Energy Audit Basics and Principles

The Lebanese Center for Energy
CRA2E (LCECP)
Conservation ProjectEtude, Contrôle et Pilotage

Energy Audit
Basics and
principles
Presented by:

MAY 2010 Mr. Hamadi Sayah
International Energy Expert

Centre Molka Escalier N°15 El Manar II – 2092 TUNIS Tél: 00 216 71 886 177 –
Fax: 00 216 71 885 010 Site Web: www.cra2e.com– E-mail: cra2e@yahoo.fr 1

The Lebanese Center for Energy Hamadi Sayah
CRA2E (LCECP)

OUTLINES
1. Definition and Objectives of Energy Audit and Management
2. Types of energy audit
3. Methodology of energy audit
4. Preliminary Consultation
5. Measurement Campaigns and Equipment
6. Approach to Energy Balance
7. Definition of an Action Plan
8. Presentation of the Audit Report
9. Audit of Electric System
10. Audit of Heating, Ventilation and Air-conditioning System
11. Conclusion
12. Study of case: Energy Audit of Establishment

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Definition and Objectives
of Energy Audit and Management

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CRA2E (LCECP)

WHAT IS AN ENERGY AUDIT?

Energy audits “periodic and mandatory” constitutes a
strategic element to help companies REDUCE ENERGY
COSTS and MANAGE ENERGY CONSUMPTION to the extent
that it will allow to examine THE STATE OF ENERGY-USING
EQUIPMENT and take necessary MEASURES to replace any
other repair or improvement and reduce energy losses.

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OBJECTIVE OF ENERGY AUDIT?

The primary objective of Energy Audit is to determine ways to
lower operating costs or to reduce energy consumption:
- per unit of product output (industry)
- ft² or person (commercial/building)
Energy Audit provides a " bench-marking“ (Reference point) for
managing energy in the organization and also provides the basis
for planning a more effective use of energy.

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WHAT IS THE ENERGY MANAGEMENT?

- "The judicious and effective use of energy to maximize
profits (minimize costs) and enhance competitive positions“
- "The strategy of adjusting and optimizing energy, using
systems and procedures so as to reduce energy requirements
per unit of output while holding constant or reducing total
costs of producing the output from these systems"

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OBJECTIVE OF ENERGY MANAGEMENT?
The objective of Energy Management is to achieve and
maintain optimum energy procurement and utilization,
throughout the organization and:

• to optimize specific energy consumption
•To minimize energy costs
• To minimise environnemental effects.

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Energy Audit is the key to a systematic approach for decision
making in the area of energy management.
It attempts to balance the total energy inputs with its use, and
serves to identify all the energy streams in a facility.
It quantifies energy usage according to its discrete functions.

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Methodology of Energy Audit

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BASIC AUDIT LEVELS

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The scope work of energy Audit :

ü Analysis of energy situation of building
üCalculate specific consumption (BTU/sq ft or BTU/person or
visitor)
ü Comparison with reference values (national and international)
of similar facilities
ü Distribution of the energy consumption by custom (usage)
ü Energy balances (electric and thermal) after measurements
ü Calculate Energy Using Index
üIdentification of potential of energy conservation
üDefinition of ECMs
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CRA2E (LCECP)

The energy audit can be divided into for tasks :

Level 1 .
Task 1 . Preliminary audit
Level II.
Task 2. Energy analyses by section
Level III.
Task 3. Campaign of measurement
Task 4. Energy balance of main energy consummer
Task 5. Audit report and actions plan

CRA2E (LCECP)

Preliminary analysis

CRA2E (LCECP)

Task 1 - Preliminary audit

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- of the audit.
-Collect of information about building
- Visit of the facility
-Evaluation of energy consumption data to
analyze energy use quantities and
comparison with similar facilities.
-Preliminary estimate of savings potential
and provide a list of low-cost savings
opportunities through improvements in
operational and maintenance practices.

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Collect of information about building:
1. Energy consumption by type of energy, by section, by major items of
process equipment, by final - use

2. Areas/ Number of passengers, patients, clients, etc… COMMERCIAL

3. Analysis of energy invoice and energy cost

4. Process and material flow diagrams

5. Generation and distribution of compressed air, hot water, cooking
water.
6. Sources of energy supply
7. Potential for fuel substitution, process modifications, and the use of
co-generation systems and tri-generation.
8. Energy Management procedures and energy awareness training
programs within the establishment

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CRA2E (LCECP)

Visit of the facility
“ ONE DAY”

to visually inspect each of the energy using systems
to give the Energy Auditor/Engineer an opportunity
to meet the personnel concerned
to familiarize him with the site
to assess the procedures necessary to carry out
the energy audit

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CRA2E (LCECP)

During the visit, Energy Auditor/Engineer should carry out the following
actions:

• Analyze the major energy consumption data with the relevant personnel.
• Obtain site drawings where available - building layout, steam distribution,
compressed air distribution and electricity distribution etc.
• visit of the sites of building accompanied with energy manager

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CRA2E (LCECP)

The main objectif of this visit are:

• To finalize Energy Audit team
• To identify the main energy consuming areas/plant items to be surveyed
during the audit.
• To identify any existing instrumentation/ additional metering required.
• To decide whether any meters will have to be installed prior to the audit
energy (Electric meters, steam meters, oïl or gas meters.
• To identify the instrumentation required for carrying out the audit.
• To plan with time frame
• To collect macro data on plant energy resources, major energy consuming
centers
• To create awareness through meetings / program

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CRA2E (LCECP)

The first visit for the establishment by experts to:
- Discuss with the site's senior management the tasks of the energy audit.
- Discuss economic guidelines associated with the recommendations
– Obtain energy consumption data for the last 3 years (include water).
– Obtain mechanical, architectural, heating, cooling, lighting and electrical drawings
specifications for the original building
– Obtain a summary description of a building and its sections
– Meeting and discuss aspects of the facility with responsible in establishment :
• Occupancy schedules
• Operation and maintenance practices
• Future plans that may have an impact on energy consumption
– Visual inspecting of equipments
– Take pictures through the building. Including mechanical equipment, lighting, interior
workspaces, common areas and halls, and the exterior including the roof

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General data :

• Base year of audit : Year of reference
• Annual hours of operation : 8 760 h/year
(AHU, boilers, etc.)

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Heating
Climatisation
flow

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Electric plan
of AITC

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Electric installation of Establishment
- Power transformer MT/BT:
Number of Type Type Compensation
Affectation Total KVA
transformer normal secours KVAR
Transf MT/MT 3 3 000 ----- 9 000 -----
STATION A 2 1 500 400 1900 90
STATION B 4 2 500 600 3 100 150
STATION STELLITE 4 1 800 400 2 200 240
STATION 4 2 930 2 930
SALLE OF MACHINES
TOTAL 17 1 400 19 130 480

Signed Power: 8000 kW

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CRA2E (LCECP)

Climatisation of Establishment

• The climatisation (heating and cooling) of Establishment is assured by:
– Air Handling Unit « AHU »
– Schillers
– Boilers
– Cooling Tower

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CONVERSION UNITS

• 1000 kWh = 0,086 TOE
• 1 thermie = 103 Kcal
• 1 TOE = 104 thermies
• PCI of Natural gas = 9,00 Th/Nm3

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CRA2E (LCECP)

We note that the maximum power drawn does not exceed 7000 kW for every time
slot, while the power is reduced out of 8000 kW. It is recommended to revise the
STEG contract for the decline of the reduced power to 6700 kW divided as follows:

Subscribed power Value kW
Daytime peak 6700
Evening peak 6700
Winter peak 6700
Summer peak 6700
Subscribed reduced power 6700

This decline of reduced power generate immediately a gain of 54 400
TND per year without penalty calculated as follows:
Gain = 3,5 X (actual reduced power – projected reduced power) x
month per year = 3,5 x(8000 – 6700) x 12 = 54 400 TND

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CRA2E (LCECP)

Distribution of energy consumption by form for
the base year of Audit :

§ Electricity : 32 004,694 MWh « 9 057 TOE »
§ Natural Gas : 242 293 Nm3 « 218 TOE »
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CRA2E (LCECP)

Annual Cost of Energy and Water 2 756 306 TND

Eau
19% Natural Gas
2%
528 574 TND
40 621 TND
2 187 110 TND

Electricity
Electricity
79% 79%

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• Cost of TOE:

– Electricity TOE = 241,483 TND
330 TND
- Natural Gas TOE = 172,126 TND
230 TND

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CRA2E (LCECP)

Passenger number for the base year of audit :
3 449 185 passengers
Specific Energy Consumption by passenger in year of reference :

Energy Value Unit
Electrical energy 9,279 kWh/passenger
Natural gas 0,684 Thermal/passenger
Global 10,074 kWh/passenger

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CRA2E (LCECP)

n Area : 57 448 m²
n Volume : 293 356 m3

Specific Energy Consumption by area/volume in year of reference :

Energy Value Unit
Electrical energy 557 kWh/m²
109 kWh/m3
Natural gas 37,959 Thermal/m²
7,433 Thermal/m3

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establishment values:
Energy Value Unit
Natural gas 38 Thermal/m²

Comparison with reference values:
Energy Value Unit

Potential energy saving:
Energy Value Unit
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Energy situation for
the 3 last years of audit

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• Evolution of passenger number :
Year 1st Years 2nd Years 3rd Years
Number of passenger 3 194 742 3 049 183 3 449 185

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CRA2E (LCECP)

• Evolution of Global energy balance :

Energy Unit 1st Year 2 nd Year 3rd Year
kWh 33 013 365 31 923 281 32 004 694
Electrical TOE 9 343 9034 9 057
energy % TOE 97,8 97,91 97,46
Nm3 218 109 199 595 242 293
Natural gas TOE 210 193 218
% TOE 2,2 2,09 2,54
Global TOE 9 553 9 227 9 293

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• Evolution of specific consumption:

Energy kWh/m² Th/m²
1st year 575 36,6
2nd year 556 33,6
3th year 557 37,9

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More Detailed Analysis « MONTHLY »

PEAK

CRA2E (LCECP)

PEAK

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Bonifications

ACEPTABLE

CRA2E (LCECP)

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Energy Use Index by Building Type

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PRELEMINAY ENERGY CONSERVATION MEASURES
§ Revision of signed power with STEG: save an annual budget of
54 400 Dinars.
§ Improving the power factor with an optimum of 0.99 would
receive an extra bonus from STEG.
§ The preliminary inspection of equipments shows an
acceptable level of maintenance, but imbalance in the air-
conditioning compared to racking requested

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Task 2 - Energy analyses by
section

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CRA2E (LCECP)
Conservation ProjectEtude, Contrôle et Pilotage Preliminary analysis
Detailled analysis

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– For the reason of absence of energy metering in the
Establishment, the Level II analysis can not be developed without
the measurement campaign (3rd LEVEL)
– We recall that Establishment has only :
• A electricity General meter as well as a set of divisional
meters accounting box and consumption of rented premises
• A natural gas General counter
• A general SONEDE meter and 5 divisional meters for
condensers

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– Establish the mass and energy balances of different areas
of the establishment and determine their energy
consumption.
- The main areas of the establishment are :
• Public "departure" on the 1st floor with easements of
checked baggage, cafes and shops
• Public 'arrival in the DRC with the relevant areas and
shops
• Bonded zone "start" with police control filter including
boarding rooms and satellite
• Bonded zone arrivals area with the baggage, customs
and police control
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CRA2E (LCECP)

The thermal and electric balances can provide the Energy
consumption by energy using section :
• Building Operation
• Lighting Systems
• HVAC Systems
• HVAC Distribution Systems
• Energy Management Control Systems
• Building Envelope
• Power Systems
• Water Heating Systems
• Heat Recovery Opportunities
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Energy Use in Office
Buildings

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Energy Use in
Schools

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Energy Use in
Hospitals

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Energy Use in
Supermarkets

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Energy Use in
Apartment Buildings

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Energy Use in
Hotels

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Energy Use in
Restaurants

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RESULTS OF PRELEMINARY VISIT

IN COOLING MODE :
After the preliminary visit, we noted following points:

• The regulation of the shutters (volets) of recycled air and the new air is
inefficient implying either an excess of new air (to cool) or an excess of
air recycled (partially polluted).
• During audited period, the outside climatic conditions were rather
favorable for a march in 100 % of new air.
• The AHU N°2,3,7,8,11 et 15 were inable to satisfy the conditions of confort
required.
• The networks of connection and distribution of Chillers are inefficient

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An important quantity of energy wasted by infiltrations of air générés
by opening (15% eletric and frigorific consumption)
The water consumption of supplement of condenser is excessive (Needs
of drainage of suffer contained (teneur en souffre)).

IN HEATING MODE :
• The regulation of the shutters of new and recycle air is inefficient
implying either an excess of new air (for heating) OR an absence of new
air (affected confort and sanitary conditions).
• The march of the ventilators of resumption(reprise) and blowing
(soufflage) in mode 50 % and 100 % implies a rate of air renewal far
from the optimum.
• The management of march of hot water generators is necessary.

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Task 3 – Campaign of measurement

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The Lebanese Center for Energy
CRA2E (LCECP)
Proposal of improvement Sayah
Hamadi
solutions
Proposal of improvement solutions

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Measurements

DO NOT ESTIMATE WHEN YOU CAN CALCULATE
DO NOT CALCULATE WHEN YOU CAN MEASURE

§ The capability of the energy auditor and the scope of an audit could be
extended by the use of in place instrumentation and temporary
monitoring equipment.
§ In-place instrumentation refers to existing utility metering, air-
conditioning control instrumentation and energy management systems
(EMS).
§ These instruments must be portable, durable, easy to operate and
relatively inexpensive.

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The parameters generally monitored during energy audit may include the
following:

Basic Electrical Parameters in AC and DC systems:
-Voltage (V)
- Current (I)
- Power factor
- Active power (kW)
- apparent power (demand) (kVA)
- Reactive power (kVAr)
- Energy consumption (kWh)
-Frequency (Hz)
- Harmonics, etc.

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Power transformer
Measuring
Description
instrument
Active power
Reactive power
apparent power
voltage
Electric power
intensity
analyzer
Energy
Power factor
Voltage harmonic 1-50
Intensity harmonic 1-50

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Electrical Measuring Instruments:
These are instruments for measuring major
electrical parameters such as kVA, kW, PF,
Hertz, kVAr, Amps and Volts.
In addition some of these instruments also
measure harmonics.
These instruments are applied on-line on
running motors without any need to stop the
motor. Instant measurements can be taken
with hand-held meters, while more advanced
ones facilitates cumulative readings with
print outs at specified intervals.

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Parameters of importance other than electrical:

-Temperature and heat flow
- Radiation
- Air and gas flow, liquid flow
- Revolutions per minute (RPM)
- Air velocity, noise and vibration, dust concentration,
-Total Dissolved Solids (TDS), pH
- Moisture content
- Relative humidity
- Flue gas analysis - CO2, O2, CO, SOx, NOx, combustion
efficiency etc.

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Luxmeter Manometer Power Electric Analyzer

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Hygrometer Combustion Analyzer

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Anemometer
Thermography

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Combustion Analyzer:
This instrument has in-built chemical cells which
measure various gases such as O2, CO, NOX and
SOX.
Fuel Efficiency Monitor:
This measures oxygen and temperature of the flue
gas. Calorific values of common fuels are fed into
the microprocessor which calculates the
combustion efficiency.

Fyrit:
A hand bellow pump draws the flue gas sample into
the solution inside the fyrite. A chemical reaction
changes the liquid volume revealing the amount of
gas. A separate fyrite can be used for O2 and CO2
measurement.
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Contact thermometer:
These are thermocouples which
measures for example flue gas, hot
air, hot water temperatures by
insertion of probe into the stream.
For surface temperature, a leaf type
probe is used with the same
instrument.

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Infrared Thermometer:
This is a non-contact type measurement
which when directed at a heat source
directly gives the temperature read out. This
instrument is useful for measuring hot spots
in furnaces, surface temperatures etc.

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Speed Measurements:
In any audit exercise speed measurements are critical as thay may change
with frequency, belt slip and loading.
A simple tachometer is a contact type instrument which can be used where
direct access is possible.
More sophisticated and safer ones are non contact instruments such as
stroboscopes.

Tachometer Stroboscope
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Leak Detectors:
Ultrasonic instruments are available which can be used
to detect leaks of compressed air and other gases
which are normally not possible to detect with human
abilities.
Lux meters:
Illumination levels are measured with a lux meter.
It consists of a photo cell which senses the light
output, converts to electrical impulses which are
calibrated as lux.

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Pitot tube

Pitot Tube and manometer:
Air velocity in ducts can be
measured using a pitot tube and
inclined manometer for further
calculation of flows.

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Water flow meter:
This non-contact flow measuring device using Doppler effect / Ultra sonic
principle. There is a transmitter and receiver which are positioned on
opposite sides of the pipe. The meter directly gives the flow. Water and
other
fluid flows can be easily measured with this meter.

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Main points of measure
by Equipment

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Hamadi Sayah
The Lebanese Center for Energy Measures
CRA2E (LCECP)
Temperature (T°)
Relative humidity (RH%)
Air Handling Unit Speed (m/s)
Dimensions of the sheath (m)

Fresh air
Air blowing
Ambiance
Air return

Air after Air after
cold hot
battery battery

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Resumption
(reprise)

T: T: Air de reprise

°C °C
RH : RH : New air
% %
V: V: Air neuf
m/s m/s

T:
°C
Air de soufflage RH :
Blowing %
(soufflage) HOT COLD V:
WATER WATER m/s
Ts Tec Tsf Tef
cC cC C cC

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AIR HANDELING UNIT EFFICIENCY
RETURN AIR

AIR BLOWER
FRESH AIR

RETURN WATER
HOT WATER

(qab × hab – qfa × hfa – qra × hra)
h AHU = ----------------------------------------------------------------------

[qhw × (Thw – Twr) × Cp]

CRA2E (LCECP)

qab = air blower flow
qfa = fresh air flow
qra = return air flow
qhw = hot water flow

hab = air blower enthalpie
hfa = fresh air enthalpie
hra = return air enthalpie

Thw = hot water temperture
Twr = water return temperture

Cp = specific heat of the hot water

CRA2E (LCECP)

Chiller Description Value Unit
Measure (Evaporator)
Description Value Unit
Chilled water flow m3/h
Evaporator entering water temperature °C
Evaporator water temperature output °C
Measure (Condenser)
Description Unit
Flow water cooling Tour m3/h
Entering condenser water temperature °C
condenser water temperature output °C
Electric power compressor KW
Measured electric power KW

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THE EFFICIENCY OF THE
REFRIGERATED PRODUCTION

(Q2 – W)
COP cool = --------------------
W

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Q2 = Power condenser = S x v x 1,2 x (Ts - ta) [kW]

S = condenser surface m²
v = air speed m/s
Ts = Air temperature at the exit of the condenser °C
Ta = Temperature of air inhaled) by the condenser °C
1,2 = is the volume heat of the air kJ/(m3.°C)

W = The energy absorbed by the compressor only

CRA2E (LCECP)

Description Measuring instrument
BOILER Combustion gas
% CO2 Combustion analyser

% O2 Combustion analyser

CO ppm Combustion analyser

Temperature Combustion analyser
Flow Pitot tube
Combustion air
Flow Anemometer
Temperature Thermometer
Relative humidity Hygrometer
Dimensions Meter
Boiler feed water
Flow Flowmeter
Hot water boiler output
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BOILER EFFICIENCY
Lrc
Lfg

Lu
Qfuel

hComb = 100 - % losses due to dry flue gas (Lfg) - %
Unbured losses (Lu) - % Losses by radiation and
convection (Lrc)

CRA2E (LCECP)

(Lfg) % = k × (Tfg – Ta) / % CO2
kfuel = 0,62
kgas = 0,47
Kpropane = 0,5

(Lu) % = b × % CO / (%CO + % CO2)
bfuel = 52
bgas = 35
bpropane = 43

(Lrc) % = 1 200 × S × (Tp – Ta) / Pb
S = surface of the boiler
Tp = average wall temperature of the boiler
Ta = ambient temperature
Pb = Power rated boiler

CRA2E (LCECP)

– The campaign of measures is done in two periods:
• Summer season : in hot season (use of cold for conditioning)
• Wintry season : in cold season (use of hot water for heating)

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§The use of in-place utility metering and temporary
monitoring equipment in energy auditing can yield
valuable information about the building systems such as:
§ Energy signature and end-use consumption analysis
§ Discovery and identification of ECMs
§ Quantification of energy use and misuse
§ Establishing bounds for potential energy reduction, and Data
acquisition for further calculation and analysis

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Existing information

• Existing instrumentation such as utility meter readings, and energy
billings could be used to establish energy consumption patterns for the
building.
• The regularity of consumption pattern is an indicator that no significant
change in consumption occurred prior to the audit.
• This can also be used to check the validity of projections based on
extrapolated short-term monitored data.

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By Measurements it’s possible to:
- Quantify energy uses and losses through a more detailed review
and analysis of equipment, systems, and operational
characteristics.

- Measurement and testing to quantify energy use and efficiency
of various systems.

- Standard energy engineering calculations are used to analyze
efficiencies and calculate energy and costs savings based on
improvements and changes to each system.

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Task 4 – Energy balance of main
energy consumer

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An estimate for annual consumption is extrapolated from the typical week
consumption profile.
Regularity of the weekly consumption profile means that the annual
consumption could be estimated with confidence and the value used to
cross check with the annual energy bills.

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Computer Simulation
• Detail use of energy by function and a more comprehensive evaluation of
energy use patterns.
• Develop a computer simulation of building systems that will account for
weather and other variables and predict year-round energy use.
• Build a base for comparison that is consistent with the actual energy
consumption of the facility.
• Make changes to improve efficiency of various systems and measure the
effects compared to the baseline.

Because of the time involved in collecting detailed equipment information,
operational data, and setting up an accurate computer model, this is the most
expensive level of energy audit but may be warranted if the facility or systems
are more complex in nature.

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Evaluation of energy consumption by equipment
in summer season

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q Air Handling unit
% Air
Air neuf Air reprise Air mélange Air soufflage Air ambiant Bilan thermique Bilan thermique eau
neuf
N° m3/h T(°C) m3/h T(°C) m3/h T(°C) % m3//h T(°C) HR T(°C) HR % 1000Kg/h KW Debit T°'entrée T° sortie
AC1 -- -- 21381 23 21381 23,0 0 21381 16,5 73 20,5 54 69,77 81 41,98 7 8,1

AC2 Bis 18144 22 13190 22,8 31334 22,5 57,9 31334 17,6 73 23,0 53 73,6 85,7 94,94 6,6 7,4
AC2 33000 23,1 26030 24,6 59067 23,8 55,9 59067 18,5 74 24,9 58 114,24 133 57,48 6,9 8,9
AC3 35510 22,5 36547 24,3 72058 23,4 49,3 72058 18,8 75 24,8 57 83,9 97 61,9 6,6 8,4
AC4 19958 23,7 25402 23,8 45360 23,4 44,0 45360 20 68 23,8 55 60,23 70 61,79 7,3 8,3
AC5 -- -- 49896 23,9 49896 23,9 0,0 49896 19,1 72 22,9 51 63,97 74 61,79 6,6 7,6
AC6 -- -- 48190 23 48190 23,0 0,0 48190 18,5 72 22,7 64 76,41 89 93,99 7,6 8,4
AC7 -- -- 40487 23,5 40487 18,3 0,0 40487 18,3 74 24,6 58 82,48 96 56,62 7,5 9
AC8 -- -- 42915 23,2 42915 23,2 0,0 42915 19 74 24,4 59 56 66 74,25 7 7,8
AC9 -- -- -- -- 15256 23,0 0,0 15256 17 72 20,4 61.0 44,02 51 42,39 7,5 8,5
AC10 -- -- 34900 23,3 34900 23,3 0,0 34900 16,6 72 23,3 52.0 90,31 105 77,4 7,5 8,7
AC11 15368 23 55457 23 70825 23 21,7 70825 17,1 74 24,9 56 155,23 180 77,4 7,5 10
AC12 25920 23 6912 23 32832 23 78,9 32832 21 63 23,1 50.0 11 13 57 7,5 7,7
AC13 -- -- 15552 23,5 15552 23,5 0,0 15552 17,3 70 22,3 51.0 50,22 58 34,5 7,5 9
AC15 -- -- 22957 23,2 22957 23,2 0,0 22957 17,6 68 25,3 55 67,12 78 41,9 7,4 9
AC16 22560 23,3 -- -- 22560 23,3 100,0 22560 16,5 70 20,8 58 81.41 95 41,98 7,5 9,4
AC17 28464 23,5 -- -- 28464 23,5 100,0 28464 17,8 73 NR NR 70,79 82 41,9 7 8,7
98

CRA2E (LCECP)

% Air
Air neuf Air reprise Air mélange Air soufflage Air ambiant Bilan thermique
N° neuf Bilan thermique eau
m3/h T(°C) m3/h T(°C) m3/h T(°C) % m3//h T(°C) HR T(°C) HR % 1000Kg/h KW Debit T°'entrée T° sortie
AC18 -- -- 14165 24,5 14165 24,5 0,0 14165 13,5 74 21,9 53 87,3 101 41,9 7,4 9,5
AC19 -- -- 16740 23 16740 23,5 0,0 16740 19,1 71 NR NR 31,27 36 41,98 7,5 8,2
AC22 8528 23,6 14026 23,4 22554 23,5 37,8 22554 17 73 22,2 52 68,63 80 53.22 7 8,3
AC24 11250 26,2 18779 25,7 30029 25,9 37,5 30029 21,3 68 25,8 59 65,44 76 53,6 8 9,2
AC25 A -- -- -- -- 38330 23,5 0,0 38330 17,5 74 23,1 58 99,93 116 65,41 7,5 9,3
AC25 B -- -- -- -- 45000 23,5 0,0 45000 17,4 73 23,2 59 117,06 136 56.41 7,3 9,4
AC25 C -- -- 31519 24.2 31519 24,2 0,0 31519 17,8 74 23,0 52 89,54 104 46,2 6 7,9
AC26 -- -- 57879 23 57879 23 0,0 57879 18,5 70 22,7 57 99,14 115 54.6 7 8,8
AC27 -- -- 38264 23,5 38260 23,5 0,0 38264 20 70 23,9 54 78,16 91 27,86 7,3 10,1
AC28 -- -- 41250 23,5 41250 23,5 0,0 41250 20,9 71 24,1 61 16,4 19 35,38 7,5 8
AC29 13323 21,7 17885 23,7 31208 22,8 42,7 31208 19,9 70 22,9 52 16,09 19 32,44 7 7,5
AC30 39593 23,0 11775 23 51368 23 77,1 51368 19,2 75 22,9 54 36,51 42 31,54 7 8,2
AC31 8482 22,5 15380 23,8 23860 23,3 35,5 23862 21 60 21,8 50 15,06 17 31,6 7 7,5
AC32 43740 23,0 -- -- 43740 23 100,0 43740 19,5 72 22,0 59 43,01 50 34,6 7.5 8,7
AC33 6420 22,6 18220 23,2 24640 23 26,1 24640 19,2 70 23,1 58 30,04 35 36.96 7.5 8,3
AC34 70056 23,3 -- -- 70056 23,3 100,0 70056 20,3 70 23,0 55 49,91 58 36,9 7 8,4
AC35 10289 22,8 14818 23,1 25107 23 41,0 25107 20,2 71 24,1 49 20,91 24 34,6 7 7,6
AC36 12999 22,4 9078 23,5 22077 23 58,9 22077 18,9 76 23,3 56 35,81 42 36,38 7 8
ACX -- -- -- -- 78000 23,5 0,0 78000 18 76 NR NR 150,74 175 79,98 7,5 9,7
99

CRA2E (LCECP)

Global analysis flows between blown and needs

Comparison between measures of ambient air in different areas of the
establishment and conditions sought confort in September 2007 when the
outside is 22 ° C as follows:

Température = 22°C
Hygrométrie = 50 % HR

CTA shows that AC2, AC3, AC7, AC8, AC11 and AC15 are not currently
developing the cooling power needed.

100

CRA2E (LCECP)

This is due either :

• “Consigne” value
• The location of temperature sensors
• The lack of cooling capacity of CTA
• On the importance of lighting (light intensity) with a warming of the
atmosphere.

101

CRA2E (LCECP)

Analysis of fresh air

Given that the audited period (end September 2007) is the end of the
summer and early fall, the outside air is at a temperature of days of
the order of 22 ° C and 55% HR

The analysis of measured data shows respectively:

- The total absence of the provision of fresh air for 18 CTA yet its
temperature is generally lower than that of air again.
- The fresh air enters partially into the mixture before the battery
level remaining 18 CTA.

102

CRA2E (LCECP)

In another aspect, by comparing the flow of fresh air compared to the hygienic needs
(25 m3/h/pax), we note the following:
N° CTA New Air : need (m3/h) Measure (m3/h) Measure/needs
AC01 3500 0 0
AC02 11975 33000 2,76
AC02 BIS 19575 18144 0,93
AC03 11000 35510 3,23
AC12 20425 25920 1,27
AC13 12075 0 0,00
AC15 11950 0 0,00
AC22 11775 8528 0.72
AC24 5750 11250 1,96
AC27 7850 0 0,00
AC18 5000 0 0,00
AC04 3100 19958 6,44
AC05 1475 0 0,00
AC06 10750 0 0,00
AC07 10250 0 0,00
AC08 2050 0 0,00
AC10 2625 0 0,00
AC11 8100 15368 1,90 103
ACX 0 0 0

CRA2E (LCECP)

N° CTA New Air : need (m3/h) Measure (m3/h) Measure/needs
AC25A&B 26950 0 0,00
AC25C 9100 0 0,00
AC26 9250 0 0,00
AC9 650 0 0,00
AC17 1250 28464 22,77
AC19 5250 0 0,00
SATELLITE
AC28 2500 0 0,00
AC29 5250 13323 2,54
AC30 5250 39593 7,54
AC31 5250 8482 1,62
AC32 5250 43740 8,33
AC33 5250 6420 1,22
AC34 5400 70056 12.97
AC35 2500 10289 4,12
AC36 1000 13000 13,00
total 249 325 401 045 1,609

104

CRA2E (LCECP)

Recommendation
The regulation of aspects of entry of fresh air must be improved.
We recommend that:

• Implementation of probes % CO2 sensors in each service area, such
information come into the logic circuit controlling the phase of fresh air.
• Levels for opening strands (volets) of fresh air and recirculated air will
depend on the respective rates of CO2, the temperature of fresh air and the
temperature and humidity of air recycled.
• Setting vouchers of fresh air by ensuring a minimum flow of air regardless
of the occupation and season through mechanical stops which closed for a
minimum of air (10 to 15% ).

105

CRA2E (LCECP)

CALCULATION OF CHILLER

106

CRA2E (LCECP)

Description Value unit
Characteristic
Cooling capacity 1938 KW
COP theory 5,34
Evaporator exit temperature 30 °C
Electrical power installed 373 KW
Electrical power absorbed 363 KW
Chilled water flow 330 m3/h
Cooling water flow 334 m3/h
Thermal balance of Evaporator
Chilled water flow 334 m3/h
Evaporator entering water temperature 9,3 °C
Evaporator water temperature output 7 °C
766 th/h
Energy exchange 889 KW
Thermal balance of condenser
Flow water cooling Tower 330 m3/h
Entering condenser water temperature 27.9 °C
condenser water temperature output 30,76 °C
942 th/h
Cooling Energy 1094 KW 107
Absorbed Power 205 KW

CRA2E (LCECP)

We observe the following:

- The group was operating at only 45.1% of its capacity to
weather external lenient evidenced by a low temperature gradient
between the entry and exit of water ice.

- The call of the power is 217 kW or a load factor of 59.78%
(nominal power of 363 kW) corresponding to a COP of 4.03.

108

CRA2E (LCECP)

SECTION % Frigorific COP % Electyricity

SMA 45,1 4,03 59,78
DES 50,3 3,42 72,4
Satellite 43,3 2,78 46
Average 47,94 3,49 64,46

We observe, during the audited period, that overall the groups of water ice
are exploited to the tune of 47.94% have gone to 64.46% of the nominal
power.

Also, we observe that groups with (satellite) have a better ratio of power
consumption during operation at about 50%.

109

CRA2E (LCECP)

CALCULATION OF COOLING TOWER

110

CRA2E (LCECP)

Valeur
Désignation Unity
Unit N°1 Unit N°2
OUTPUT
HR 100 97 %
Output T° of Tower °C 26,7 26,7 °C
H2O fraction input 22,24 21,55 g/Kg air sec
Wet Air « humide » density 1,159 1,16 Kg/m3
Wet Air « humide » Enthalpy 83,6 82,8 Kj/Kg
INPUT
Flow 56757 59786 m3/h
HR 52,1 51 %
Input T°of tower °C 27,2 27 °C
H2O fraction input 11,74 11,35 g/Kg air sec
Wet Air « humide » density 1,164 1,16 Kg/m3
Wet Air « humide » Enthalpy 57,32 56,1 Kj/Kg
Massic flow Dry Air « sec » 65348 68923 Kg/h
111

CRA2E (LCECP)

Thermal balance and massique (applied to the air)
Exchanged Thermal power 477 511 KW
Quantity of evaporated water 0,69 0,70 m3/h

Quantity of water purged of bottom 0,69 0,70 m3/h

Quantity of water of supplement 1,38 1,41 m3/h

Total supplement of the tower 2,78 m3/h

Total power Exchanged by the tower 988 KW

112

CRA2E (LCECP)

Assessment of global climate establishment

We recall at this level the surfaces and volumes of spaces
constituting establishment and their assignments machinery room.

Machinery room Surfaces ( m²) Volumes (m3)
S.M.A 26 175 130 875
DSE 22 690 124 795
Satellite 7 958 35 811
Other 625 1 875
TOTAL 57 448 293 356

113

CRA2E (LCECP)

The results of air conditioning consumption during the day audited are respectively:

SECTION Wf/m2 Frigories/m2 h W élec/m2 Wf/m3 Frigories/m3 h W/m3
SMA 33,4 28,76 8,29 6,68 5,75 1,66
DSE 84,4 72,69 24,68 15,34 13,21 4,49
Satellite 38,4 33,12 13,82 8,54 7,36 3,07
Autres - - - - - -
TOTAL 53,87 46,40 15,44 10,55 9,09 3,02

For an optimal ratio of 70 Wf/m² corresponding to local public attendance average for non-
smokers, we observe that :

- The AHU provide standards of comfort above the needs.
- The station “SMA”, expanding 45.1% of its capacity, has a ratio of 33.4 Wf/m², to below the
level of comfort. This confirms the failure of CTA 2,3,7 and 8.
114

CRA2E (LCECP)

Energy balance of power transformer

115

CRA2E (LCECP)

Called Power
Transformer Power KVA Rate %
KVA
Transformer terminal S/SB 400 140 35
Transformer of secour S/SB 1000 450 45
Transformer of air conditioning SAT 1000 214 21
Transformer of secour SAT 400 38 9
Transfo Normal 1&2 SAT 800 415 52
Normal transformer S/SA 1500 1202 80
Transformer of secour S/SA 400 236 59
Transformer of air conditioning
DSE 2000 1032 52
Transformer of eclairageDSE 300 182 61

We note that a total of 7 800 KVA installed and the call in power
during the days audited, processors are responsible for overall
height of only 50.11% for a nominal 65%. 116

CRA2E (LCECP)

Energy consumption By station
Consumption/hour Consumption/day
Désignation %
(Kwh) (Kwh)
Under station B 1 513 36 312 39
Station SATELLITE 367 8 808 9
Under station A 1 161 27 864 30
Station room of machines 834 20 016 21
TOTAL 3 875 93 000 100

117

CRA2E (LCECP)

Energy Consumption by use
ACTIVE POWER KW
AFFECTATION S/S A SATEL S/SB SM TOTAL %
AHU 79,7 96,4 108,4 284,5 7,3
LIGHTING 922 95,5 674 158 1849,5 47,7
CHILLERS 471,5 152,9 199,7 659,4 1483,5 38,3
Batteries de
5,6 19 2,6 27,2 0,7
compensation
BOILERS 17 17 0,4
OTHERS 34 3,1 176,4 213,5 5,5
TOTAL 1512,8 366,9 1161,1 834,4 3875,2 100,0

We note that lighting accounts for 47.7% of the active power drawn with 1 followed by
849.5 KW stations production of ice water with 38.3% and 1 483.5 KW.

118

CRA2E (LCECP)

REACTIVE POWER (KVAR)
AHU 57,9 84 89,6 231,5 8,4
LIGHTING 322,8 69,3 410 89,5 891,6 32,3
CHILLERS 198,1 102,4 409,3 536,7 1246,5 45,1
Batteries de
36,9 200,4 37,5 274,8 9,9
compensation
BOILERS 14,5 14,5 0,5
OTHERS 23,3 8,9 73,1 105,3 3,8
TOTAL 639 465 1019,5 640,7 2764,2 100,0

In against part, we observe that CHILLERS generate reactive power kVAR 1 246.5
representing 45.1% of the total reagent indicating that electric motors are operated GEG
limited mode (rate infrequent use) involving assets of over a generation and a strong back
current (reactive) on the circuit.

119

CRA2E (LCECP)

Tension and POWER FACTOR average
AFFECTATION S/S A SATEL S/SB SM TOTAL
Cosinus 0,92 0,62 0,75 0,79 0,81
Tension(Volt) 355,3 357,5 343,4 382,2 351,8

Lighting

Cosinus 0,94 0,81 0,85 0,87 0,90
Tension (Volt) 360,6 359,9 376,0 389,7 366,6

Chillers
Cosinus 0,92 0,83 0,44 0,78 0,77
Tension(Volt) 357,5 398,1 318,4 381,4 349,0

120

CRA2E (LCECP)

AMPERAGE
AHU 156,6 184,4 211,5 552,5 7,1
LIGHTING 1564,1 189,3 1211,5 269 3233,9 41,4
CHILLERS 825,9 266,9 825,9 1287 3205,7 41,0
Batteries de compensation 57,3 299,9 59,8 417 5,3
BOILERS 33
33 0,4
OTHERS 65 16,1 288,9 370 4,7
TOTAL 2668.9 956,6 2597,6 1589 7812,1 100
Again, we see that the lighting and CHILLERS appeal to 82.4% of the
intensity.

121

CRA2E (LCECP)

Compensation batteries

Tension Active Power similar Réactive Power
POSITION Current (A) Cos φ
(V) Power (KW) (KVA) (KVAR)
S/S B 366 57,3 5,6 0,15 37,3 36,9
401 123 6,48 0,08 81,0 80,7
SATELLITE 391 57,9 3,5 0,09 38,4 38,3
390 119 9,01 0,11 81,9 81,4
S/S A 388 59,8 2,63 0,07 37,6 37,5

We find that the batteries are inserted in good condition.
However, the battery under the S / SB beginning to show signs of
degradation whose cosine was around 0.15 against a 0.07 nominal
practice.

122

CRA2E (LCECP)

Wintry season

The 2nd compaign of measurement took place in January, when the
outside temperature was about 16 ° C with relative humidity averaging
30% (dry but cold atmosphere).

123

CRA2E (LCECP)

Combustion efficiency generators HOT WATER

124

CRA2E (LCECP)

The measurements in the boiler combustion are concerned, analysis of
smoke, losses by convection and radiation, temperatures and natural gas
consumption.
HOT WATER GENERATOR
DESIGNATION Unity Value
Puissance Calorifique Heat capacity th/h 1500
Temperature smokes °C 104
Temperature air combustive °C 17,5
Percentage O2 % 3,4
Percentage CO2 % 9,9
Percentage CO ppm 0
Losses by heat
Sensitive of smokes
% 4,11

Rendement de Combustion % 95,9
Losses by convection and brilliance % 1,0
Thermal return % 94,9
Coefficient of excess of air(sight 1,19
125

CRA2E (LCECP)

Energy Conservation Measures
ECMs for Establishment

126

CRA2E (LCECP) SAVING SAVING INVESTMENT
ECM DESCRIPTION
Conservation ProjectEtude, Contrôle et Pilotage PAYBACK
TOE/YEAR TND/YEAR EN DT

IMPLEMENTATION OF AN ENERGY
1 MANAGEMENT SYSTEM
232 55700 120 000 2Y2M

INTER CONNECTION OF DISTRIBUTION
2 NETWORKS OF CHILLERS FOR THE AIR 65,9 15 923 65 000 4Y 1M
CONDITIONING

IMPROVMENT OF FLOW AND
3 RETURN OF BLOWING
329,8 79 640 230 000 2 Y 11 M

4 IMPROVMENT OF THE FRESH AIR FLOW 183,4 36 000 100 000 2Y9M
REDUCING INFILTRATION
5 AND AIR CURRENTS
302,6 96 235 270 000 2 Y 11 M

IMPROVEMENT OF THE ELECTRICAL
6 NETWORK LIGHTING CONSUMPTION
458 110 721 200 000 1Y 10 M

ASSISTANCE TECHNIQUE ET
7 ACCOMPAGNEMENT POUR LA MISE EN - - 40 000 -
PLACE DES ACTIONS RETENUES

TOTAL 1 571 ,7 394 219 1 025 000 2Y7M
127

CRA2E (LCECP)

Audit of Electrical System

128

CRA2E (LCECP)

The electrical consumption in most commercial
facilities can easily account for 50 to 75% of the total
utility costs. Because of this, special attention must be
paid to evaluating electrical consuming equipment and
systems within the facility

129

Energy Audit Basics and Principles

Energy Audit Basics and Principles

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