20. BUILDING SERVICES Thai Binh 2 Thermal Power Plantdocshare01.docshare.tips/files/29382/293822471.pdf · standard if it is achieved by calculation sheets, ... TCVN 2622 - 1995 Fire

20. BUILDING SERVICESThai Binh 2 Thermal Power Plant

20.2.1 Air Conditioning and Mechanical Ventilation

20.2.1.1 General

This specification covers the detailed design, supply, and delivery to site, installation, testing,

commissioning and acceptance testing of the air conditioning and mechanical ventilation system. The

Contractor shall furnish labor, materials, equipment, certificates, drawings, temporary work and carry

out design, engineering, supply, manufacture, erection, installation, inspection, testing, commissioning

to complete the work.

20.2.1.2 Scope of Work

The work covered under this specification shall include the complete air-conditioning and mechanical

ventilation (ACMV) systems for buildings/areas, as well as details, accessories, electrical and other

associated services required for the complete installation to operate safely, reliably and properly.

Equipment and/or accessories not specifically mentioned in this Specification, but which are

necessary for a safe, reliable and proper operation of the ACMV system, shall be deemed to be

included in the package.

The scope of work shall include but not be limited to the following:

Detailed design of ACMV systems for buildings, including cooling load calculating by E-20-II

software or other approved software, cooling load calculation shall be meet current Ashrae

standard if it is achieved by calculation sheets, ACMV equipment sizing, pipe sizing

calculations, duct sizing, ductwork pressure loss calculations, electrical voltage drop

calculations, cable sizing calculations, isometric drawings, pipe support design, pipe stress

analysis and design report.

Supply and installation of ACMV equipment inclusive of air cooled chillers, chilled water

pumps, air cooled roof top package units, air handling units, air cooled split condensing units,

direct-expansion air handling units, supply ventilation fans and extract ventilation fans.

Supply and installation of chilled water distribution system inclusive of pipes, pipe fittings,

valves, and pipe supports, expansion tanks and piping instrumentation.

Supply and installation of thermal insulation to chilled water distribution systems inclusive of

vapor barrier and pipe cladding.

Supply, installation of air distribution system inclusive of ductwork, duct fittings, balancing

dampers, fire dampers, volume control dampers, air grilles and diffusers, fresh air louvers,

split dampers, duct support and duct instrumentation.

Supply and installation of thermal insulation to air distribution system inclusive of vapor

barrier.

Supply and installation of acoustic duct lining, vibration isolation to rotating equipment, sound

attenuators and other acoustic measures.

Supply and installation of electrical power distribution system to ACMV equipment inclusive of

starter panels, motor control centers, cabling and wiring, conduit, trunking and cable support

system for the ACMV System unit’s electrical and instrumentation control loads.

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Electrical and structural earthing of the entire ACMV System.

Supply and installation of instrument and control equipment inclusive of building local control

panel, distributed control system, intelligent outstations, control valves, field devices, sensors

and transmitters, gauges and flow meter.

Water and air balancing of ACMV system.

Testing and commissioning of the ACMV system inclusive of ductwork air pressure test,

hydraulic pressure test for piping installation, loop test, polarity test, meggar test for cabling

system and function test of control system.

Cleaning and flushing of the completed water distribution system.

Submission of shop drawings, as-built drawings, method statements, installation procedures,

material specification, catalogues and datasheets, samples, quality control procedures,

health, safety and environment procedures and work procedures.

Engage a Professional Engineer to carry out the following ACMV work:

- Design in detail

- Endorse on calculations, drawings and certificates

- Submission to local authorities and to obtain approval/clearance for the ACMV system

The Contractor shall furnish documentation including provision of full warranty for defects

arising during the defects liability period.

The Contractor shall provide submission drawings in electronic format (AutoCAD and PDF) as

well as hard copy for submission to local authorities.

The Contractor shall provide AutoCAD native files as well as in PDF format for drawing

submissions for review and approval. This shall include but not limited to shop drawings,

authorities submission drawings and as-built drawings.

The Contractor shall provide “As-Built” drawings and two electronic copies of the drawings

(one in AutoCAD format, one in pdf format) after completion of work.

Submission of Operation & Maintenance Manual, both hard-copy and electronic copy in pdf

format.

Supply and delivery of spare parts.

Training of Operating staff.

20.2.1.3 Codes, Standards, Specifications and Regulatory Requirements

The ACMV System shall be provided in accordance with the following local / international codes and

standards:

TCVN 4088- 1985 Climatic data in construction design Standard, design requirements are

applied with following standards:

TCVN 5687 -1992 Air ventilation, conditioning and heating design standard

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TCVN 5938 - 1995 Air quality. Maximum permissible concentration of some toxic matters in

surrounding environment.

TCVN 5940 -1995 Air quality. Industrial waste air for organic matters.

TCVN 4605 - 1988 Thermal technical. Enclosure structure. Technical standard.

TCVN 5945 -1995 Industrial waste water. Waste standard

TCXD 188 - 1996 urban waste water. Waste standard.

TCXD 232 - 1999 Air ventilation, conditioning and cooling system. Fabrication, installation and

taking over.

TCVN 2622 - 1995 Fire fighting and protection for house and work. Standards and regulations

for commissioning mode

TCVN. 3993 - 1985 Anti-corrosion in construction International standards and codes

NFPA 90A Installation of air conditioning and ventilation system

ASHRAE 70 Methods of testing for rating the air flow performance of outlet and

inlets

ASHRAE Standard 62 Ventilation for Acceptable Indoor Air Quality

The codes, standards and specifications referenced in the Specification shall include addenda and

amendments and shall govern in all cases where references to them are made.

The precedence applying for use of the Codes, Standards, Specifications and Regulatory

requirements for this project is as follows:

Regulatory requirements

Project specific requirements

Vietnam standards

International standards

The Contractor shall comply with rules and regulations of Vietnam and any other International

Standards and Codes of Practice relevant to the type of system in similar Power Plants.

In case of any conflict between these codes and standards and the Specification, the more stringent

standard shall prevail to the extent of such difference.

20.2.2 Design Requirements

20.2.2.1 General

Air conditioning or mechanical ventilation shall be provided within the areas/rooms to prevent the

accumulation of stale air and the build up of dangerous fumes, to reduce the temperature rise caused

by items of electrical equipment and to maintain a comfortable environment for working.

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20.2.2.2 Design Services

The Contractor shall perform design functions necessary for the development, procurement,

installation, testing and commissioning of the ACMV system and components to provide a complete

and safe ACMV system. Design functions shall include but not be limited to the following:

Cooling load calculation using computer software such as E20-II, Trace 700 or equivalent,

cooling load calculation sheets shall be meet current Ashrae standard.

Building material U-value calculation.

Equipment sizing. 10% safety margin shall be allowed for in equipment sizing.

Pipe stress analysis to verify adequacy of piping design.

Hydraulic calculation of pipe sizing, flow rates and pressure drop calculation for pump sizing.

Fan static pressure loss calculation.

Voltage drop and cable sizing calculation.

Preparation of drawings which clearly illustrate the system concept of chilled water distribution

system, air distribution system, refrigerant piping system, electrical power and control system.

Drawings shall include floor layout plans, schematic flow diagrams, process flow diagrams,

process and instrument (P&I) diagrams, single line diagram, control logic diagram and system

architecture drawing.

Preparation of piping general arrangement drawings and piping isometric drawings.

Preparation of detail duct routing general arrangement.

Preparation of electrical and control cable routing plans.

Preparation of construction details shop drawings which clearly illustrate pipe fabrication

details, pipe support details, duct fabrication details, cable termination details and

construction/installation details.

Submission to local Authorities and obtaining their approval.

Supervise the installation work and certify fitness of use upon completion of ACMV work.

Toilet, kitchen, battery room and laboratory shall have a slight negative pressure.

Each air-handling unit and exhaust fan shall be interlocked with and shut down by the

appertaining smoke detectors, via fire alarm panel.

Unless otherwise specified, equipment and materials within the scope of this Specification shall be of

a standard proven design. Designs incorporating components which may be considered prototype will

not be accepted.

Equipment and components shall be designed and supported to permit free expansion and

contraction without causing leakage, excessive strain and distortion.

20.2.2.3 Design Criteria

Air conditioning, mechanical ventilation and natural ventilation shall be provided in accordance with

the following table:

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Building Name AirConditioning

MechanicalVentilation

NaturalVentilation

1 Turbine-generator House

2 Boiler House

3 Central Control House

4 Administration Building

5 Common Service House

6 Reception house at main gate

7 Switchyard Control House

8 CHP Control House

9 ESP House

10 Fuel Oil Pumping Equipment

11 Diesel Generator House

12 Hydrogen Generation Plant

13 Water Treatment SystemHouse

14 Chlorination Plant

15 Return Water Pump House

16 Bulldozer Garage

17 Mechanical EquipmentWarehouse

18 Cooling Water Pump House

19 H.F.O Unloading Jetty

20 Limestone Storage and Milling

21 Maintenance Workshop

22 International and LocalConsultant Office

23 Electrical and I&C warehouse

24 Coal Milling Station

25 Other Auxiliary EquipmentHouse

20.2.2.4 External Design Criteria

The ACMV system shall be designed based on the following external conditions:Outdoor design ambient conditions: 38°C DB maximum air temperature

37°C WB with 93% max. monthly avg. relative

humidity

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20.2.2.5 Internal Design Criteria Air Conditioning System

Air-conditioned areas shall be designed to maintain the following internal conditions with appropriate

duty and standby provision:

Building/Level Room No.

Indoor ConditionNoiseCriteria(NC)

RedundancyRelativeHumidity/%

Dry BulbTemp0C

AdministrationBuilding

Ground Floor Working Room 13 555% 2310C 45

Duty & ServiceRoom

1 555% 2310C 45

Guest Room 1 555% 2310C 45

Operator Room 2 555% 2310C 45

Document Room 1 555% 2310C 45

Storage Room 1 555% 2310C 50

Health Room 1 555% 2310C 45

Store Room 1 555% 2310C 50

1st Story Working Room 16 555% 2310C 45

Meeting Room 2 555% 2310C 45

Guest Room 1 555% 2310C 45

Secretary Room 1 555% 2310C 45

Director Room 1 555% 2310C 45

Vice Director Room 3 555% 2310C 45

Director MeetingRoom

1 555% 2310C 45

2nd Story Working Room 23 555% 2310C 45

Meeting Room 1 555% 2310C 45

3RD Story Working Room 21 555% 2310C 45

Small MeetingRoom

1 555% 2310C 45

Library 2 555% 2310C 45

Traditional Room 1 555% 2310C 45

Hall

Hall Hall 1 555% 2310C 45

Central Control

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Dry BulbTemp0C

Building

Ground Floor Laboratory 555% 2310C 45 N+1

HP DistributionRoom

555% 2310C 50 N+1

AC DistributionRoom

555% 2310C 50 N+1

3rd FloorBreaker & LVDistribution Room

555% 2810C 50 N+1

Marshalling Room 555% 2810C 45 N+1

4th FloorMain ControlRoom

555% 2310C 45 N+1

System & TestDeveloping Room

555% 2310C 50 N+1

Computer Room 555% 2310C 45 N+1

Shift-handlingRoom

555% 2310C 45 N+1

SCADA Room 555% 2310C 50 N+1

Control Cubicle 555% 2310C 45 N+1

Working Room 1 555% 2310C 45 N+1


Document &General Storage

555% 2310C 45 N+1

CommunicationRoom

555% 2310C 50 N+1

Dining Room 555% 2310C 45 N+1

Meeting Room 555% 2310C 45 N+1



Electrical and I&CWarehouse

Warehouse 555% 2310C 50 N+1

Common ServiceHouse

Dining Room 555% 2310C 45 N+1

Switchyard ControlHouse

Ground Floor Relay Room 555% 2310C 50 N+1

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Dry BulbTemp0C

Control Room 555% 2310C 45 N+1

DC Room 555% 2310C 50 N+1

Duty Room 555% 2310C 45

2ND FloorCommunicationRoom

555% 2310C 45 N+1

Working Room 555% 2310C 45 -

Meeting Room 555% 2310C 45 -

Small WorkingRoom

555% 2310C 45 -

CHP Control House

Electrical Room 555% 2810C 50


Control Cubicleand EquipmentRoom

555%2810C

45 N+1

Reception House atMain Gate

Guest Room 555% 2310C 45 -

Shift Handling OverHouse

555% 2310C 45 -

Security ReceptionRoom

555% 2310C 45 -

International andLocal ConsultantOffice

Office 555% 2310C 45 -

ESP Control House

Electrical Room 555% 2810C 50 N+1


Fuel Oil PumpingHouse


Diesel EquipmentHouse


Hydrogen House


Water TreatmentHouse

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Dry BulbTemp0C

Electrical House 555% 2810C 50


Office 555% 2310C 45

Laboratory 555% 2310C 45 N+1

Chlorine House

Control & ElectricalRoom

555% 2310C 45 N+1

Return Water PumpHouse

Rest Room 555% 2310C 50

MCC Room 555% 2310C 45 N+1

BulldozerGarage

Office 555% 2310C 45 N+1

MechanicalEquipmentWarehouse

Office 555% 2310C 45 N+1

Cooling Water PumpHouse

Electrical Room 555% 2810C 50 N+1


H.F.O. UnloadingJetty

Rest Room 555% 2310C 50


Limestone storageand milling

ElectricalEquipment Room

555% 2810C 50 N+1

C&I Room 555% 2310C 50 N+1

MaintenanceWorkshop

Welding EquipmentRoom

555% 2310C 50

Laboratory 555% 2310C 45

Meeting Room 555% 2310C 45

Electric TechnicianRoom

555% 2310C 50

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Dry BulbTemp0C


555% 2310C 50

Manager Room 555% 2310C 45

Storage Room 555% 2310C 50

Locker 555% 2310C 50

Turbine

Building

Laboratory 555% 2310C 50 N+1

Note:

N+1 means a HVAC system in which N units have at least one independent backup component to

ensure system functionality continues in the event of a system failure. To be at a level of N+1, the

overall system integrity should not be impacted by the failure of any one component, and should

continue to function at acceptable performance levels after the loss of any component.

20.2.2.6 Internal Design Criteria for Mechanical Ventilation System

The mechanical ventilated space shall be designed to maintain the following internal condition with

appropriate redundancy provisions:

Building/ Level Room Air Change per HourNoise Criteria(NC)

Remarks

AdministrationBuilding

Ground Floor HVAC Room

Minimum 6 or to be calculated byheat load calculation to main roomtemperature not more than 40°C ornot more than +5°C above ambienttemperature whichever higher.

50

Toilet 12 50 (N+1);

1st Story Toilet 12 50 (N+1)

2nd Story Toilet 12 50 N+1

3Rrd Story HVAC Room


50

Toilet 12 50 N+1

Central Control

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Remarks

House

Ground Floor Toilet 12 50

Battery Room


60 N+1

2nd Floor Cable-room


60 N+1

HVAC Room


50N+1

Toilet 12 50

4th Floor Antechamber - Natural Ventilated

Toilet 12 50

CommonService House

Mechanical Room 12 50

Kitchen 20 60 N+1

Women Toilet 12 50N+1

Man Toilet 12 50

Man ChangingRoom 12 50

Woman ChangingRoom 12 50

Man Bath Room 12 50

Woman BathRoom 12 50

SwitchyardControl House

Ground Floor Battery Room


50N+1

Toilet 12 50

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Remarks

2ND Floor Toilet 12 50

International andLocal ConsultantOffice

Toilet 12 50

Electrical andI&C Warehouse

Toilet 12 50

Coal MillingStation

Coal Milling House 6 50 N+1

Fuel Oil PumpHouse

Maintenance Area


50 N+1

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ReceptionHouse at MainGate

Toilet 6 50

Toilet 12 50

MechanicalEquipmentWarehouse

Storage Area Natural Ventilated

Toilet 12 50

Hydrogen House

Hydrogen PlantHouse

Minimum 12 or to be calculated byheat load calculation to main roomtemperature not more than 40°C ornot more than +5°C above ambienttemperature whichever higher..

50 N+1

Rectifier Room


50 N+1

CHP ControlHouse

Toilet 12 50

Return WaterPump House

Toilet 12 50

Chemical Room

Minimum 12 or to be calculated byheat load calculation to be not morethan +5°C above ambienttemperature whichever higher.

50

Maintenancearea 12 50

H.F.O UnloadingJetty

EquipmentStorage


50


Minimum 12 or to be calculated byheat load calculation to main roomtemperature not more than 40°C ornot more than +5°C above ambienttemperature whichever higher..

50 N+1

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Pump Room


50 N+1

LimestoneStorage andMilling

Limestone storagearea


50

Cooling WaterPump House

Pump house area


60

Fire PumpHouse

Fire Pump House


60

Diesel GeneratorRoom

Diesel GeneratorRoom


50

Ash Slurry PumpHouse

Ash Slurry PumpHouse


60

Turbine-generator House

Turbine House

To be calculated by heat loadcalculation to be not more than+5°C above ambient temperaturewhichever higher.

60 N+1

Deaerator House - Natural Ventilated

Coal BunkerHouse

-Natural Ventilated

MaintenanceWorkshop

Fabricating Minimum 12 or to be calculated by 60 N+1

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Machine Roomheat load calculation to be not morethan +5°C above ambienttemperature whichever higher.

Toilet 12 50

Note:

N+1 means a ventilation system in which N units have at least one independent backup component to

ensure system functionality continues in the event of a system failure. To be at a level of N+1, the

overall system integrity should not be impacted by the failure of any one component, and should

continue to function at acceptable performance levels after the loss of any component.

Indoor air quality shall be in accordance with Vietnam standards. Areas shall be positively

pressurized as necessary to prevent the ingress of dust.

20.2.2.7 Fresh Air and Internal Load

Fresh air to air conditioned space shall be provided based on 8 liters/s/person. Laboratory shall be

provided with 100% fresh air.

Internal heat gain from occupant, lighting, office equipment, electrical equipment shall be considered

in the cooling load calculation. For those areas where internal heat gain is not available, 30 W/m2

shall be allowed for miscellaneous equipment load.

20.2.2.8 General Requirement

Standardization of the major items of equipment and their constituent components is required where

practicable.

Refrigerants supplied with all equipment shall be 'ozone friendly' refrigerants as approved by the

Montreal Protocol.

Duty and standby units shall be provided for the room with important equipment such as control room,

power cubicle room, control cubicle, electrical room and key areas.

Fresh air supply ventilation shall be designed to ensure that the indoor environment is positively

pressurized to prevent the infiltration of dust laden outside air.

Mechanical ventilation shall be provided where necessary to remove heat gains from equipment or

hazardous fumes.

The extract fans shall be suitably protected against the corrosive marine environment and located so

ease of maintenance is achieved.

20.2.2.9 Noise Limits

In general, equipment noise levels shall not exceed 85 dB(A) at a distance of one meter from the

equipment.

The far-field noise level shall be designed to meet 60 dB (A) at the project property boundary.

Noise levels shall be measured in accordance with appropriate ISO Standards. Background noise

generated from ACMV equipment, air grilles and ductwork shall not exceed the value as specified in

the internal design criteria.

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20.2.3 SYSTEM DESCRIPTION

20.2.3.1 Administration Building

Three air cooled chillers (2 duty, 1 standby) with matching chilled water pumps (2 duty, 1 standby)

shall be provided at the roof to distribute chilled water to various air-side equipments for air

conditioning purposes.

Chilled water pipes shall be arranged in single primary loop manner with gravity feed and expansion

tank located at 1.5 m above the highest water side equipment to prevent air lock.

Modulating control valves shall be provided at cooling coils for proper control of space air temperature

or supply air temperature as required.

Air constant air volume air handling units with appropriate duty and standby redundancy shall be

provided at each HVAC room. Proper zoning shall be designed and each zone shall be equipped with

electric duct re-heater for part-load space temperature control. Digital thermostat with manual

adjustable set point shall be provided in air condition space for control purposes.

Ducted return shall be used and fresh air shall be connected at the return plenum before the air filter.

Air filter shall be provided upstream of the cooling coil to provide 95% up to 5 micro filtration efficiency.

Toilet exhaust shall be ducted to the roof for centralize exhaust. Duty and standby toilet exhaust fan

shall be provided.

For HVAC rooms, N (N duty without redundancy) unit exhaust fan and ducted supply fan c/w supply

grilles shall be provided.

20.2.3.2 Central Control Building

Three numbers of air cooled chillers (2 duty, 1 standby) with matching chilled water pumps (2 duty, 1

standby) shall be provided at the roof to distribute chilled water to various air-side equipment for air

conditioning purposes.

Chilled water pipes shall be arranged in single primary loop manner with gravity feed and expansion

tank located at 1.5 m above the highest water side equipment to prevent air lock.

Modulating control valves shall be provided at cooling coils for proper control of space air temperature

or supply air temperature as required.

Air constant air volume air handling units with appropriate duty and standby redundancy shall be

provided at each HVAC room. Proper zoning shall be designed and each zone shall be equipped with

electric duct re-heater for part-load space temperature control. Digital thermostat with manual

adjustable set point shall be provided in air condition space for control purposes.

Air constant air volume chilled water precision air conditioning units with appropriate duty and standby

redundancy shall be provided for main control room and control cubicle room. Digital thermostat with

manual adjustable set point shall be provided in air condition space for control.



Laboratory shall be equipped with its own duty and standby air handling units using 100% fresh air.

Proper zoning shall be designed and each zone shall be equipped with electric duct re-heater for part-

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load space temperature control. Digital thermostat with manual adjustable set point shall be provided

in laboratory for control purposes.

Laboratory exhaust via fume cupboards and air grilles shall be ducted to the roof for air discharge.

Exhaust duct shall be of stainless steel grade 314. Constant air volume air valve shall be provided at

each fume cupboard connection. Duty and standby laboratory exhaust fan shall be provided.

Battery room shall be equipped with its own duty and standby mechanical ventilation system.

Exhaust duct of the battery room shall be made of stainless steel grade 314 and shall be ducted to the

roof for air discharge. Fresh air shall be filtered and taken from side of the room. Fans and

equipments shall be explosion proof.

Toilet exhaust shall be ducted to the roof for centralize exhaust. Duty and standby toilet exhaust fan

shall be provided.

Ducted mechanical ventilation system shall be provided to HVAC rooms and cable room respectively.

20.2.3.3 Common Service House

Localized air-cooled direct expansion units c/w wireless remote control shall be provided to serve the

dining room and other space require air conditioning. Indoor units shall be ceiling cassette type c/w

fresh air intake kit.

Ducted mechanical ventilation system shall be provided for toilet, male shower room, female shower

room, male locker room, female locker room, male toilet and female toilet respectively.

For kitchen, the intake air shall be transferred from dining room. Kitchen exhaust shall be ducted to

the roof by exhaust fan. Duty and standby exhaust fan shall be provided.

Grease intercepting filters shall be provided at kitchen exhaust air grilles. Grease filters media to be

woven aluminum with expanded metal cover on both sides.

20.2.3.4 Switchyard Control House

Duty and standby localized air-cooled direct expansion units c/w wireless remote control shall be

provided to serve the Control room, relay room, communication room and AC/DC room respectively.


working rooms, meeting room and working reception room respectively.

Indoor unit shall be wall mounted type.

Ducted exhaust shall be provided for the toilet. Make up air shall be through the door louver.

Battery room shall be equipped with its own duty and standby mechanical ventilation system. Supply

and exhaust ducts installed shall be made of stainless steel grade 314. Exhaust shall be at high level

and make up air at low level. Intake air shall be filtered and taken from side of the room. Fans and

equipments shall be explosion proof.

20.2.3.5 CHP Control House

Duty and standby units localized air-cooled direct expansion units c/w wireless remote control shall be

provided to serve the control room and control equipment room respectively.


electrical equipment room.

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20.2.3.6 Reception House at Main Gate


bedroom, general office and waiting room respectively. Indoor unit shall be wall mounted type.

Ducted mechanical ventilation system shall be provided toilet and changing room respectively.

20.2.3.7 ESP Control House


provided to serve the Control room.


electrical equipment room.



20.2.3.8 Fuel Oil Pumping House


provided to serve the MCC room. The indoor unit shall be wall mounted type.

Ducted mechanical ventilation system shall be provided to toilet.

20.2.3.9 Car Garage


driver’s room. The indoor unit shall be wall mounted type.

Ducted mechanical ventilation system shall be provided to toilet.

20.2.3.10 Diesel Generator House


provided to serve the Control and Electrical room. Indoor unit shall be wall mounted type.

Mechanical ventilation system shall be provided for diesel generator room.

20.2.3.11 Hydrogen Generation Plant


provided to serve the Control room. Indoor unit shall be wall mounted type.

Rectifier room and hydrogen plant house shall be equipped with its own duty and standby mechanical

ventilation system. Supply and exhaust ducts installed shall be made of stainless steel grade 314.

Exhaust shall be at high level and make up air at low level. Intake air shall be filtered and taken from

side of the room. Fans and equipments shall be explosion proof.

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20.2.3.12 Water Treatment House


equipment room, laboratory and office respectively. Indoor unit shall be wall mounted type.

Laboratory shall be equipped with its own duty and standby direct expansion air conditioning units

using 100% fresh air. Wireless remote control shall be provided for each indoor unit.




Mechanical ventilation system shall be provided for toilet.

20.2.3.13 Limestone Storage and Milling


provided to serve the electrical equipment room and C&I room respectively. Indoor unit shall be wall

mounted type.

Roof ventilator with appropriate duty and standby redundancy shall be provided mechanical

ventilation area. Make up air shall be through the weatherproof louver c/w insect screen and filter with

dust spot 65% efficiency and approved by BS 6540.

20.2.3.14 Cooling Water Pump House


provided to serve the electrical room and Control room respectively. Indoor unit shall be wall mounted

type.

Roof ventilator with appropriate duty and standby redundancy shall be provided for mechanical

ventilation space. Make up air shall be through the weatherproof louver c/w insect screen and filter

with dust spot 65% efficiency and approved by BS 6540.

20.2.3.15 H.F.O Unloading Jetty


provided to serve the Control room and rest respectively. Indoor unit shall be wall mounted type.

Duty and standby mechanical ventilation system shall be provided for electrical equipment room,

equipment storage and pump house respectively.

20.2.3.16 Mechanical Equipment Warehouse


office. Indoor unit shall be wall mounted type.


20.2.3.17 Fire Pump House

Ducted mechanical ventilation system shall be provided for fire pump house.

20.2.3.18 Ash Slurry Pump house

Ducted mechanical ventilation system shall be provided for the ash slurry pump house.

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20.2.3.19 Return Water Pump House


provided to serve the MCC room.


rest room.


Ducted mechanical ventilation system shall be provided for toilet and maintenance area.

Chemical room shall be equipped with its own duty and standby mechanical ventilation system.

Supply and exhaust ducts installed shall be made of stainless steel grade 314. Exhaust shall be at

high level and make up air at low level. Intake air shall be filtered and taken from side of the room.

Fans and equipments shall be explosion proof.

20.2.3.20 Emergency Generator Room

Ducted mechanical ventilation system shall be provided for the Emergency Generator room.

20.2.3.21 Chlorination Plant


provided to serve the Control and Electrical room. Indoor unit shall be wall mounted type. The

Contractor shall provide ventilation fans and ducting for the Chlorination Plant including the

neutralizing room.

20.2.3.22 Bulldozer Garage


office. Indoor unit shall be wall mounted type.

20.2.3.23 Coal Milling Station

Roof ventilator with appropriate duty and standby redundancy shall be provided mechanical

ventilation area. Make up air shall be through the weatherproof louver c/w insect screen and filter with

dust spot 65% efficiency and approved by BS 6540.

20.2.3.24 Maintenance Workshop

Duty and standby centralized ducted air-cooled packaged units c/w control shall be provided to serve

the meeting room, manager room, corridor and other space require air conditioning. The outdoor

condensing unit c/w condenser enclosure shall be mounted outside the building.

Laboratory shall be equipped with its own duty and standby air-cooled direct expansion units using

100% fresh air. Wireless remote control shall be provided for each indoor unit. Laboratory exhaust

duct shall be of stainless steel grade 314 and shall be ducted to the high level for air discharge.

ACMV equipments shall be explosion and acid proof.



For mechanical ventilation system, duty and standby ducted supply and exhaust fan c/w supply and

exhaust grilles shall be provided for mechanical ventilation space. Ducted exhaust fan c/w exhaust

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grilles shall be installed for female toilet and male toilet. The exhaust air shall be ducted to the high

level for air discharge. Supply air taken by infiltration through the louver.

20.2.3.25 Electrical and I&C Warehouse

Duty and standby centralized ducted air-cooled packaged units c/w control shall be provided to serve

the warehouse and other space require air conditioning. The outdoor condensing unit c/w condenser

enclosure shall be mounted outside the building.

Ducted exhaust fan c/w exhaust grilles shall be installed for female toilet and male toilet. The exhaust

air shall be ducted to the high level for air discharge. Supply air taken by infiltration through the

louver.

20.2.3.26 International and Local Consultant Office


office and other space require air conditioning. Indoor unit shall be wall mounted type.


20.2.3.27 Turbine Generator House

Laboratory shall be equipped with its own duty and standby direct expansion air conditioning units

using 100% fresh air. Wireless remote control shall be provided for each indoor unit.




Roof ventilator with appropriate duty and standby redundancy shall be provided for turbine building

generator building.

Make up air shall be through the weatherproof louver c/w insect screen and filter with dust spot 65%

efficiency and approved by BS 6540.

The ventilation shall be adequately sized to ensure that the turbine generator house is slightly

pressurized.

20.2.4 Material and Workmanship

Equipment, material, installation, workmanship, testing and commission of the ACMV system shall

comply with this Specification.

20.2.5 Air-Conditioning System

20.2.5.1 Centrifugal Type Chillers

General

The air cooled centrifugal liquid chiller shall be completely assembled with refrigerant piping and

internal wiring, ready for field installation. The unit shall be pressure tested, evacuated and fully

charged with refrigerant R134a or other equally acceptable Ozone friendly refrigerant and includes an

initial oil charge. After assembly, an operational test shall be performed with water flowing through the

cooler to check that each refrigeration circuit operates correctly. The unit structure shall be heavy

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gauche, galvanized steel, coated with backed-on enamel. Based rails shall be of formed double

thickness, painted galvanized plate steel.

Each chilling unit shall be mounted on vibration isolators under feet. Isolators shall be proportioned

for the loads at points and isolators for one unit shall be mounted on floating concrete base extending

under the entire unit and isolating the building construction from any vibrations.

Compressor

The compressor shall be single stage centrifugal type powered by an open drive electrical motor. The

housing shall be fully accessible with vertical circular joints, with complete operating assembly

removable from the compressor and scroll housing. Compressor castings shall be designed for the

highest working pressure and hydrostatically tested in accordance with the design standard. The

rotor assembly shall consist of a heat-treated alloy steel drive shaft and impeller shaft with a cast

aluminum, fully shrouded impeller. The impeller shall be designed for balanced thrust, dynamically

balanced and over speed tested for smooth, vibration-free operation. Insert-type journal and thrust

bearings shall be fabricated of aluminum alloy, precision bored and axially grooved.

Internal single helical gears with crowned teeth shall be designed so more than one tooth is in contact

all the times to provide even distribution of compressor load and quiet operation. Each gear shall be

individually mounted in its own journal and thrust bearings to isolate it from impeller and motor forces.

The shaft seal shall be a spring loaded carbon ring with precision lapped collar cooled by oil during

operation. A gravity-fed oil reservoir shall be build into top of the compressor to provide lubrication

during coast down in the event of a power failure.

Capacity Control

Capacity control shall be achieved by use of pre-rotation vanes to provide fully modulating control

from full load to minimum load. Pre-rotation vane position shall be automatically controlled by an

external electric actuator to maintain constant leaving chilled water temperature.

Compressor Motor

The compressor motor shall be an open squirrel cage induction motor. The open motor shall be

provided with a D-flange, bolted to the cast iron adapter mounted on the compressor to allow the

motor to be rigidly coupled to the compressor to provide factory alignment of motor and compressor

shafts. Motor drive shaft shall be directly connected to the compressor shaft with a flexible disk

coupling. The coupling shall be of metal construction with no wearing parts and no lubrication

requirements.

Lubrication

Lubrication oil shall be force-fed to bearings, gears and rotating surfaces by an oil pump which

operates prior to start-up, continuously during operation and during coast down. An oil reservoir,

separate from the compressor shall contain a submersible oil pump and immersion-type oil heater,

thermostatically controlled to remove refrigerant from the oil. Oil shall be filtered in an externally

mounted 0.5 µm replaceable cartridge oil filter equipped with service valves. An automatic oil return

system to recover any oil that may have migrated to the evaporated shall be provided. Oil piping shall

be completely factory installed and tested. The lube oil system shall be designed so sufficient oil is

supplied during coast down and in the event of power failure.

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Power and Control Panel

The unit shall be supplied complete with a microprocessor based control system in a lockable

enclosure, factory-mounted, wired and tested. The control system includes a 40 character alpha-

numeric display showing all system parameters with numeric data in S.I. units.

Digital programming of essential set points through a color coded keypad includes:

Leaving chilled water temperature.

Percent current limit.

Pull down demand limiting.

Seven-day time clock for starting and stopping chiller.

Remote reset temperature range.

20.2.5.2 Screw Type Chillers

General

The air cooled screw liquid chiller shall be completely assembled with refrigerant piping and internal

wiring, ready for field installation. The unit shall be pressure tested, evacuated and fully charged with

refrigerant R134a or other equally acceptable Ozone friendly refrigerant and includes an initial oil

charge. After assembly, an operational test shall be performed with water flowing through the cooler

to check that each refrigerant circuit operates correctly. The unit structure shall be heavy-gauche,

galvanized steel, coated with backed-on enamel. Base rails shall be of formed double thickness,

painted galvanized plate steel.

Compressors

The rotary twin-screw compressor shall be engineered and constructed to meet the exacting

requirements of the industrial refrigerating market, utilizing the latest technology to provide the most

reliable and energy efficient compressor available at all operating conditions. The compressor shall

be driven by an electrical motor via a gear speed control for increased capacity and improved

volumetric efficiency. The compressor housing shall be made of cast iron, precision machined to

provide minimal clearance for the rotors. The design pressure shall be in compliance with the chiller

as well as the cooling medium conditions.

The rotors shall be manufactured from forged steel and use asymmetric profiles. The compressor

shall incorporate a complete anti-friction bearing design for reduced power and increased reliability.

Four separate, cylindrical, roller bearings handle radial loads. Angular-contact ball bearings handle

axial loads. Together they shall maintain rotor positioning at all pressure rations thereby minimizing

leakage and maintaining efficiency.

Capacity Control

The compressor motor shall preferably be an open squirrel cage induction type motor. The motor

stator is of epoxy bonded core construction with glass-served windings, and insulation for maximum

durability. The terminal boxes are rain-tight. Heat sensing thermistors are an integral part of the motor

of reliability protection.

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Lubrication

The compressor shall have a closed coupled oil separator with no moving parts to minimize oil carry-

over for optimum heat exchanger efficiency. Impingement, direction change, and low velocity provide

effective separation over a wide range of operating conditions. The main oil reservoir shall be located

in the oil separator. The compressor also shall have an oil reservoir located at the rotor bearings to

provide lubrication during start-up, coastdown and in the event of power failure. During operation,

system pressure differential provides proper oil flow without the need of an oil pump.

An immersion oil heater shall be located in the oil separator reservoir and compressor. It shall be

temperature-actuated to effectively remove refrigerant from the oil during shutdown. Power wiring

shall be provided to the control centre. An external, replaceable-cartridge oil filter shall be provided

with manual isolation stop-valves.

Oil cooling, when required, shall be provided by liquid injection into the compressor and discharge

temperatures for all conditions. The control center provides consistent oil temperature to ensure

proper oil viscosity independent of system conditions

Economizer

An economizer shall be included in each refrigerant circuit to enhance the overall system

performance. The refrigerant to refrigerant plate type economizer shall be constructed of acid

resistant stainless steel. The heat exchangers shall be designed according to the requirements of the

system. The temperature limits are -195oC to +185oC.

Refrigerant Circuit

Independent refrigerant circuits shall be furnished on each unit. Piping is ACR copper, with brazed

joints. The liquid line includes:

A shutoff valve with charging port

Sight glass with moisture indicator

Thermal expansion valve

Solenoid valve

Filter-drier

Power and Control Panel

Controls and motor starting equipment necessary for unit operation shall be factory wired and function

tested. Components shall be mounted on galvanized steel back plates and enclosed in the relevant

power or control compartment of the galvanized steel enclosure. On the main control panel door a

further door, with Perspex viewing window shall be located on the exterior of the control compartment

door to house the microcomputer keypad and display. Doors shall be hinged and lockable and include

door stays. The control panel shall be designed to IP65 for outdoor weather protection and finished in

zinc phosphate pre-treated bake enamel.

Each power compartment shall contain:

Star/delta compressor starting contractors, if required

Fan fuses

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Control interface relays

Incoming mains terminal block per compressor

Incoming mains bus bars

Control circuit (220/230V) serving compressor solenoids

Compressor heaters

Compressor and fan contractor coil with residual current circuit breaker

The 24V compartment contains:

Auto/off switch mounted on the door

Microprocessor board

Power supply board

Keypad

Display mounted under a Perspex door

20.2.5.3 Reciprocating type Chillers

General

Hermetic reciprocating air-cooled chiller sets shall be supplied and installed where required. Each set

shall be a complete one packaged system with multiple serviceable compressors, two condensers

having built-in sub-coolers, a direct expansion chiller with two refrigerant circuits, one for each

condenser and a control console.

The refrigerant shall be of a type recommended by the Montreal protocol. A full change of refrigerant

necessary for efficient operation of the chiller system shall be provided by the Contractor. The chiller

shall be capable of working at reduced load to at least 15% of its design cooling capacity.

The chiller sets shall be basically standard arrangements as supplied by individual manufacturers, if

detailed items on standard equipment differ from those specified, it shall be the Contractor's

responsibility to ensure controls are supplied and installed as part of this Contract.

The complete unit shall be factory assembled and tested to conform to ANSI B9.1 Safety Code for

Mechanical Refrigeration, The chillers shall be ARI certified.

Internal wiring of controls shall be complete to terminal strips and shall be designed for installation in a

tropical climate.

Tenders shall be accompanied by evidence of ready availability of all spare parts, for immediate and

future supply including availability of complete components such as compressor and motor and the

duration of replacement in the event of a major breakdown. Names of local suppliers shall be

included.

Compressors

Each chiller set shall incorporate at least four reciprocating compressor/motor assemblies as specified

hereunder:

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The compressor shall be of the reciprocating, serviceable hermetic type of modern design and shall

be fully equipped in accordance with the latest practice. Such equipment shall include shut-off valves,

refrigerant strainer/dryers and all necessary safety-controls including over-temperature protection for

motors.

Compressor speed shall not exceed 1450 rpm. The number of cycles per hour permitted per

compressor shall not exceed 6. Lead-lag selection shall be provided for the compressors of each

chiller set. Also, hour-rated meter shall be incorporated for every compressor.

Compressors shall be mounted on spring vibration isolators to minimize sound and vibration

transmission to the unit frame and the building structure. Hot-gas mufflers shall be installed to give

smooth and quiet operation. Each compressor motor shall have internal motor protection against

overheating, provided by quick-sensing elements embedded m motor windings. Compressor

crankcase heaters shall be provided for protection against refrigerant migration and oil dilution, and

shall be on during compressor off cycle.

Compressor castings shall be completely sound and free from porosity.

Evaporators

The chiller shall be of the uni-shell construction and in accordance with ASME Boiler and Pressure

Vessel Code Section VIII and TEMA.

The chiller shall be a shell-and-tube type and shall have four direct expansion refrigerant circuits.

Each refrigerant circuit shall have its own thermostatic expansion valve. Flow of refrigerant from

condenser to the chiller shall be monitored by the sight-glass provided. Eliminators shall be provided

to prevent carry-over of liquid refrigerant to the compressors. The shell of the chiller shall be covered

with a layer of closed cell foam plastic insulation with a vapor barrier. The shell safety devices shall

conform to the latest appropriate codes.

Seamless copper tubes shall be rolled into the tube sheets. Taps shall be provided in the shell heads

for thermometers, control bulbs and gauges.

The fouling factor for the chiller shall be suitable for the conditions of service. Minimum quality shall be

1 x 10-4 m2 K/W.

Condensers

The air-cooled condensers coils shall be complete with integral sub-coolers. They shall have copper

fins mechanically bonded to seamless copper tubes, cleaned, dehydrated sealed; leak tested at 1034

kPa and pressure tested at 3103 kPa. The condenser fan motors shall have inherent overcurrent

protection.

Noise Level

Each chiller shall be of low noise type. The measured sound pressure level (dBA) at a distance of

5m from each chiller shall not exceed 67.5 measured according to ISO 3746 International Standard.

Controls

Each chiller set shall be provided with control console which shall contain indication lamps, gauges,

manual controls and automatic controls and safety cutouts as required to ensure safe operation of the

machine.

The controls shall Include but not be limited to the following:

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Pressure gauge, oil pressure gauge, condenser pressure gauge, evaporator pressure gauge,

ammeter, operation indicators, safety control indicators, control switches and start-stop

indicator flush mounted on the control panel

A multi-step controller shall be provided for optimum control of chilled water temperature for

closer capacity control.

Manual transfer switch shall be provided which changes the lead compressor in the stopping

sequence to assure balanced wear on compressors.

Other accessories to be included shall be high-low pressure switch, low temperature cut-out

switch, chilled water thermostat, solenoid valve, moisture indicator, filter drier and time delay

relay to have a minimum of 5 minutes between each start-stop of the compressor.

The console shall be factory wired to a terminal strip ready for connection to remote controls

and interlocks.

Accessories and Equipment

One set of special tools and equipment required for service, maintenance and repair shall be provided

and handed over together with the air conditioning system.

The Contractor shall provide full charge of oil and refrigerant for the satisfactory operation of the

chillers. The refrigerant shall be pure and free from moisture.

The Contractor shall replace at his own cost all refrigerant lost, during the period from completion to

handover and during the Defects Liability Period, due to mechanical failure of any part, faulty design,

and all other leakages in the refrigerant system.

At the completion of the Defects Liability Period, the Contractor shall fully charge the system with

refrigerant to the maximum running level

Chemicals used in the chilled water treatment system shall also be fully topped up upon expiry of the

Defects Liability Period.

The Contractor shall submit details of the chilled water treatment system for approval.

Vibration Isolation

The Contractor shall consult with the chiller manufacturer to determine the exact requirements for

vibration isolation of the chiller' sets. The final selection .of vibration isolators shall be based on at

least 97% efficiency of the predominant frequency. Water and refrigerant pulsation through the chiller

sets must be considered during final selection.

Operation of the Reciprocating Chiller Units

The starting of each reciprocating chiller unit shall be arranged so that any compressor will only start

when no adverse conditions are present.

The reciprocating unit and its auxiliary equipment shall be started in the following sequence:

1. AHU blowers

2. Any chilled water pump

3. First duty compressor

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After the first set of chilled water pump and chiller set is in operation, the second and third sets shall

come into operation when the control system senses that additional cooling capacity is required. The

sets will be automatically rotated weekly so each set experiences approximately equal running hours.

The Contractor shall submit details of his proposed control system for approval before

implementation.

Corrosion Control

The Contractor shall supply and install the equipment in the pump room, for a complete automatic

water treatment system for the chilled water circuit. The proposed scheme shall be approved before

implementation.

Nitrate based chemicals shall be used and the Contractor shall engage specialists to provide water

treatment and water analysis to control corrosion. The Contractor shall supply chemicals for testing

and commissioning and operation of the installation during the period after completion to handover

and during the Defects Liability Period.

The quantity of chemical shall be delivered on a regular interval of no more than 3 months to site to

avoid deterioration and storage problems and shall be sufficient for continuous water treatment of the

system for three months. The storage of chemicals delivered shall be confined to the space

designated.

Packaging, storage and handling of chemicals shall be in accordance with manufacturer's

recommendation and shall comply with the practice and requirements stipulated by the relevant local

Authority.

The chemicals used shall have no detrimental effect on non-metallic materials such as rubber, epoxy

anti-corrosive lining etc. which may be used in the piping system. It shall be compatible and neutral to

the pipe material.

The Contractor shall ensure the chemicals and the end products of the water treatment program do

not have adverse effect on the environment. The discharge of the said chemicals into any sewer shall

comply with the requirements stipulated by the local Authority. The chemicals used for treatment and

the methods used to feed the chemicals shall comply with the local health codes. The Contractor shall

carry out monthly water analysis and submit monthly reports with comments and recommendation on

remedial action for chilled water circuits. This shall be done throughout the period between

completions to the end of the Defects Liability Period. The Contractor shall also carry out all the

necessary remedial actions.

20.2.5.4 Air Handling Units

General

Air handling units shall be certified in accordance with ARI Standard or approved equivalent standard

by an independent testing laboratory. These units shall include, but not be limited to the following

components:

Sheet metal housing coated with baked enamel finish to BS 3830 or approved equivalent

standard;

Fans, drives and motors;

Cooling coils;

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Insulation - acoustic as well as thermal in accordance with this Specification;

Drain pans and drain piping;

Air filters;

Vibration isolators and flexible connections;

Supports and brackets.

The air handling units shall be the standard draw-through single outlet type with an internally mounted

motor unit. The units shall be mounted on vibration isolators and properly sloped to facilitate drainage

of condensate.

Access doors shall be air tight and provided to each AHU for maintenance purpose.

Draw-Through Type Air Handling Units

Unit Casing and Fan Sections

Component modules shall be constructed of sectionalized heavy gauge, galvanized steel formed

panels, rigidly reinforced with external hat channels. Casing panels shall be removable for easy

access to the unit.

The casing panels shall be constructed so they shall comprise of two layers of galvanized metal sheet

sandwiching the insulation in-between.

Casings, housings, plenums and chambers in low and medium pressure systems, having greatest

dimensions between 1000 mm and 1500 mm shall no be less than 1.3 mm thick galvanized sheet

metal.

Casings, housings, plenums and chambers in low and medium pressure systems which exceed

1500 mm in any dimensions shall be no less than 1.6 mm thick.

Casings, housings, plenums and chambers in high pressure systems which have greatest dimensions

between 1000 mm and 1500 mm shall be no less than 1.6 mm thick,

Casings, housings, plenums and chambers in high pressure systems which exceed 21,500 mm in any

dimensions shall be no less than 2.0 mm.

Coil and fan section panels shall have 1.4 kg density glass fiber insulation which shall be secured to

casing with waterproof adhesive and permanent fasteners and shall meet NFPA 90A flame spread

and smoke generation requirements.

The condensate drain pan shall have double wall construction with threaded drain connections on

both sides and shall extend under the complete long coil section of the horizontal draw-through units.

On single coil horizontal draw-through units with short coil sections, drain pan shall extend under

complete fan and coil section.

Condensate drain pan shall be made of stainless steel material constructed to prevent water leakage

and rust. It shall be insulated with 16mm thick iso-cyanurate foam faced with an additional aluminum

foil vapor barrier and cemented between the steel outer pan and the heavy gage steel inner pan.

Inner pan shall be coated with corrosion-resistant elastromeric based material. Insulation, adhesive

and inner coating shall comply with NFPA-90A flame spread and smoke generation requirements.

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Coil sections shall be constructed of galvanized steel, and have a formed channel base for integral

mounting of fan, motor and casing panels. Fan scroll and bearings shall be mounted on an “A” or “H”

frame rigidly secured to the channel base. Internally mounted motor shall be factory installed on slide

rails which have 2 adjusting screws. A removable panel located on the drive side of the unit, of

adequate size to permit removal of the fan wheel, motor and drive shall be provided.

Bearings

Bearings shall be self-aligning, heavy duty pillow block regreaseable ball types selected for an

average life of 300,000 hours at design operating conditions. Bearings shall have a grease line

extending to one side of fan scroll. Shafts shall be solid steel, turned, ground and polished.

Fans

Fans shall be of the centrifugal type backward curved with non-overloading characteristics. Fan

wheels shall be keyed to the shaft and designed for continuous operation at the maximum rated fan

speed and motor horsepower. Fans and shafts shall be selected to operate at least 25% below the

first critical speed. Fan wheels and shafts shall be statically and dynamically balanced as an

assembly. After final assembly, the entire unit shall be given final vibration test.

Low and medium pressure fans (for total static pressures up to 140 mm wg) shall be double width,

double inlet type with backward curved blades. Wheels shall be bonderized steel painted with baked-

on enamel or galvanized steel.

Medium and high pressure fans (for total static pressures to 230 mm w g) shall be double width,

double inlet type with backward curved airfoil blades. Wheels shall be painted with a zinc-chromate

primer and an enamel finish coat.

Motors

Units shall be supplied with factory-installed motors of-totally enclosed fan-cool type with protection to

IP 55.

Coils

Coils shall be of the cartridge type, removable from coil connection side of casing and supported in

tracks over the entire length of the coil.

Chilled water coils shall be of aluminum plate fins on 13 mm OD staggered copper tubes. Fins shall

have belled collars and shall be bonded to tubes by mechanical expansion. Chilled water coils shall

have galvanized steel casings and steel header. Maximum working pressure shall be

2.07 MN/m2 (G). Chilled water coils shall be drainable and have non-trapping circuits. Each coil unit

shall be fitted with an automatic air vent with vent line leading to the floor drains system. Chilled water

supply to coil shall be complete with petcocks for pressure gauges connection and provisions for dial

type thermometers at supply and return sides of pipes.

Air Filters

Air filters shall be 50 mm thick of the steel wire type. Each filter shall consist of a holding frame and a

complete filter cell, equipped with spring clips to hold it securely in the holding frame. The frame

material shall be aluminum.

A tap point shall be provided with basin for washing the filters. The size of the basin should be large

enough for washing the filters.

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Operation of The Air Handling Units

On completion of one operating cycle, the duty unit(s) shall be automatically shut down by a timer

which shall then start the standby AHU, where standby is provided. Changeover of chilled water flow

and air outlet dampers for this operation shall also be automatic and shall be interlocked with the AHU

fan motors. Additionally the AHU fan motors shall be interlocked with the smoke detector at the return

air duct to shut down the units in the event of fire occurring in any of the conditioned areas, a manual

selector shall be provided for overriding the timer when manual selection of the AHU Is desired.

20.2.5.5 Chilled Water Fan Coil Units

General

Each chilled water fan coil unit shall comprise cabinet, fans, filter, heating/cooling coils and all

necessary wiring and controls.

The fan coil unit shall be rated to ARI standard and sized for the room design cooling loads including

fan heat.

The fan coil unit shall incorporate an effective thermal and acoustic insulation with self extinguishing

characteristics to BS 2972 Class 2.

Units shall be provided with supply and return air openings with grilles made from die-cast non-ferrous

metal.

The drive motor shall be of the variable speed totally enclosed squirrel cage type with twin drive

shafts and shall comply with the appropriate parts of BS 4999, BS 5000 Part 10, Part II, and Part 99.

Coils shall be manufactured from solid, drawn copper tube to BS 2871 Part 1 Table 'X' with aluminum

fins which shall be bonded onto the tubes. The tubes shall terminate in copper or steel headers that

are screwed BSP female parallel thread or flanged.

The coil shall be designed to permit movement of the tubes during expansion and contraction.

Secondary drip trays shall also be provided and arranged to catch drips from the whole of the fan coil

unit and control valves. They shall be manufactured from hot dipped galvanized heavy gauge sheet

steel 1.2 mm thick, heavily protected against moisture by bitumen coating, insulated and provided with

a drain connection. A drain pipe shall be taken to the nearest gully.

The fan coil units shall be provided with a washable foam filter. The filter media shall be germicidally

treated and easily removable from the unit.

Each fan coil shall have isolating and automatic chilled water supply "on/off" valves.

Fan coil units shall be securely fixed to the building structure. Vertical units shall be fixed to the rear

wall and horizontal units to the soffit. The proposed method of fixing shall be submitted for approval.

20.2.5.6 Chilled Water Precision Air Conditioning Unit

General

Chilled Water Precision Air Conditioning Unit shall comprise cabinet, fans, filter, heating/cooling coils

and all necessary wiring and controls.

The precision air conditioning unit shall be rated to ARI standard and sized for the room design

cooling loads including fan heat.

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The precision air conditioning unit shall incorporate an effective thermal and acoustic insulation with

self extinguishing characteristics to BS 2972 Class 2.

Units shall be provided with supply and return air openings with grilles made from die-cast non-ferrous

metal.

The drive motor shall be of the variable speed totally enclosed squirrel cage type with twin drive

shafts and shall comply with the appropriate parts of BS 4999, BS 5000 Part 10, Part II, and Part 99.

Coils shall be manufactured from solid, drawn copper tube to BS 2871 Part 1 Table 'X' with aluminum

fins which shall be bonded onto the tubes. The tubes shall terminate in copper or steel headers that

are screwed BSP female parallel thread or flanged.

The coil shall be so designed as to permit movement of the tubes during expansion and contraction.

Secondary drip trays shall also be provided and arranged to catch drips from the whole of the fan coil

unit and control valves. They shall be manufactured from hot dipped galvanized heavy gauge sheet

steel 1.2 mm thick, heavily protected against moisture by bitumen coating, insulated and provided with

a drain connection.

The fan coil units shall be provided with a washable foam filter. The filter media shall be germicidally

treated and easily removable from the unit.

Each fan coil shall have isolating and automatic chilled water supply "on/off" valves.

Fan coil units shall be securely fixed to the building structure. Vertical units shall be fixed to the rear

wall and horizontal units to the soffit. The proposed method of fixing shall be submitted for approval.

20.2.5.7 Chilled Water Expansion Tank

General

The Contractor shall supply one pressed steel Chilled Water Expansion Tank complete with

accessories for a fully functioning system.

The Contractor shall completely design the expansion tank and associated piping to suit the chilled

water systems. Any raised platform including a platform for maintenance (with safety railings) and its

support structures shall be in the Contractor's supply.

Tank Construction and Accessories

Construction

The chilled water expansion tank shall be made from pressed steel sections. The steel tank shall be

made from hydraulically pressed steel sectional plates with external flanges and shall be supplied and

erected complete with internal bracings, cleats, nuts, and bolts, washers, jointing compound, cover

bearers, stiffeners and piping. The tank shall be roofed with steel plates. Vents shall also be

provided.

The 1.22 m square panels shall be pressed from BS 4360 M.S. plates of 4.78 mm and 0.35 mm thick.

The plates shall be pressed with a combined double flange at an angle of 45° and 90° to the face of

the plate.

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The stays and cleats shall be designed to give complete rigidity to the tank under the imposed loads.

The stays shall be constructed of angle sections and the box section cleats shall be fabricated from

mild steel plates conforming to BS 4360.

Non-contaminating and non-toxic bituminous compound shall be supplied for jointing between flanges

and for finishes.

Painting

The external surfaces of the tank and supports and other appurtenances shall be prepared for

painting by power wire brushing. Grease and oil shall be removed by wiping with clean cloth soaked in

Xylol. The surface shall be clean and dry before application of the primer. The primer shall-be a zinc

chromate iron oxide primer.

The interior surfaces of the tank shall be cleaned by wiping with dry cloth soaked in Xylol, shot blasted

to remove residual plate-scale and then painted with two coats of epoxy paint as approved by the

local Authority.

As soon as possible after the completion of the erection and painting of the pressed steel tank, the

Contractor shall remove all dirt, debris, materials and shall wash and brush down all internal surfaces.

After cleaning and when water for filling becomes available to the Contractor, the tank shall be

gradually filled to the intended working level.

After the tank has been filled to the intended working level the surface level of the water shall be

measured by an approved means, and if after a period of three days there is no measurable drop in

level nor any sign of leakage from any point in the tank or any pipe and fittings, the tank shall be

deemed to be watertight.

If any leaks or defects are observed, these shall be made good at the expense of Contractor, and

testing of the tank shall be repeated.

Design

In addition, the expansion tank shall be insulated with polyurethane of 50 mm thickness and 49 kg/m3

density minimum, and covered with weatherproof aluminum cladding of 0.6 mm minimum.

Ancillary Work

The Contractor shall include in the price quoted for the tank, the supply and installation of the

following:

1. Access manhole in the roof of the tank complete with hinged cover and padlock.

2. Roof vent sized to prevent collapse of the tank.

3. Galvanized access ladder with cage.

4. A level indicator of approved material.

20.2.5.8 Centrifugal Pumps

Chilled water centrifugal pumps shall be supplied where required.

The manufacture, inspection and testing of the pumps supplied shall comply with the appropriate

standards of the Hydraulic Institute Standards or governing specification. The pumps selected shall be

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able to handle the capacities as required. The Contractor shall guarantee the performance of the

pumps and to submit for approval the hydraulic calculations and the characteristic curve of the pump

offered. Any curve indicating excessive shut-off head will not be approved. The pumps supplied shall

be the non-overloading type.

The pumps shall be of approved manufacture of the centrifugal end suction type, and-shall be directly

coupled to the drive.

The pumps shall be for horizontal mounting and shall be complete with motor, common base plate,

anti-vibration devices and all accessories necessary for the proper functioning of the units. Suction

and discharge connections shall be flanged.

The pumps shall incorporate shaft wearing sleeves, mechanical seals and drip wells with screwed

outlets.

The stuffing boxes provided shall have the primary function of protecting the pumps against leakage

at the point where the shaft passes out through the pump casing.

The pumps shall be of adequate strength to withstand the hydraulic and other forces encountered.

The impellers are to suit the performance duty specified. The speed shall not exceed 1450 rpm.

The pumps shall have cast iron casings and pedestals, bronze impellers and stainless steel shafts.

The pumps shall be direct coupled to the motors by means of rubber sheathed pin type flexible

couplings sized to suit the horsepower of the motors. The couplings shall be guarded-in accordance

with the appropriate code requirements.

The Contractor shall ensure all pumps are adequately primed at ail times,

Pumps shall also be fitted with mechanical seals.

Each pump casing shall have ample space to take an impeller one size larger than that capable of

performing the required duty.

The automatically controlled pumps shall be provided with a 20 mm relief valve set slightly below the

shut-off pressure and arrange to permit circulation of sufficient water to prevent the pump from over-

heating, when operating with a closed discharged valve.

The following fittings shall be required for the pump installed:

1. Automatic air relief valve

2. Circulation relief valve

3. Flexible connections at pump suction and discharge

4. Approved strainer at suction

5. Approved check valve at discharge

6. Gate valves at suction and discharge

7. Pressure gauges

8. Eccentric tapered reducer at suction

9. Globe valves

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20.2.5.9 Air-Cooled Split Units

General

The unit shall contain an outdoor compressor-condenser section and a direct expansion fan coil

section. Components shall be factory assembled and tested, pre-charged and with all necessary

controls pre-wired.

Compressor

The compressor shall be external spring mounted serviceable hermetic type with automatic

reversible oil pump, suction and discharge service valves.

Fan Coil Unit (FCU)

The evaporator fan shall be capable of delivering the desired quantity of air. The fan shall be a

centrifugal blower driven by a permanently lubricated motor. The fan is required to be silent and free

of all vibrations during operation. The fan speed shall be variable by means of a Hi-Med-Lo switch.

In general, the sound pressure level at 1 m away from the fan-coil shall not exceed 54.

The fan-coil cabinet shall be constructed of galvanized steel, bonderized and finished with epoxy

powder coatings. The side and bottom shall be fully insulated to prevent external condensation and

muffle noise. There shall be a provision for draining the base pan through heavy duty UPVC drain

pipe to the nearest floor trap. Panels shall be easily removable for servicing and maintenance.

Coils shall be non-ferrous, with aluminum plate fins mechanically bonded to seamless copper tubing

with joints brazed.

Controls

The electrical control assembly shall incorporate a compressor motor timer circuit to prevent the

restarting of the compressor more than once every four minutes. Compressor protection devices

shall be of the auto-reset type.

A built-in thermostat shall be incorporated into the controls to de-energize the condensing unit when

the return air is at a set temperature. The controls shall give a temperature tolerance of ± 0.5°C.

The wall mounted fan-coils shall be provided with remote control switch-cum-thermostat with at least

3 m control wiring.

The system shall be protected by high and low pressure stats and temperature sensitive compressor

motor overloads. A liquid line dryer shall be provided.

Condensing Unit (CU)

The condensing unit shall be for outdoor installation.

The casing shall be made of epoxy powder coated galvanized steel plates.

The compressor shall be hermetically sealed type.

The condenser shall be fitted with coils construction from copper tubes with aluminum fins and be

for outdoor installation and corrosive/aggressive environment.

The condenser fan shall be of the direct driven axial type with vertical or side discharge for low

power consumption and quiet operation.

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20.2.5.10 Air-Cooled Packaged Units

General

The air-cooled packaged units shall contain a fan coil unit/packaged unit and an outdoor packaged

condensing unit which shall be factory assembled and tested with all necessary electrical controls

pre-wired, ready be installed and operated. The Contractor shall propose a minimum coefficient of

performance (COP) of the equipment as per local codes and regulations.

Packaged Condensing Unit (PCU)

The packaged condensing unit shall consist of compressor(s), condenser and condenser fan

enclosed in a single weatherproof casing.

The condenser coil shall be of non-ferrous construction with aluminum plates mechanically bonded

to seamless copper tubing with all joint brazed. The condenser shall be for outdoor installation and

corrosive/aggressive environment.

The condenser fan shall be of the propeller type direct-driven by a drip-proof permanently lubricated

motor.

The packaged condensing unit casing shall be constructed of galvanized steel bonderized and

finished with epoxy powder coatings. Panel shall be easily removable to provide access for

servicing.

The compressors shall be of the serviceable hermetic or semi-hermetic type with built-in reversible

oil pump and mounted on external spring isolators. The compressor shall be of the same

manufacture as the unit. Units above 28 kW cooling capacity shall be the twin-compressor type.

Fan-Coil Unit/Packaged Unit (PU)

The fan coil unit shall consist of compressor(s), direct-expansion evaporator coil, blower fan and

motor enclosed in a water-proof casing.

The evaporator coil shall be of the same construction as the condenser coil. The fan coil unit

casing, shall be of the same construction as the condensing unit casing. Top, bottom and side shall

be fully insulated to prevent sweating and to muffle noise. The blower fan shall be of centrifugal

forward curve type, belt driven by a permanently lubricated motor. The evaporator fan shall be

capable of delivering the rated quantity of air against the total external system static pressure.

The fan coil unit shall have a fabricated drip tray complete with a drainage system incorporated.

Controls

The built-in electrical controls shall contain a low voltage control circuit transformer compressor

relay, fan relay and a compressor motor timer circuit. The timer circuit shall prohibit starting of the

compressor motor more than once every six minutes. The system shall be protected by high and

low pressure and temperature sensitive compressor overloads.

The control panel shall be provided with the following control and indicating devices:-

Circuit breakers of suitable ratings for short-circuit protection;

Thermal overload relays for overcurrent protection;

Unit selector switch, where necessary;

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Unit start/stop flush mounted push buttons;

"Emergency Stop" mushroom-type pushbutton with reset;

Motor Run/Stop/Trip/Outdoor PCU Emergency Stop indicating lights;

Unit voltmeter, ammeter and hour-run meter;

Lamp test flush mounted push button;

Power "On” indicating lights;

'Smoke Detector Trip" indicating light;

Crankcase heater "On" and 'Off' indicating lights;

Alarm bell silence pushbutton.

Refrigerant and Condensate Drain Pipework

Refrigerant piping shall be copper. The suction line shall be insulated with 50 mm thick Armaflex®

or approved equivalent insulation. The copper pipes shall be sized in accordance with the

recommendation of the air-conditioning equipment manufacturer. A liquid line dryer and sight glass

shall be provided for each circuit.

The condensate drain pipe shall be 25 mm diameter heavy duty UPVC type and run to the nearest

drain floor trap. The condensate drain pipe shall be insulated with 25 mm thick Armaflex® or

approved equivalent insulation.

Refrigerant pipes shall be run in high impact UPVC and electrical wiring shall be run in conduits.

The UPVC shall be secured to the wall and floor by brackets which are corrosion/rust-resistant.

UPVC subject to ingress of water shall be sealed tight with approved sealing compound.

Thermostat

Thermostat of approved type shall be supplied and installed. In case where there are two

compressors in the condensing unit, the thermostat shall be of two stages. The thermostat shall be

of the on/off type and operating range of 15°C - 30°C with a differential of 1°C suitably mounted in

the respective Plant Room(s) to sense the return air temperature to cycle the compressor for

temperature control. A built-in thermometer shall be incorporated too. This thermostat shall be for

operation on 24 VAC.

20.2.5.11 Ductwork, Dampers and Accessories

Sheet Metal Ductwork

Ductwork shall be constructed of galvanized steel sheet metal and shall be fabricated in the

Contractor's own workshop prior to installation. Ducts shall be straight and smooth on the inside

with all joints neatly finished. Ducts shall be free of waves, buckles or leaks and shall be machine

bent. Ductwork in which the galvanizing of the inside surface has been damaged will not be

accepted. Ducts shall be anchored securely to the structural slab or framing in an approved

manner. Ducts shall be constructed and installed to be free from vibration under all operational

conditions. The Contractor is to take precautions to ensure the air distribution system is reasonably

silent during operation.

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Duct Dimensions

The Contractor shall develop and install ductwork which shall include but not necessarily be limited

to duct sizing, position of duct as is necessary for the installation of the air-conditioning system. The

Contractor shall ensure sufficient bracing is provided to prevent sagging, drumming or vibration of

the ductwork.

The zinc coating on sheet metal shall be in accordance with Clause D of BS EN 10143.

Unless otherwise specified, all changes in duct size shall be made in a gradual manner with a

tapering slope 1: 7 or less, but not exceeding 1:4. Bends shall be made with an inside radius not

less than the width of the duct in the plane of the bend, but where this is not possible due to space

constraint, small radius bends with approved turning vanes may be used. The angle of all branches

shall be no more than 45 degree from the axis of the main duct and shall be fitted with folded metal

splitter dampers fixed in position with a rod and clamp.

At flanged connections, the angle iron shall be riveted to ducts at no more than 65 mm centers and

a mastic material shall be inserted between angle iron and the sheet metal. The flanges shall be

painted with one coat of primer and two coats of anti-corrosive paint before they are bolted together.

Angle iron in flanges shall be welded at the corners. A 3 mm thick continuous rubber insertion

gasket shall be used between flanges.

Ductwork shall be painted externally. Duct surfaces behind registers, diffusers and grilles shall be

painted matt black on the inside.

Sheet metal ductwork shall be earthed.

Fire-Rated Duct

Fire-rated duct shall be provided in accordance with the requirements of the Local Authorities. The

fire rating shall be indicated on the Drawings. The specified fire rating shall be with respect to a fire

inside and outside the duct.

The hangers and fixings shall be capable of supporting the total applied load for the period of the fire

resistance required and the duct, rivets, fixings and hangers shall be of hot-dipped galvanized steel

construction. The fire-rated duct materials and method of construction shall be of a type approved

by the local authority.

Spiral Round and Duct Construction

Spiral round duct shall be formed by continuous galvanized iron strip. The grooved seam (4-ply lock

seam) of duct shall be tightly formed to produce a rigid duct and air tight to the requirement of all

pressure classification without sealant application in the seam.

Material Thickness For Round Duct

Nominal Diameter G I Sheet Thickness

Up to 205 mm 0.6 mm

Over 205 mm up to 760 mm 0.8 mm



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Prefabricated Fitting Construction

Round duct fittings shall be socket and spigot joints. Care shall be taken to ensure dimension of

ducts and fittings are correctly related, so that joints can be effectively scaled.

Duct Supports, Hangers and Openings

Ductwork shall be supported to prevent vibration but shall allow for expansion without distortion of

the ductwork, rupture of insulation or, damage to the supporting structure or insulation.

Ducts are to be supported at approved intervals according to size and construction, with approved

hot-dipped galvanized steel hangers, cradles or angle iron supports. Where ductwork is supported

from below, neat hot-dipped galvanized steel angle supports shall be used. Supports shall be

painted with aluminum or bitumastic paint.

Where ducts pass through floors and walls, the clearance space shall be filled with the local

authority approved fire stop and covered with a close fitting metal angle flange.

The Contractor shall provide a sealed access opening complete with access door to each duct in

which dampers are located. The openings shall be clearly marked.

Support Rod Size

The support rod sizes shall be as follows:

Duct Width Minimum Rod Size

Up to 450 mm 6 mm diameter

451 mm to 2100 mm 10 mm diameter

Above 2100 mm 12 mm diameter

Support Angles

The support angles shall be as follows:-

Duct Width Minimum Angle Size

up to 600 mm 32 x 32 x 3 mm

601 mm – 1500 mm 38 x 38 x 3 mm

1501 mm – 2100 mm 51 x 51 x 5 mm

2101 mm – 2500 mm 51 x 51 x 6.5 mm

Angle supports, hanger rods, cradles and brackets shall be made of hot-dipped galvanized steel,

and bolts, nuts, washers and screws used in the installation shall be of stainless steel.

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Round Duct Support

The supports shall be as follows:-

Max DuctDia.

Drop Rod Hanger FlatStrap

Stir Up Bearer WrapRound

MaxSpacing

(mm) (mm) (mm) (mm) (mm) (mm)

305 8 25 x 0.8 - 25 x 0.8 3000

813 8 25 x 3 30 x 4 25 x 3 3500

1016 10 25 x 4 40 x 4 - 3500

1524 10 25 x 4 40 x 4 - 3500

Fire Dampers

Fire dampers shall be of the continuous interlocking blade type closed by the action of a stainless

steel spring and operated by a fusible link designed to function at 69oC. Damper blades over

1000 mm long shall be controlled by two linkage tie rods. Each fire dampers shall be provided with a

casing of the same material and shall be physically built-in or securely bolted to the wall or floor

structure through which the duct penetrates. Damper installations shall be in accordance with a

method approved by the damper manufacturer.

Steel parts used in the construction of the fire dampers shall be galvanized or zinc sprayed.

Fire dampers shall be provided wherever fire compartmentalization is breached by the air-

conditioning and mechanical ventilation systems in accordance with the local authority requirement.

Access doors shall be provided in the ductwork adjacent to the fire dampers to permit inspection and

replacement of fusible links

Fire dampers shall be designed and installed so they will fully close, when necessary, under full

design flow conditions.

20.2.5.12 Air Diffusion Equipment

The Contractor shall supply and install air diffusion equipment required on the Air-conditioning and

Ventilation System. The air diffusion equipment shall include but not necessarily be limited to grilles,

diffusers, registers and concealed damper units. The type of material and the external finish for the

grilles, diffusers or registers shall be submitted and approved.

Air diffusion equipment shall be selected for quiet operation when handling the specified volume of air

and shall provide uniform velocity across the face. Openings in ducts to receive air diffusion

equipment shall be reinforced around to perimeter. Gaskets shall be used to prevent leaks at the

necks or around the air diffusion equipment.

External Grilles and Insect Screens

Unless otherwise indicated on the Drawings, all external grilles for air intake and air exhaust shall be

supplied and installed by the Contractor. Fresh air louvers shall be of the sand trap type with vertical

fixed blades manufactured from anodized extruded aluminum. The Contractor shall also provide and

fix bird-proof galvanized steel wire screens behind all such grilles.

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Air Grilles

Air grilles shall be anodized aluminum and be of robust construction and be fitted with adjustable

blades. Vanes shall have provision for individual adjustment, and shall be rigidly fitted on spindles so

that they will not vibrate or generate noise. Each register shall be provided with stream splitter

damper. External grilles shall match with the architectural finishes. External air grilles shall be lined

with bird-proof galvanized steel wire mesh.

Construction of Air Diffusion Equipment

Openings in ducts to receive air diffusion equipment shall be reinforced around the perimeter.

Care should be taken and gaskets used when necessary to ensure leaks do not occur at the necks or

from air diffusion equipment.

Fixing of air diffusion equipment shall be of the concealed type.

20.2.5.13 Duct/Pipe Insulation

Thermal Insulation

Thermal insulation with thermal conductivity "K" factor of not greater than 0.035 shall be applied to hot

or cold equipment, ductwork and piping, unless otherwise specified. The Contractor shall supply and

install insulating materials together with all necessary associated materials such as fastenings, vapor

barriers and adhesives which are used in the application of insulating materials when applied to

piping, vessels, ductwork and equipment to reduce heat loss or the prevention of condensation.

Insulation materials and vapor barriers shall be non-flammable and shall be of a type approved by the

local authority for use in this installation. The type and thickness of insulation materials shall be

suitable for the specific type of surface to be covered and shall not harm the surface.

Insulation shall be installed according to the manufacturer's recommendations and by experienced

workmen. Surfaces to be insulated shall be dry, grease-free and cleaned of dirt, scale and rust,

before the insulation is applied.

Special care shall be taken to ensure a complete vapor barrier over the surfaces of the insulation.

The aluminum foil used shall be double-sided and reinforced.

Insulation on Factory Assembled Plant

The factory assembled plant shall be insulated as recommended by the manufacturer and as

specified above. Insulation shall be applied at the manufacturer's factory and where unavoidable be

applied on site.

Duct Insulation

(a) External Insulation:

Air-conditioning ductwork shall be insulated with fiber glass or mineral have a thermal or factory

applied vapor barrier. The insulation material shall conductivity of not more than 0.0332 W/m° K at a

mean temperature of 24°C.

The insulation thickness and density shall be 50mm thick, 32 Kg/m3 density for supply duct and

25 mm thick, 32 Kg/m3 density for return and exhaust duct. The vapor barrier shall consist of double-

sided aluminum for with glass fiber reinforcement and kraft paper.

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Duct surfaces shall be cleaned and applied with one generous layer of Flinkote before application of

insulation material. A further layer of Flinkote shall be applied on the insulation before they are

wrapped with vapor barrier. In lieu of Flinkote, other approved adhesive may be used. The vapor

barrier shall have a minimum of 70 mm overlap at all joints and securely sealed with cover strips and

75 mm aluminum adhesive duct tape to form a perfect barrier.

Anti-corrosion steel tape 25 mm wide shall be strapped around the insulated ductwork at maximum

1.2 m centers to prevent insulation from sagging.

(b) Internal Insulation:

The main supply ducts shall be acoustically lined with 25 mm thick of rigid mineral wool insulation of

140 kg/m3 nominal density indicated in the drawing. The mineral wool shall be fixed behind a

0.46 mm thick perforated aluminum sheet reinforcement. The perforation holes shall be approx 30%

to 40% of the total surface area.

Insulation at duct corners shall be either butt joint or mitered and the aluminum lamination shall

overlap by not less than 80 mm in the direction of air flow and glued securely with an approved

adhesive. The insulation shall be held by galvanized steel studs and clips. Duct walls shall not be

punctured when securing acoustic insulation. Where the insulation terminates, it shall be tapered and

the aluminum lamination shall extend beyond the end of the insulation by at least 150 mm and

securely taped to the duct. The Contractor shall ensure the insulation is odorless and is able to resist

disintegration due to the air-stream.

The centre spacing of studs shall be:

Duct Wall Min Center Spacing (mm)

Top side 150

Vertical side 250

Bottom side 300

Insulation for chilled water pipe

Insulation for chilled water pipe work shall be of rigid pipe sections of 48 kg/m3 density and 75 mm

thickness. Self adhesive aluminum foils shall be used to fasten joints. Glass cloth of 200 gm/m 2

density shall be applied over the insulation with adhesive and vapor barrier such as Foster or

equivalent. A further 2 coats of the vapor barrier shall be given over the wrapped up glass cloth. Hard

wood half sectional inserts shall be used where the support clamps are fixed. Exposed chilled water

pipe insulation on roof and other areas shall be provided with 24 gage aluminum cladding. Insulation

for condensate pipes shall be flexible 25 mm thick fiberglass of 24 kg/m3 density and shall be wrapped

with cotton canvas cloth of 4 oz density. Insulation on pipes and ducts shall not be applied without

adequate application of adhesives on the pipe/duct surfaces.

20.2.5.14 Acoustic and Anti-vibration Requirements

General

This Section of the Specification sets out the minimum precautions to be taken to control sound and

vibration levels throughout the building resulting from the operation of equipment provided under this

Contract. Vibrating mechanical equipment shall be mounted on vibration isolators to prevent

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transmission of vibration and sound to the building structure. Vibration isolators shall be submitted for

approval.

Careful attention shall be paid to rotating equipment for prevention of noise and excessive vibration.

The noise level created by the air-conditioning and mechanical ventilation system throughout the

normally occupied air conditioned area shall not exceed 40. In other areas, the noise level created by

the air conditioning and mechanical ventilation system shall be less than 45. Sound attenuation

devices shall be incorporated wherever required to achieve.

Equipment Mountings

Ceiling mounted Fan Coil Units – These shall have spring hangers with neoprene pads at top and

bottom.

Plinth Mounted Roof Top Ventilations Fans – Plinth mounted ventilation fans shall be mounted on

spring isolators on non-skid neoprene acoustical isolation pad.

20.2.5.15 Piping Specification

Piping material of the ACMV system shall comply as follow:

Service Chilled Water

Design pressure 10 bars for chilled water

Nominal Rating ASME B16.5 Class 150

Pressure/Temp. Limit20 Bars at -10 deg C to 37.7 deg C, 16 Bars at 37.8 deg C to 93 deg C

Nominal corrosion allowance2 mm minimum. The wall thickness stated below has alreadyincorporated the required corrosion allowance.

Pipe finishes Sand blasted and 2 coats of primer

Pipe DN 15 to DN 50 ASTM A 53/A 53M Grade B, seamless, Sch 80,

Pipe DN 65 to DN 350 ASTM A 53/A 53M Grade B, seamless, Sch 40

Fittings DN 50 and below ASTM A 234/A 234M screw, sch 80

Fittings DN 65 and aboveASTM A 234/A 234M Butt end weld,

DN 65 to DN 600 long radius bend wall thickness to match pipe

Flange for pipes Slip on flange, ASME B16.5 Class 150, raised face

Gasket ASME Class 150, Neoprene, 3 mm thick

Bolt, Nuts and strapHexagon-Head Machine Bolt, ASTM A307 grade B galvanizedand ASTM A563 grade B nuts, galvanized.

20.2.5.16 Valves

Isolating valves shall be provided on piping services to each item of plant and equipment and on each

main and sub-main.

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Drain cocks and vent cocks shall be provided where necessary on the dead side of isolating valves,

on branch mains and on items of plant in order to facilitate emptying the pipes.

Double regulating valves, in place of isolating valves shall be installed on return piping main branches

to facilitate balancing of the system.

Valves and cocks shall be fitted so they are accessible for operation and maintenance.

Screwed valves shall have heavy hexagon reinforcements at openings, threads of ample length, and

heavy shoulders to prevent over-entry of pipes or adaptors.

Valves and valve components (e.g. seats, packing) shall be for the working pressures and also

operating temperatures of the systems in which they shall be installed. Valves shall be hydraulically

tested to at least 1½ times the working pressures of the systems in which they shall be installed.

Body castings of valves and cocks shall be gunmetal, brass or bronze for valves up to 50 mm nominal

bore and of cast iron for valves 65 mm nominal bore and above. They shall be of even thickness

throughout, clean and smooth and free from scale and flaws. Holes in the valve bodies for spindles

shall be machine-sealed to prevent water leakage. Plugs for gland cocks shall be ground in and shall

be operated by a loose key.

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Valves used for the ACMV systems shall comply as follow:

Service Chilled Water

Design pressure 10 bars for chilled water

Nominal Rating ASME B16.5 Class 150

Pressure/Temp. Limit20 Bars at -10 deg C to 37.7 deg C, 16 Bars at 37.8 deg C to 93 deg C

Gave Valve DN 15 to DN 50 Class 150, raised face flanged, bronze body, non rising stem.

Gave Valve DN 65 to DN 150 Class 150, raised face flanged, Cast iron body, non rising stem.

Globe Valve DN 15 to DN 50 Class 150, raised face flanged, bronze body, non rising stem.

Globe Valve DN 65 to DN 150 Class 150, raised face flanged, Cast iron body, non rising stem.

Check Valve DN 65 and aboveClass 150, wafer type, cast iron body, silent check with bronzeplate

Strainer DN 15 to DN 50 Class 150, y-strainer, raised face flanged, bronze body

Strainer DN 65 to DN 150 Class 150, y-strainer, raised face flanged, cast iron body

Flexible connector all sizesClass 150, stainless steel convolutions, raised face flanged, castiron body with tie-rods.

Butterfly Valve DN 80 andabove

Class 150, Cast iron body, EDPM lined, Worm gear, raised faceflanged, with electrical actuator

For valves installed below ground, valve chambers of approved size complete with cover shall beprovided.

20.2.6 Mechanical Ventilation System

General

The mechanical ventilation provided shall include propeller flow fans, centrifugal flow fans, anti-

vibration mountings, flexible connectors, ductwork, acoustic insulation, fresh and exhaust air grilles,

external louvers and equipment necessary for the efficient operation of the system.

The Contractor shall design, supply and install acoustic internal insulation to the mechanical

ventilation ductwork.

20.2.6.1 Wall Mounted Supply and Extract Fans

The fans shall be the silent running direct driven, axial flow, single stage, aerofoil type with non-

overloading characteristics. Each shall comprise a direct-driven aerofoil cross-sectioned impeller, a

totally-enclosed squirrel-cage induction motor (of short length, aluminum construction, finned for

efficient cooling), a fan casing, an automatic non-return damper, protection guard, grille and a curtain

fire damper, where applicable.

Fans shall be individually controlled from starter switches and cabling from distribution boards to

switches and fans shall be supplied by the Contractor.

Fractional hp fans shall be rated 230 V, single phase and all others shall be rated 400 V, three phase

and as specified in Electrical Work Section.

Parts of the fans shall be resistant to sea-water corrosion, fire resistant and painted gray.

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Fan motors for battery rooms shall be flame-proof type rated for 250oC operation. The standby fan for

the Battery Room shall operate automatically when the duty fan fails. The fresh air fan shall be de-

energized and exhaust fans shall operate in the event of a fire in the room.

The Contractor shall be responsible to provide the cabling and termination from the fans to the Sub-

Fire Indicator boards.

20.2.6.2 Exhaust and Supply Fans with Ductwork

Exhaust and supply fan systems, complete with ductwork and grille shall be supplied in accordance

with Specification and Drawings.

The fans, which shall be mounted to metal sheet ducts, shall run at a speed below 1500 rpm. The

fan shall be substantially supported and all supported frames shall be provided by the Contractor.

Fans shall be individually controlled from starter switches and cabling shall be supplied by the

Contractor.

Parts of the fan shall be resistant to sea water corrosion, fire resistant and painted gray.

The material, construction and installation of ductwork, exhaust air grilles and louvers and

accessories to be used shall be in accordance with those specified under the appropriate sections of

the air conditioning system.

20.2.6.3 Centrifugal fans

The fan provided shall be compatible with the air to be handled and suitable to operate at the

ambient conditions listed above. The fan shall be for the hazard classification of the area concerned.

Fan performance shall be tested in accordance with BS 848 Pt 1, 1980 or approved equivalent

standard.

Fan casing shall be of mild sheet steel construction, with the scroll plate seam welded to the volute

sides. Discharge shall be flanged and bolting holes provided. Side plates shall be of mild steel

fabricated construction bolted to permit assembly to any standard discharge angle. A venturi shaped

inlet shall be provided and an inlet spigot fitted. Inspection door shall also be provided.

Impeller shall be manufactured from mild steel and be fitted to the fan shaft by a taper bush, parallel

key and keyway. The blades shall be straight backward inclined or backward curved, flanged and

riveted/plug welded to the backplate and shroud. Impellers shall be dynamically balanced to ISO

1940:1973 and BS5265 Grade G6.3 or approved equivalent standard.

Motors shall be enclosed, fan cooled squirrel cage induction type (or of flameproof enclosure

standard, Ex.d or EX.e Bs 5501, Part 1 or approved equivalent standard), single speed or 2-speed,

as required, continuously rated and sized to BS 4999/5000 or approved equivalent standard.

Winding insulation shall be to Class ‘F’ specification. Class ‘B’ winding insulation is acceptable for

fractional power motors.

Motor manufacturer’s installation, operation and maintenance instructions shall be submitted prior to

commissioning of the fan.

Installation: Motor and steel frame attached to the unit shall be kept out of contact with fumes which

may give rise to corrosion formation. In mildly corrosive environment, metal surfaces of motor and

steel frame shall be given a protective coating of chlorinated rubber paint. The fan unit shall be

mounted away from direct radiant heat which might cause excessive heating of the casing. Prior to

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installation, the manufacturer’s installation and commissioning instructions shall be submitted for

reference.

In-line centrifugal fans shall be installed in ducted systems as indicated, they shall deliver the

specified flow rates and pressures when tested to BS 848 PT 1:1963 or approved equivalent

standard. The design and manufacture of fans and the quality control standards used shall comply

with BS 5750 Quality Systems or approved equivalent standard.

20.2.6.4 Propeller Fan

The blades shall be made of hot-dipped galvanized, heavy gauge pressed steel for use in

corrosive/aggressive environment and shall be statically and dynamically balanced to give maximum

airflow per watt at minimum noise level. Fan size up to 250 mm shall have six blades, 315 mm to

710 mm to have four blades and sizes 800 mm and above three blades. The impeller shall be

directly coupled to the motor for efficient operation.

Fans shall deliver the specified flow rates and pressures when tested to B.S. 848: Pt 1, or AMCA

standard 210-74 or approved equivalent standard. Sound Power Levels shall be measured in

accordance with B.S. 848: Pt. 2, or AMCA standard 300 or approved equivalent standard to within

one standard deviation of 3. The design and manufacture of fans and quality of control standards

used shall comply with B.S. 5750 and BS EN ISO 9000 to BS EN ISO 9004 Quality Systems or

approved equivalent standard.

For wall mounting, manufacturer supplied aerodynamically designed plastic bell mouth or steel ring

mounting plate shall be provided to ensure the required airflow is achieved. For mounting within

duct section, the fan should be sized for such installation and the Contractor shall ensure the

necessary diaphragm plate shall match the duct section and at the same time accommodate the

recommended opening required for the airflow/fan. Where recommended by the fan manufacturer,

anti-vibration mounts should be used as integral part of the fan installation.

The impellers and motors shall be those designed as completely integrated units delivering

guaranteed performance and electrically, in terms of power, matched to fan duties for each size in

order to achieve higher power factors and efficiency. For motor enclosures to meet flameproof

requirements, standard flameproof, power motors of bulkier construction and thus restricting fan

performance will not be acceptable. Instead fan manufacturer's own specially designed flameproof

motor is preferred. Motors shall be of totally enclosed, squirrel cage induction design, aluminum

construction, finned for efficient cooling and airstream rated for continuous operation at the ambient

conditions listed above. Insulation and rating shall be to BS 5000: Part 11 or BS 5000: Part 99 and

BS EN 60034-1, , with protection to BS EN 60034-5 Group IP44 minimum or approved equivalent

standard.

Single phase motors shall be preferred up to less than 0.70 kW and suitable for capacitor-start-and-

run starting. For three phase operation, motors shall be of Direct-On-Line starting type. Where

flameproof motors are required, they shall comply with Exd requirements and are certified to BS 229

and BS 4683: Part 2 for Groups IIA and IIB gases and for Zone 1 and 2 working environments or

approved equivalent standards. For such duties, the start-and-run capacitors supplied with single

phase fans should be sited outside the hazardous area if the capacitor boxes are not rated for such

environment.

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20.2.6.5 Silencers

General

Silencers shall be provided for ventilation fans. Silencers, shall where possible, be provided in

conjunction with the fan manufacturer, in order to ensure both items of equipment are satisfactorily

matched. Silencers installed shall be of approved design and shall be manufactured to a fully

developed design currently in production

Construction

Its casing shall be constructed of 1.2 mm thick galvanized steel sheet and sound absorbent lining

material of non-flammable glass fiber infill with a non-eroding facing material held securely in place

behind perforated galvanized steel sheet of minimum 0.9 mm thickness.

Performance Requirements

Cylindrical silencers shall be tested by the method specified in BS 848 Part 2:1966 or approved

equivalent standard. The pressure losses as a result of air flow through the silencers should be added

to the static pressure requirements indicated for the associated fans given in the fan schedule. The

Contractor shall be responsible for ensuring the fans shall be capable of delivering the required flow

rates against the system resistance as well as that through silencers fitted, without overloading or

exceeding the limits of the fan motors.

The silencers shall provide at least the following dynamic attenuation or insertion loss:

Frequency (Hz) 63 125 250 500 1k 2k 4k 8k

Attenuation 1 2 4 9 11 10 9 7

20.2.6.6 Flexible Connectors for Fans

Flexible Connection

Flexible connections shall be provided to isolate fans and other equipment from ductwork to prevent

transmission of vibration. Flexible connections shall be provided on both suction and discharge side

of fans.

Flexible connections shall be made of approved flame retardant fabric (possessing flame spread

rating not exceeding 25 without evidence of progressive combustion and a smoke developed rating

of not higher -than 50 as determined by 'Method of Test of Surface Burning Characteristics of Build-

ing Materials' NFPA No 255 ASTM E84 Underwriters' Laboratories Inc Standard), or approved

equivalent standards or shall consist of sleeve joints with packing of non-combustible material. They

shall be of length not less than 100 mm and not longer than 250 mm between parts to be connected

and shall have sufficient slack to compensate for free movement of equipment on vibration isolators.

Flame retardant fabric connections shall be made of fiber glass cloth impregnated with lead loaded

vinyl or other approved material. The surface density shall not be less than 5 kg/m3

Flexible connections shall be air-tight and shall have 25 mm to 50 mm length free of stress to permit

renewal of fabric without disturbing ductwork or other part of equipment.

Flexible connections shall not be used for connections between ductwork and staircases

pressurization or smoke stop lobby ventilation fans. In such cases flanged joints shall be used.

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20.2.6.7 Roof Extract Fans

Roof extract fans shall run at a speed below 1500 rpm.

The fans shall be curb mounted to opening in the building roofs. Concrete curbs around the openings

and frames for curb mounting of the fans shall be provided by the Contractor.

The fans shall be the silent running, direct driven, centrifugal flow, single stage with non-overloading

characteristics. The impellers shall be of steel construction and the hub shall be of either steel or

aluminum construction. Both shall be protected against the effect of the sea water and acidic fallout

from the chimney.

Each fan shall have automatic non-return shutters which open with the fan on and close with the fan

off.

The fan motor shall be mounted in a flame retardant glass reinforced resin body with an integral skirt

for curb mounting. The weather cap for the extract fan shall also be of flame retardant glass fiber

reinforced resin. Fan body and cap shall be painted grey.

The motors shall be horizontally mounted, the totally enclosed, squirrel-cage induction type. The

motors shall be capable of continuous running in ambient temperature of 50°C

Fans shall be individually controlled by starters on the control panel located within each building.

Cabling from the distribution board to switches and the fans shall by supplied by the Contractor.

During Installation, the Contractor shall ensure that good workmanship is applied. If leakages occur,

the Contractor shall undertake to repair and also to make good any damages at his own expense.

20.2.7 Electrical System

Electrical System, which is inclusive of sub-distribution board, small power and lighting, and

communication system, shall be furnished in accordance with Section 9 of the technical specification.

20.2.8 Instrumentation And Control

A group fault alarm for each chiller air-conditioning unit shall be wired to the Common DCIS for

monitoring as specified in Section 11.

20.2.9 Shipping, Packing, Storage And Tagging

Equipment, pipe delivered to site shall be new, cleaned, capped, deburred, free from scale, rust,

grease and colored banded to identify different grade.

Piping, valves and fittings shall be given acceptable industry standard protection to prevent damage,

corrosion and entrance of foreign matter during shipment and storage. Equipment/material storage

shall be under the Vendor’s scope.

Tags for the valves shall be provided and shall be of stainless steel with the identifying numbers and

descriptions embossed or engraved. The tags shall be securely and permanently affixed to the

equipment with screws.

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20.2.10 Piping Installation and Workmanship

General

Pipe runs and locations indicated on the Drawings are approximate and are a guide to indicate the

general runs and locations. The exact runs and locations of all pipes shall be determined by the

Contractor on site and subject to approval.

Pipes shall be installed clear of one another and arranged to provide easy access for maintenance

and repair. Where pipes are runs in parallel to one another or close to walls, floor slabs, beams and

columns, a minimum clearance of 50 mm shall be maintained between the pipes and between the

pipes and all adjacent surfaces.

Pipes shall be handled with care to prevent breakage or damage and shall ensure the inside of the

pipes, particularly at the ends are clean. Where the coating has been damaged by handling, the

Contractor shall make good the coating.

Pipes and fittings shall be thoroughly cleansed internally before pipe laying and jointing. In addition,

the Contractor shall ensure no foreign matter is allowed to enter the pipes after laying and jointing. A

temporary stopper shall be provided to cover each open end of the pipes whenever work is stopped.

Pipes shall be cut in a neat and workman like manner without damage to the pipe. Cutting shall be

done with approved cutters where practicable. Pipe ends shall be reamed to remove burrs. Cutting of

pipes and fittings with gas torch is not acceptable.

Parts subject to wear, corrosion or other deterioration, or requiring adjustment, inspection or repair

shall be accessible and capable of reasonably convenient removal, replacement and repair.

Terminal screws, studs, nuts and bolts shall be of the ISO Metric Thread Standards. Nuts and bolts

shall be of hexagonal heads. Bolt holes shall be spot-faced for nuts. Pipe weld ends shall be to

ASME Standards unless otherwise specified.

Flange faces shall be machined and square with equipment centerline.

Equipment shall be lifted to avoid distortion or deformation. Approved lifting gear and slings shall be

used at all times. Lifting lugs or eyebolts shall be used where provided. Qualified riggers shall carry

out slinging of equipment.

Exposed non-current carrying metal parts of the cold water supply installation shall be effectively

earthed. Earth continuity conductor shall have cross-sectional area of no less than that specified

under local rules and regulations.

Valve chambers of approved design shall be provided for valves installed below ground level.

Where any equipment forming part of the installation is situated outdoor or subject to damp condition,

such equipment shall be of weatherproof design and shall be housed in specially designed enclosure.

Metal surfaces subject to corrosion shall be cleaned and painted.

Interconnecting joints in carbon steel pipes shall be made by butt welding without the use of backing

rings. Butt weld profiles shall be in accordance with ASME B16.25.

The Contractor shall supply the welding rods and inserts used for fabrication. In addition, the

Contractor shall ship to site sufficient consumable insert material, filler wire and electrodes for field

welds.

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Electrodes, filler wire and consumable insert materials shall be selected to match the mechanical and

chemical characteristics of the parent pipe.

Welding materials shall be packed in moisture proof containers until required for use.

Flanges shall only be used for valves, flexible connections, temporary piping service, expansion joints,

and field instrument.

Testing

Upon completion of installation, the Contractor shall arrange in advance for an inspection. No

covering up of installation shall be carried out unless it has been satisfactorily inspected and tested.

The Contractor shall arrange at his own cost the supply of water and power for the testing, flushing

and sterilization of the piping installation.

Upon completion of the installation, pipe shall be tested hydraulically in convenient lengths before

being covered up. The completed pipes and fittings shall be hydrostatically tested at 12.5 bar or 1.5

times the maximum service pressure for 2 hours whichever is greater. The Contractor shall supply

and manage water requirements and the expenses incurred due to tests and inspections shall be

borne by the Contractor.

Water shall be forced into the pipes by a pressure pump fitted with a pressure gauge, which shall be

calibrated by accredited organization, until the air is expelled from the pipeline and joints before

pressure is applied. Air release cocks shall be provided wherever necessary.

The testing apparatus shall be provided with an isolating valve, which, when closed, shall leave the

pressure gauge connected to the length of pipeline under test, and at the same time isolate the pump.

When the specified pressure has reached, the isolating valve shall be closed and remain closed for 30

minutes. At the end of that time, if the pressure has dropped, the isolating valve shall be opened and

the loss of water shall be determined by pumping into the mains a measured quantity of water

sufficient to bring the pressure up again to the initial pressure.

If the loss of water so determined is at a rate less than 10 cc per mm diameter per km of pipeline for

30 minutes, the test shall be considered satisfactory.

Pipe Markers

The Contractor shall supply and apply pipe markers and arrow tapes in accordance with the

manufacturer’s instructions.

Pipe markers and arrow tapes shall be of durable, dimensionally stable, glossy vinyl film with pressure

sensitive (self-sticking) adhesive and it shall be for outdoor application in an acidic and tropical marine

environment. Product technical data shall be submitted for approval prior to the purchase and

installation.

Pipe markers shall be banded on both ends with arrow tapes of width not less than 50 mm width to

show the flow or process direction of pipe contents.

Pipe markers and arrow tapes shall be applied next to each valve, and adjacent to changes in

direction, branches and where pipes pass through walls, floors and ceilings, and at intervals of

maximum 12 m on straight pipe runs.

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Attention shall be given to visibility with reference to pipe markings. Where pipelines are located

above or below the normal line of vision, the lettering shall be placed below or above the horizontal

centerline of the pipe respectively.

Pipe markers’ legend of service shall be distinctly marked to identify each pipe and its destination.

20.2.11 Water Treatment

General

The Contractor shall supply and install the equipment for a complete automatic water treatment of

chilled water circuits and engage approved specialists to provide water treatment and analysis to

control organic growth, corrosion and fouling.

Water treatment shall be employed to prevent and minimize:

Scaling of pipes and condenser, by salts of hardness ions, silica or silicates,

Corrosion of the system by oxygen or low pH,

Presence of algae, bacteria or fungi,

Fouling of pipes and condenser internal surfaces by suspended solids and organisms.

Multiple metering pumps and chemical dosage pots shall be provided for feeding the chemicals for

each condenser circuit.

The Contractor shall supply chemicals for testing and commissioning and operation of the installations

in accordance with the contract.

The application of non-chemical treatment technologies for water treatment is preferred. The

increased cost in the associated equipment shall be favorably evaluated in the context of increased

operating efficiency and reduction in water consumption.

Control Limits of Water Condition

The water condition of the condenser water circuits shall achieve, throughout the duration of the water

treatment program, the following control limits (henceforth referred to as the contract control limits):

Control Parameters Chilled Water/ Unit ofMeasurement

pH Value 7 – 9 pH

Total Hardness 0 – 400 ppm CaCO3

P Alkalinity 0 – 25 ppm CaCO3

M Alkalinity 0 – 300 ppm CaCO3

Iron (Fe+2) 0 – 0.2 ppm Fe + 2

Copper (Cu+2) 0 – 0.2 ppm Cu + 2

Chloride (CI-) 0 – 100 ppm CI-

Total Dissolved Solids (TDS) 200 (Max) ppm

Nitrites (NO2) 600 – 800 ppm (NO2)

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Control Parameters Chilled Water/ Unit ofMeasurement

Total Bacteria Count 0 - 10 Per ml water

Legionella Bacteria Zero per 10 ml

Corrosion rate(by corrosion coupon test) Copper : Less than 3

Mile Steel : less than 5

mil per year

Calcium Hardness 0 – 300 ppm CaCO3

Supply of Chemical

The Contractor shall supply sufficient chemicals for the Defects Liability Period.

The quantity of chemicals shall be delivered on a regular interval of not more than 3 months to the site

to avoid deterioration of chemicals and excessive storage requirements and shall be sufficient for

continuous water treatment of the systems for 3 months.

Handling of Chemicals

Packaging, storage and handling of chemicals shall be in accordance with manufacturer's

recommendation and shall comply with the practice and requirements stipulated by the relevant local

authority. Eye washer and shower facilities shall be installed near the storage room.

Properties of Chemicals

The chemicals used in the water treatment program shall have no detrimental effect on non-metallic

materials such as rubber and epoxy anti-corrosive lining which may be used in the piping system. It

shall be compatible and neutral to the pipe materials.

The Contractor shall ensure the chemicals and the end products of the water treatment program do

not have an adverse effect on the environment. The discharge of the chemicals into any sewer shall

comply with the requirements stipulated by the local authority. The chemicals used for the treatment

program and the methods used to feed the chemicals shall comply with the local health codes.

20.2.12 Testing and Balancing (ACMV Systems)

General

The Contractor shall perform tests and balancing necessary to ensure the systems installed conform

to the specification and that such tests are adequate to demonstrate the equipment will comply with

the requirements of this Specification and meet the guarantees specified. A schedule of the type of

tests, proposed dates and durations shall be submitted for approval prior to the tests.

Testing and measuring equipment shall be supplied by the Contractor and testing and balancing shall

be carried out.

The Contractor shall provide smoke test to the air-conditioning duct system and shall ensure there is

no leakage in the air supply and return ducts.

Inspection and Testing

No covering up of installation shall be carried out unless it has been satisfactorily inspected and

tested. The Contractor shall arrange at his own cost the supply of power for the testing of the ACMV

installation.

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Air Quantity Balancing

Registers, grilles and dampers shall be correctly adjusted to give design air figures as quoted unless

otherwise directed.

Fixed dampers are to be set and the final position shown with a painted arrow, and saw cut.

Test Log Sheets

The Contractor shall submit full detailed test log sheets for inspection and approval.

The test log sheets shall present a clear and precise record of tests carried out during the

commissioning of the project.

The test log sheet shall include, but not be limited to where applicable, the following data:

Fan type, speed, static pressure reading and amps drawn and include the fan curve to

indicate the running condition.

Compressor commissioning data, including control equipment, pressure settings, and the set

point of all safety control pressure-stats.

The commissioning data for the setting of the chiller set, including load limit demand relay and

water thermostat settings, control thermostats setting, and differential and control reset if

applicable.

Zone temperature reading

The testing records for the chilled/low temperature hot water piping, including flow rate,

pressures, temperatures and pump motor power rating.

Other items of equipment shall be recorded and tested in a similar manner to that specified above so

a true indication is given of the plant performance.

The above test log sheet shall form the basis of the plant operator’s log sheet.

Performance Test

A performance test shall be carried out by the Contractor to show the system specified fulfils all

requirements of the specification.

At 3-month intervals during the maintenance period, the Contractor shall test the air-conditioning

system for maximum capacity and performance and tabulate the results of the tests, The Contractor

shall carry out adjustments of air quantities and controls during this period to ensure areas are

controlled as specified.

The Contractor shall provide temperature and humidity recorders.

20.2.13 Spares and Consumables

One set of pulley and belt per different sizes shall be provided for Air Handling Unit.

The Contractor shall identify spares required during normal servicing and planned outages and

recommend the spare parts to be included in the Schedule of spare parts.

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Spares shall be directly interchangeable with the corresponding parts installed under the contract and

shall meet the requirements of the original specification.

20.1 POTABLE WATER SYSTEM

Potable Water Supply inside the building is specified in Section 20 of the Specification. The work

covers the design, manufacture, supply, delivery to site, installation, testing and commissioning,

maintenance and acceptance testing of the potable water supply systems, including associated civil,

electrical, control and instrumentation work.

Potable Water Supply shall be designed for the following areas in the buildings:

Battery Rooms

Laboratories

Workshop

Toilets/Bath Rooms

Kitchen/Meal Hall

Water Jug locations

Emergency Supply to the CCW Head Tanks in Turbine Building

The Electric Storage Water Heater shall be provided at the Bath Rooms. The Electric Hot Water

Dispensers shall be installed at Mess Room/pantries. Besides, water jugs completed with water

supply points shall be provided at strategically locations in the office area of the building.

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Documents

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