Energy Audit of IIT Campus

ENERGY AUDIT OF IIT-BOMBAY CAMPUS

Draft Final Report

Ist Year M.Tech Students of the

Department of Energy Science and Engineering

INDIAN INSTITUTE OF TECHNOLOGY – BOMBAY

POWAI, MUMBAI – 400 076.

JULY, 2008

This report has been prepared by:

Chikku Abraham (T.A. for the project)Mel GeorgeVictor Jose

and Sharath Deshpande

with the support and cooperation of the following students of the Department of Energy Science and Engineering.

Manoj KumarMahendra RaneMs. Debasmita PandaMs. Ragini AgarwalB. Kiran KumarHrushikesh PatadeHardik PatelA. Senthil KumarMs. Harathi NandaDeepak YadavChinmay KinjavdekarAnand UpadhyayYajnavalkya K. Nookala Ravindra NarkhedeS. Nagaraja RaoAnoop S.Prasad WaniKalpesh KarnikShiva KumarD. Surendranath Vineet P.Ms. Riddhi PanseVikrant Bhalerao

under the guidance of Prof. Rangan Banerjee

as a part of the course work for the subject EN 607: Energy Management

2

--------------------------------------------------------------------------------------------------Disclaimer

The views expressed in this report are those of the authors and may not represent or reflect the

views of IIT - Bombay.

--------------------------------------------------------------------------------------------------

3

PREFACE

An energy audit is a study of a plant or facility to determine how and where energy is

used and to identify methods for energy savings. There is now a universal recognition of the

fact that new technologies and much greater use of some that already exist provide the most

hopeful prospects for the future. The opportunities lie in the use of existing renewable energy

technologies, greater efforts at energy efficiency and the dissemination of these technologies

and options.

This energy audit of the IIT-B academic area and the hostels was carried out by the

students of the Department of Energy Science and Engineering as a part of the course work for

the project EN 607. This report is just one step, a mere mile marker towards our destination of

achieving energy efficiency and we would like to emphasise that an energy audit is a

continuous process. We have compiled a list of possible actions to conserve and efficiently

utilize our scarce resources and identified their savings potential. The next step would be to

prioritize their implementation. We look forward with optimism that the institute authorities,

staff and students shall ensure the maximum execution of the recommendations and the success

of this work.

To all of you, we hope that the ideas and pages that follow will give as much enjoyment

and challenge as they have given us in their development, synthesis and writing. Any

suggestions to further enhance the quality of this work are always welcome. Kindly email your

comments and suggestions to [email protected] or [email protected] by 25th July,

2008.

- Authors

4

TABLE OF CONTENTS

List of figures

List of tables

1. Introduction

1.1 Objective of the energy audit

1.2 IIT present energy scenario

1.3 Specific Energy Consumption (SEC)

1.4 Segmentation

2. Energy Audit

2.1 Methodology

2.2 Grouping and strategy

3. Quantification by end use

3.1 Departments, library, main building

3.2 Hostels

3.3 Gulmohar and guest houses

3.4 Street lighting

3.5 Water pumping

3.6 Energy consumption in hostel kitchens

3.7 Central air conditioning for library

4. Measurements performed

4.1 Room air conditioners

4.2 Lighting and fan loads

4.3 Energy usage in hostels-washing rooms and geysers

4.4 Computers/printers

4.5 Water pumping

5

5. Benchmarking

5.1 Energy performance of various departments

5.2 Per unit area energy consumption

5.3 Per capita energy consumption

5.4 Per capita electrical energy consumption in hostels

5.5 ECBC standards and comparison

6. Energy conservation and efficiency

6.1 Implementation measures

6.2 Energy management structure

Appendix A – List of instruments used

Appendix B – Distribution of room ACs

Appendix C – BEE thumb rules for air conditioning loads

Appendix D – Calculations for Solar Water Heating Systems (SWHS) in hostels

Appendix E – Calculations for power savings in computers

Appendix F – Operating schedule of pumps at main pump house

Appendix G – General recommendations

Appendix H – Summary of hostel electricity bills

Appendix I – Details of library central air conditioning

Bibliography and websites

Acknowledgements

6

LIST OF FIGURES

Figure no. Title1.1 Recorded monthly peak demands at IIT-B during the year 20073.1 Distribution of connected load by end use in IIT-B3.2 Room air conditioning load (ton per unit of total floor area) for different

departments3.3 Room air conditioning load (ton/ air conditioned sq.m) for offices in Main

Building3.4 Distribution of connected load in hostels (excluding computers)3.5 Connection diagram of Main Pumping Station3.6 Per capita consumption of energy (as LPG) for different hostels4.1 AC Load curve for the day without the energy saver for ACs (on 12th May,

2008)4.2 AC Load curve for the day with the energy saver for ACs (on 7th May, 2008)4.3 Power consumption in H5 washroom for 5 hrs. on 5th April 20084.4 Power consumption of 2 kW Bajaj geyser in Hostel 5 on 6th April 20084.5 Efficiency-discharge for various pumps at Main Pump House5.1 Total annual energy consumption of different departments5.2 Normalized per unit area energy consumption (kWh/sq.m/year) for

departments5.3 Normalized per capita electrical energy consumption (kWh/person/yr.) for

departments5.4 Annual electricity consumption in hostels over the years 2005-20075.5 Annual electricity bills for hostels: student and institute contributions

7

LIST OF TABLES

Table no. Title1.1 Time of Day Tariff as per MSEDCL Tariff Order for HT-I

category3.1 AC loads in various departments3.2 Computers and printers in departments and Main Building3.3 Connected loads (excluding computers) in hostels3.4 Connected Load in kW for Gulmohar and Guest Houses3.5 Common area lighting loads3.6 Ratings of pumps in IIT-B3.7 Capacity of water storage tanks3.8 Details of energy consumption and food wastage in hostel kitchens

and staff canteen4.1 Energy savings achieved by installation of the energy saver for a

1.5 ton AC4.2 Measurements for lighting in hostels4.3 Lux meter readings for departments4.4 Lux level measurements for common area lighting4.5 Sample measurements on fans in hostels4.6 Measured power consumption for computers and printers in

different operating modes4.7 Details of pumps for departments and residential complexes4.8 Details of pumps in some hostels5.1 ECBC recommended levels for lighting power density5.2 Measured values of lighting power density at select locations in

IIT-Bombay6.1 Implementation Measures

8

1. INTRODUCTION

The Indian Institute of Technology - Bombay (IIT-B), set up by an Act of Parliament,

was established in 1958, at Powai, a northern suburb of Mumbai. Today, the Institute is

recognised as one of the centres of academic excellence in the country. Over the years, there

has been significant progress at IIT Bombay in all academic and research activities, and a

parallel improvement in facilities and infrastructure, to keep it on par with the best institutions

in the world. Institutes in positions of excellence grow with time. As on date, it has 14

Departments, 10 Centers, 3 Schools and 4 Interdisciplinary programs. The student strength of

the institute is about 5300, with faculty strength of about 450 and supporting staff of about

1500 over an area of about 500 acres.

1.1 Energy audit objective

This energy audit assumes significance due to the fact that the IIT-B electricity bill had

crossed Rs. 10 crores during 2007, and it was aimed at obtaining a detailed idea about the

various end use energy consumption activities and identifying, enumerating and evaluating the

possible energy savings opportunities. The target is to achieve savings in the electrical energy

consumption to the extent of 20%. The audit was also aimed at giving the students a feel of the

practical problems and difficulties in carrying out energy audits. As energy engineers, the

students of the department enthusiastically participated in the endeavour.

1.2 IIT present energy scenario

The energy consumption on campus is mainly in the form of electricity, apart from the

use of LPG as cooking fuel in the hostels.

The campus had a connected electrical load of 5.3 MW as on April 2008 and a contract

demand of 4.5 MVA. The monthly recorded peak demand for the year 2007 is given in Fig.

1.1. The IITB energy bill for the year 2007 was Rs. 10.2 crores. The electricity bill comprises

two parts: one related to the energy consumed (per kWh or per unit energy consumed) and the

other is the maximum demand charge (per kVA of maximum demand during the month). There

also exists a penalty for low power factor. Furthermore, the energy charge includes a

component based on time of use. The Time of Day (TOD) tariff as per the MSEDCL

9

(Maharashtra State Electricity Distribution Company Ltd.) for category HT-I is as given in

Table 1.1. The existing tariff rate is Rs. 300/kVA for maximum demand and Rs. 4.3 /kWh on

an average.

The maximum demand in April 2008 was 4168 kVA and corresponding power factor

was 0.97. The energy charges during the month were Rs. 3.1 per unit for industrial use, Rs. 2.6

p.u. for residential users and Rs. 4.5 p.u. for commercial activities. The average power factor

for the year 2007 was 0.98 which was achieved by means of power factor correction units.

The contract demand in the year 2001-02 was 3000 kVA, which was increased to 3708

kVA and then finally to 4500 kVA in 2005-06. Before the last extension, the institute was

paying a penalty to MSEDCL (Maharashtra State Electricity Distribution Company Ltd.) for

drawing more than the contract demand. Recently, IIT-B had again applied for extension of

present contract demand to 5000 kVA, which was not granted by MSEDCL/ Tata Power

Supply Company.

Monthly maximum demand for IIT-B in 2007

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Months

Max

dem

and

in k

VA

Fig. 1.1: Recorded monthly peak demands at IIT-B during the year 2007

10

Table 1.1 Time of Day Tariff as per MSEDCL Tariff Order for HT-I category

(since December 2003)

Consumption during following hours of the day Energy Charge (p/u)2200hrs-0600 hrs (-)850600hrs-0900 hrs 00900hrs-1200 hrs 601200hrs-1800 hrs 01800hrs-2200 hrs 100

1.3 Specific Energy Consumption (SEC)

The Specific Energy Consumption (SEC) is defined as the energy consumption per unit

of product output. The specific energy consumption considering students, faculty and staff

members were calculated which forms the institute SEC and was taken as reference for

comparison. The SEC was calculated to be 1384 kWh/person/annum (for 2007) for the

academic area and Rs. 5950 per person per annum.

1.4 Segmentation

This energy audit report has segmented the energy consumption patterns both by

departments/ hostels/ offices and by end use activities (lighting, cooling, pumping, washing

etc.). The details are provided in the subsequent chapters.

11

2. ENERGY AUDIT

2.1 Energy audit methodology

The methodology adopted for this audit was

• Formation of audit groups for specific areas and end use

• Visual inspection and data collection

• Observations on the general condition of the facility and equipment and quantification

• Identification / verification of energy consumption and other parameters by

measurements

• Detailed calculations, analyses and assumptions

• Validation

• Potential energy saving opportunities

• Implementation

As a first step in this regard, 13 teams of total 27 students from the department were formed

and each group was assigned a particular area or application of energy in the campus. The

activity was organized as a Graded Course Project for the course EN 607 (Energy

Management) during January-April 2008.

2.2 Grouping and strategy

The following groups were formed with specific target areas and end uses assigned.

Group 1: Lighting and fans in Main building, Library and staff canteen

Group 2: Lighting and fans in Departments (all departments, offices, class rooms and labs)

Group 3: Lighting common area – Covering street lights, corridors, grounds

Group 4: Lighting and fans in Hostels (Hostel 1 to 7)

Group 5: Lighting and fans in Hostels (Hostel 8 to 13)

Group 6: Electric water heating and washroom/ironing loads in all Hostels (Hostel 1-13)

Group 7: Total energy audit of Gulmohar, old guest house and new guest house

12

Group 8: Energy use in Kitchen – Hostels (1-13) and staff canteen

Group 9: Room air conditioners in main building, departments and labs.

Group 10: Central air conditioning (library)

Group 11: Computers/printers – All departments, labs, library and main building

Group 12: Water Pumps in the entire campus

Group 13: Benchmarking of electricity consumption

The groups were allowed the use of various measuring instruments like Power demand

analyzers and Lux meters to assist in the auditing activity. Also, cooperation of the Electrical

Maintenance Section was sought to collect past data and for taking measurements.

13

3. QUANTIFICATION BY END USE

The loads were segregated based on the end use as lighting and fans, air

conditioning, Computer/printers, water pumping, hostel mess cooking loads, washing machines

and irons. Quantification, types and necessary measurements were carried out. The details are

given here.

40%

26%

6%

7%

6%

4%

11%Airconditioning

Lights and fans-hostelsand academic areaGulmohar and guesthouseComputers and printers indepts.Water pumping

Common area lighting

Hostel-geysers andwashrooms

Fig. 3.1 Distribution of connected load by end use in IIT-B

3.1 Electricity use in departments, library, main building

3.1.1 Lighting and fansThe Institute has about 14,000 Fluorescent tube lights in different departments and labs.

Out of which about 3,500 tube lights are fitted with electronic ballast and rest are with

electromagnetic ballast.

The Institute is having 3,670 fans in different departments and labs. Out of which about

3,000 fans are fitted with resistance type regulator and rest are with electronic regulator.

The library and Main Building together have a total of 2,480 lights and 880 fans

(including table fans and exhaust fans).

The total lighting load from the above is 501 kW and the connected fan load is 307 kW.

14

3.1.2 Air Conditioners

On using the rated capacity details supplied by the manufacturers, the total room AC

load is about 1.991 or 2 MW. The total AC load (rated) is about 1,450 tons of refrigeration.

The distribution of ACs in different departments is as shown below in Table 3.3.

Table 3.1 AC loads in various departments

Deptt/capacity 1 ton 1.5 ton 2 ton 3 ton othersAerospace 0 62 2 3 0ASC 0 3 1 0 0Bio school 7 25 0 0 0CDEEP 0 0 12 0 0CFDVS 0 4 0 0 0Chemical 5 93 0 0 0Chemistry 2 65 2 0 0Civil 2 34 0 0 0Comp. Sc. 0 43 10 0 0Earth Sc. 0 12 0 0 0Electrical Gaitonde bldg 0 18 0 0 0Electrical Main+annex 0 93 3 0 0Energy Science and Engg. 0 6 0 0 0Humanities 0 19 0 0 0IDC 0 14 0 0 0IRCC 0 9 6 0 0KReSIT 0 105 0 0 6Main Bldg. 6 37 21 0 0Mathematics 0 13 3 0 0Mechanical 0 27 4 0 0Metallurgy 0 73 1 0 0Physics 0 57 2 0 0SOM 0 15 1 0 0Total 22 827 68 3 610% excess assumed for

unaccounted areas 1020

This is 44.3% of the contract demand at unity pf and 63.2% at 0.7 pf lag. But the whole

demand is not usually at one time due to a diversity factor. The kW/ton based on the rated

values was found to be 1.375. As air conditioning load is about 50% of the campus contract

demand, any savings achieved in this field would be significantly important.

The tonnage of AC per unit of total area for different departments is shown below in Fig.

3.2. A wide variation in the values can be seen in this plot, but the numbers of labs in the

department which are air conditioned have a clear influence on this.

15

0

0.005

0.01

0.015

0.02

0.025

0.03

ESE

chemistr

y

chemica

l

physics

bio school

aerospace

metallurgy

electr

ical g

aitonde b

ldg.

electr

ical m

ain+annexe

civil

mechanical

humanities

mathematic

s

comp. sc.kres

it

CFDVS

CDEEPSOM

IRCC IDC

Earth Sc.

ASC

Main bldg.

departments

AC

tonn

age

per s

q.m

.

Fig. 3.2 Room air conditioning load (ton per unit of total floor area) for different

departments

A study of the AC tonnage per unit air conditioned area for the Main Building was done

and it was found that the average is about 0.08 T/m2 which is fine by the standards specified

[Please refer to Appendix C]. Few areas exceed the limits specified and resizing in future could

be an option. In many cases, the utilisation of the area has changed when compared with the

building plans.

16

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0.04

0.06

0.08

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0.16

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tonn

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ton/

sq.m

Fig. 3.3 Room air conditioning load (ton/ air conditioned sq.m) for offices in Main Building

3.1.3 Computers/printers

Computers and monitors account for 30%-40% of the energy used by office equipment.

Their energy consumption is second only to office lighting. It is estimated that a power

managed computer consumes less than half the energy of a computer without power

management.

The total number of computers and printers in different departments in the campus is as

shown below. The computers in hostels and residential area are not included here.

17

Table 3.2 Computers and printers in departments and Main Building

S No Department/BuildingComputer PrinterCRT

Monitor

LCD

MonitorLaser Jet DeskJet

1 Aerospace 77 12 8 3

2 CESE 41 4 5 4

3 Bio-school 38 8 7 -

4 SOM 104 11 9 1

5 Chemical/Chemistry 194 44 29 3

6 HSS 32 1 1 -

7 Metallurgy 63 24 11 4

8 Earth Science 39 8 7 1

9 IDC 42 33 8 -

10 KRESIT 160 81 15 2

11 Electrical 226 170 33 -

12 Civil 90 36 10 1

13 Main Building 171 92 83 8

14 Mechanical 76 36 13 1

15 CSRE 71 11 9 4

16 Physics 90 23 8 5

17 Energy Systems 24 3 4 2

18 Central Library 31 7 3 1

19 SYSCON 27 11 4 -

20 CFILT 8 5 1 1

21 CFDVS 18 17 2 -

22 CDEEP 20 22 7 3

23 Mathematics 39 24 3 1

24 CSE 20 126 3 1

25 IEOR - 8 - -

26 CTARA 3 1 3 -

27 Faculty 288 145 371 62

18

S No Department/BuildingComputer PrinterCRT

Monitor

LCD

MonitorLaser Jet DeskJet

1 Aerospace 77 12 8 3

Total 1992 963 657 108

Thus there are a total of about 3,000 computers and about 800 printers in the departments.

3.2 Hostels

There are 14 hostels in IIT Bombay, having an aggregate connected load of 1.25MW.

The loads are analyzed after segregating them into lighting, fan, geyser and wash room loads.

Here, the personal computers or laptops of individual students in their rooms or in hostel

computer rooms are not included.

Table 3.3 Connected loads (excluding computers) in hostels

Fig. 3.4 Distribution of connected load in hostels (excluding computers)

Hostel

Connected

Load of

Light & Fan

in kW

Connected

Load of

Geysers in

kW

Connected

Load of

Wash

Room in

kW

Total Connected

Load of Light, Fan,

Geysers & Wash

Room in kW

Average

Load of the

Hostel in

2007 in kW

H1 42.5 18 4.42 64.92 30.7H2 46.6 24 1.76 72.36 26.22H3 46.3 28 2.52 76.82 38.25H4 52.1 24 2.31 78.41 44.55H5 40.3 12 1.76 54.06 32.64H6 49.8 16 5.9 71.7 37.72H7 34.9 40 2.52 77.42 39.73H8 37.64 19 2.02 58.66 37.93H9 38.47 39 2.05 79.52 24.75H10 19.74 36 3.72 59.46 21.8H11 38.4 42 3.38 83.78 33.35H12 97.28 108 4 209.28 77.03H13 97.28 108 4.6 209.88 80.87

Tansa 15.72 32 2.32 50.04 29.29Total 657 546 43 1246 555

19

3.3 Gulmohar and guest houses

Gulmohar is the alumni building of the campus in which a cafeteria, a banquet hall, a

bank and the placement office are situated. There are two guest houses in the campus. The first

one is the Jal Vihar, also called old guest house with 25 rooms and two suit rooms. The second

is Vanvihar with 51 rooms. The connected load details are as shown below.

Table 3.4 Connected Load in kW for Gulmohar and Guest Houses

Jal Vihar Van Vihar GulmoharLighting 7.6 34.26 1.68

Air Conditioners 19.05 35.19 43.2Others 52.67 112.05 1.21Total 79.32 181.5 46.09

The cumulative connected load of these buildings comes to 307 kW.

3.4 Street lighting and common area lighting

All street lights and garden lights in the campus, corridor lights, and lights on

gymkhana grounds were accounted. The connected load is 193.7 kW, and about 60% of this

includes the illumination in the Gymkhana grounds, and these lights are normally operational

only in the evenings. The quantification is as follows.

Table 3.5 Common area lighting loads

A. Street & Corridor Lighting

No Fitting Rating

(W)

Number

of

Fittings1 Filament Lamp 100 162 Compact Fluorescent Lamp 18 103 Fluorescent Lamp 40 334 Fluorescent Lamp 80 525 Sodium Vapour Lamp 70 5116 Sodium Vapour Lamp 150 997 Sodium Vapour Lamp 250 148 Mercury Vapour Lamp 150 1469 Metal Halide Lamp 400 2

20

B. Gymkhana Grounds

No Ground/Court Fitting

Rating

(W) Nos.1 Football Metal Halide 2000 242 Hockey Metal Halide 800 163 Basketball Metal Halide 800 244 Volleyball Metal Halide 800 325 Badminton Metal Halide 250 16

The total number of lighting fixtures in common area is 985.

3.5 Water pumping

The water supply to the institute is taken from the BMC (Brihan-mumbai Municipal

Corporation) lines which pass just outside the campus. The connection diagram of the main

pumping station is as in the following Figure 3.5.

There are two water tanks which store water coming from the BMC lines. One of the

tanks stores water which is supplied to all departments and residential complexes. Water from

this tank is pumped on to an overhead tank which is located next to ANANTA building. Water

from this overhead tank gets distributed to various pumps by the effect of gravity. The second

tank stores water for supplying the same to all hostels and Tansa house.

The ratings of the pumps are as shown in table 3.6, and it comes to a connected load of

343.2 kW. The motors are operated in a daily pattern as shown in Appendix F.

Table 3.6 Ratings of pumps in IIT-B

Serial

no

Motor

capacity

Electrical

loading

Flow rates

in m3 / hour1 160 HP 0.71 308.72 75 HP (new) 0.68 227.673 75 HP (old) 0.70 212.234 60 HP 0.89 208.375 30 HP - 1 0.94 92.616 30 HP – 2 0.94 92.61

21

Fig. 3.5 Connection diagram of Main Pumping Station

.

The water storage tanks in the campus are as shown in Table 3.7 and the total storage

capacity is about three times the average daily water consumption of the campus.

Table 3.7 Capacity of water storage tanks

No. Tank Capacity ( m3)1 Tank 1 5002 Tank 2 5003 Overhead 900

22

3.6 Energy usage in hostel kitchens

Each of the hostels in the campus is equipped with a kitchen, except hostel 7, where it

is under re-construction. The staff canteen in the campus is also having an associated kitchen.

The connected load and LPG usage pattern in these hostels is shown below.

Table 3.8 Details of energy consumption and food wastage in hostel kitchens and staff canteen

No Kitchen Connected Electrical Load (kW)

LPG Usage per day (kg)

Food Wastage per day (kg)

1 H 1 11.49 67 202 H 2 8.5 57 203 H 3 6.58 43 204 H 4 7.75 50 205 H 5 10.7 36 256 H 6 10.9 50 207 H 8 10.7 43 208 H 9 10 57 209 H 10 5.3 28 1010 H 11 10.7 50 1511 H 12 & 13 10.7 133 12812 Staff Canteen 3.2 57 10

Total 106.5 671 328

Assuming the calorific value of LPG as 46.4 MJ/kg, the daily energy consumption in

LPG is 31 GJ. Thus the major energy consumption is from LPG only. LPG consumed per

student in different hostel kitchens is as shown below.

Fig. 3.6 Per capita per day consumption of energy (as LPG) for different hostels (red line indicates Institute average)

23

3.7 Central air conditioning for library

The system has a rating of 110 ton refrigeration capacity and mostly operates at part

load. It has been discussed in Appendix I. The savings could not be quantified due to

difficulties in taking measurements. However, considerable potential for energy savings may

exist as the efficiency of the system will be lower at part loads.

24

4. MEASUREMENTS PERFORMED

Data obtained based on measurements are included in this chapter.

4.1 Room air conditioners

A commercially available energy saver for room ACs was procured* and measurements

were carried out for over 60 hrs, with and without the saver, for a typical 1.5 ton Voltas Vertis

AC in the DESE Urja Computational Lab from 7th- 12th May, 2008.

0

500

1000

1500

2000

2500

900 1100 1300 1500 1700

Time (hrs.)

Pow

er (w

atts

)

Fig. 4.1 AC Load curve for the day without the energy saver for ACs (on 12th May, 2008)

0

500

1000

1500

2000

2500

900 1100 1300 1500 1700

Time (hrs.)

pow

er (w

atts

)

Fig. 4.2 AC Load curve for the day with the energy saver for ACs (on 7th May, 2008)

---------------------------------------------------------------------------------------------------------

* The Aircosaver was procured from M/s Ecopower Ltd., Mumbai. These measurements are purely from a study point of view and are applicable only in the specific context. They should not be construed as an endorsement of the merits or deficiencies of the said product(s) by IIT-Bombay.

25

Table 4.1 Energy savings achieved by installation of energy saver for a 1.5 ton AC

Time hrs. Energy consumed without

saver (in Watt hrs.)

Energy consumed with saver

installed(in Watt hrs.)

% savings

1000-1110 2532 1368 461140-1230 1886 1086 42.41250-1310 372 334 10.21340-1430 1900 1050 44.71530-1650 1650 1544 41.7Whole working

day (7.5 hrs)

14880 8887 40.3

Thus savings of the order of 35-40% was seen when the energy saver was fitted with

some deterioration in comfort conditions. It can be inferred that the apparatus provides better

savings when used for oversized ACs with a higher duty cycle.

4.2 Lighting and fan loadsThe energy consumption of FTLs (Fluorescent Tube Lights) which are commonly used

in the campus is shown below. The energy consumption of the FTLs used in hostels is found to

be high compared to 28W T5 FTL.

4.2.1 Lighting in Hostels

Table 4.2 Measurements for lighting in hostelsFTL with Electronic Ballast [Room

No.48, H5 (3rd April 2008)V(volts) I(Amp) P(W) P.F.

226.5 0.54 38 0.522

Few of the lux measurements taken in the campus are as shown below.

Hostels Hostel 5 Hostel 3Room No #52-FTL #48-FTL #49-FTL #49-14W CFL #289Day without Fl. lamp 85 31 38 87Day with Fl. lamp 170 133 150.6 64 107Night 75 95 105 52 78Study Table 70 31 55 10 98

The lux levels are found to be far less than the standard values in hostel rooms.

FTL with Magnetic choke [Room No. 49,H5](3rd April 2008)

V(volts) I(Amp) P(W) P.F.224.3 0.532 42.5 0.5813

26

4.2.2 Lux meter Readings for Departments:Table 4.3: Lux meter readings for departments

Mechanical Engg.location With daylight+lights Only daylight Only lightsNuclear Engg Lab 180,162 110,120 135Refrigeration lab 183,156 120 155Metal Forming lab 119,104 44,32,22 101Testing of material 91,87,61 90Robotics Lab 112,126 30 100Fracture Mechanics 119,130 31 102CAM 481,400 220,120 395,400Room no. 303 134,113 78323 188 128301 193CFDL 198 65IEOR 178 62308 193 80309 193 82311 144,136 88201 150 81202 136 79217 136 77104 122 65Electrical Engg.Machine Lab: 185,180,170 110,105 140,150Field computation lab: 210,200 150,155 170,175Power electronics research lab 190,185,180 130,140 155power electronics hardware lab

200,210,195 65,120 140,160

power system computation lab 250,225 105,110 170,180Micro electronics lab 360,400 110,105 220,200Gaitonde Building:R-001 340,300 127,120 221R-002 350 180 282,234Library 436,446 250,285 379,300

27

4.2.3 General LightingTable 4.4: Lux level measurements for common area lighting

Here:Average Horizontal Illumination- AH

Variation in Horizontal Illumination- VH

Average Vertical Illumination- AV

4.2.4 FansFrom the power consumption of ceiling fans with resistance and electromagnetic

regulators, it was seen that the latter consumes less power at lower speeds of the fan.

Table 4.5 Sample measurements on fans in hostels

Sample reading [Room No 49, H5] (4th April 2008)

Ceiling Fan Resistance regulatorFanSpeed V(volts) I(Amp) P(W) P.F.

1 224.7 0.43 41 0.7912 225.6 0.43 56 0.93 223.81 0.453 63 0.9564 223.4 0.45 66 0.984

ON 223.3 0.452 70 0.996

Sample Reading [H5 Mess] (4th April 2008)

Ceiling FanElectronic Regulator

Fan Tab V(volts) I(Amp) P(W) P.F.1 233.7 0.26 13 0.3852 233.6 0.396 37 0.663 233.7 0.382 49 0.815

ON 233.18 0.405 68 0.997

28

4.3 Energy consumption in Hostels: Wash Room & Geysers

The power consumption of H5 wash room for 5 hours is shown in Fig. 4.3. The

measurements were taken at 15 minute intervals.

Fig. 4.3 Power consumption in H5 washroom for 5 hrs. on 5th April 2008

The typical power consumption of geysers installed in Hostel 5 is shown below in Fig. 4.4.

Fig. 4.4 Power consumption of 2 kW Bajaj geyser in Hostel 5 on 6th April 2008

29

4.4 Computers & Printers

The power consumption by the computer and printer under different modes of operation are shown below.

Table 4.6: Measured power consumption for computers and printers in different operating modes

S No System EquipmentMode of

OperationPower (W)

Power

factor1 LCD Monitor On 29.8 0.596

2 Jwala CPU On 56.0 0.620

3 JwalaMonitor &

CPUOn 105.5 0.650

4 Vayu CPU On 60.0 0.650

5 Prithvi Monitor On 53.4 0.620

6 Urja CPU On 48.0 0.560

7 Urja System Hibernate 2.5 0.200

8 Urja Monitor On 55.0 0.634

9 Urja System Sleep Mode 3.0 0.225

10 - Laser Printer On 3.0 0.360

4.5 Pumping

The power consumption and efficiency of the pumps used in the campus are as shown below.4.5.1 Pumps for Department and Residential complexes

Table 4.7: Details of pumps for departments and residential complexes

Pump Hydraulic Power(kW)

Electrical PowerConsumption

(kW)

Overall systemEfficiency

160HP 37.0 78.6 0.4775HP NEW 24.3 37.7 0.6575HP OLD 22.2 38.6 0.58

60HP 21.7 33.2 0.65

30

Fig. 4.5 Efficiency-discharge for various pumps at Main Pump House

It is observed that the 75HP (new) pump set is giving the best performance among all, since it

has high discharge as well as high efficiency.

4.5.2 Hostel PumpsTable 4.8 Details of pumps in some hostels

Pump Hydraulic Power

Electrical PowerConsumption

Overall system

Efficiency30HP 13.5 21.2 0.6430HP 13.5 21.2 0.64

31

5. BENCHMARKING

Energy benchmarking involves the development of quantitative and qualitative

indicators through the collection and analysis of energy-related data and energy management

practices. Benchmarking in simplistic terms is the process of comparing the performance of a

given process with that of the best possible process and to try to improve the standard of the

process to improve quality of the system, product, services etc. It allows organizations to

develop plans on how to adopt such best practices, usually with the aim of increasing some

aspect of performance. Benchmarking may be a one-off event, but is often treated as a

continuous process in which organizations continually seek to challenge their practices.

Benchmarking is a method which should be used on a continual basis as best practices are

always evolving.

Benchmarking of energy consumption is a powerful tool for performance assessment

and logical evolution of avenues for improvement. Historical data, well documented, helps to

bring out energy consumption and cost trends month-wise / daily. Trend analysis of energy

consumption, cost, relevant production features, specific energy consumption, help to

understand effects of capacity utilization on energy use efficiency and costs on a broader scale.

The basis for benchmarking the energy consumption at IIT-B is energy consumed per person

(includes teaching staff and students). The benchmarking parameters here are,

• Departmental energy performance

• kWh consumed per sq.m of area and

• kWh consumed per capita

5.1 Departmental energy performance

The details of the annual energy consumption in various departments are as shown here

in Fig. 5.1.

32

0

200000

400000

600000

800000

1000000

1200000

1400000

Compu

ter sc

.

Electric

al Eng

g.

Chemist

ry

Chemica

l

Mecha

nical

Bio Scie

nces

Metallu

rgy

Mathem

atics

Aerosp

ace

Civil

Physic

sCSRE

IDC

SJM S

OM

Human

ities

Earth S

c.

CESE

Reliab

ility

departments

kWh

ener

gy c

onsu

mpt

ion

Fig. 5.1 Total annual energy consumption of different departments in 2007

5.2 Per unit area energy consumption

The energy consumption per sq. m for each department is determined and it is

normalized with respect to average value of per sq. m energy consumption of the institute,

which was set as the basis. For normalizing, the Institute average of 75 kWh/sq.m./year is

taken as the denominator.

The results are shown in Fig. 5.2.

33

Fig. 5.2 Normalized per unit area energy consumption (kWh/sq.m/year) for departments

From the above graph it can be observed that Chemistry, KReSIT, Electrical,

Mathematics, Mechanical and Bioscience departments are above the base line of per sq. m

energy consumption as their values are greater than one.

5.3 Per capita energy consumption for departments

The per capita (student + faculty) consumption for each department is determined and it

is normalized with respect to the average value of the per capita consumption for the institute.

Basis for 2007: 1384 kWh/person/year.

From the graph (Fig. 5.3) it can be observed that Chemistry, KReSIT, IDC,

Mathematics, Bio-science, CSRE are above the base line of the per capita consumption as their

values are greater than one.

34

Fig. 5.3 Normalized per capita electrical energy consumption (kWh/person/yr.) for

departments

5.4 Per capita electrical energy consumption in hostels

The general trend of electricity consumption in the hostels for last three years is as

shown below in Fig. 5.4.

The average tariff for the hostels is about Rs. 5.13 per kWh** of electrical energy

consumed. For the year 2007, the average electricity cost for hostels on per student basis is

calculated to be Rs. 4,300 per annum. The actual amount paid by the students during 2007-08

as the fee contribution (electricity, fan and water charges) was Rs. 600 per annum. This amount

has since been raised by Rs. 2000 and so the subsidy has been eliminated.

** Please refer to Appendix H for the hostel bills. There seems to be some discrepancy in the way the Electrical Maintenance Section calculates the amounts as hostels should come under residential tariff which is Rs. 2.6 per kWh (basic charge).

35

A graph showing the present institute subsidy and the student fee contribution to the

annual hostel electricity bills in 2007 is shown below (Fig. 5.5). The institute subsidy is to the

extent of 85% of the bills. So, any savings achieved in the hostel bills is directly beneficial to

the institute and can be used for other works.

Electricity consumption in hostels (2005-2007)

0

100000

200000

300000

400000

500000

600000

700000

800000

1 2 3 4 5 6 7 8 9 10 11 12 13

hostel no.

units

of e

lect

ricity

con

sum

ed

200520062007

Fig. 5.4: Annual electricity consumption in hostels over the years 2005-2007

36

electricty bill in hostels: student and institute contributions

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

4000000

1 2 3 4 5 6 7 8 9 10 11 12 13

hostel no.

annu

al a

mou

nt p

aid

in R

s.

institute subsidystudent fee contribution

Fig. 5.5: Annual electricity bills for hostels: student and institute contributions

during the year 2007

5.5 ECBC Standards and comparison

As per the Energy Conservation Building Code (ECBC) – 2006, published by the

Bureau of Energy Efficiency (BEE), Govt. of India, the recommended levels of lighting power

density are as given below in Table 5.1.

Table 5.1: ECBC recommended levels for lighting power density

Space/ application Lighting power density in W/sq.m.Enclosed offices 11.8Offices-open plan 11.8Conferences/meeting rooms/ multipurpose 14.0Classrooms/ lecture theatres 15.1Lounge 12.9Dining area 09.7Food preparation 12.9Library stacks 18.3Library reading area 12.9Workshops 15.1Cafeteria 15.1

37

The measured values for locations at IIT-Bombay are as follows.

Table 5.2 Measured values of lighting power density at select locations in IIT-

Bombay

Space/ application Lighting power density in W/sq.m.Main Building office 07.8Conference room 14.8Classrooms in Main Building 13.5Library reading area 07.3Hostel Lounge (Hostel 5) 08.1Hostel mess (Hostel 13) 07.6Hostel mess (Hostel 5) 10.7Staff Canteen 05.2Hostel rooms (Hostel 13, Room B 108) 04.5Hostel rooms (Hostel 5, Room 52) 05.6Hostel rooms (Hostel 5, Room 49) 03.8

It can be seen that the lighting power density values in the Institute are not higher than

the ECBC standards.

38

6. ENERGY CONSERVATION AND EFFICIENCY

6.1 Implementation Measures

No Recommended MeasureEnergy savings per year

Savings in Rs. Per

year

Capital Investment

in Rs

Simple Pay Back

Period

1

Replacing Electromagnetic ballast by Electronic

ballast in FTL in study room and using 18W

CFLs in staff canteen

7400 kWh 38,000 10,000 4 months

2Replacing Electromagnetic FTLs by T5 in

Departments (10500 Fittings)

6,95,500

kWh34.8 lakhs 63 lakhs 19 months

3Replacing common area lighting in departments

with T5 FTL /CFL

1,18,800

kWh2.7 lakhs 4.32 lakhs 17 months

4Replacing 1970 FTLs used in student rooms in

H1 to H7 with 28W ballast FTLs.

1,11,000

kWh5.4.lakhs 2.56 lakhs 6 months

5

Replacing rheostatic speed regulators of 1950

fans in the student rooms (H1 to H7) with

electronic speed regulators

59,300

kWh2.8 lakhs 2.7 lakhs 1 year

6Replacing 1700 FTLs used in student rooms in

H8 to H11 with 28W ballast FTLs.

72,100

kWh3.4 lakhs 3.4 lakhs 1 year

7

Replacing rheostatic speed regulators of 1045

fans in the student rooms (H8 to H11) with

electronic speed regulator

15,600

kWh79,300 1.57 lakhs 2 years

8Installing solar water heaters in all hostels [For

calculations, refer Appendix D]

10,35,000

kWh49.68 lakhs 182 lakhs 3.7 years

9 Solar Water Heater for Guest Houses15,700

kWh80,000 2.6 lakhs 3.3 years

10

(a)NISARGUNA biogas plant for food waste

processing (300 kg capacity)

OR

1825 LPG

cylinders of

14.2 kg6.41akhs 6.54 lakhs 13 months

(b)ARTI biogas plant for food waste

processing(300 kg capacity)

900 LPG

cylinders of

14.2 kg

3.1 lakhs 95,000 4 months

11 Installing 200 Aircon savers for 1.5 Ton ACs with 4,38,000 21.9 lakhs 13 lakhs 8 months

39

a higher duty cycle (> 8 hrs./day) kWh

12If 300 AC users can be made to switch of the ACs

15 mins. prior to leaving the office.

51,300

kWh2.5 lakhs nil nil

13

Adopting a normal energy saving power setting

for computers [For calculations, refer Appendix

E]

6,20,000

kWh31.1 lakhs nil nil

14Rescheduling the pump operating pattern [New

pattern is given in Appendix F]

50,420

kWh2.42 lakhs nil nil

15

Replacing faulty non-return valves of pumps,

replacing 75 hp motors with 55 hp and 160 hp

motor with 90 hp motor

49,100

kWh2.4 lakhs 1 lakh 4 months

16

Replacing 160HP motors with an energy efficient

55 kW motor and changing its piping with

diameter of 250 mm.

1,07,300

kWh5.3 lakhs 23 lakhs 4 .2 years

Total savings

34,46,500

kWh and

1825 / 900

LPG

cylinders

1.75 crores 3.05 crores 1.7 years

Implementation of all the above measures can bring about a total saving of around Rs.

1.75 crores per year, i.e. 17% of the present electricity bill. The total investment required

would be to the extent of Rs. 3.05 crores and an average simple payback period of around

1.75 years.

In addition to the above, a set of general recommendations is provided in Appendix G.

6.2 Energy Management Structure

In order to streamline the use of energy in the IIT-B campus and to ensure its efficient

utilization, we propose three possible energy management structures. A final decision on

the type of energy management structure suitable for the institute should be taken by the

Institute management.

40

I. Appointment of an Energy Manager for the institute, with suitable experience and a

proven track record. The person shall be responsible for the day to day energy

conservation activities. New staff should be allotted to the Energy Manager or some

staff members from Electrical Maintenance Section be made responsible to him/her.

An annual review of the energy performance of the institute is to be performed and

a certain percentage of the quantified savings be shared with the Energy Manager.

II. The Executive Engineer (Electrical) should himself take over the responsibility of

ensuring efficient energy use on the campus. This will ensure prompt

implementation of measures. This system may also require additional staff. A

performance related incentive in the form of a bonus can be provided to the

Electrical Maintenance staff based on savings achieved.

III. Formation of an Institute level committee headed by the Dy. Director to review the

implementation of energy conservation measures. All departments and section

heads should submit a bi-annual report of compliance for review and action.

Sections/ departments not achieving savings to be penalized and suitable incentives

may be given to the performing departments.

An annual review of the implementation of the energy saving measures should be taken up

and performance should be monitored. A report of the same should be sent to the Director.

Electrical energy consumption should be made a subject in the Institute budget with

separate heads for departments and hostels. Energy performance can be a basis for providing

incentives to hostels and departments.

41

APPENDIX A

LIST OF MEASURING INSTRUMENTS USED

1. Power analyzer (measures active, reactive, apparent power, power factor, energy

consumed)

2. Lux meters (to measure lighting levels in lux or lumens per sq.m.)

3. Thermometers –digital

4. Thermocouples

42

APPENDIX B

DISTRIBUTION OF ROOM ACsThe distribution of the room air conditioners by type and utilization location is as

shown below in Fig. B.1 and B.2 respectively.

71%

29%

window

split

Fig. B.1: Distribution of room air conditioners by type

57%

19%

24%

labs

rooms

offices

Fig. B.2: Distribution of room air conditioners by utilization areas

43

APPENDIX C

BEE THUMB RULES FOR AIR CONDITIONING LOADSThe recommended levels for comfort air conditioning loads as per the BEE (Bureau of

Energy Efficiency) thumb rules are as given below in Table C.1.

Table C.1: BEE thumb rules for comfort AC loads

Type of office Heat load in ton rating per sq.m.Small office cabins 0.10Medium size offices (seating 10-30 people) 0.06Large multi-storied office buildings with

centralized air conditioning

0.04

44

APPENDIX D

CALCULATIONS FOR SOLAR WATER HEATING SYSTEMS (SWHS)

FOR HOSTELSA sample calculation for the storage tank volume, collector area requirement and

payback period for the hostel no. 5 has been done below.

Total no. of hot water users in hostel = 329

Assume that amount of hot water used per student = 20 litres / day.

Total amount of water used per day in the hostel = 6580 litres.

Now typically 2 m2 of collector gives 125 Litres per day of hot water output at 60 °C

Normal tolerable hot water temperature by measurement we found to be 40 °C.

However, assuming that the end user consumes hot water at 60 °C (since piping losses are also

involved) the collector area required for the hostel is 106 m2.

The option is either to go for forced circulation or natural circulation. Forced circulation

requires various accessories and proper control of the pump. Hence selecting natural

circulation system and considering three wings in hostel, the collector area required on each

wing is 37 m2.

Cost of collector = Rs. 10,000 / m2.

Total capital cost required for installation of solar water heater in the hostel = 10,000*106

= Rs 10,60,000

The total energy consumption in the hostel considering 12 hours of geyser operation is found to

be 6*1.5*12=108 kWh/day

Total energy consumption in a year = 27,000 kWh (assuming 250 days operation)

Assuming the cost of electricity as Rs. 4.8 / kWh,

Total electricity bill due to geysers in the hostel = 27000*4.8

= Rs. 1, 29,600 /-

Simple Payback period (SPP) = (capital cost of SWHS / Electricity bill per year)

= 8 years.

This is a bit on the higher side due to the lower number of geysers in Hostel 5.

45

The same calculations are done for each hostel in which, capital required and payback

period are calculated and are listed below.

Table D.1: Calculations for SWHS in hostels

Comments:

1. The pay back periods of the hostels are found to be in between 1.8 to 8 years.

2. The discrepancy in the payback period can be attributed to the variation in no. of

students per geyser as reported earlier.

3. Solar heater option is looking quite attractive but, some efforts are needed for

synchronization of output of solar heater system and geyser.

4. Natural circulation system is recommended.

Sr. no.

Hostel Numbers of geysers

Energy consumed

(kWh)

Energy Cost(Rs.)

No. of students

Water requirement

per day

Collector Area reqd.

Cost of collectors

SPP in years

1 H-1 9 40500 202500 315 6300 100.8 1008000 52 H-2 12 54000 270000 396 7920 126.72 1267200 4.73 H-3 12 54000 270000 414 8280 132.48 1324800 54 H-4 12 54000 270000 512 10240 163.84 1638400 65 H-5 6 27000 135000 329 6580 105.28 1052800 86 H-6 8 36000 180000 432 8640 138.24 1382400 7.67 H-7 18 81000 405000 279 5580 89.28 892800 28 H-8 8 36000 180000 416 8320 133.12 1331200 79 H-9 18 81000 405000 485 9700 155.2 1552000 3.8

10 H-10 18 81000 405000 437 8740 139.84 1398400 3.511 H-11 21 94500 472500 430 8600 137.6 1376000 2.912 H-12 36 162000 810000 514 10280 164.48 1644800 213 H-13 36 162000 810000 530 10600 169.6 1696000 2.114 Tansa 16 72000 360000 200 4000 64 640000 1.8

46

APPENDIX E

CALCULATIONS FOR POWER SAVINGS IN COMPUTERS

Formula used:

Total energy consumed for each setting

= No of computers x Duty cycle x 24 x Average power x No of operating days in a year.

The table below shows the existing settings for monitors on the campus. There are 1992

CRT monitors and 963 LCD screens. The CRT monitor consumes 66 W and LCD monitors

consume 30 W. We have assumed 6.5 hrs of monitor ON (i.e. in use) and 17.5 hrs when it is

not being used and 300 days operation in a year.

Table E.1 Present annual energy consumption for computer monitors on campus

S NoTurn off Monitor

Percentage of existing

monitorsEnergy Consumed

(kWh)1 Never 16 1847372 20 min 54 1815513 30 min 16 550534 40 min 14 49274

In addition, the CPUs consume 40 W. Using a similar assumption as given above, the

annual energy consumption is as tabulated in Table E.2.

Table E.2: Present annual energy consumption for CPUs

S No System Standby PercentageEnergy Consumed

(kWh)1 Never 83 7063632 10 min 17 45255

Now, using the recommended settings for all the computers, the energy consumption

would be as per Table E.3.

47

Table E.3: Annual energy consumption for all computers with recommended power

settings

ItemTurn off Monitor Percentage

Energy Consumed (kWh)

Monitors 10 min 100 328796CPUs 20 min 100 271455

The annual energy savings thus obtained is about 6, 20,000 kWh, i.e. about Rs.31.1

lakhs (assuming Rs. 5 per kWh).

48

APPENDIX F

OPERATING SCHEDULE OF PUMPS AT MAIN PUMP HOUSE160 HP:

This pump is operated in the peak hours, when water is required the most. On the

whole, this pump operates for 8 hrs every day.

75 HP AND 60 HP PUMPS:

The two 75 hp and the 60 hp pump are set into operation for four hours alternatively.

30 HP PUMPS

The 30 hp pumps are in operation from 0500 to 0100 hours everyday. Hence, the

pumps are in operation for 20 hours in a day and each pumps alternatively works for 4

hrs. There fore, each of these pumps is on for ten hours in a day.

The prevailing operating schedule and a new proposed schedule are shown in Fig. F.1.

Fig. F.1: Comparison of the existing and proposed loading of pumps at Main Pump

House

49

An annual saving of Rs. 2.42 Lakhs can be achieved using the modified schedule.

In order for this proposal to work, the pumps at various buildings have to run after 22:00 hrs so

that the water demand is lowered during peak hours. This will also bring in savings due to time

of usage tariff for those smaller pumps.

50

APPENDIX G

GENERAL RECOMMENDATIONS

In addition to the recommendations given in section 6.1, a few more general ones are

presented here. The savings due to their implementation could not be easily quantified, but

their importance cannot be understated. Implementing all these measures, a total saving of

20-25% can be achieved without compromising much on the existing facilities and comforts.

G.1 Lighting

• Photo sensors to be installed in central library to utilize optimum day lighting. A

scheme for the same has been proposed here.

Proposed areas:

1) Central Library Ground Floor Reading room near window:

Currently 10 FTL are controlled with one switch. Since it is near to window, sufficient

day lighting is available. So if we use photo sensor to control this lights we can reduce

the duty cycle and energy consumption.

2) Central Library G Floor Reference section near window:

Presently 5 FTL are controlled with one switch. By slight modification in the circuit we

can use photo sensor to control 5 lamps.

3) Second Floor Journal reading room near window:

Presently 5 FTL are controlled with one switch .photo sensor can be installed to control

lights in the alternate row.

• Currently, approximately 50% of the street lights are controlled by timers. It is

recommended that all the lights be taken under this control scheme to reduce chances of

over-usage due to human error.

• The existing split switching system to be further enhanced/improved in inside corridors

of Hostels 12 and 13

• Hostels 12 and 13: Natural lighting can be considered for corridors.

• Split switching: In the internal corridors of H13, the present arrangement is that

alternate lights are clubbed together in one switch. Yet, the distance of them is 7 m and

seems to be too close to each other. As such the tubes are at a distance of approx 3.5 m

51

So, the split switching may be such that far off ie., may be the first and fourth tubes

may be included in one switch. Alternatively, the alternate tubes may be removed

form the installation.

G.2 Geysers

• It is advisable to have manual switching of the geyser in peak periods, as most of the

geysers were ON for 24 hours.

G.3 Room Air Conditioners

• It was found that in many cases, the utility type of the area has changed and the AC

may no longer be required there. This can save expenses on procurement of new ACs.

• Proper maintenance of ACs is not being done. Many of the older ACs could be

replaced. About 20-22 % of all installed ACs suffer from some or the other defect. In a

large number of cases, the filters were found to be dirty (3%), thermostats not working

(7%), ice formation/ water leakage (1%), rusting (3%), fans not working (4%), swing

problems (3%) etc. were observed.

• The heating load can also be reduced by reducing the consumption by other sources

like lights, computers etc. and the occupancy needs to be considered. Explore the

possibility of occupancy sensors.

G.4 Pumping

• Rescheduling of small pumps at individual buildings to late night timings

• Installation of water meters at every building to make sub-sections inside IIT

accountable to the water being used.

52

APPENDIX H

SUMMARY OF HOSTEL ELECTRICITY BILLSTable H.1 Hostels electricity consumption during 2007 and amounts paid in rupees

Month

Hostel 1 Hostel 2 Hostel 3 Hostel 4 Hostel 5 Hostel 6 Hostel 7Units Amount Units Amount Units Amount Units Amount Units Amount Units Amount Units Amount

Jan 21223 95003 22591 101114 30025 134326 33277 149254 23106 103415 26613 119083 30576 1369897Feb 22235 129776 23398 136558 34762 202827 37734 220558 27064 157936 29601 172730 38112 222562Mar 20342 117234 18116 104418 31399 180895 34536 199356 25474 146782 28106 161935 33209 191516Apr 23221 113851 16676 81803 37105 181834 40468 199773 29364 143930 29013 142211 41076 201478May 19745 111762 12775 72350 18700 105834 25127 142594 18382 104055 28391 160651 22057 125035Jun 22330 108491 5608 27364 23816 115700 26274 128025 21161 102819 27932 135669 24575 119582Jul 23312 99835 9162 39351 17698 75838 24408 104920 18123 77654 27042 115779 21256 91246Aug 25260 134141 33606 178421 29356 155872 35810 190514 26145 138836 28896 153432 35164 186887Sep 26122 129655 30638 152046 32337 160469 36879 183389 27519 136582 26828 133156 39668 197076Oct 23960 127205 10692 56838 31343 166360 35859 190711 26597 141190 29354 155812 27385 145569Nov 22526 113905 24830 125540 28529 144220 34212 173319 26512 134034 27757 140321 20736 105065Dec 18968 91793 21638 104692 19977 96668 25633 124392 16489 79817 20912 101185 14259 69244

MonthHostel 8 Hostel 9 Hostel 10 Hostel 11 Hostel 12 Hostel 13

Units Amount Units Amount Units Amount Units Amount Units Amount Units AmountJan 27600 123692 17047 76347 15541 69594 22078 98798 49154 220385 57995 259882Feb 31340 183071 20005 116771 17396 101532 24913 145367 48990 286397 62446 364866Mar 28618 165083 18377 105921 16743 96488 23452 135115 46299 261282 56947 328587Apr 32763 160773 22407 109865 20953 102721 27094 132790 55314 271594 71551 351099May 21673 122864 12862 72842 11794 66778 21508 121706 47395 268709 44981 255059Jun 22937 111635 13522 65759 12311 59858 25485 123772 43894 213708 40381 202017Jul 21100 90580 12703 54487 10893 46725 24512 104939 47526 203938 38988 167442Aug 30652 162948 20537 109083 18428 97869 26287 139565 47412 252268 55301 294123Sep 32832 163124 22403 111217 19772 98147 27214 135044 46705 232306 57864 287632Oct 31034 164922 20986 111432 18254 96918 27505 145981 47757 254012 58700 312048Nov 30005 151874 21621 109334 17647 89241 22391 113198 40644 206001 49809 252284Dec 21684 105114 14340 69435 11227 54371 19690 95256 41432 200917 41534 201410

53

APPENDIX I

DETAILS OF LIBRARY CENTRAL AIR CONDITIONINGThe schematic is as shown in the following figure.

Fig. I.1: Schematic of central air conditioning system for library

The refrigerant used is R-22 and water. The total rating is 110 tonnes, comprising two

compressors, three condensers (including one on standby) and an air handling unit.

The following procedure is proposed for auditing:

Thermocouples should be installed at each inlet and outlet to measure temperatures.

Install flow meters/pressure gauges to obtain the flow rate of refrigerant, water. Using

temperatures & flow rates obtained, apply energy balance equation for each component.

Identify losses.

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BIBLIOGRAPHY AND WEBSITES1. S.P. Sukhatme, Solar Energy, Tata McGraw Hill Publ., New Delhi, 1996.

2. L.C.Witte, P.S.Schmidt, D.R.Brown, Industrial Energy Management and Utilisation,

Hemisphere Publ, Washington, 1988.

3. W.C.Turner, Energy Management Handbook, Wiley, New York, 1982.

4. Guide Books for the National Certificate Examination for Energy Managers and Energy

Auditors (set of four books, available at

http://www.energymanagertraining.com/new_course.php)

5. J.C. Andreas, Energy Efficient Motors, Marcel Dekker Publ., New York, 1992.

6. Nisarguna Biogas Plant by Bhabha Atomic Research Centre, details available at

www.barc.ernet.in/webpages/technologies/kitchen/kitchen_br

7. Compact biogas plant by Appropriate Rural Technology Institute, Pune, details

available at http://www.arti-india.org/content/view/46/43/

8. US Government’s Energy Star page for fluorescent bulbs,

http://www.energystar.gov/index.cfm

9. Explanatory video on various types of lamps, www.commoncraft.com/cfl

10. Typical lumen outputs and energy costs for outdoor lighting,

www.nofs.navy.mil/about_NoFs/staff/cbl/lumentab.html

11. General Electric and lighting products,

www.gelighting.com/na/home_lighting/products/energy_smart

12. Information on energy saver for room air conditioners, www.aircosaver.com

13. Official website of the Bureau of Energy Efficiency, Govt. of India, www.bee-

india.nic.in

14. Detailed information and case studies on energy audits,

www.energymanagertraining.com

15. www.en.wikipedia.org/wiki/Energy_audit

16. Website of the Ministry of Power, http://powermin.nic.in/distribution/energy_audit

17. The Energy Conservation Act, 2001,

http://powermin.nic.in/acts_notification/energy_conservation_act/index.htm

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ACKNOWLEDGEMENTS

We would like to express our heartfelt gratitude to the following persons for the support

and cooperation they rendered during the course of this energy audit.

• The Dean and Associate Dean (Planning) and other Institute functionaries

• Mr. B.K. Sahoo (Executive Engineer), Ms. Y. Naik, Mr. Yadav, Mr. Mohandas, Mr.

Adhare, Mr. Kishor Mali and other staff members of Electrical Maintenance Section

• Prof. B.G. Fernandes, Prof. K. Chatterjee (Dept. of Electrical Engg.), Prof. C.S. Solanki

(Energy Science) and Prof. Anand B. Rao (CTARA)

• Mr. K.G. Kale, Mr. Kharte, Mr. Ajay, Mr. V. Chaudhari (all of DESE)

• Mr. Sawant and other staff members (Estate Maintenance Section)

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