work plane

illumination and surround luminance can be effectively enhanced.

b. For corridors and staircases direct type of luminaries with wide spread of light distribution

are recommended.

c. In residential buildings, bare fluorescent tubes are recommended. Wherever the

incandescent lamps are employed, they should be provided with white enamelled conical

reflectors at an inclination of about 45°from vertical.

Inactive Storage 3.2 Indoor Field Area 15.1

For Museum 8.6 Warehouse

Electrical/Mechanical 16.1 Fine Material Storage 15.1

Workshop 20.5 Medium/Bulky Material Storage 9.7

Sleeping Quarters 3.2 Parking Garage – Garage Area 2.2

Convention Center – Exhibit Space 14.0 Transportation

Airport – Concourse 6.5

Air/Train/Bus – Baggage Area 10.8

Terminal – Ticket Counter 16.1


Ballasts

All discharge lamps, including fluorescents, require ballast for proper operation. Typical ballast

losses are taken as approximately 15% of the lamp wattage. It is important to include calculation

of ballast losses when comparing consumption and savings fo different kinds of lamps. New

electronic or solid state ballasts, now available in market, save approximately 20—30% in energy

consumption over standard ballasts.

Lamps available in market

There are lamps that can deliver all the above qualities and still consume less than half the

electricity of some other (mostly technologically older) types. The reduction in energy consumption

is possible with proper choice of lighting fixtures and the lamp types. Lighting output and wattage

should be seen before choosing the lights. There are four types of lights commonly used in houses

these are:

Incandescent lamps

Incandescent lamps are the oldest electrical light sources and produce light by

the electric heating of a filament to such a high temperature that radiation in the

visible region of the spectrum is emitted. GLS (general lighting service) lamp is

shown in figure. The HPS lamps radiate energy across a large part of the visible

spectrum, but give a moderately poor colour rendering they have a distinct yellow

or golden appearance. Due to the high efficacy, they are commonly used for

lighting of public places.

Fluorescent lamps.

The lamp, in the form of a long tubular bulb with an electrode sealed into each end, contains

mercury vapour at low pressure with a small amount of inert gas for starting and regulation.

Standard fluorescent lamps

They are 40-W lamps with a diameter of 38 mm. Their lumen output varies

between 2450 lm and 2270 lm, and colour temperature from warm water

(4300 K) to cool daylight (6500 k). They are also available in 20 W and 80

W.

T5 lamps

These are fluorescent lamps with a diameter of 16 mm, which is 40% less

than the diameter of existing slim fluorescent lamps. They are designed for

higher efficacy and system miniaturization. The daylight life of T5 lamps is

also very long, around 18 000 hours as compared to 8000 hours of

standard fluorescent lamps.

Compact Fluorescent Lamps

CFLs (Compact fluorescent lamps) produce light in the same manner as linear fluorescent lamp.

Their tube diameter is usually 5/8 inch (T5) or smaller. CFL power is 5-55W. Typical CFLs have

been presented in figure

Keeping all the above in mind, there are lamps that can deliver all the

above qualities with comparatively less consumption of electricity of

some other (mostly technologically older) types. Bureau of Energy

Efficiency (BEE) has labelled these lamps and one can obtain the list

of BEE labelled lamps on its official website.

Light Emitting Diodes:

A Light Emitting Diode (LED) is a semiconductor device which converts electricity to light. Though

it has been in around since 1960, it is only until now that it is being explored for residential and

commercial application . Each diode is about 1/4 inch in diameter and operates at about a tenth of a watt. LEDs are small in size but can be grouped together for higher intensity. The efficacy of

Fig 1 Incandescent Lamp

Fig 2 Fluorescent Linear Lamps

Fig 3 Compact Fluorescent Light


a typical residential application LED is approximately 20 lumens per watt though 100 lumens per

watt have been created in laboratory conditions. LEDs are better at placing lighting in a single

direction than incandescent or fluorescent bulbs. LED strip lights can be installed under counters, in hallways, and in staircases; concentrated arrays can be used for room lighting.

Waterproof, outdoor fixtures are also available. Some manufacturers consider applications such

as gardens, walkways, and decorative fixtures outside garage doors to be the most cost-efficient.

LED lights are more rugged and damage-resistant than compact fluorescents and incandescent

bulbs. LED lights don't flicker. They are very heat sensitive; excessive heat or inappropriate

applications dramatically reduce both light output and lifetime. Uses include:

Task and reading lamps

Linear strip lighting (under kitchen cabinets)

Recessed lighting/ceiling cans ·

Porch/outdoor/landscaping lighting

Art lighting

Night lights

Stair and walkway lighting

Pendants and overhead

Retrofit bulbs for lamps

LEDs last considerably longer than incandescent or fluorescent lighting. LEDs don't typically

burn out like traditional lighting, but rather gradually decrease in light output.

Ultrasonic sensors –

These detect movement by sensing disturbances in high-frequency ultrasonic patterns. Because

this technology emits ultrasonic waves that are reflected around the room surfaces, it does not

require a direct line of sight. It is more sensitive to motion towards and away from the sensor and

its sensitivity decreases relative to its distances from the sensor. It also does not have a definable

coverage pattern or field of view. These characteristics make it suitable for use in layer-enclosed

areas that may have cabinets, shelving, partitions, or other obstructions. If necessary, these

technologies can also be combined into one product to improve detection and reduce the

likelihood of triggering a false on or off mode.

Photocells

These measure the amount of natural light available and suitable for both indoor and outdoor

applications. When available light falls below a specified level, a control unit switches the lights

on (or adjusts a driver to provide more light). Photocells can be programmed so that lights do not

flip on and off on partially cloudy days

Case Study of lighting design of a large office room

Energy efficient lighting optimisation

The main objective of lighting system optimisation is to achieve energy efficiency as recommended

in the Energy Conservation Building Code (ECBC) 2007 without compromising on visual comfort

requirements of the National Building Code (NBC) 2005.

Cost effectiveness of a lighting scheme is also considered as an important factor in optimisation

process. The lighting design optimisation has been carried out for typical room. The lighting

analysis has been done using standard lighting simulation software for various areas as

mentioned above.

Philips Lighting India Ltd has provided the electronic photometric files, which are used in the

software for analysis. The methodology followed for the lighting design optimisation is as follows:

Step 1: Analysis of lighting schemes as proposed by the architect/ consultant using lighting

simulation software. Check the conformance of calculated lighting levels with recommended

lighting levels in National Building Code (NBC) 2005Check the conformance of calculated

lighting power densities (LPD) defined as ratio of connected lighting load to built-up area


(W/m2) with recommended LPDs in Energy Conservation Building Code (ECBC) 2007.

Step 2: Modification of proposed lighting scheme if required to meet NBC 2005 recom-

mended lighting levels.

Step 3: Design and recommend an optimised lighting scheme meeting recommendations of

both NBC 2005 and ECBC 2007.

Step 4: Life cycle cost analysis of proposed, modified and recommended lighting schemes

Step 1: Analysis of the proposed lighting scheme:

Assumptions

The following assumptions have been made for the analysis.

Project maintenance factor : 0.8

Reflectance of ceiling : 0.7

Reflectance of walls : 0.5

Reflectance of floor : 0.1

Luminaire type : Batten type fixture equivalent to Philips TMC501

Lamp type : 40W fluorescent lamps (2450 lm)

The lighting schemes and calculated lighting levels of a typical room is as follows:

Table 5 : Calculated lighting levels for typical large rooms

Fig 4: Iso-contour diagram and rendered image of proposed case

Observations

It has been observed from the above Table-5 that the average lighting level of the above room is

well below the recommended lighting levels as per NBC-2005 standard. In order to provide

adequate visual comfort the proposed design need to be modified.

Step 2: Modified lighting schemes to meet NBC 2005 illumination levels.

Area Fixture type Lamp type No. of Fixture in

each area

Average Illumina-

tion Level

(Lux)

NBC Recom-

mended Illumina-

tion level

(Lux)

LPD

(W/m2)

ECBC Recom-

mended LPD

(W/m2)

Reading room

(Library)

TMC 501 or

equivalent with

copper ballast

1x 40W TLD 15 99.4 300 5.7 12.9


The modified scheme along with calculated lighting level is given in table-6 below. The

assumptions taken in Step-1 also holds good for Step-2 analysis.

Table 6: Modified Schemes along with calculated lighting level

Fig 5: Iso-contour diagram and rendered image of modified case

Observations

As shown in the table 6, with modified lighting schemes the recommended illumination levels

have been achieved, however, the LPD in that room exceeds the recommended LPD of ECBC-2007

making designs highly energy inefficient. Therefore it is required to design lighting schemes in

such a way that will not only meet the required lighting level but also be energy efficient.

Step 3: Recommended lighting scheme:

Various combinations of efficient luminaire (luminaire with mirror optics reflector to reflect more

light to the work plane and bat wing louvers to control the glare effectively) with efficient lamps

having luminous efficacy more than the 40 W TL have been tried. Life cycle cost analysis was also

carried of few selected combinations. Based on performance, efficiency and cost the final

optimised scheme has been selected and it would include following lighting equipment.

1. Luminaire type : Philips TCS306 or equivalent with electronic ballast (as shown in

Annexure-2)

2 Lamp type :36 W tri-phosphor coated Fluorescent lamp with high lumen output of

3250 e.g., Philips Trulite

The performance (lighting levels) and efficiency (LPD) of optimized lighting schemes are given in

table below.

Table 7 Calculated lighting levels and LPD of optimized lighting schemes

Area

Fixture type Lamp Type No. of Fixture in

each area

Average Illumination

Level

(Lux)

NBC Recommended

Illumination level

(Lux)

LPD

(W/m2)

ECBC Recommended

LPD

(W/m2)

Reading

room(Library)

TMC 501 or equivalent

with copper ballast

1x 40W

TLD 48 313 300 18.4 12.9

Area Fixture type Lamp type No. of Fixture

in each area

Average Illumination Level

(Lux)

NBC Recom-

mended Illumina-

tion level

(Lux)

LPD

(W/m2)

ECBC Recom-

mended LPD

(W/m2)

Reading room

(Library)

TCS 306 or

equivalent with

2x 36W Trulite 15 306 300 7.5 12.9


(The life cycle cost analysis for the proposed, modified and recommended schemes for a typical

space has been given in Annexure-1.)

Observations

It is quite evident from the above table-7 that the optimized lighting schemes in most of the

spaces provide illuminations, which conform to the recommended lighting levels as recommended

in NBC-2005. The calculated LPD of these schemes are also below the recommended LPD in

ECBC-2007.Therefore the optimized lighting schemes are recommended for various spaces in the

building.

Conclusion:

The main findings of the study are as follows:

With proposed design the illumination level is very low. No doubt, lighting load will be less but

this may cause visual discomfort and not advisable.

Inefficient lighting equipment may produce required illumination but at a higher energy

demand which will add to the existing energy problem.

Use of efficient lighting equipment will not only produce the required illumination but also

provide check on the increasing energy demand. Therefore it highly recommended using these

equipment in place of inefficient lighting equipment used in existing lighting schemes. Using

efficient lighting equipment will definitely increase the initial or first cost but the total cost or

the life cycle cost which includes both the first cost and recurring cost (energy & maintenance

cost) of such lighting schemes if calculated for a period of fifteen years comes out to be less

than the LCC of a system which is designed with cheaper and inefficient equipment to

produce same illumination.

References

1. A Knowledge Bank for Sustainable Building Design – CD, MNRE & TERI, New Delhi

2. Energy Conservation Building Code 2007, Bureau of Energy Efficiency, Ministry of Power,

3. Government of India·ICAEN (Institut catala d’ Energia), 2004, Building Design Manual,

TERI Press, New Delhi·

4. BIS, 1988, Handbook on Functional Requirements of Buildings, Bureau of Indian Stan-

dards, New Delhi·

5. BIS, 2005, National Building Code of India 2005, Bureau of Indian Standards, New Delhi.

6. Outputs from AGI 32: Lighting simulation tool


Life cycle cost analysis of a typical space

Space: Reading room (Library)

Architectural details

Length : 14.37 M

Width : 10.00 M

Height : 3.0M

Lighting schemes & equipment cost

i. Proposed/Modified lighting schemes

Luminaire type : Single TMC 501 with copper ballast

Cost of luminaire : Rs. 510/-

Type of lamp : 40 W ordinary tube light

Cost of lamp : Rs. 46/-

ii. Recommended lighting scheme

Luminaire type : Twin TCS 306 with electronic ballast

Cost of luminaire : Rs. 2640/-

Type of lamp : 36 W Trulite

Cost of lamp : Rs. 80/-

Operating hours : 8 hrs and 300 days a year

Electricity tariff : Rs 6/kWh

Table8: Calculated lighting levels & LPD of various Lighting Schemes

Table 9: Life Cycle Cost Analysis and savings of Lighting Schemes

S No. Lighting scheme Luminaire type Lamp type No. of fixtures No of lamp. Avg.Lighting Level (lux) LPD

(W/m2)

1 Case -1(proposed)

TMC501or eqivalent

with copper ballast 40W TL 15 15 192 5.7

2 Case -2(modified)

TMC501or eqivalent

with copper ballast 40W TL 48 48 313 18.8

3

Case- 3(recommended)

TCS 306 or equiva-

lent with Electronic

2x36 W Trulite 15 30 306 7.5

Sl.No. Lighting scheme Total Load

( kW)

Energy Consumption

(kWh)

Initial Cost

(Rs)

Life Cycle Cost

(Rs)

1 Case -1(proposed) 0.8 1980 8340 135465

2 Case -2(modified) 2.6 6336 26688 439564

3 Case- 3(recommended) 1.1 2592 42000 231323

Annexure 1


Fig 6 Life Cycle Cost graph for lighting schemes

Observation:

As can be seen in the graph above, the recommended luminaries would have an initial incre-

mental cost of Rupees 15312/- for the room, however the payback period would be less than

one year. As compared to the modified lighting scheme, an amount of Rupees 208241 /- would

be saved over a period of fifteen years by applying the recommended scheme.

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