particular hvac

Volume 3 – MEP SpecificationsParticular – Air Conditioning & Ventilating Services

AP 1 : DESIGN CRITERIA..........................................................................................2

AP 1.1 CODES AND STANDARDS...................................................................................................2

AP 1.2 EXTERNAL DESIGN CONDITIONS.......................................................................................2

AP 1.3 INTERNAL DESIGN CONDITIONS........................................................................................2

AP 1.4 FRESH AIR SUPPLY..............................................................................................................3

AP 1.5 OCCUPANCY LEVELS..........................................................................................................3

AP 1.6 AIR MOVEMENT....................................................................................................................3

AP 1.7 EXTRACT VENTILATION.......................................................................................................3

AP 1.8 NOISE LEVELS...................................................................................................................... 3

AP 2 : MECHANICAL ENGINEERING SERVICES....................................................4

AP 2.1 GENERAL............................................................................................................................... 4

AP 2.2 VENTILATING AND AIR CONDITIONING SYSTEM (VAC)...................................................4

AP 2.3 THE AIR CONDITIONING SYSTEM......................................................................................4

AP 2.4 FRESH AIR SUPPLY..............................................................................................................5

AP 2.5 CHILLED WATER SYSTEM...................................................................................................7

AP 2.6 NOISE AND VIBRATION CONTROL.....................................................................................9

AP 2.7 CHILLED WATER PIPE INSULATION...................................................................................9

AP 2.8 REFRIGERATION AND EQUIPMENT..................................................................................11

AP 2.9 FRESH AIR HANDLING & FAN COIL UNITS.......................................................................14

AP 2.10 FANS.................................................................................................................................... 19

AP 2.11 CHILLED WATER PUMPS...................................................................................................21

AP 2.12 VALVES................................................................................................................................ 27

AP 2.13 DUCTWORK AND ANCILLARIES........................................................................................31

AP 2.14 DUCT INSULATION.............................................................................................................35

AP 2.15 AIR OUTLET AND INLET.....................................................................................................37

AP 3 : AUTOMATIC CONTROL SYSTEM (IF APPLIABLE)....................................40

AP 3.1 GENERAL REQUIREMENTS...............................................................................................40

AP 3.2 DESCRIPTION OF OPERATION.........................................................................................40

AP 4 : list of approved manufacturers........................................................................44

Project : Al Abbas Twin Building on plot no.22-008, Dubai Silicon Oasis 1/50

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AP 1 : DESIGN CRITERIA

AP 1.1 CODES AND STANDARDS

The Design Criteria listed below shall comply with all Government and local authorities regulations, byelaws etc. as applicable to the works including the following:

Dubai Silicon Oasis Regulations.

Dubai Civil Defence Regulations.

Dubai Electricity and Water Authority Regulations.

British Standards and Codes of Practice.

The Chartered Institute of Building Services Engineers (CIBSE) Guide books.

American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE).

The Institute of Mechanical Engineers.

American Society of Mechanical Engineers.

Institute of Plumbing Data guide book.

National Plumbing Code.

Institution of Electrical Engineers.

SMACNA.

MEW Regulations

Insurance Companies

Any other related Local Authority Regulations

AP 1.2 EXTERNAL DESIGN CONDITIONS

Ambient design conditions shall be taken as follows:

Summer: 46oC dry bulb, 30oC wet bulb

Winter: 8oC dry bulb

AP 1.3 INTERNAL DESIGN CONDITIONS

In general, inside design conditions shall be in accordance with CIBSE standards, according to space utilisation.

For offices, the design conditions to be achieved are:

Summer: 23oC 1.5oC dry bulb50 % nominal Relative Humidity

Winter: 20oC 1.5oC dry bulb

For public circulation corridors, lift lobbies, entrance and reception areas, the design conditions to be achieved are:


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Summer: 24oC 1.5oC dry bulb

Winter: 20oC 1.5oC dry bulb

AP 1.4 FRESH AIR SUPPLY

Shops and Offices 8 l/s/person

AP 1.5 OCCUPANCY LEVELS

As per the Architect and / or Interior Designer’s layout.

AP 1.6 AIR MOVEMENT

8-12 Air Changes per Hour, depending on room usage.

AP 1.7 EXTRACT VENTILATION

Toilet areas: 8-10 Air Changes per Hour

Pantry areas: 10-15 Air changes per hour

Note: The total extract from the building with all fans working shall not exceed the total fresh air supply

AP 1.8 NOISE LEVELS

The HVAC systems shall be designed with so that the noise levels shall not exceed the following noise criteria:

Offices NR 40 – 45

Bedroom NR 30

Living/Dining NR 35

Corridor, Lobby NR 38 – 40

Pantry and toilets NR 38 – 40


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AP 2 : MECHANICAL ENGINEERING SERVICES

AP 2.1 GENERAL

The air conditioning system used for this project shall be chilled water type for Offices Building and Ducted split type for Residential Building with fresh air handling units and fan coil units.

AP 2.2 VENTILATING AND AIR CONDITIONING SYSTEM (VAC)

The system chosen shall provide cooling, dehumidification, space ventilation, air filtration and smell extraction

Chilled water air-conditioning system shall be utilised in order to satisfy the cooling requirements of the building.

Fan coil units mounted above the suspended ceiling shall provide the means by which the air-conditioning of all level space is achieved.

Fresh air shall be introduced into each offices via a dedicated ducted system from fresh air-handling units equipped with heat recovery wheel.

A common extract fans to be provided for all the toilets and to be connected to Fresh air AHU through plate to plate heat exchanger for heat recovery.

Positive pressurisation of the space shall be adopted in order to minimise the infiltration of outside air.

AP 2.3 THE AIR CONDITIONING SYSTEM

An all-air system shall be installed utilising a Constant Air Volume (CAV) air conditioning system. The air shall be circulated to the various spaces via dedicated fan coil units (FCU’s).

The fan coil units shall provide the means by which the air conditioning of all level space is achieved. The conditioned air shall be circulated into the space via insulated galvanised steel ductwork and suitable ceiling or wall mounted supply air diffusers.

The return air path shall be provided via dedicated return air grilles or ceiling diffusers, which shall allow the air to flow into the ceiling void. The ceiling void shall be utilised as a return air plenum and the air shall be collected and directed to the FCU’s. Temperature sensors shall act upon the two port chilled water control valves to achieve the room temperature set points requirements.

All the units shall be provided with a combined wall mounted thermostat and three-speed manual operation switch (Off – Low –Medium- High).


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AP 2.4 FRESH AIR SUPPLY

Fresh air shall be provided to each apartment via ductwork from fresh air AHU’s equipped with heat recovery wheel. The fresh air shall be regulated by a volume control damper mounted on each ductwork branch in order to maintain a constant flow of required fresh air to each area served.

AP 2.4.1 THE VENTILATION SYSTEM

The ventilation system shall be designed to maintain a positive pressure in the space in order to prevent and/or minimise the infiltration of outside humid air, which can otherwise result an internal condensation on cold surfaces.

Dedicated extract systems shall be used in order to meet the general, toilet and pantry ventilation requirements.

The pantry and toilet exhaust shall be achieved via a common fan extract system. This system shall be designed to maintain a negative pressure in the pantry and toilet areas. Air shall be drawn into each toilet via under-cut doors. The fans shall be mounted on the roof and to be connected to heat recovery wheel.

AP 2.5 DUCTED SPLIT UNITS(RESIDENTIAL BUILDING)

Supply and install air to air condensing units in combination with direct expansion coil indoor units where shown on drawings. The units shall be designed and tested for use with Refrigerant 22.

The unit shall be selected based on equipment schedule provided in the relevant drawing/specification. Units shall be ARI rated. All units shall be selected to achieve the specified duty and noise criteria against an external static pressure shown in the schedule.

The complete split unit assembly shall be manufactured and tested in accordance with ANSI/AHAM RA C-1-1992 and shall be installed in accordance with the manufacturers recommendations.

The indoor unit shall have a solid casing, supply air fan, cleanable filter and controller.

The controller shall be fixed to the wall 1.500m above finished floor level and shall provided the following minimum facilities:

Fan : ON/OFF

Cooling: ON/OFF

Digital display and set points


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The indoor units shall be provided with a condensate drain. The condensate drain pipe shall be tested, insulated and should connect to network floor drain.

The outdoor unit shall have a corrosion resistant casing and be bolted to either a wall bracket or to a concrete base. The wall bracket shall be fabricated from mild steel and be hot dipped galvanised after fabrication. The outdoor unit shall house the compressor, condenser fan, condenser soil, expansion valve, filter / drier and controls.

Refrigeration pipes shall be pre-charged copper type, be securely supported and insulated with 25 mm thick closed cell elastomeric foam insulation as detailed elsewhere in the specification and cladded with aluminium sheet.

AP 2.6 DECORATIVE SPLIT UNITS

Supply and install air to air condensing units in combination with direct expansion coil decorative indoor units where shown on drawings. The units shall be designed and tested for use with Refrigerant 22.

The unit shall be selected based on equipment schedule provided in the relevant drawing/specification. Units shall be ARI rated.

The complete split unit assembly shall be manufactured and tested in accordance with ANSI/AHAM RA C-1-1992 and shall be installed in accordance with the manufacturers recommendations.

The indoor unit shall have a decorative casting, supply air fan, cleanable filter, air inlet grille, adjustable air outlet grille and controller.

The controller shall be fixed to the wall 1.500m above finished floor level and shall provided the following minimum facilities:

Fan : ON/OFF

Cooling: ON/OFF

The indoor units shall be provided with a condensate drain. The condensate drain pipe shall be tested, insulated and should connect to network floor drain.

The outdoor unit shall have a corrosion resistant casing and be bolted to either a wall bracket or to a concrete base. The wall bracket shall be fabricated from mild steel and be hot dipped galvanised after fabrication. The outdoor unit shall house the compressor, condenser fan, condenser soil, expansion valve, filter / drier and controls.

Refrigeration pipes shall be pre-charged copper type, be securely supported and insulated with 25 mm thick closed cell elastomeric foam insulation as detailed elsewhere in the specification and cladded with aluminium sheet.


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AP 2.7 CHILLED WATER SYSTEM(OFFICE BUILDING)

The design intent for the air conditioning system shall be chilled water system through seamless schedule 40 insulated pipes and associated pumps and pressurization units. A variable flow hydraulic system shall be adopted and the FCU’s shall be fitted with two – way modulating valves and controllers. The chilled water pumps shall be located on Basement level positioned to suit the buildings served. They shall be of the long coupled, direct drive, centrifugal type.

AP 2.7.1 CHILLED WATER PIPING (ABS)

(a) Material

Acrylonitrile Butadiene Styrene (ABS) pressure pipes and fittings for chilled water supply and return water piping system all in accordance with the following specifications. The pressure rating of the pipes to be subject to the approval based on the maximum operating pressure of the chilled water system.

(b) Regulatory Requirements:

AS/BS Compliant: Comply with the applicable Australian or British standards AS 3518.1/AS 3518.2 and /or BS 5391.1/BS 5392.2

(c) Installation:

1 Installation shall be in accordance with AS 3690 “Installation of ABS Pipe systems” and in accordance with manufacturers recommendations.

2 The contractor shall ensure that all personnel involved with the installation are familiar with the installation procedure for ABS piping systems. Provide certified personnel subject to the approval of the engineer.

3 The layout of all pipe work shall be checked on site prior to installation and during installation to ensure a workmanlike appearance of installation.

4 Locate groups of pipes parallel to each other, spaced to permit applying full insulation and servicing of valves.

5 Where pipes pass through partitions, ceiling, and external wall – seal space between construction opening and pipe with insulation, metal sleeve, and metal flange. Apply fireproof sealant when required.

6 The complete pipe work has to be pressure tested at 1.5 times the design pressure before the application of the insulation.

(d) Jointing:

Jointing to be with cold solvent welding technique according to manufactures installation handbook.

Use only approved ABS solvent cement and MEK cleaner.


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All pipes shall be cut square, chamfered and all burrs removed prior to joining. Pipe shall be inserted to full depth of socket. Installed fittings which do not have pipe inserted to full depth shall be considered below required standard and shall be rectified at contractor’s expense.

Backing rings and gaskets should be used on all flanged joints.

The use of solvent welded sockets, flanges and shoulder style couplings are permitted to join pipe and fittings as required. Equipment connections 50mm ( 2”) and less may be threaded and equipment connections above 50 mm (2”) to be with stub flange and backing rings to manufacturers recommendations.

ABS pipe connections to other materials may not be made by cementing or glued joints.

The use of hand operated lever winch or similar mechanical means of supplying a sufficient axial load is required for pipe sizes 100 mm ( 4”0 and above. The use of hammers etc. to apply fittings is NOT permitted at any time.

(e) Support:

The maximum distance between pipe supports shall be in accordance with manufacturer recommendations.

The width of pipe support will be in accordance with manufacturer recommendations.

Pipe supports shall not exert undue pressure on the pipe wall or deform the pipe wall against the clamp or support. All clamps on horizontal pipe shall allow axial movement of the pipe.

The contractor to follow manufacturer’s recommendation to ensure that adequate allowances have been made for the expansion and contraction of the piping system without creating undue stresses.

(f) Acceptable manufacturers:

Subject to compliance with requirements of the contract documents acceptable manufacturers to be firms regularly engaged in the manufacture of ABS pressure piping systems, materials and sizes required, whose products have been in satisfactory service for not less than five (5) years in Gulf, and approved by the Engineers Representative.

All insulation shall be applied in a workman like manner as recommended by the manufacturer. No insulation shall be applied until all piping and equipment have been tested and cleaned. All hangers should be outside the insulation. Density shall be minimum 35 kg/m3 and conductivity of 0.035 W/mK at 50C.

Fibreglass Insulation Thickness Schedule

PIPE NOMINAL DIA. INSULATION THICKNESS


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Concealed Exposed

15- 50mm 15mm 25mm

65- 150mm 25mm 32mm

200 mm and above 32mm 50mm

AP 2.8 NOISE AND VIBRATION CONTROL

Special consideration shall be given to vibration isolation of the mechanical equipment. Vibration isolators shall be selected according to type and location of equipment. In critical cases vibration isolators shall be at least 95% efficient. All AHU`s on the roof shall be put on floating structural base.

Special care shall be given in the vibration and noise isolation of the plant rooms from nearby areas.

AP 2.9 CHILLED WATER PIPE INSULATION

AP 2.9.1 MATERIAL:

The material shall be Closed Cell Elastomeric Foam Insulation preformed sections with the following properties.

7 Thermal conductivity () BS 874 Part 2-86 (DIN 52613, 52612, ISO 8497), max. values.

-20 C 0.034 W / mK

0 C 0.037 W / mK

20 C 0.034 W / mK

Thermal Conductivity values shall be governed by a Third party Supervisory Control Agreement which shall be available for attestation of conformity purposes.

8 Water Vapour Diffusion Resistant () DIN 53122 Part 2, DIN 52615) 7000 Water Vapour Diffusion Resistant ( ) values shall be governed by a Third party. Supervisory Control Agreement which shall be available for attestation of conformity purposes.

9 Water vapour permeability (BS 4370/2, DIN 52675) < 0.09 gm / Nh.

10 Closed Cell Content - > 90%

11 Fire Rating :-

BS 476 Part 6 1989 (Fire propagation) : Fire index <12 (Class O rated).

BS 476 Part 7 1987 (Surface spread of flame) : Class 1 rated. (UNI 845 - UNI 9174)


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Reaction to Fire Certification tests shall be available for all commercial insulation thickness upto 50mm.

12 The FM (Factory Mutual) product approval should be available for the insulation material.

13 Wall and ceiling penetration of insulated pipes should have a minimum of R90 fire resistancy rating of DIN 4102 Part 11 (or EN 1366-3, penetration seals)

14 Smoke and Toxicity (for public and high rise buildings). The insulation product and system should meet the following requirements:

ASTM E662 – Smoke density Dm< 400

Carbon monoxide (CO) concentration <1450 ppm.

Limit concentration, are in line with IMO requirements and AIRBUS specification.

15 Corrosion risk assessment DIN 1988 / 7 certified.

“Material should be nitrite free and can contain no more than 0.2% of ammonia.

Insulating material for stainless steel must contain no more than 0.05% of water soluble chloride ions “the PH value should be limited to PH = 7 + 0.5.

Corrosion risk assessment values shall be governed by a Third party Supervisory Control Agreement which shall be available for attestation of conformity purposes.

AP 2.9.2 IMPORTANT NOTE :

Manufacturer should be certified in accordance with ISO 9002/UNI EN 29002 which includes production control procedures and systems as pre-requisite.

All tests should be conducted by independent , accredited institutes and the supervisory (third party) control agreements should be available for attestation of conformity purposes .

At all support points for the pipes, the Contractor shall provide manufacturer’s recommended pipe supports or approved equal material subject to Engineer’s approval.

The insulation laggers shall be trained by the manufacturer’s local agents before commencement of works. The manufacturer’s local agent shall visit the site periodically to inspect the insulation work.

The insulation thickness shall be as follows:

In conditioned areas : Upto 4” pipes 19mm thickness, 55 to 70 kg/m3

5” and above 25mm thickness

In unconditioned areas: Upto 5” pipes 25mm thickness

Above 5” to 10” pipes 32mm thickness


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Above 10” 50mm thickness

Note :- In areas with no U.V radiation, vapour barriers/coatings are not required. Protection against high U.V light radiation, e.g areas exposed to sunlight, is required U.V resistant paint coatings or claddings with metal can be used.

AP 2.9.3 METHOD STATEMENT FOR APPLICATION OF KAIMANNFLEX (K-FLEX) INSULATION

ON CHILLED WATER PIPES

Pipe section tubing to be cut along its length using a sharp knife.

Position the tube so that the edges are separated and apply an even layer of manufacturers recommended glue.

Once the glue has become dry reseal the tube pressing the edges firmly together.

In areas where the pipe hangers come in contact with the pipes, a rigid support is recommended, such as a section of wood to prevent the rubber insulation from compression and hence damage.

To insulate the pipe where pipe hangers come in contact with the pipe the following procedure to be followed :-

a) The pipe has to be wrapped with self adhesive insulating foam tape.

b) The wooden support should be placed above the pipe wrapped with foam tape.

c) The wooden support should then be wrapped with self adhesive insulating foam tape ensuring that both the joint on either side of the support are covered 50%

d) Method statement of application for outdoor usage: -

Avoid working under direct sunlight and exposure of glued joints to sunlight for at least 12 hrs after glue application as sunlight prevents proper curing.

Prolonged Exposure of K-flex elastomeric foam to direct sunlight is not recommended as this will eventually result in deterioration of the surface. Do not keep the glue under direct sunlight as this will result in rapid evaporation of the solvent and affects the performance of the glue.

AP 2.10 REFRIGERATION AND EQUIPMENT

AP 2.10.1 PACKAGE AIR COOLED WATER CHILLERS

Packaged air-cooled water chillers shall be of the screw type, fully assembled at the factory and charged with R134a refrigerant and shall be suitable for outdoor opera-tion in ambient temperatures from 5ºC up to 55oC.


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Each chiller shall be complete with screw compressors, evaporators, electrical starting, interlocked, safety and refrigerant controls and air-cooled condensers with low noise type fans. Chillers with multiple compressors shall have same number of independent refrigeration circuits. Minimum number of circuits shall be two.

The units shall have the capacities as specified on the drawings. All ratings shall be ARI certified. The COP must not be less than 2.50 at design conditions. Catalogues shall be stamped with quality certification.

Electrical power shall be 380 volts 3-phase 50 cycle and the chiller shall be capable of operating within line voltage plus or minus 6%. The control power shall be 220 volts single phase.

The Sound Power level shall not exceed 82 dB (A) at a distance of 1m from the chiller. Contractor must ensure that Indoor sound conditions do not exceed those specified. No vibrations shall be transferred to the building structure. The compressor compartment shall be provided with purpose made acoustic insulation installed at the factory.

Units to be CE marked and the manufacturers to have the ISO 9001.

1 Screw compressors - Compressors shall be serviceable direct drive, semi-hermetic of the twin or single screw type with integral suction accumulator, oil pump, oil filter screen, oil charging valve, unloading valve control and crankcase heater. If the compressor is refrigerant cooled then the oil system may be replaced by the equivalent refrigerant cooling system as designed by the chiller manufacturer. The motor shall be hermetically sealed suction gas cooled. Motor power factor must be over 0.90. Compressors to be mounted on spring or rubber in shear isolators.

2 Casing - Unit shall be 16 gauge galvanised and phosphatised steel in large removable panels. All internal parts shall be accessible. The units shall be mounted on a structural galvanised steel base. Casing, base and accessories shall be coated with a baked enamel primer finish before assembly. Finish coat of air-dry enamel shall be applied to all exterior surfaces after final assembly. Colour shall be to Architects approval.

3 Evaporator - The evaporator shall be of the direct expansion, shell and tube design with seamless copper tubes either straight or finned. The shell shall be constructed with carbon steel tube sheets, fully weatherised to resist corrosion, factory insulated with cell foamed rubber of not less than 20mm thickness.where flooded evaporators are utilised they shall be provided complete with marine type water boxes in order to facilitate maintenance, and refrigerant isolation system.

The evaporator shall be built and tested in accordance with ASME code for Unfired Pressure Vessels or other European Union recognised equivalent standard.


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4 Condenser Coil - Direct expansion condensing coils shall be constructed of 15mm seamless copper tubes with aluminium fins mechanically bonded tubes tested at 30 bar under water. Coils to have an integral sub-cooler circuit. The coil surface area to permit low air velocity. Coils shall be dehydrated, pressure tested with refrigerant and then sealed with holding charge of dry nitrogen. All coils shall have an integral sub-cooling and external liquid receiver. Coils to have factory applied anti-corrosive coating for highly saline environment and shall be fitted with hail guard protection.

5 Condenser fans - Condenser fans shall be low speed of the propeller or axial type. All fans shall be statically and dynamically balanced and factory tested with the fan installed in the casing. Drip-proof protected motor with built-in three-phase overload protection, to IP55 suitable for operation from -10ºC to 55ºC, factory mounted and wired. Fans to be supplied with antirust fan guards and mounted on resilient mountings.

6 Control panel - The control panel shall be weatherproof with NEMA 4 or IP55 rating, mounted on the unit. It shall have two sections, one section for the refrigerant controls and the other for the electrical controls. Power and starter controls compartment access door must be mechanically interlocked with disconnect switch.

The control panel shall be equipped with all controls required for a fully automatic operation and protection of the chiller, including but not limited to, differential oil pressure controls, high and low pressure, safety controls, signal lights, capacity modulation, compressor lead- lag, temperature and sequence of operation controls. The control module shall be microprocessor based complete with diagnostics with BMS interfacing capabilities.

7 Isolation - spring type vibration isolators at least 99% efficient and 50mm static deflection, shall be provided for mounting the unit.

Selection of the isolation system shall be carried out by the chiller manufacturer and shall be supplied with earthquake restrictors ,sandwich base or floating base, as approved by the Engineer.

8 Commissioning - The commissioning of the chillers shall be done by a competent person of the Contractor or the Supplier, fully authorised by the manufacturer and at least the following shall be reported to the Engineer (see also Section 15504 for more information on commissioning procedures to be followed)

PRESSURES

e) Discharge and Suction pressures

f) Differential oil pressure.

g) Water pressure drop in the cooler.

WATER AND AIR FLOW

a) Water flow through the heat exchanger


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b) Airflow through condenser.

TEMPERATURES

c) Ambient ‘db’ and ‘wb’.

d) Condenser entering and leaving.

e) Water entering and leaving.

ELECTRICAL

f) Power consumption.

g) Voltage per phase.

h) Running amps.

SOUND POWER

i) Within the building rooms below the chillers.

j) 3m away from units.

AP 2.11 FRESH AIR HANDLING & FAN COIL UNITS

AP 2.11.1 FRESH AIR HANDLING UNITS

The air handling units shall be of the draw-through type with variable speed, self contained including cooling coils, mixing box, 50mm thick washable permanent pre filter and heat recovery pipe section, supply fans, condensate drain, eliminator etc. as specified and as shown on drawings. For air handling unit sections are indicated on the drawing.

The air moving, coil capacities, fan and other characteristics shall be as shown on the drawings, and shall be ARI certified.

1 Casing - Frame shall be made with anodised aluminium, or steel coated with antirust paint, sections specially designed to avoid bridging. All casing panels to be of substantial gauge steel metal) heavily protected against corrosion or alternatively, anodised aluminium. It should be double skin of airtight design with approximate thickness of 50mm for all units, high quality mineral wool, sound and thermal insulation in between the two skins and inside the frame. All panel sections shall be air tight and joint with a continuous neoprene gasket. U-value not to exceed 0.65 w/m²K.

As an alternative to the high quality mineral wool, other types of insulation such as polyurethane may be accepted subject to the following:

Melting points of mineral wool is about 1100 – 12000C and should omit hazardous and toxic gases.


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The units for outdoor installation shall be fully weatherised and externally sealed with permanent elastic sealing compound. Hinged access doors with heavy-duty handles are to be provided on all compartments for maintenance purposes. These shall be tightly sealed with neoprene gaskets.

The unit shall include one-piece insulated drain pans, one under the coil section and one under the fan section and shall have drain connections on both sides.

All unit panels shall be chemically cleaned, spray painted baked and coated with an additional exterior coat of enamel after final assembly.

The casing shall be designed so that assembling and disassembling of the unit on site can be easily carried out.

Sections shall be supported on a painted metal base of a minimum height of 150mm. The units shall be properly secured on their base through rubber in shear isolators. The base frame shall be constructed from galvanised steel with adjustable feet.

All units, indoor or outdoor, shall be equipped with an explosion proof light fixture, one per section, controllable from externally mounted light switch in the fan section

2 Motor - The Motor shall be especially designed for quite operation. It should be totally enclosed, fan-cooled class F, suitable for 380V - 3phase - 50Hz. Motor over load protection shall be provided to cut off electrical supply to the motor when drawn current exceeds a pre-set value. Motor shall be mounted on common, torsionally rigid galvanised steel base frame.

3 Fan - The unit fans shall be double width double inlet type with GI steel casing backward inclined airfoil construction. Fan shall have a minimum balancing accuracy of G 2.5. Fan shaft bearings shall be designed for at least 200,000 running hours life expectancy. All rotating parts shall be dynamically balanced, individually and after final assembly. Bearings shall be mounted externally for servicing without dismantling of unit. The shaft shall be designed for a critical speed at least 10% higher than the maximum fan speed.

All fans shall be tested in accordance with AMCA 300 & 301 standard and all components shall be factory approved by AMCA or other competent authority and shall be currently catalogued product. Fan shall be tested AMCA 300 –85.

The fan shall be reinforced with suitable bolted angle flanges or by any other approved means to safeguard full rigidity of the unit.

The fan shall be belt driven with adjustable motor sheaf. Belts shall be of the oil resistant V-type to suit horsepower transmitted.


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The fan motor and belt drive shall be mounted on a robust beam frame effectively separated from the unit casing by internal spring type anti-vibration mountings, so that the vibration and noise from the units shall not be transmitted to the building structure. Belt drive guard shall be factory supplied and installed. Back curved fan should be coated with 60-micron epoxy painting of high quality. Fan shall not exceed a maximum outlet velocity of 15 m/sec.

The static resistance of the various systems have been calculated by the Engineer and the Sub-Contractor shall be required to check and recalculate the resistance in the system taking into consideration the resistance through the equipment that is finally approved and satisfy himself that the resistance figures for the fan is adequate. If necessary the total fan resistance shall be adjusted and agreed with the Engineer. No claim shall be allowed by the Engineer if the Sub-Contractor fails to fully acquaint himself with the capabilities of the various systems. The fan shall have provision for connecting variable frequency device.

4 Sound attenuator - Sound attenuators shall be provided on all AHU/FAHU. The sound attenuators shall consist of baffle elements of a non-flammable sound absorption material of mineral wool retained by an outer layer of woven glass fibre fabric. The sound attenuator shall be installed at both the inlet and the outlet of each air-handling unit to maintain the specified sound pressure levels.

5 Coils - Heating and Cooling Coils shall have capacities as shown on the drawings.

The water coils shall be of the continuous aluminium plate fin and copper tube type assembled in zinc - coated steel frame.

The coils shall be fitted with a sloping stainless steel dip tray (SS 304) insulated with pitched slope with outside connection.

The coils shall be designed for a face velocity up to 2.5 m/s without any condensate transfer away from the coil.

The coils shall be for a maximum working pressure of 16 bar and shall be factory tested to at least 21 bar. The coil shall be fitted with connections for vents and drains and they shall be brought to outside casing.

6 Mixing Box (if applicable)- The filter mixing box shall be of the high efficiency type with opposed blade dampers for the recirculated, fresh and exhaust air, as shown on the AHU schedule on the drawings, positioned across the short dimension of each air - opening.


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The mixing box shall be especially designed to provide high efficiency mixing of air streams at different temperatures. The dampers shall have extended shafts and galvanised pivot rods, suitable for the control sequence specified. The blades of the dampers shall be airtight of airfoil design made of rigid, double skin construction of painted galvanised steel or extruded aluminium sections.

7 Filters- The pre-filter section shall contain 50mm thick throw-away heavy duty filters, glass-fibres of progressive density, with 75%(EU4) arrestance efficiency. Air face velocity through the filters shall not exceed 2m/s. Filter frame shall be permanent type aluminium with pull-out hooks. Filter elements shall be held in place with sturdy metal retainers.

The bag filters shall be high capacity filters with dust spot efficiency of 85%(EU7). They shall comprise of a corrosion resistant frame housing the filter media, which shall be supported by a 3mm-dia. wire assembly, designed to keep the media cartridge in a fully open position. The media cartridge shall be preformed and shall consist of glass fibres. Filter shall be capable to operate under high humidity conditions. The bag length shall not be less than 500mm.

Filter efficiencies shall be according to EUROVENT 4/5.

Filters shall be flame retardant to BS 5588.Pt. 9:1989. Pressure tappings together with inclined manometers for visual indication of filters pressure drop shall be provided before and after each filter. See Control section for any additional tappings.

8 Heat Recovery Unit

k) Rotary Heat Exchanger (Thermal Heat Wheel)

The wheel shall be made of layers of corrugated and intervening flat aluminium foil of uniform width to ensure smooth surface. This wheel material is bonded together to form a rigid transfer medium forming a multitude of narrow channels thus ensuring a laminar flow. The rotary heat exchanger shall be hygroscopic type for the transfer of sensible and latent heat. The whole rotor shall be chemically treated by controlled corrosion process to produce hygroscopic layer on aluminium foil. The chemically attached layer should have high affinity to moisture. Pre-caoted aluminium foil should not be used.

The dessicant shall be water molecule selective and not migratory and shall be molecule sieve 3A.


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Rotor shall be mounted in a sturdy casing with an access door and sealed against casing by means of wear resistant, adjustable seal. The casing shall be equipped with purging sector. The wheel shall be cleanable by spraying its surface with compressed air, low temperature steam, hot water or by vacuum cleaning without affecting its latent heat recovery properties. The casing shall be equipped with adjustable brush seals which minimise carry-over to max 0.5-0.2%. The wheel shall be belt driven along its perimeter. A constant speed drive motor shall be used. The motors shall be mounted on a self adjusting base to provide correct belt tension.

The rotary wheel should confirm to ASHRAE 84-78, EN 29001 and BS 7550.

For one-piece rotor, hub and spoke shall be in aluminium. On sectorised rotor, hub made of steel, painted with anticorrosion paint, galvanised sheet steel spokes.

The directions of airflow through the rotor should be reversing continuously to give excellent self-cleaning effect. In order to prevent fouling and clogging of the rotor, a standard EU-4 filter (synthetic washable) should be in position and the rotor should always be rotating when the fans in the system are running. A double glass inspection window should be provided in this section.

The Heat Recovery Wheel shall be constant speed. The HRW shall be provided with speed detector.

AP 2.11.2 CHILLED WATER FAN COILUNIT

1 Type - The fan coil unit shall be of the factory assembled, integral fan type with chilled water cooling coil and shall be made for decorative type with filter back.

2 Capacity - Shall be as shown on the specification equipment schedules. Units shall be ARI rated. All units shall be selected to achieve the specified duty and noise criteria against an external static pressure of minimum 50 Pa at medium speed. Contractor’s responsibility to select exact static pressure.

3 Chassis - The chassis shall be constructed of attractive backed on off white enamel finish. All cold panel surfaces shall be covered with not less than 15mm thick coated glass fibre insulation 32 kg/m3.

4 Mounting - The concealed fan coil unit shall be securely attached to the building structure and shall be set dead level in both directions.

5 Coil - The coil shall be constructed of aluminium fins mechanically bonded to copper tubes. The minimum fin thickness shall be 0.115 mm and the tubes shall not be less than 15 mm OD and the minimum wall thickness shall be 0.5 mm. Provide an air vent and drain plug in the coil. Coil shall be tested at 30 bar while submerged in water.


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6 Drain pan - shall be provided under the cooling coil supply and return lines, and valves. The pan shall be of sufficient size to catch all drippage of condensation from any part of the unit. The drain pan shall be fabricated of not less than 1.5 mm galvanised steel with all corners welded and coated with antirust inhibiting paint. The pan shall be insulated with not less than 15mm thick glass fibre insulation to effectively prevent condensation from the pan.

7 Fan and Motor – The motor shall be Squirrel Cage with low starting torque. It shall be multi-speed (min. 4 tappings) and have built-in thermal overload protection. The fan shall be suitable for the external static pressures as specified and as required for the installation shown on the drawings. Fans shall be centrifugal type with aluminium or galvanised scroll, self-lubricating bearings, mounted on resilient suspension for quiet operation.

8 Temperature and Fan speed Control - The unit shall have wall mounted temperature control unit, offering OFF / LOW / MEDIUM / HIGH fan speed control and operating the 2-way valve. The control unit shall further incorporate a manual changeover switch for Summer/Winter mode of operation. See the Automatic Controls Section for more details.

9 Sound levels - Units shall be tested in accordance with ARI Standard 443-66. "Standard for sound Ratings of Fan Coil Air conditioners" or ISO 3742. Manufacturer shall submit Octave Band analysis from 125 Hz to 4000 Hz showing sound power levels resulting in dB (A) not exceeding 55, based on high speed in a "medium hard room". The Sub-Contractor shall take all measures required so that the specified room noise levels are not exceeded.

10 Air filters - shall be accessible by dropping down bottom panel of the filter back. Filter shall be 15-25mm permanent, cleanable aluminium mesh 65% efficiency to ASHRAE 52/68 mod.72 or Eurovent EU2.

11 Valves - Each Fan Coil Unit shall be provided at least with one isolating and one self balancing valve, in addition to the modulating control valve.

12 Electrical supply – All FCU’s shall be fitted with a purpose made electrical connections compartment incorporating a surface mounted local electrical isolator with ON/OFF indication. The compartment shall be made of galvanised steel with minimum dimensions of 200mmLx120mmHx100mmD with a front removable access panel. The box shall serve as power supply to the FCU motor as well as the control components and shall incorporate all necessary junction boxes, fuses, relays control valve transformer and all available motor speed connections.


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AP 2.12 FANS

(g) Fans General

The static resistance of the various systems have been calculated by the Engineer and the Sub-Contractor shall be required to check and recalculate the resistance in the system taking into consideration the resistance through the ducts and equipment that is finally ordered and satisfy himself that the resistance for the fan are correct. If necessary the total fan resistance shall be adjusted and agreed with the Engineer. No claim shall be allowed by the Engineer if the Sub-Contractor fails to fully acquaint himself with the capabilities of the various systems.

All fans shall be selected for quite operation and their performance and noise levels shall be tested in accordance to BS 848 part 1(1980) and 2(1985).

Attenuators shall be supplied where shown or where required to meet specified noise levels. These shall be made of galvanised casing, suitably reinforced and the internal sound absorbing material shall be effectively fixed to prevent loose material carried away.

Each fan impeller shall be carefully balanced, both statically and dynamically and rigidly keyed to the fan shaft. The fan shaft shall be constructed from best quality 40 ton mild steel, each shaft being adequately sized to ensure that running speed is not more than 55% of the first critical speed.

All the bearings shall be grease lubricated ball roller bearings. All necessary precautions shall be taken to prevent the ingress of dirt and dust to the bearings, and adequate facilities for bearings lubrication shall be furnished.

Any exposed fan inlets or outlets shall be protected with stout galvanised wire mesh guards.

All fans shall be selected at a point of pressure volume curve, which allows for a twenty per cent variation in volume, without operating in unstable range.

The Sub-Contractor shall furnish all fan driving motors, and these shall not run at more than the recommended r.p.m. and be of the TEFC type motor.

The motors shall be selected for the fan duty specified taking into account the torque required for starting the fans.

(h) Duct Mounted Fans

Fans should be of high efficiency double inlet multi-vane impeller and direct mounted electric drive motor. The motor should be attached to the fan scroll plate via resilient mounts and the whole assembly should be tested and balanced. The motors should have three speed settings.


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Auto changeover controller should be provided and indication facility /volt free contact should be provided such as power on, fan running and fan failure for connecting with BMS system. Duty sharing facility should be provided. The following accessories should be provided:

Top access panel

Flanged connections

Acoustically lined casing

Flexible connections

Matching duct attenuators, etc.

(i) Axial Fans

All in-line axial fans shall have long galvanised casings with flanges. Casings to be painted as required by the Engineer. The fans shall be of single or multi-stage contra-rotating, construction.

The impellers shall be designed with a special airfoil section for maximum performance and low noise characteristics. These shall be of die-cast aluminium alloy construction. The impellers shall be assembled with plated set screws and self-locking nuts.

For improved efficiency fans shall be supplied with inlet cones.

The motors shall be speed controllable, TEFC, weatherproofed to IPP55. Output and performance to comply with BS 5000, part 10, part 99 and IEC 34.1.

The fans shall be supported with approved type mounting feet or anchors, supplied with vibration isolators.

(j) Roof & Wall Fans

The impellers shall be of axial or centrifugal type constructed from aluminium alloy. In the case of the axial fans, polypropylene impellers are also acceptable.

Fans to be supplied complete with bird screen, inlet guards, roof flashing or wall mounting plate

The motors shall have thermal protection and shall be speed controllable, TEFC, weatherproofed to IP55. Output and performance to comply with BS 5000, part 10, part 99 and IEC 34.1.

AP 2.13 CHILLED WATER PUMPS

(a) End-Suction Type

1 Water pumps shall be single stage with constant speed, base plate mounted, centrifugal with flexible coupling. See pump schedule for more information on pump selection and capacities. Maximum Working Pressure 16 bar. Maximum Working Temperature 120oC.


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2 Pump casing to be of cast-iron construction with bronze or stainless steel impeller, and stainless steel shaft running in lubricated ball bearings. Port flanges shall be PN16. Pump shall be fitted throughout with renewable wearing rings, provided with mechanical rotating carbon seal. Provide drainpipe to floor drain and 20mm drain cock with pipe in pump casing discharging into base plate. Pumps shall be set on a concrete pad 150mm high.

3 Pump Motor shall be 380 volts 3 phase 50 cycles for motors 1 kW and over. Motor speed shall be 1450 RPM and shall be of the totally enclosed fan cooled type with internal fan circulating air between interior and exterior shell. Motor shall be suitable for 45oC and 90% RH ambient conditions. All electric motors shall be of the high efficiency type suitable for variable speed operation. Protection to IP 55 with class “F” insulation.

4 Final Pump sizing (capacity and head) shall be the responsibility of the Sub-Contractor based on the installed system configuration and final equipment selection. Sub-Contractor shall submit all selections including pump curves for single and parallel operation (official submittals by the manufacturer) to the Engineer for approval prior to ordering. All sizes indicated on the pump schedule are for bid purposes. Any deviation from the capacities given on the contract drawings shall be at no extra cost to the owner.

5 Noise and vibrations- The Sub-Contractor shall take all measures required so that no vibrations are transmitted to the building structure and the specified room noise levels are not exceeded

(b) In-Line Type

1 Water pumps shall be of mono block design for vertical installation, vibration free operation, single stage, and centrifugal type. See pump schedule for more information on pump selection and capacities. Maximum Working Pressure 12 bar. Maximum Working Temperature 120oC.

2 Pump casing to be of cast - iron construction of in-line design with bronze or stainless steel impeller and stainless steel shaft running in lubricated ball bearings with bronze shaft sleeve and a mechanical rotating carbon seal. Pump shall be fitted throughout with renewable wearing rings. Suction and delivery ports to have flanges with gauge tapping.

3 Pump Motor shall be for 220 volts, 1 phase, 50 cycles for motor up to 0.75KW and 380 volts 3 phase 50 cycles for motors 1 kW and over. Motor shall be of the totally enclosed fan cooled type with internal fan circulating air between interior and exterior shell. Speed shall be 1450 RPM. Performance and size frame shall conform to IEC standards. Motor shall be suitable for 45oC and 90% R.H. ambient conditions. All electric motors shall be of the high efficiency type suitable for variable speed operation. Protection to IP 55 with class “F” insulation.


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4 Final Pump sizing (capacity and head) shall be the responsibility of the Sub-Contractor based on the installed system configuration and final equipment selection. Sub-Contractor shall submit all selections including pump curves for single and parallel operation (official submittals by the manufacturer) to the Engineer for approval prior to ordering. All sizes indicated on the pump schedule are for bid purposes. Any deviation from the capacities given on the contract drawings shall be at no extra cost to the owner.

5 Noise and vibrations- the Sub-Contractor shall take all measures required so that no vibrations are transmitted to the building structure and the specified room noise levels are not exceeded

AP 2.13.1 EXPANSION SYSTEM

1 Expansion vessels shall control any change in volume due to expansion and contraction and pressure fluctuations in the cooling system. The capacity and pressure rating of the vessels shall be determined by the pump and/or tank manufacturer to suit the specific requirements of the system. The Sub-Contractor shall submit tank selections to Engineer for approval prior to ordering. Sizes given on Tank schedules are for Bid purposes only.

2 The steel pressure vessel to contain internally a durable India rubber bladder complete fitting the interior shape of the vessel, containing the compressed air buffer and separating it positively from the media liquid of the installation. The rubber to be connected on the vessel by a flange and shall be of the replaceable type.

3 Protection against excess air pressure shall be effected by means of a certified pressure relief valve.

4 The filling of the system shall be effected by an automatic system, consisting of isolating valve, strainer, pressure reducing valve, check valve and inlet outlet pressure gauges.

5 Vessels to be factory supplied with a steel base and shall be suitably painted red with heat resisting paint.

AP 2.13.2 MOTORS FOR HVAC APPLICATIONS

(c) General

Motors over 500W shall be in accordance with British Standard 5000 Part 99 'The Electrical Performance of Rotating Electrical Machinery or IEC-34-1, in respect of mechanical details and British Standard 2757 'Classification of Insulatory Materials for Electrical Machinery and Apparatus on the basis of Thermal Stability in Service' or IEC-85 in respect of electrical details and the windings shall be as Class F, derated as necessary in respect of the operating conditions.


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All motors shall be in accordance with the requirements of the British Standards. All motors shall operate satisfactorily under rated load at 10% rated voltage. Motors shall be suitable for high ambient temperature of 60 degrees Celsius. Class "F", except where they are in equipment that may be subject to higher temperatures e.g. air handling units, where they shall be suitable for the operating conditions.

(d) Load

Motors shall be capable of continuous operation at rated full load horsepower or current without exceeding rated temperature rise at site conditions.

(e) Service Factor

Motors, except totally enclosed, shall have a rated service factor of 1.15 minimum. Totally enclosed motors may have a service factor of 1.0. Rated motor hp shall exceed the calculated required Bhp of the driven equipment by 15% for single phase motors and 10% for three phase motors.

(f) Bearings & Wound:

Shall be mounted in protective housing and shall include fittings for adding, draining and replacing the lubricant and removing cleaning and replacing the bearings. Design shall prevent lubricants from entering the motor space during normal operation and during lubrication.

Two speed motors shall be double wound.

(g) Electrical Characteristics

6 Building voltages for this project shall be:

220 volts 1 phase 50 Hz

380 volts 3 phase 50 Hz

7 All motors 250W and lower shall be 220 volt, 1 phase, 50 Hz, unless otherwise specified.

8 All motors 350W and above shall be 380 volt, 3 phase, 50 Hz, unless otherwise specified.

(h) Enclosures & Starting

Open, drip-proof motor or totally enclosed, fan cooled motor unless otherwise specified.

Split, package, room and small chilled water unit compressor motors shall be special refrigerant gas cooled 3 phase motors arranged integrally with the compressors.

Motors up to and including 5kw shall be arranged for direct-on line starting and over 5kw shall be arranged for star/delta starting, except if otherwise required by local authorities and/or approved by the Engineer.


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The cold water pumps and centrifugal fan motors shall be specially arranged for quiet running and have one size larger frame than standard to reduce magnetic hum.

Generally, motors driving centrifugal fans through V-belts shall be arranged to run at nominally 950 r.p.m.

Generally, motors driving pumps and compressors shall be arranged to run at nominally 1450 rpm and shall be non-overloading.

(i) Motor Starters

All motors shall be supplied with combined starter/ isolator switch units. Where it is necessary to fit a second isolator, due to the remote location of the motor from the starter/ isolator, it shall be supplied by the Sub-Contractor. The starters shall be supplied by the manufacturer of all the panel and control boards.

Where motor starters are supplied by others, the Sub-Contractor shall install and connect as a part of the Contract Works.

All starters shall be automatic unless otherwise specified.

Care shall be taken in installing each starter to ensure that it shall not be subjected to excessive vibration during operation and ensure that overload settings are correctly calibrated against the motor load after connection.

The Sub-Contractor shall demonstrate that the overload trips are correctly set to afford protection to the motor.

Each starter shall be housed in a dustproof casing, having front access door. Each starter shall be complete with the following:

1 On-load isolators to isolate all power and control circuits simultaneously.

2 Thermal trips for overload.

3 Single phase preventors.

4 No-volt trip coils with auto reset.

5 All necessary auxiliary contacts, switches, etc.

6 Contactor coil arranged to operate off 220V line voltage A.C Supply.

7 An interlock relay fitted inside. The relays shall have a 24V A.C. 2 Watt maximum coil, contacts rated for line voltage and equipment controlled, sealed transparent cover, pin contacts and plug in base. The relays and the wiring shall be arranged to bring the starter control in operation.

8 Ammeter with protective fuse for all 3 phase starters only.

9 Auxiliary contacts and fuses for feeding filter motors etc.

10 Control circuit fuses.

11 Remote/local control switch. This switch shall work in the 24volt control circuits only and not the 220v line voltage contactor coil circuit.


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12 Local ON/OFF or where duplicate motors with automatic changeover ON/DUTY/STANDBY/OFF or where two-speed motor the ON shall be replaced with HIGH/LOW switch. This switch shall work in the 24-volt control circuit only and not the 220V line voltage contactor coil circuit.

13 220/240-volt double wound transformer. This transformer shall be supplied from the switched side of the on-load isolator to ensure correct control and signal indication. This transformer shall feed the control circuits and pilot lights in the starter and the various control panels associated with the starter.

14 RUN/DUTY/STANDBY/FAULT or RUN/FAULT pilot lights or if a two speed motor, then the RUN shall be replaced with HIGH/LOW.

The Sub-Contractor shall supply and fix all automatic starters for each item of equipment and these shall be built into control panels.

Starters for motors rated at 5kW and over shall be star/delta.

Where particularly specified the Sub-Contractor shall supply and install an isolator switch adjacent to each starter so arranged to achieve total isolation of the starter for maintenance and other purposes.

Each motor frame shall be provided by the Sub-Contractor with a substantial terminal box so arranged for the reception of not less than 25mm OD Conduit. The Sub-Contractor shall install circuits to the motors comprising PVC or Butyl rubber insulated cable in conduit to a fixed position adjacent to each motor on the wall, column steelwork or plinth. From each location to the motor terminal box the end of the cable conductors shall be enclosed in PVC covered flexible conduit shall be provided by inserting a BESA through box drilled to receive a bare copper earth wire connected to the corresponding earth terminal provided on the motor frame.

All starters shall be equipped with suitable run/trip indication lights.

AP 2.13.3 VARIABLE SPEED DEVICES FOR PUMPS (IF APPLICABLE)

The system shall include the adjustable frequency drive(s), remote sensor/transmitter(s), motor(s), and a programmable logic controller.

The pumps shall be sized to meet duty system conditions as indicated on the schedules and according to the specifications.

Submittal for approval for above pumps shall include a complete system profile analysis (variable speed pump curves and system curve, motor and adjustable frequency drive efficiencies, load profile and KW/HR drawn).

The pump manufacturer shall either supply the variable frequency speed control system together with the pumps/fans or at least approve the system for the specific application.

The adjustable frequency drives shall be controlled by the BMS through a local stand-alone controller.


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The controller shall select the analogue signal that has deviated the greatest amount from its set point. This selected signal shall be used as the command feedback input for a closed loop stabilisation function, which shall have the capability of performing the proportional integral and derivative mode. The proportional function shall have a range and shall be infinitely programmable within that range. The integral function shall be also infinitely programmable and compatible with the adjus-table frequency drives and the hydraulic/air system.

The system controller shall be capable of operating in automatic, manual or off-line diagnostics mode.

The system shall also include a manual by-pass across the line adjustable frequency drive.

The sensors shall send a signal to the controller indicative of process variable conditions.

The controller shall compare each signal to the independent determined set points.

When all set points are satisfied by the process variable, the pump speed shall remain constant at the optimum energy consumption level.

The controller shall continuously scan and compare each process variable to its individual set point and control to the least satisfied zone. As the worst case zone deviates from set point, the pump/fan controller shall sent the appropriate analogue signal to the adjustable frequency drive to speed up or slow down the motor.

The variable torque AC drive shall consist of an adjustable frequency controller capable of driving a standard A/C induction motor.

The adjustable frequency drive shall convert 415V + 10%, three phase, 50Hz utility power to an adjustable frequency output for speed control from 0-100 percentage of base speed. The drive shall be modifiable to accept all standard input voltage from 200-500 VAC. The adjustable frequency control shall be designed exclusively for variable speed applications.

The adjustable frequency drive shall produce adjustable frequency and voltage output. To eliminate the need for isolation transformers and/or line suppression equipment, input line filters shall be an integral part of the input section of the drive.

To minimise motor noise generation, the drive output shall be six step.

The pressure sensors shall have an adjustable span limit between 0 and 20 bars, and shall have watertight electrical enclosure. All sensor wiring shall run in a suitable conduit separate from power wiring to prevent interference with low voltage sensor signals.

The flow sensors shall be insertion type flow transducers, located where indicated by the Engineer. The transducer shall produce a voltage signal proportional to flow. Accuracy shall be within + 1% of flow rate.


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The transducer shall be capable of being inserted and removed when the pipe/duct served is under pressure.

AP 2.14 VALVES

AP 2.14.1 GATE VALVES

(a) BS 5154

15-50mm Gate valves:

Ends: Threaded to BS 21

Stem: Inside screw non-rising stem

Trim Material: Manufacturers standard

Temperature: 00C to 1200C

Pressure: Pn16

Body: Bronze

Bonnet, Wedge and stem: Brass

(b) BS 5150

65mm and above:

Ends: Flanged to BS 4504

Stem: Inside screw non-rising stem

Trim Material: Manufacturers standard


Pressure: Pn16

Body, Bonnet and Stuffing box assembly: Cast Iron

AP 2.14.2 GLOBE VALVES

(a) DN 15 – DN 50

Body: Bronze according to DIN 1705 standard.

Brass Bonnet, Teflon impregnated gland packing.

Handwheel: Metal Disc with PTFE (Teflon) Seal

Temperature: Maximum upto 1500C

Pressure rating: PN16


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(b) 65mm and above

Body, Bonnet and Handwheel made of Cast Iron GG25.

Valve seat inside the body and sealing surface on the disc and stem should be made of Stainless Steel.

Lengths and Leg Lengths should be according to DIN 3202 F1.

Dimensions and Tapping points of flanges according to DIN

Stem: Rising Stem

Pattern: Straight Pattern

AP 2.14.3 CHECK VALVES

(a) 15 MM – 50 MM: Swing Type

Body: Bronze

Inner Parts: Brass

Temperature: upto 1200C

Pressure: PN16

(b) 65 MM and Above: Swing Type

Body, Cover & Stuffing box assembly: Cast Iron (EN-GJL-250 DIN EN 1561)

Seat Rings: Brass

Asbestos free gaskets.

Flanges to BS 4504 PN16.

CE – marking according to directive 97/23/EC.

Pressure: PN16.

AP 2.14.4 Y STRAINERS

(a) 15 – 50 MM

Body: Bronze

Bonnet: Brass

Wire Basket: Stainless Chromium Steel

Mesh Size: To be 0.6mm (100 meshes/cm2)


Pressure: PN16


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(b) 65 MM – 150 MM

Body and Cover: Cast Iron (EN-GJL-250 DIN EN 1561)

Wire Basket: Stainless Steel

Mesh Size: to be 1.5 MM

Asbestos free gasket.

Flanges According to BS 4504 PN16

Lengths According to DIN EN 558-1, Basic Series 1.

CE-marking according to directive 97/23/EC.

AP 2.14.5 DOUBLE REGULATING VAVE

(a) 15 – 50 MM

Body and Bonnet: Bronze.

Stem and disc: Brass resistant to dezincification (DZR)

Disc: with PTFE seal.

Pressure test points: to be made of Brass

Ends: Threaded to BS 21

(b) 65 MM –150 MM

Body: Cast Iron (GG 25 DIN 1691)

Bonnet and Disc: Bronze

Stem: Brass resistant to dezincification

Disc: with PTFE seal.

Stem seal to have Double EPDM O-rings.

Flanges should be according to BS 4504

Lengths according to DIN 3202 F1 and BS 7350.

AP 2.14.6 BUTTERFLY VALVES

(a) Construction

Body: Cast Iron

Disc: Aluminium Bronze

Shaft: 316 Stainless Steel

Seats: EPDM

Shaft Bushing: Polyester


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Shaft Packing: Buna N

Upper & Lower Bearing: Sintered Metal

Pressure: Vacuum to 1200 kPa

Temperatures: Minus 400C to 1200C

End Connections: AS 2129 E & ANSI 150 as Standard

AP 2.14.7 DYNAMIC BALANCING VALVES (AUTOFLOW VALVES)

(a) General

The manufacturer of Dynamic Balancing valves shall have ISO 9001 certification for Design, Manufacturing, Sale and Delivery. The valves shall have marking for Country of Origin on the valve body (No sticker’s or plate to show the will be accepted).

All valve parts including the Body and Cartridge should be manufactured in the same factory (Cartridges manufactured and supplied by sub-suppliers will not be accepted). Al cartridges should be tested for the flow and corresponding differential pressure. Manufacturer should have testing facility for the same.

AP 2.14.8 TECHNICAL SPECIFICATION

Autoflow valves shall automatically control specified flow rates with 5% accuracy. Valves shall have replaceable cartridges with flow rates determined at the factory. The flow cartridge shall be Tin-Nickel coated DZR Brass, which should be anti corrosive. Each cartridge should be coded to indicate specific flow rate.

(a) For sizes upto 40mm

The valve shall be made of hot stamped Brass and shall operate by means of an automatic flow balancing flow rate cartridge, that is accessible without dismantling the valve from the piping system. The valve should have integral isolating Ball valve with union programmes and test points. The Cartridges shall be Tin-Nickel Coated DZR Brass Cartridges with replaceable fixed orifice. The differential pressure range should be 12-600kPa.

The pressure class shall be PN 25.

(b) For sizes 50mm and above

The valve shall be made from Ductile iron GGG40 and shall operate by means of one or more automatic balancing flow Cartridge(s). The flow rate cartridge shall be able to maintain a constant flow at a differential pressure upto 600kPa.

The cartridges shall be Tin-Nickel coated DZR Brass Cartridges with replaceable fixed Orifice. The differential Pressure range should be 13-600kPa.

The pressure class shall be PN 16.


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AP 2.15 DUCTWORK AND ANCILLARIES

AP 2.15.1 GENERAL

The Sub-Contractor shall furnish and install all sheet metal work and appurtenances indicated on the drawings or otherwise required to connect all ventilating and air-conditioning equipment and accessories complete and ready for regular operation and flexible connections between ducts and fans.

The drawings shall be adhered to as closely as possible but changes in duct routes and shape if found necessary due to interference or other work shall be made without extra charge. Dimensions shall be changed without decreasing cross sectional area.

All ductwork shall be constructed of best quality cold, annealed, perfectly flat, hot dipped galvanised mild steel (BS 2989, group II, clause "F" and BS115 and amendments) material shall be clearly stamped and marked with grades and gauges.

Ducts where shown circular shall be spirally - wound ducts fabricated to the sizes shown on the drawings. All take-off, reducers, bends, dampers etc shall be constructed with purpose made fittings. Use cross joints in accordance to DW 142 and tested to DW/TM1.

Minimum sheet thickness for sheet metal, ductwork method of construction, leakage testing and all other details of manufacture and erection shall be as recommended by the practical guide DW 142 and DW 143 as issued by the Heating and Ventilating Sub-Contractor's Association of the U.K. and the latest amendments and revisions coming into force during the time of preparing the tender.

Construction and erection of ductwork to any other standard or guide shall be authorised in writing by the Engineer.

All ducts shall be free from "drumming" due to air-movement and truly air-tight under all operating conditions. Where square elbows are shown, factory made turning vanes shall be used. Long radius elbows shall be used in all other cases. Where branch ducts take off at right angles to the mains, provide adjustable air extractors, factory made.

All curves, bends, offsets and other transformations shall be made for an easy and noiseless flow of air. Generally, straight transformations shall be made at an angle not to exceed 15 degrees.

Volume dampers shall be provided on all main branches and/or as shown on the drawings.

Provide hangers and supports throughout in accordance with DW 142, DW 151 or DW191 as appropriate.


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All ductwork, generally, shall be supported from the slab by galvanised straphangers fastened to the slab construction by means of anchor bolts and approved type inserts. Straps shall be not less than 4 mm by 25 mm flat iron spaced approximately 1200mm on centres and screwed or bolted to the duct or as otherwise directed by the Engineer or shown on the drawings

Vertical ducts passing through floor shall be supported at each floor level by 40x40x4mm angles bolted or screwed to the ductwork and fastened to the floor slab or sides of the shaft in an approved manner.

Access doors shall be installed in casings, plenum chambers and ducts where shown and wherever else required for ready access to the operating parts of any kind such as dampers, thermostats, valves, bulbs, etc. Doors shall be constructed of steel angle frame with builder’s cleats and a double wall insulated door panel fitted with a profiled rubber seal and handles. Provide access panels where adjustable air-extractors/dampers cannot be reached through inlet or discharge grilles or through lift-out ceilings.

Where the sheet metal connects to the intake and discharge of each fan or fan unit, there shall be installed a flexible canvas connection which shall be securely fastened to the apparatus and adjacent ductwork in such a manner that it may be readily adjusted or replaced. Such canvas connection should have adequate length to avoid any transfer of vibration. Flexible canvas connections shall also be installed at all building expansion joints.

In cases where this canvas is exposed to adverse atmospheric conditions, the material should be able to withstand such conditions. The Sub-Contractor shall supply and install steel sleeves 4 mm thick where duct passes through wall or slabs. The gap between the sleeves and the duct shall be filled with fire resisting material. Sealing materials and method of use to comply DW/142, DW151 as appropriate.

Ensure ductwork does not come in direct contact with the building elements except in case of the fire dampers, silencers and building frames. Isolate all supporting members from ductwork and secure lining of 6mm thick rubber support by means of adhesive.

Provide test holes at each side of all equipment for commissioning and upstream of all dampers. Number of holes, maximum 4 (four), according to duct diameter.

Provide holes for all instruments and control equipment is required.

AP 2.15.2 CASINGS AND PLENUMS

All casings and plenum chambers shall not be less than 1.5 mm thick. All exposed uninsulated ductwork shall have flat seams and be properly stiffened over 450 mm width. Plenums for supply and return slot diffusers shall be supplied from the manufacturers of the diffusers.


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All joints in casings and plenum chambers shall be standing seam (screwed, bolted or riveted) with angle bracing. Angles shall be screwed or bolted to the casing on 150 mm centres. Angles shall be spaced not more than 600 mm apart. All joints in casing shall be completely airtight. Casings shall be arranged substantially as shown on drawings, but shall be modified to the extent required to make fit filters, coils etc.

Casing angles shall be securely fastened to the floor or ceiling construction by means of expansion bolts.

AP 2.15.3 FLEXIBLE DUCTS

The flexible duct shall be suitable for high medium and low pressure applications and shall comply with DW 142.

Duct shall be fire resistant and shall satisfy the requirements of BS 476 parts 6, 7 and 8.

Duct shall be constructed from two layers of fabric with each layer being 3-ply laminated (aluminium/polyester/aluminium) and supported by a high tensile steel wire helix.

The flexible duct shall be site or factory insulated with 30 mm flexible fibreglass ‘k’ value 0.04 W/mK with density 30kg/m3 and covered by a tough, reinforced aluminium fabric.

The fixing of the flexible duct to duct spigots shall be done with "Ovide clamps" and all joints shall be sealed with sealant or duct tape recommended by the manufacturer of the flexible duct.

The flexible duct shall have a maximum length of 1500mm.

AP 2.15.4 CONTROL DAMPERS

Type - The dampers shall be of the opposed blade, 100% shut-off type, suitable for the static pressures shown on the drawings.

Frame - The damper frame shall be 2 mm zinc-coated steel and shall be provided with mounting holes. The frame shall be roll-formed, interlocked, and welded at corners. The frame shall be 100 mm, width minimum.

Blade - Blades shall be constructed of 2 mm roll formed, zinc-coated steel not to exceed 150mm in depth and shall be formed with double 90 degrees bends to insure positive air lock and maximum strength. Blades shall be felt tipped to insure tight closure and noiseless operation. Where these are not motorised this shall be supplied with normal control with position indicator and locking device.

Sections - Damper and damper frame may be made in one section up to 1200 mm in width and 1000 mm height. Larger sizes shall be made in sections.


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Linkage - The damper shall have dual blade linkage concealed in the jambs and connected with steel rods.

The blades shall rotate on 12 mm diameter pivot assembly in permanently lubricated bearings. Blades shall be capable of opening to a full 90 degrees and linkage shall incorporate positive 90 degrees opening stop. Operation shaft shall be suitable for motor operation. All dampers to be provided with position indicators. Where these are not motorised, shall be supplied with handle and locking device.

Installation - The damper and damper frame shall be installed dead level in both directions. The blades shall not touch any adjacent material throughout the full travel of the blades. The damper and damper frame shall be installed so that there is no torsion or twist in the frame to prevent smooth operation of the damper.

Pressure Drop - Pressure drop through the damper shall not exceed 5mm W.G. at 2.5m/s velocity based on the face area.

Final Adjustment - After installation, the damper shall be adjusted to the airflow quantities shown on the drawings.

Cleaning - The dampers and linkages shall be cleaned of all construction dirt. Any debris or dirt that could cause binding shall be thoroughly removed.

Manufacturer - The damper, damper frame and linkage shall be the product of a manufacturer regularly engaged in the production of high quality dampers.

Each motorised damper shall also have an airflow measuring device, linked to the BMS.

AP 2.15.5 FIRE DAMPERS

Type - Dampers shall be manufactured to DW142 shall meet the local codes, the standards of the "National Fire Protection Association" and shall comply with BS 476. Dampers shall be sized so that the free air space is not less than the connected duct free air space. Location shall be as shown on drawings and as re-quired by Local Authority.

Material - Frame shall be constructed to be unaffected by corrosion of high heat. Mechanical parts shall have bronze or SS non-corrosive pins. When closed, the dampers shall be held closed by a catch arrangement.

Fuse links - Fire dampers shall be arranged to close automatically and remain tightly closed upon the operation of an approved fusible link or other approved heat actuated device, located where readily affected by an abnormal rise of temperature in the duct. Fusible links shall have a temperature rating approximately 30oC above the maximum temperature that would normally be encountered when the system is in operation or shut down.


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Workmanship - Fire dampers shall be installed so as to provide the positive barrier to passage of air when in a closed position. Dampers shall be installed so they shall be self-supporting in case of duct destruction due to heat. Care shall be exercised that the frame shall be set so that closing device shall not bind.

Access Hole - Suitable hand hole openings with tightly fitted covers shall be provided to make accessible for inspection and maintenance, or resetting.

Manufacture - Fire dampers and access doors shall be the product of a manufacturer regularly engaged in the production of high quality products.

All fire dampers shall be supplied with a visual indicator of the damper blade status, which shall be shown externally on the false ceiling.

The level of cleanliness and protection internal to the ductwork shall be as defined in HVCA document DW/TMC.

AP 2.16 DUCT INSULATION

AP 2.16.1 MATERIAL:

The insulation used shall be Flexible Closed Cell Elastomeric Foam with the following properties :-

1 Thermal conductivity ( ) BS 874 Part 2-86 ( DIN 52613, 52612, ISO 8497) max. values.

-20 C 0.034 W / mK

0 C 0.037 W / mK

20 C 0.034 W / mK

Thermal Conductivity values shall be governed by a Third party Supervisory Control Agreement, which shall be available for attestation of conformity purposes.

2 Water Vapour Diffusion Resistant ( ) (DIN 53122 Part 2, DIN 52615). 7000 Water Vapour Diffusion Resistant ( ) values shall be governed by a Third party. Supervisory Control Agreement, which shall be available for attestation of Conformity purposes.

3 Water vapour permeability –(BS 4370/2, DIN 52615) < 0.09 gm / Nh.

4 Closed Cell Content - > 90%.

5 Fire Rating:-

BS 476 Part 6 1989 ( Fire Propagation ) : Fire Index < 12 (Class O rated)

BS 476 Part 7 1987 (Surface spread of flame) : Class 1 rated. (UNI 845 – UNI 9174)

Reaction to Fire Certification shall be available for all commercial insulation thickness upto and including 50mm.


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6 The FM (Factory Mutual) product approval should be available for the insulation material.

7 Smoke & Toxicity (for public and high rise buildings).

The insulation product and system should meet the following requirements:

ASTM E622 – Smoke density Dm < 400. Carbon monoxide (CO) Concentration <1450 ppm.

Limit concentrations are in line with IMO requirements and AIRBUS specification.

8 Corrosion risk assessment DIN 1988/7 certified.

“ Material should be nitrite free and contain no more than 0.2% of ammonia. Insulating material for stainless steel must contain no more than 0.05% of water soluble chloride ions, the PH value should be limited to PH = 7 + 0.5

Corrosion risk assessment values shall be governed by a Third party Supervisory Control Agreement, which shall be available for attestation of conformity purposes.

9 Noise reduction DIN 4109 upto 32dB(A).

AP 2.16.2 IMPORTANT NOTE:

1 Manufacturer should be certified in accordance with ISO 9002/UNI EN 29002 which includes production control procedures and systems as a pre-requisite.

2 All tests should be conducted by independent, accredited institutes and the supervisory (third party) control agreements should be available for attestation of conformity purposes.

At all support points for the ducts, the Contractor shall provide hard wood insulators or approved equal material subject to Engineer’s approval.

The insulation laggers shall be trained by the manufacturer’s local agents before commencement of works. The manufacturer’s local agent shall visit the site periodically to inspect the insulation work.

The insulation thickness shall be as follows :

Supply air ducts, extract air ducts, transfer duct etc. within the building and in the return air path (i.e. all ducts in conditioned areas) to be 13mm thickness.

All ducts outside the building or not in return air path (i.e. all ducts in unconditioned areas) to be 25mm thickness.

* Note :- Aluminum cladding / jacketing 0.6mm thick is to be applied on insulation in areas with a high U.V. radiation e.g. areas exposed to sunlight. All insulation in conditioned are to be wrapped with canvas cloth and apply two coats of vapour barrier.


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AP 2.16.3 METHOD STATEMENT FOR APPLICATION OF KAIMANNFLEX (K-FLEX)

INSULATION ON DUCTS

1 Clean area of duct to be insulated to make it dust free, apply thinner / cleaner wherever necessary to make the area grease free.

2 Apply glue recommended by manufacturer with an even spread on complete surface of insulation sheet.

3 Once the glue on the sheet gets dry, apply glue on the G.I. duct and let it dry, then stick the sheet on one end and slowly press the sheet on the duct from one end to the other so as to ensure that the sheet sticks on the G.I. duct completely avoiding air bubbles between the insulation sheet and G.I. duct.

4 In areas where the G.I. duct comes in contact with the duct hangers, rigid support is recommended such as section of wood. The wood piece should be glued onto the duct hanger and a layer of rubber to be glued on the wood, so that there is no direct contact between the duct insulation and the wooden piece thus preventing tearing of the duct insulation.

In case the positioning of the support is available in advance, wood by itself can be used. In this case it has to be made sure that the insulation will be glued to the wood from both sides accordingly. For proper wood thickness selection please contact manufacturers representative.

5 Method statement of application for outdoor usage: -

Avoid working under direct sunlight and exposure of glued joints to sunlight for at least 12 hrs after glue application as sunlight prevents proper curing.

Prolonged Exposure of Kaimannflex elastomeric foam to direct sunlight is not recommended as this will eventually result in deterioration of the surface. Do not keep the glue under direct sunlight as this will result in rapid evaporation of the solvent and affects the performance of the glue.

AP 2.17 AIR OUTLET AND INLET

AP 2.17.1 GENERAL

All grilles-registers and diffusers shall be constructed from extruded aluminium with factory baked on colour to the Engineer’s approval. For tender purposes, Sub-Contractors shall assume a white colour (RAL 9010).

The duct behind all grilles, registers and diffusers shall be painted black to obstruct the sight behind the fitting.

All grilles registers and diffusers shall be suitable for concealed fixing. No screws shall be used on the front frame of the same.


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The Sub-Contractor shall co-ordinate the location of diffusers, ceiling lights and any other ceiling mounted fittings and shall produce working drawings to indicate the position of the diffusers relative to these. Lengths of diffusers although stated on the drawings are indicative only and the Sub-Contractor shall confirm exact length from false ceiling layouts. Corner pieces and end caps shall be provided as shown on the drawings and as required.

Sub-Contractor shall make sure that air velocity at occupancy level does not exceed 0.445 m/s. Blades on supply grilles and diffusers shall have a profile for aerodynamic performance and minimal noise, generation. Apply protective wrapping prior to dispatch to site.

All grilles, registers diffusers, shall be supplied from a well known reputable manufacturers specialising in this field.

AP 2.17.2 SUPPLY GRILLES

Shall be double deflection with horizontal face bars and vertical rear bars complete with damper, rubber gasket between the periphery of the register and the building surface. The effective area of the register shall be not less than 80%. Bars shall be adjustable and shall hold deflection setting under all conditions of velocity and pressure.

The damper shall be of the opposed blade type and shall be key operated with a detachable key. An adequate number of keys shall be furnished for these registers.

AP 2.17.3 RETURN OR EXHAUST GRILLES

Shall be of the single deflection with fixed horizontal front bars complete with rubber gasket. The grilles shall have the horizontal front bars set at an angle of 35 degrees downward where installed below 1500mm and 35 degrees upward where installed more than 1500 mm from the floor. Exhaust grilles to have volume control damper.

Effective area of the grilles not to be less than 75%.

Return or exhaust grilles to be similar to supply grilles if in the same space.

AP 2.17.4 DOOR GRILLES

Adjustable frame from 25 mm to 65mm to fit on wooden doors. V-blade design shall not permit vision through the grille. Spacing between inverted V-blades shall not be more than 12mm and the grille free area not less than 65% Aluminium extruded frame shall have a rounded edge with all corners mitred and rigidly staked to angle corner piece.


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AP 2.17.5 FRESH AIR LOUVERS

Frame and blades shall be heavy gauge, sturdy construction from anodised ex-truded aluminium. Louvers shall be fitted with insect/vermin screens, constructed of galvanised steel, wire woven to form fine square mesh, fitted into a stainless steel angle frame. Fresh air louvers fixed at the elevations of the building shall be coloured to the approval of the Engineer.

AP 2.17.6 LINEAR SLOT DIFFUSER

The air terminal shall be finished in powder coated to BS approved colour / RAL colour or be satin anodised as determined by the Engineer prior to sample being given.

Each slot of the diffuser houses rotating air control cylinders, which can be adjusted in 150mm partitioned increments to provide horizontal, alternating and angular patterns.

The diffuser shall be capable of blanking off from the face by rotating the cylinders without the introduction of additional blanking plates.

The slot diffuser range should include three standard airway width’s, 10mm, 15mm & 24mm, each with control blades available in white or black.

Alternative standard border styles shall be include integral and slid-in with a range of end caps to suit.

The plenum box should be available with 1st and 2nd fix options and shall be of shouldered constructions.

The plenum and slot diffuser shall be of a low height construction as standard, with an unlined height of a 4-slot unit not exceeding 283mm for 1st fix and 308mm for 2nd

fix.


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AP 3 : AUTOMATIC CONTROL SYSTEM (IF APPLIABLE)

AP 3.1 GENERAL REQUIREMENTS

An integrated BMS system shall be provided. All items of MEP equipment except FCU’s in each apartments shall be addressable via the BMS central interface station with the ability to report, monitor, interrogate and modify set points. The BMS system is equipped with a modem facility in order to notify and report equipment failure and/or other data as required, to a remote location.

The system shall be designed not only to achieve maximum possible savings in energy but also to receive full data on the performance of the main equipment for maintenance purposes.

The BMS shall interface with the Fire Alarm system in order to shut down all AHU’s in the event of a fire.

The system shall be linked with other items of the installation and the lighting control system in order to monitor their operational status.

The system shall generally provide the following functions:

AHU operation and optimisation.

On/Off control of selected equipment in accordance with given programme.

Optimum start-stop.

Maximum Demand Control.

Duty Cycling.

Alarm and Fault Indication.

Electrical panel status, DB status

External Lighting control and operation

Fire fighting pump and transfer pump control status

Status and control of all LV system.

Management Reports.

AP 3.2 DESCRIPTION OF OPERATION

AP 3.2.1 AHU’S WITH HEAT RECOVERY WHEEL

This AHU’s shall comprise of exhaust fan with damper and supply fan with fresh air damper, CHW cooling coil with 2-way modulating valves, filter bank & heat recovery wheel.


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The BMS shall takeover the operations of the AHU’s when the Hand-Off-Auto switch is in the ‘AUTO” position. The AHU’s shall be switched on automatically as per the dictates of the time channels defined in the DDC controllers. Under normal conditions the AHU’s shall run in the ‘AUTO’ mode. The AHU’s shall run in the “hand” mode only for testing purposes.

Temperature sensor shall be located in the supply air duct. The space temperatures shall be maintained at the desired set point via the 2-way modulating valve located on the chilled water coil.

Differential pressure switches are located across the filters (one across each filter bank). In case the filter is clogged beyond the value set in the differential pressure switch, a contact is made which the DDC controller recognizes. The DDC controller raises an alarm after a pre-determined time delay.

The ‘overload trip’ condition of the motor is monitored at the DDC controller via a volt-free contact from the Motor Control Centre.

The motor control centre serving the AHU shall have the "HAND-OFF-AUTO" switches. The airflow switch (AFS) is mounted across the exhaust and supply fan to detect airflow. The airflow switch is connected to a digital input of the DDC controller.

Motorised dampers shall be provided in the fresh air and exhaust air duct and these 2 dampers shall be operated On/Off as per the FAHU operations.

The BMS shall monitor the ambient temperature/humidity and the treated air inlet temperature after the plate heat exchanger.

When the fire alarm panel relays a fire alarm to the DDC panel the DDC controller will shut down the AHU.

The DDC controllers for these AHUs shall be housed in a separate compartment of the AHU MCC.

In addition to the functions normally carried out by the BMS the following information shall also be provided at the head-end:

a) Fan(s) running / fail status.

b) Fan speed as a percentage of maximum speed, and inverter output.

c) Supply air temperature.

d) Return air temperature.

e) Duct mounted pressure sensors reading.

f) Panel filter pressure drop.

g) Bag filter pressure drop.

h) Fresh air volume flowrate and damper position as a percentage of fully open position.

i) Exhaust air fan run/fail status.


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j) Exhaust air damper position (on/off).

The controls shall be programmed to operate the AHUs as per following modes.

(c) Normal mode:

As described above

(d) Night setback mode:

The fresh air shall work at low speed & all exhaust air fans shall be switched off except toilet extract fan.

The supply air temperature from the AHU’s shall be 16.0 deg C.

(e) Fire mode:

Upon activation of the fire alarm system, a volt-free contact situated within the associated MCC panel shall switch off the AHU’s, fresh air and exhaust air fans through hardwiring (not through software).

AP 3.2.2 CHILLED WATER PUMPS

The chilled water system consists of 3 pumps (2 Duty +1 Stand By) .The pumps are VFD driven.The BMS shall monitor the H-O-A switch “Auto” Position, “Run” Status, “Trip” Alarm via volt free signals from the MCC panel. A constant pressure is maintained in the chilled water circuit by modulating the speed of the pumps, which are controlled by the VFD’s. The speed of the pumps shall be modulated as per the pressure variations caused in the circuit, which are monitored by the pressure sensors mounted at 2/3rds of the index circuits. The BMS shall also monitor the VFD speed feedback, VFD “Trip” Alarm & VFD “Common Fault”

AP 3.2.3 EXTRACT FAN

These fans shall be under the control of the BMS. The extract fans shall receive ‘start/stop’ command from the DDC controller via pre-determined time channels, but only when the hand-off-auto switch is in ‘auto’ position. The airflow status of the fan shall be monitored on BMS. The ‘overload trip’ status of these fans shall also monitor by the BMS via volt free contacts from the motor control centers.

AP 3.2.4 FAN COIL UNITS

The fan coil units comprise filter, supply fan and a cooling coil. The FCU shall be controlled by a FCU controller mounted in the conditioned space. The controller should have a built-in temperature sensor, with set point adjustment, fan speed selection switch and a digital display.

The wall-mounted controller shall sense the space temperature and compare it with the set point signal desired by the occupant.


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The controller shall compare these two signals and shall generate a linear proportional output based on the difference in the two values. This cooling output is fed to the 2-port modulating valve, in a way to achieve the desired room temperature.

AP 3.2.5 FAN COIL UNITS – LIFT LOBBIES AND SERVICE ROOMS

The fan coil units comprise filter, supply fan and a cooling coil. The FCU shall be controlled based on a return duct temperature sensor .The room unit shall be used only to adjust the set point. The temperature controller shall be mounted in the control box near the FCU. The duct temperature sensor shall relay the temperature input to the controller and the set point signal shall be relayed to the temperature controller via the same bus, which connects the room unit to the controller.

The controller on comparing these two signals shall generate a linear proportional output based on the difference in the two values. This cooling output is fed to the two-port modulating valve, in a way to achieve the desired room temperature.

AP 3.2.6 LIFTS

The "Healthy” status of the Lift shall be monitored through volt free contact from the respective panels. In addition to the above, ‘’Passenger Car / Cabin alarm’’ for the individual lifts shall also be monitored. The electrical panel manufacturer shall render all the digital signals to the BMS as volt free signals.

AP 3.2.7 LV PANELS

The breaker "Trip” Alarm, Breaker “ON” Status & Breaker “OFF” Status shall be monitored through volt free contact from the respective panels. The electrical panel manufacturer shall render all the digital signals to the BMS as volt free signals.

AP 3.2.8 CHILLED WATER ENERGY METERING

The BMS shall monitor the thermal energy at the chilled water inlet of each apartment as indicated on the chilled water schematic drawings.

AP 3.2.9 POWER MONITORING

The BMS shall monitor the Kw-Hr for the MDB’s as indicated on the schematic drawings.

AP 3.2.10 FIRE ALARM SYSTEM

There shall be a software interface connecting the fire alarm system to the BMS via industry standard open protocols depending upon fire alarm system installed.


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AP 3.2.11 EXTERNAL LIGHTING CIRCUITS

The DDC controller shall control the lighting circuits via time based ON/OFF command to the lighting circuits DB’s


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AP 4 : LIST OF APPROVED MANUFACTURERS

ITEM MANUFACTURER LOCAL AGENT

1 CHILLER (R134A)

TRANE

CARRIER

YORK

TRANE

CARRIER

YORK

2 AHU’s

FAHU’s & FCU’s

WEST AIR

EUROCLIMA– ITALY

CARRIER

YORK

SAIF INT’L GROUP

FAISAL JASSIM

CARRIER

YORK

3 CHILLED WATER PUMPS

TACO- USA

ITT BELL & GOSSET – USA

SPP

ENERGY INT’L

FAISAL JASSIM

AL SAGAR TRADING

4 PRE-INSULATED DUCT

ALP

P3 GROUP

PAL

FAISAL JASSIM

P3 – DUBAI

DRAKE & SCULL – DUBAI

5G I SHEETS METAL

(IF APPLICABLE)

ISCOR STEEL - SOUTH

AFRICA

NISHIN - JAPAN

KOBE CO.- JAPAN

SEAGULL TARD – DUBAI

BIN DASMAL

JUMA AL MAJID

6

ABS PIPES FOR

CHILLED WATER

SYSTEM

EUROPIPE

DURAPIPE

HEPWORTH

FIKREE PIPE


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7 SOUND ATTENUATORS

SAFID – SAUDI ARABIA

SEAGUL NOISE

CONTROL – UK

SOUND ATTENUATORS LTD.

- UAE

INTER TECHNO – DUBAI

SEAGULL TRADING- DUBAI

GULF ACCOUSTICS – DUBAI

8EXHAUST & VENTILATION

FANS

PENN VENTILATOR

LOREN COOK – USA

DYNAIR

ENERGY INTERNATIONAL

SAIFMIDDLE EAST

HIRA TRADING

9

CHEMICAL DOSING

SYSTEM WITH

CHEMICALS (CHILLED

WATER)

WATER BIRD

CLEVER BROOKS

HOUSEMAN

WATER BIRD

FAISAL JASSIM

CORODEX TRADING

10 PRESSURISATION UNIT

HOLDEN & BROOKE

IBAIONDO - EUROPE

PILLINGER

IMEC-SHARJAH

CHEQ POINT

DANWAY

11GRILLES, DIFFUSERS,

AND SAND LOUVRES

TECHNALCO – UAE

METAL AIR

TROX

TUTTEL & BAILLEY – USA

AIR MASTER

TECHNALCO – UAE

ENERGY INT’L

AL AMANA TRADING

SAIFMIDDLE EAST

AIR MASTER

12 BINDER TEST POINT

HOLMES

ECONOSTO

INDUSTRIAL HANGER

IMEC

ECONOSTO

FIKREE PIPE CO.

13 ALUMINUM TAPES

ADVANCED-U.K

IDEAL USA

P.P.C. AUSTRALIA

ASTIC GENERAL TRADING

MEAPTASHI CORP.

INTERTECHNO


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14 FIRE DAMPERS & VCD’S

TECHNALCO – UAE

AIR MASTER

AIRDYNE – UAE

TECHNALCO – FUJEIRAH

AIR MASTER

RAPID COOL - DUBAI

15 ACCESS DOOR

AIR MASTER

SEAGUL TRADERS – UAE

TECHNALCO - UAE

AIR MASTER

SEAGULL TRADING- DUBAI

GULF ACCOUSTICS - DUBAI

16 AIR FILTERSBINAIR – UAE

FCR- ITALY

BINAIR-DUBAI

RAPID COOL TRAD.- DUBAI

17 ADHESIVE

NAPCO – UAE

FOSTER – UK

KOOLTERM - UK

NAPCO – SHARJAH

BIN DASMAL – DUBAI

ZAINAB AIR CONT. - DUBAI

18DIGITAL ROOM

THERMOSTAT

KING - USA

HONEYWELL – USA

STAEFA & SIEMENS -

GERMANY

SAIF MIDDLE EAST – DUBAI

HONEYWELL - DUBAI

STAEFA – DUBAI

19FLEXIBLE DUCT

CONNECTIONS

DURA DYNE – USA

ZEST - UK

HIRA TRADERS – SHARJAH

ADVANCED TECHNOLOGY -

DUBAI

20 VALVES, STRAINERS

HATTERSLEY – UK

NIBCO (USA)

ECONOSTO - Holland

AL AMANA TRADG – DUBAI

ENERGY INT’L

ECONOSTO

21DYNAMIC BALANCING

VALVES

CRANE – UK

FRESE – DENMARK

CONTROFLOW

T.P.C. - DUBAI

TECHNOFLOW – DUBAI

AL AMANA TRADING


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22 A. AIR VALVES

SPIRAX SARCO - UK

FLAMCO - HOLLAND

ECONOSTO - HOLLAND

TECH PARTS – DUBAI

MEPTASHI – SHARJAH

ECONOSTO

23 VIBRATION ISOLATORS

MASON – USA

UNISON – USA

KYNETICS - USA

ENERGY INTERNATIONAL

FAWAZ REFRI & AC

FAISAL JASSIM

24EXPANSION JOINTS /

FLEXIBLE CONNECTION

TOZEN – JAPAN

UNISON – KOREA

VIBRATION CO. - USA

TECH PARTS – DUBAI

FAWAZ REFRI & AC – DUBAI

MEAPTASHI – CORP.

25THERMOMETERS AND

PRESSURE GAUGESWEISS

VIBRATION M CO, - USA

ENERGY INT’L

ECONOSTO - SHARJAH

26 CONTROLS

HONEYWELL – USA

ERIE CONTROLS – USA

STAEFA SIEMENS

HONEYWELL – SHARJAH

SAIF MIDDLE EAST

STAEFA SIEMENS

27MOTOR CONTROL

CENTRE

SIEMENS –GERMANY

KLOCKNER MOLLER

ABB - UK

SCIENTECHNIC – DUBAI

JUMA AL MAJID – DUBAI

FAISAL JASSIM - DUBAI

28 HANGERS & SUPPORTS

WEICCO – INDIA

FLAMCO – HOLLAND

UNISON - KOREA

LAMINAR AIR CONDITION –

DUBAI

HIRA TRADERS – SHARJAH


29FIBRE GLASS PIPING

INSULATION

URSA – EUROPE

KIMMCO

ISOVER

SAIF MIDDLE EAST

KIMMCO – DUBAI

ISOVER


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30 DUCT, ACCOUSTIC LINER

KIMMCO INSULATION –

KUWAIT

MANSON - UK

KIMMCO - DUBAI

LEMINAR AC


31

ELASTOMERIC FOAM

INSULATION

(IF APPLICABLE)

KAIMANNFLEX – ITALY

ARMAFLEX

EURUBATEX

UNIGULF

BINDASMAL

GULF REFRIGEATION

32 BTU METER SONTICS SWITZERLAND –

EQUAL OR APPROVED.SAIF MIDDLE EAST

33 BMS (IF APPLICABLE)

HONEYWELL – USA

STAEFA & SIEMENS –

GERMANY

INVENSIS CONTROL

HONEYWELL - DUBAI

STAEFA – DUBAI

INVENSIS

34 VAV (IF APPLICABLE)TUTTEL & BAILEY - USA

EQUAL & APPROVEDSAIF MIDDLE EAST


04/03/07

particular hvac

Documents

lsperson ap

design criteria ap

oc dry bulb ap

total fresh air supply

air changes

air movement

air outlet

internal design conditions