TNB ENGINEERINGCORPORATION (TNEC)

District Cooling System (DCS)

DCS incorporating TES technology offers the following major benefits to building owners:• Low air-conditioning running cost• High efficiency system• Optimum operation and maintenance

TNB Engineering Corporation Sdn Bhd (TNEC) is able to assume the following roles in the implementation of the above technologies:• System developer• Build-Own-Operate (BOO) & Build-Operate-Transfer (BOT) packager• Engineering, Procurement & Construction (EPC) contractor• Comprehensive Operation & Maintenance (O & M) contractor

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District Cooling System (DCS)A system where a central chiller plant provides chilled water for air-conditioning purposes for multiple buildings.

Thermal Energy Storage (TES)The storage of cooling energy during low air-conditioning load periods and used later to meet the air-conditioning loads.”

Cool, smart and elegant solution for large air-conditioning systems

District Cooling System (DCS) is an economical, efficient and elegant concept for air-conditioning in high-density property developments. Time-tested for over 30 years in developed countries, more Malaysian companies in business and industry are turning to DCS for immediate and long-term solutions to contain high air-conditioning costs.

Proven BenefitsIn Malaysia, several DCS plants with comprehensive operations and maintenance (O&M) are currently in operation, serving mainly office, commercial complexes and universities. TNEC has successfully developed a few of these plants, where clients enjoy:

• Significant cost savings in air-conditioning expenses• Environmentally-friendly technology• Peace of mind for not having to deal with the operation and maintenance of chiller plants• More resources and time to focus on core businesses• Raised property profile and image, adding prestige and modernity.

DCS is the future trend in large air-conditioning systems and the natural choice for far-sighted property owners.

SMART CHOICE FORAIR-CONDITIONING SYSTEM

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TNB ENGINEERING CORPORATION (TNEC)

The District Cooling System (DCS) Concept

A district cooling system that gives HUGE COST SAVINGS is certainly a smarter choice.

In a typical air-conditioning system, the chiller plant produces the building’s required cooling energy in the form of chilled water. The chilled water is then passed through air handling units that cool the air inside the building.

In modern day development, especially in urban or high-density developments, many such buildings would each have their own chiller plant, which does not constitute an efficient overall system, both technically and economically.

• Office buildings• Shopping centres• Universities• Hospitals• Apartments• Hotel• Conference centres• Airports• Factories

DCS Applications

THE DISTRICT COOLING SYSTEM(DCS) CONCEPT

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TNB ENGINEERING CORPORATION (TNEC)

Benefits of DCS

A DCS is space saving, allowing more space for other uses since the combined chiller plant is smaller and may be located away from the consumer’s premises.

A DCS essentially delivers its benefits through economies of scale. Larger and more efficient chillers can be installed in places of the many scattered smaller and less efficient ones required in a conventional system.

A higher efficiency system translates directly into both capital and running cost savings. Similar savings can be achieved for other plant equipment such as cooling towers and pumps.

It also allows operating flexibility since many buildings now share the chillers. As the energy custodian of the consumers with various load profiles, the overall system can also be operated or optimum energy management.

A DCS is space saving, allowing more space for other uses since the combined chiller plant is smaller and may be located away from the consumer’s premises.

Operations and maintenance are reasonably simple, offering more convenience, ease and peace of mind in addition to reducing costs and is time saving.

• Higher efficiency system• Savings of capital and running cost• Operating flexibility• Optimum energy management• Saves building space for other uses• Simple operations and maintenance

Benefits of DCS

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DCS Technology OptionsA DCS normally incorporates one of a few technological options available, each with its own benefits and advantages. These options can be classified as follows:

• Thermal Energy Storage (TES) – can be further divided into ice storage, chilled water storage, ice harvester, etc.• Co-Generation – can be utilized for electricity and steam production

TNB ENGINEERING CORPORATION (TNEC)

The plant consumes less electricity during the day, when electricity tariff is high.The Thermal Energy Storage (TES) Concept

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During the day, when the air-conditioning demand is high, the stored cooling energy is released by circulating chilled water through the storage system and onto the buildings. Only a limited amount of chiller capacity needs to operate during this period.

By adopting this concept, the plant consumes less electricity during the day, when electricity tariff is high.This leads to significant savings in operating costs.

As the electrical power demand for this plant is also low during the day, further cost saving is achieved through reduced maximum (MD) charges.

TES System TypesBroadly, TES system can be categorized into two types:• Ice storage• Chilled water storage

Each system has its own advantages and disadvantages, depending on the specific application.

Thermal Energy Storage capitalises on the cheaper off-peak tariff offered by the electric utility company. The system produces cooling energy at night when the electricity tariff is low.

The Thermal Energy Storage (TES) Concept

TNB ENGINEERING CORPORATION (TNEC)

The chiller would run at full capacity for most of the time. Benefits of TES

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Technical:• Reduction of the installed chiller capacity• Reduction of short cycles• Increased system efficiency and reliability• Simplified maintenance• Flexible system

Environmental:• Limited use of ozone-depleting refrigerants• Reduced noise pollution

Financial:• Shifting of electricity consumption from day to night• Saving on the maximum demand charge• Reduced average cost of air-conditioning

How TES Technology Saves Energy CostsIn a typical TES application, the chiller capacity is less than the design air-conditioning demand. The chiller meets part of the on-peak cooling load and the storage meets the rest.

The chiller would run at full capacity for most of the time. When the load is less than the chiller output, the excess charges storage. When the load exceeds chiller capacity, the additional requirement is discharged from storage

The diagram below clearly shows that the plant installed chiller capacity can be greatly reduced when compared to the conventional system.

Since the chiller is operated at full capacity most of the time, it is now better utilised and able to perform at high efficiencies.

The TES plant load is also more levelled compared to the conventional plant where its load must follow the cooling load very closely. The conventional system would be charged higher for its high maximum electrical demand.

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Reduction in chiller installed capacity

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Benefits of TES

TNB ENGINEERING CORPORATION (TNEC)

TES Basic System Operation

During the night, when electricity tariff and cooling demands are low, the chiller is used to store cooling energy in the storage tank.

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A TES incorporating a storage system comprises the following basic components:

• Chiller• Ice storage tank• Heat exchanger• Pumps• Valves

The system configuration can vary depending on the operating strategy adopted. Users can choose between full storage and partial storage. In many instances, partial storage system is preferred to ensure full utilization of the installed chiller.

During the night, when electricity tariff and cooling demands are low, the chiller is used to store cooling energy in the storage tank.

• Heat transfer fluid at temperatures below the freezing temperature of the storage media circulates through the tank, causing the formation of ice inside the tank.

• The bulk of the stored energy is stored at constant temperature as latent heat during the phase-change period. During the day, when the cooling demand is high, cooling energy is provided by the combined efforts of the chiller and the ice storage tank.

• The chiller works at full capacity with the storage tank providing the shortfall.

• The fluid passes through the storage tank at temperatures higher than the melting temperature of the ice.

• The pumps and valves regulate the output temperature.

• The heat exchanger provides the isolation between the storage tank brine loop and the distribution system water loop.

TES Basic System Operation

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TNB ENGINEERING CORPORATION (TNEC)

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TNB Engineering Corporation Sdn Bhd (TNEC) is a wholly-owned subsidiary of Tenaga Nasional Berhad (TNB), Malaysia’s largest electricity utility and a leading utility company in Asia.

The company has extensive experience in the development, design, construction, operation and maintenance of DCS plants and networks, spanning more than 10-year period.Drawing on its expertise, experience and resources, TNEC is able to offer property owners and developers an individual packaged system fitting each one’s respective needs.

About Us

Bangsar Energy Systems Sdn Bhd (407209-K) is the District Cooling Owner Company in Bukit Pantai area in Kuala Lumpur, and is a wholly-owned subsidiary of TNEC.

It is the project developer, owner and operator of the Bangsar Energy Systems Sdn Bhd (BES) plant located at TNB Headquarters Complex in Bangsar, Kuala Lumpur.

The Bangsar DCS is one of the largest in Malaysia.

Developed under the Build, Own and Operate (BOO) concept, the project was financed through external borrowings, backed by the Chilled Water Purchase Agreement (CWPA).

At present, BES is the dedicated subsidiary company of TNEC to develop and promote the application of district cooling system in the country and world over.

TNB ENGINEERING CORPORATION (TNEC)

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District Cooling System (DCS) using Thermal Energy Storage (TES) with Build-Operate-Transfer (BOT) Scheme

Institut Jantung Negara (IJN), in expanding their hospital facilities and additional buildings, seek ways to minimize the air-conditioning cost and to interconnect with the existing air-conditioning facility for operation flexibility.

TNEC was awarded the contract for design, procurement, installation, testing and commissioning and Supply of Chilled Water for twenty (20) years through Build-Operate-Transfer (BOT) Scheme.

TNEC’s ResponsibilitiesOperation and Maintenance Costs, inclusive of :• Electricity Consumption• Consumables• Spares Equipment Replacement• Staffing• Chemicals and other consumables

Financial Advantages• Savings on operation costs, maintenance, demand charge and off peak consumption• Lower initial investment for clients

Parameters of the plant are as follows :Cooling Load Maximum 1,9370 RTDaily Energy Usage 30,197 RThEnergy Storage 7,100 RThPeak Supply From Brine Chiller/Storage 1,930RTTotal Storage Volume 450m3

Charging Time 9 hoursDistribution Temperature Supply 6.0°C Return 12.0°CCoefficient of Performance (COP) 3.10

INSTITUT JANTUNG NEGARA

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Airport Cooling Energy Supply Sdn BhdMain Customers:• Main Terminal Building (MTB)• Airport Mall and Transportation Hub• Landside Hotel 1• Air Asia Building

Main scope of works:• District Cooling Plant (DCP).• The 132/33 kV substation with 132 kV Cable Incomers from TNB’s PMU Bukit Changgang• External distribution piping from plant to various buildings• Energy Transfer Stations (ETS)

TNEC Roles• Investor through ACES• EPC Contractor• Comprehensive Operations & Maintenance (O&M) Contractor

Airport Cooling Energy Supply Sdn Bhd (ACES), a joint venture company between TNEC & Malaysia Airports Holdings Berhad (MAHB) is the Concession Holder.

Project Name : Kuala Lumpur International Airport 2 (KLIA2) DCS PlantLocation : Sepang, MalaysiaContract Delivery Method : BOT (Build, Operate and Transfer under a 20-year concession)Project Size : 18,000 RTConstruction Period : January 2011 – April 2012

DCP Configuration

Plant installed configurationElectrical centrifugal chiller 6 nos x 2,000 RTChilled water TES tank 2 nos x 30,000 RThPlant installed capacity 18,000 RT

Plant ultimate configuration after future expansionElectrical centrifugal chillers 8 nos x 2,000 RTChilled water TES tank 3 nos x 30,000 RThPlant ultimate installed capacity 25,000 RTOverall system efficiency (kW/RT; COP) 0.858; 4.1Chilled water reticulation piping distance 2.5km

KUALA LUMPUR INTERNATIONAL AIRPORT 2

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TNEC’s Responsibilities• Plant rehabilitation costs including new chillers and TES equipment

• Operation and Maintenance Costs, inclusive of: • Electricity Consumption • Consumables • Spares Equipment Replacement • Staffing • Chemicals and other consumables

TNEC Guarantees• Chilled water supply temperatures• 24 hours chilled water availability• Plant Performance

MAJLIS BANDARAYA SHAH ALAM

Thermal Energy StorageRehabilitate, Operate & Maintain (ROM) with Financing

Construction And Commissioning :January 2006 – July 2006Client :Majlis Bandaraya Shah Alam

Majlis Bandaraya Shah Alam (MBSA), the forward looking City Council has been actively seeking ways to minimize its air conditioning costs.

TNB Engineering Corporation Sdn Bhd (TNEC) offered to finance the replacement of the existing chillers and the installation of an ice Thermal Energy Storage (TES) System. Through its Rehabilitate, Operate and Maintain (ROM) Concept, TNEC also undertakes the comprehensive plant operations and maintenance and charges MBSA a monthly bill for cooling energy utilization.

Master PlanThe plant has been expanded to form a District Cooling System (DCS) to connect to the Selangor Theatre and Musuem.The TNEC ROM solution has helped MBSA reached its costs savings target without any capital investment.

Parameters of the plant are as follows:

Cooling Load Maximum Demand 1,300RTDaily Energy Usage 15,088 RThEnergy Storage 5,200 RThPeak Supply From Brine Chiller/Storage 1,300 RTPeak Supply From Base (Water) Chiller 1,000 RTTotal Storage Volume 340m3

Charge Time 10 hrsDistribution Temperature 6.7°C supply 14.0°C return

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UiTM Faculty of MedicineSungai BulohSelangor Darul Ehsan

Project Name : DCS UiTM Faculty of Medicine, Sungai Buloh, Selangor.

Location : UiTM, Sungai Buloh, Selangor Delivery Method : Engineering, Procurement, Construction and Commissioning (EPCC)

Detail construction are as belowProject Installation Period 2008 – 2009 (First Phase) 2009 – 2011 (Second Phase)Owner Universiti Teknologi MARA (UiTM)

Parameters of the plant are as follows:Cooling Load Maximum Demand 3200 RTEnergy Storage (Ice On Coil) 48 nos x 240 RT 11520 RThBrine Chiller Capacity 3200 RTEnergy Efficiency 0.70 kW/RTSupply temp. 4.44°CReturn temp. 14.4°C to 14.9°C

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Universiti Kebangsaan Malaysia’s (UKM) fast growing student population had its electricity consumption and costs spiralling every year. A comprehensive energy audit identified the urgent need for retrofitting work to address increasing maximum demand immediately and long term.

TNEC was awarded the contract for the design, engineering installation testing & commissioning of a Thermal Energy Storage DCS Scheme and other system rehabilitation works, and thereafter to operate and maintain the system.

UKM achieved an average savings of RM 120,000 in monthly electricity cost or RM1,315,000 for a year of electricity billings.

The average maximum demand was reduced from 8,592 kW to less than 7,500 kW.

The comprehensive O&M responsibility includes:• Manpower• Routine maintenance• Electricity and water usages• Chemicals and other consumables• Equipment replacement major overhauls

TES incorporated in a DCS is one of the most effective energy management schemes for air-conditioning applications of large scale development projects or building complexes,

The TNEC-UKM partnership effort to improve energy management was awarded with the Plaque of Recognition at the 2nd ASEAN Energy Efficient Building Best Practices competition for the Retrofitted Building category in 2001.

Thermal Energy StorageDCS Scheme and system rehabilitation

Project installation period : October 1999 – November 2000Owner : Universiti Kebangsaan Malaysia

Parameters of the plant are as follows:Cooling Load Maximum Demand 3,700 RTDaily Energy usage 46,600 RThEnergy Storage 11,318 RThPeak Supply from Brine Chiller/Storage 2,900 RTPeak Supply From Base (Water) Chiller 800 RTTotal Storage Volume 800 cubic metersCharge Time 10 hoursDistribution Temperature 5°C supply 12.8°C returnTotal Cooling Plant Reduction Capacity 36.65%Overall Plant Efficiency 0.5853 kW/RT 0.9216 kWh/RTh

INSTITUT JANTUNG NEGARAUNIVERSITI KEBANGSAAN MALAYSIA Loop 1

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INSTITUT JANTUNG NEGARA

District Cooling system (DCS) using Thermal Energy Storage – Engineering, Procurement and Construction Contract

Project Installation Period : July 2010 – August 2011Owner : Universiti Kebangsaan Malaysia

Universiti Kebangsaan Malaysia (UKM), during the Eighth and Ninth Malaysia Plans has constructed new campuses and facilities within the vicinity of the second loop of its main campus in Bangi, Selangor Darul Ehsan. The development is known as UKM Loop 2.

The DCS System was developed to cater for the air-conditioning load of the buildings like Faculty of Engineering and Architecture, Faculty of Technology & Science Information, Faculty of Education, Faculty of Law, Architectural building (future), Language Teaching and Linguistic Centre, Computer Centre, Kompleks Tun Abdullah Mohd Salleh, Department of Development & Management Office and Printing and Publishing Centre. The total connected loads for these buildings are 4500 RT.

DCP ConfigurationCooling Load Maximum Demand 4,500 RTEnergy Storage Capacity 2 nos x 7,898 RThSupply/Return Temperature 5.6°C / 12.2 °CCharging Time 10 hours Base Chillers 3 nos x 850 RTTank Capacity (RC tank) 2 nos x 2,916m3

Network Piping 3.2 km

UNIVERSITI KEBANGSAAN MALAYSIA Loop 2

Technical Advantages• Smaller chiller capacity• Smaller heat rejection plant• Reduced maintenance• Efficient and reliable system• Increase of plant life time• Flexible system available for efficient energy management

Financial Advantages• Savings on operating costs, maintenance, demand charge and off peak consumption• Lower initial investment for clients

Project installation period : 1997 - 1998Owner : Bangsar Energy Systems Sdn Bhd

The Pantai District Cooling system, located in Bangsar, was developed by TNEC to provide chilled water for air-conditioning purposes for major buildings in the vicinity of Pantai Baru and Jalan Bangsar areas. This development includes the prestigious Menara TM, TM Annexe, TNB Corporate HQ Complex, Pullman Bangsar hotel and Pantai Plaza commercial developments.

Bangsar Energy Systems Sdn Bhd, a subsidiary of TNEC, acts as project developer, owner and operator of the plant.

It is a success story with the system being able to increase the plant efficiency with a 24% saving on operating costs.

Parameters of the plant are as follows:Cooling Load Maximum Demand 9,800 RTDaily Energy Usage 127,257 RThEnergy Storage 30,650 RThPeak Supply from Brine Chiller/Storage 7,680 RTPeak Supply from Base (Water) Chillers 2,120 RTStorage Volume 1,900 cubic metersDistribution Temperature at plant outlet 5°C5 centrifugal brine chillers 1,036 RT @ 3.3/8.6°C(capacity & temperatures) 588 RT @ -5/-2°C2 base centrifugal water chillers 1,060 RT @ 5/14.5°C(capacity & temperatures)Length of reticulation piping networks Approx. 1.75 km

PANTAI DISTRICT COOLING SYSTEM

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INSTITUT JANTUNG NEGARAMALAYSIAN NUCLEAR AGENCY

Air-conditioning rehabilitation worksProject installation period :September 2001 – March 2002Owner :Malaysian Nuclear agency (Nuclear Malaysia)

Parameters of the plant are as follows:Cooling Load Maximum Demand 1,500 RTDaily Energy usage 16,500 RThEnergy Storage 5,659 RThPeak Supply from Brine Chiller/Storage 1,500 RTTotal Storage Volume 400 cubic metersCharge Time 10 hoursDistribution Temperature 5°C supply 12.8°C returnOverall Plant Efficiency 0.9216 kWh/RTh

Nuclear Malaysia is the national research institute whose core activities are nuclear science and other related technologies.

TNEC was awarded the contract for the design, procurement, installation and commissioning for the Air-Conditioning Rehabilitation Works (conversion to TES scheme) at Nuclear Malaysia.

The storage tank combines the ability to discharge energy at a high rate with low operating cost, achieving an estimated 30% savings on the electricity bill.

TNB Engineering Corporation Sdn Bhd

TNB ENGINEERING CORPORATION SDN BHD (279964-A)

1701, Level 17, Block B, Menara Amcorp18, Persiaran Barat, Peti Surat 152, Jalan Sultan,46000 Petaling Jaya, Selangor, Malaysia

T: +603-7958 2121 F: +603-7958 2626E: tnec@tnb.com.myhttp://www.tnec.com.my

(A wholly-owned subsidiary of Tenaga Nasional Berhad)