HVACDG_R2

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HVAC DESIGN GUIDELINE

This guideline outlines information to all building and system type and is not intended to enforce/ include all efficiency measures, technology or scope outlined in thedocument. The user/designer to use their discretion by employing appropriate tools/skills to employ measures or technology outlined. However all mandatory and

regulatory requirements including target cooling load should be followed in all cases as applicable to the scope of the project/development.

DESIGN BRIEF FOR HVAC SERVICES – R2 Page 1 of 18Nakheel September 2007

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Contents 1. STANDARDS AND REGULATIONS...................................................................................................................3

2. INFRASTRUCTURE............................................................................................................................................3

3. NOTICES AND FEES..........................................................................................................................................3

5. HVAC DESIGN COORDINATION.......................................................................................................................4

6. DESIGN COORDINATION CHECKLIST ............................................................................................................4

7. ACOUSTICAL REQUIREMENTS .......................................................................................................................4

8. LIFE CYCLE COST ANALYSES.........................................................................................................................5

9. ACCESS TO MACHINES AND EQUIPMENT ....................................................................................................5

10. INSTALLATION OF EQUIPMENT FOR PROPER OPERATION .......................................................................5 11. UTILITY PROTECTION AND COORDINATION.................................................................................................5

12. VENTILATION SYSTEM .....................................................................................................................................5

13. FILTER SYSTEMS..............................................................................................................................................6

14. AIR DISTRIBUTION DEVICES ...........................................................................................................................7

15. PIPING SYSTEM.................................................................................................................................................7

16. EQUIPMENT SELECTION..................................................................................................................................7

17. DATA AND OPERATIONS MANUAL..................................................................................................................7

18. ENVIRONMENTALLY SUSTAINABLE DESIGN ................................................................................................7

19. ENERGY CONSERVATION MEASURES..........................................................................................................8

20. EQUIPMENT AND SERVICE SPACE ................................................................................................................8

21. HVAC...................................................................................................................................................................9

22. PERFORMANCE CRITERIA – BUILDING COMPONENTS ............................................................................11

23. MOISTURE MIGRATION..................................................................................................................................11

24. GLAZING...........................................................................................................................................................11 25. HEAT RECOVERY SYSTEM............................................................................................................................11

26. EQUIPMENT SIZING: .......................................................................................................................................11

27. EQUIPMENT REDUNDANCY:..........................................................................................................................11

28. EQUIPMENT EFFICIENCIES: ..........................................................................................................................11

29. ELECTRICAL POWER AND DEMAND: ...........................................................................................................12

30. SYSTEM DESIGN............................................................................................................................................12

31. DESIGN CALCULATIONS AND DRAWINGS ..................................................................................................12

32. VENTILATION SYSTEMS.................................................................................................................................12

33. CAR PARK VENTILATION ...............................................................................................................................12

34. GENERAL VENTILATION.................................................................................................................................12

35. PLANT ROOM VENTILATION..........................................................................................................................12

36. MECHANICAL VENTILATION TO SUBSTATION AND SWITCH ROOM FACILITIES ...................................12

37. GARBAGE, WASTE COLLECTION AND GREASE TRAP EXHAUST ............................................................12

38. TOILET /SHOWER/CLEANER ROOM EXHAUST SYSTEM ...........................................................................12 39. SMOKE MANAGEMENT SYSTEM...................................................................................................................12

40. CHILLED WATER SYSTEM .............................................................................................................................12

41. BUFFER STORAGE TANK...............................................................................................................................13

42. PUMPING SYSTEM..........................................................................................................................................13

43. COOLING OF WATER COOLED CHILLERS:..................................................................................................13

44. METERING DEVICES.......................................................................................................................................13

45. AIR HANDLING SYSTEMS...............................................................................................................................13

46. PIPED WATER SYSTEMS................................................................................................................................14

47. THERMAL AND ACOUSTIC INSULATION ......................................................................................................14

48. ELECTRICAL SYSTEMS..................................................................................................................................14

49. CONTROL SYSTEMS.......................................................................................................................................14

50. FIRE CONTROL PANEL...................................................................................................................................14

51. DESIGN RESPONSIBILITIES...........................................................................................................................14

52. QUALITY ASSURANCE....................................................................................................................................14

53. PROGRAM........................................................................................................................................................14

54. HVAC GENERAL REQUIREMENTS................................................................................................................14

55. COOLING LOAD TARGET VALUES: ...............................................................................................................17

56. HVAC SERVICES – QUALITY ASSURANCE ..................................................................................................17

57. DESIGN CERTIFICATION................................................................................................................................18


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HVAC SERVICES DESIGN GUIDELINES

INTRODUCTION

The HVAC Services Design Guidelines (“The Guideline”) was prepared to establish standards for the design of Villas,Low and high rise residential buildings, office buildings with small retail components. This guideline is intended to set outto achieve optimum, reliable and energy efficiency design. The Engineering Services shall be designed to suit thebuilding aesthetic and surroundings and shall have environmental compliance such as noise, air, water etc.

1. Standards And Regulations

All work shall meet all the requirements of national and local authorities and shall be in accordance with the following inso far as they apply to the work:

1.1. Dubai Municipality Rules and Regulations

1.2. Dubai Civil Defence Regulations

1.3. Jebel Ali Free Zone Authority Rules and Regulation

1.4. Relevant International Standards such as ANSI, ASTM, British and ISO Standards

1.5. ASHRAE

1.6. ASHRAE: Standard 15: Safety Code for Mechanical Refrigeration

1.7. ASHRAE: Standard 62.1/62.2 – Ventilation Requirements (Current Edition)

1.8. ASHARE: Guideline 12: Minimizing the Risk of Legionellosis Associated with Building Water Systems

1.9. ASHARE – Standard 90.1/90.2 – Energy Standard for Buildings (Current Edition)

1.10. Standard 111: Practices for Measurement, Testing, Adjusting and Balancing of Building HVAC&R Systems1.11. Standard 114: Energy Management Control Systems Instrumentation

1.12. CIBSE – Testing and Commissioning

1.13. Duct Work –SMACNA or DW 142

1.14. HVAC System Duct Design.

1.15. HVAC Duct Construction Standards: Metal and Flexible.

1.16. HVAC Air Duct Leakage Test Manual.

1.17. Fire, Smoke and Radiation Damper Installation Guide for HVAC Systems. Seismic Restraint Manual Guidelinesfor Mechanical Systems

1.18. NFPA

1.19. All Local Government Regulations;

1.20. Dubai Water and Electricity Authorities.

1.21. EPA Regulations

1.22. Nakheel Environment Management Guidelines (EMG 01, EMG 02 & EMG 03)

2. Infrastructure

Nakheel to arrange the external services up to the site boundary or at the building entry as coordinated and agreed withthe developer. The services as applicable to be provided are:

2.1 External Substations, MV cabling, Street Lighting.

2.2 Waste water and water pumping and treatment facilities or services.

2.3 LPG network including gas trains and bulk storage tanks or tank farms if applicable

2.4 Portable water supply , Sewer and drainage network 2.6 Telecommunication, Satellite, data, internet services

2.9 Chilled water from district cooling service provider if applicable

The developer of the plot to provide required information such as capacity, demand, routing, location etc and should bewilling to enter into a contract and co-ordinate approvals with service provider/s as necessary for electricity, water, LPG,Telecom, District cooling etc.

3. Notices and Fees

Give all notices, pay all fees, charges, levies, and deposits and otherwise conform to the requirements of all properlyconstituted authorities with respect to the documents.

4. Design Submission and Coordination

4.1 Submit mechanical design concepts, drawing, sketches, calculation, specifications, etc. at various stagesthroughout the design process as outlined in the contract.

4.2 Coordination checklist. To insure inter-discipline and intra discipline coordination, a review checklist is provided insection 6. The consultant shall make sure that all of these items, and others that pertain to good projectcoordination, are reviewed and addressed before submission of the documents to TDG.


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5. HVAC Design Coordination

HVAC design shall be coordinated with other facets of construction. The following factors require special consideration.5.1 Mechanical equipment rooms:

Rooms shall provide adequate space for equipment installation and maintenance. If expansion is planned, the size shallbe based on future requirements. Equipment removal access shall be provided where required. Proper location of thesespaces is necessary of economical air and water distribution.

5.2 Shafts:

Size and location of shafts for ductwork and pipes shall be checked before ductwork and piping system design. Effectsof shaft location on mechanical equipment and distribution systems shall be carefully determined.

5.3 Louvers:

Location and size of outdoor air intakes, relief air discharge and exhaust air discharge louvers shall be coordinated withthe architectural design. Outdoor air intakes shall be located so as to avoid intakes of dust, smoke, generator and truckdiesel fumes and exhaust air.

5.4 Cooling Tower Location:

The cooling tower shall be located at least 5 metres away (measured from the base of the cooling tower) from air circulating and ventilating inlets, open windows and occupied areas, pedestrian thoroughfares, trafficable areas, areas of public access, exhaust discharges from kitchens, air handling system or other areas where nutrients conveyed fromthese systems could assist in the growth of legionella.

When locating a cooling tower, the influence of adjacent buildings and of prevailing wind direction and the winddistribution over these buildings shall be taken into account. It shall be located away from the downwind of air intakes for the building.

5.5 Access:

Location and size of control panels and the type of service and maintenance a facility requires shall be coordinated withthe architectural design to allow personnel access to an area or to a piece of equipment.

5.6 Wind Forces:

Design of outdoor equipment, such as cooling towers, stacks, and their supports, shall be based on the maximum windvelocities prevalent at the site. Exterior mechanical equipment shall be anchored, braced or guyed to withstand theprevailing wind velocity.

5.7 Seismic Considerations:

If sites are subject to earthquakes, design of equipment especially outdoor cooling towers and water tanks, pipingsystems, ductwork, and foundation, shall include suitable allowance for horizontal forces. Equipment and piping shall beseismically braced.

6. Design Coordination Checklist

General

6.1 Interference with structural framing members coordinated.6.2 Equipment pad locations coordinated with structural drawings

6.3 Adequate clearances to service and replace mechanical equipment

6.4 Hoists (or other means of equipment replacement) coordinated with structural drawings

6.5 Motors and special power needs coordinated with electrical drawings.

6.6 Location of roof drains and floor drains coordinated with architectural and structural

6.7 Air diffusers and registers coordinated with architectural drawings and electrical lighting plains

6.8 Location of supply and exhaust systems coordinated with security barriers, detection devices and other relatedconcerns.

6.9 Louver sizes and locations coordinated with architectural drawings

6.10 Inverts of piping coordinated with civil drawings.

6.11 Supports and bracing of major piping, ductwork and equipment coordinated with structural drawings.

6.12 Penetrations through rated walls/floors/roof assemblies detailed and specified.6.13 Building automation system specified, including software and point schedules

6.14 Start up and testing requirements specified.

7. Acoustical requirements

7.1 General. Acoustical and noise level criteria for all building spaces are described in this this manual.

7.2 Noise and vibration isolation. Refer to and incorporate the basic design techniques as described in ASHRAEapplications handbook, sound and vibration control. Isolate all rotating equipment in the building.

7.3 Mechanical room isolation. Floating isolation floors should be considered for major mechanical rooms located inpenthouses or at intermediate levels in mid- rise and high-rise construction.

7.4 Mechanical chases. Mechanical chases should be closed at top and bottom, as well as the entrance to themechanical room. Any piping and ductwork should be isolated as it enters the shaft to prevent propagation of vibration to the building structure. All openings for ducts and piping must be sealed, except that shafts dedicatedto gas piping must be ventilated.


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8. Life Cycle Cost Analyses

8.1 General. A major concern in the design of a project is energy conservation and the need for all facilities to beenergy efficient. For this reason, the consultant must direct attention to all areas where the greatest impact inenergy savings can be made.

8.2 Life-cycle cost analyses. Considering the requirements for hvac on an integrated basis, the consultant shallperform life cycle cost (LCC) analysis comparing three viable energy efficient HVAC systems. The consultantshall use the life-cycle cost methodologies. The life cycle cost analysis must include investment costs, energycosts, non fuel operation and maintenance costs, repair and replacement costs, and salvage values. For newconstruction, hvac alternative shall utilize the particular site conditions e.g., if district chilled water is available.

8.3 Analyses of energy-conserving designs shall include all relevant effects of the building envelope, lighting energyinput, domestic water heating, efficient use of local ambient weather conditions, building zoning, efficient partload performance of all major hvac equipment and the ability of involved building automation equipment toautomatically adjust for building partial occupancies, optimized start-stop times and systems resets.

9. Access to Machines and Equipment

Space shall be provided around all equipment as recommended by the manufacturer and in compliance with local coderequirements for routine maintenance. Access doors or panels should be provided in ventilation equipment, ductworkand plenums as required for in-situ inspection and cleaning. Equipment access doors or panels should be readilyoperable and sized to allow full access. Large central equipment shall be situated to facilitate its replacement.

In addition, adequate methods of access shall be included for items such: chillers; boilers; heat exchangers; coolingtowers; reheat coils; VAV boxes; pumps; hot water heaters; and all devices which have maintenance servicerequirements.

The clearance required for filter coil/tube removal shall be indicated on the drawings Access to elevated major equipment (such as ash’s, cooling towers, chillers, and boilers) must be by stairs, not by ladders. Unitary equipmentinstalled on the roof may have an access via ladder but with safety cover if it exceed 3.0m

10. Installation of Equipment for Proper Operation

The design drawings shall show the space/installation requirements for proper performance of all equipment andappurtenances. The necessary straight upstream and downstream duct/pipe diameters shall be shown for air flowmonitoring stations, sound attenuators, VAV boxes, humidifiers (where installed), duct traverse locations, hydronic flowswitches, pressure reducing valves, etc.

11. Utility Protection and Coordination

11.1 Utilities and Feeders.

Locate utilities away from vulnerable areas. Utility systems should be located at least 15m from loading docks, frontentrances, and parking areas.

11.2 Incoming utilities.

Protect incoming utilities within building and property lines, incoming utility systems should be concealed and givenprotection, including burial or proper encasement wherever possible

Incoming utilities to the building is coordinated with infrastructure services and should have the isolating facilities withsufficient access at the building entry.

12. Ventilation System

12.1 Outside Air Requirements

12.1.1 In no building shall the total exhaust air quantity exceed the total outside air intake quantity.

12.1.2 Buildings shall be maintained at a positive pressure with respect to atmospheric pressure.

12.1.3 Outside air intake shall be sufficient to maintain a positive static pressure of 5/7 Pa inside thebuilding, with doors and windows closed.

12.1.4 Ventilation air shall be provided at a minimum rate as specified in ASHRAE 62

12.1.5 Fresh air intakes shall not be located where air contaminants are brought in from, for example,vent pipes, vehicles, kitchen exhausts and cooling tower or pooled water emissions.

12.1.6 The distance from the air intake to sources of contamination; prevailing wind speed and direction; and objectsthat might influence air flow should be considered in this evaluation. The elevation of the fresh air intake for all HVAC systems shall be minimum of 1.6 m above the building grade level


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12.2 Exhaust Air Requirements

12.2.1 All Janitors closets break rooms, toilets, shower rooms, locker rooms and change rooms shall be exhausted.

12.2.2 Battery room exhaust shall be taken from a point at and near the ceiling level, using an explosion proof fan.The battery room shall be exhausted at a rate equal to the quantity of air supplied to the battery room. No air from the battery room shall be returned to the system. If battery room is ventilated, only exhaust fan shall besized to exhaust as a minimum the quantity of air necessary to meet temperature and dilution requirements.

12.2.3 Make-up air shall be provided for all areas provided with exhaust.

12.2.4 Where exhausting of air is required, air shall be exhausted in sufficient quantities to provide the necessary air changes per hour specified.

13. Filter Systems

13.1 Air Filter Criteria

All re-circulating and outside air systems shall be provided with air filters. Filter type and efficiency shall be based on therequired cleanliness of the supply air, to meet the objectives of the conditioned space. Systems shall be provided withimpingement type mechanical filters unless otherwise specified.

Filters installed close to an air inlet shall be protected from the weather by suitable louvers (double deflection type). Alarge mesh 12 mm wire screen (non corroding metal) also shall be provided.

Filters shall have permanent indicators to give a warning when the filter resistance reaches the recommended changevalue where applicable. Air filters shall be provided with access doors, sized to allow filter maintenance.

Reusable washable all aluminium filters may be used for the pre filter or as a main filter in the residential or zone

application (FCU) where treated fresh air supplied separately.

Disposable factory-fabricated mechanical panel filters shall meet the following requirements:

• Filter media shall be interlaced glass fibres sprayed with non-flammable adhesive

• Filter frame shall be cardboard, with perforated metal retainer

Extended-surface disposable panel filters shall meet the following requirements:

• Filter media shall be a fibrous material formed into deep V-shaped pleats held by a

• self-supporting wire grid

• Filter frame shall be non-flammable cardboard

All filters shall conform to UL 900 Class 2 for combustibility and smoke generation.

Filtering efficiencies shall be in accordance with ASHRAE 52 and ASHRAE HVAC Application Handbook.13.2 Sand Filter Criteria

A sand trapping box (STB) shall be provided for the fresh air inlet of each HVAC system servicing areas housing vitalequipment.

Each STB shall consist of a sand louver, pre-filter, a pressure differential indicator.

STB casing shall be rigidly constructed with galvanized steel sheets and supporting members.

STB shall capture sand in the fresh air at the sand louver and clean out facilitate.

13.3 Smoke evacuation.

Protect ventilation equipment and locate away from high risk areas. In the event of a fire, the ventilation system may beessential to smoke removal, particularly in large, open spaces. Ventilation equipment should be located away from highrisk areas such as loading docks and garages. The system controls and power wiring to the equipment should beprotected. The ventilation system should be connected to emergency power to provide smoke evacuation.

The designer should consider having separate HVAC systems in lobbies, loading docks, and other locations where thesignificant risk of an internal event exists.

Ventilation and smoke evacuation equipment should be provided with stand-alone local control panels that can continueto individually function in the event the control wiring is severed from the main control system.

During an interior bombing event smoke evacuation and control is of paramount importance. The designer shouldconsider the fact that if window glazing is hardened, a blast may not blow out windows, and smoke may be trapped inthe building.

13.4 Pressurized Stairways:

Maintain positive pressure in stairways. A stairway pressurization system should maintain positive pressure in stairwaysfor occupant refuge, safe evacuation, and access by fire fighters. The entry of smoke and hazardous gases intostairways must be minimized.


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14. Air Distribution Devices

Air outlets shall be selected and located to provide proper throw, drop, and spread. Air should not blow againstobstructions such as beams, columns, lights or sprinklers, or on occupants. Supply outlets shall be uniformly locatedwithin range of throws to distributed loads with air velocity at the occupant's level not exceeding 0.25 m/s. Where loadsare concentrated, supply outlets shall be located near the load source. Noise level criteria shall be included on thedrawing schedule.

Air terminals for variable air volume (VAV) systems shall be selected to be compatible with characteristics of VAV box;i.e., outlets must be capable of performing at full and partial loads. Flow patterns must be properly evaluated. Standardair outlets do not perform satisfactorily with variable air-volume

15. Piping System

The following selection criteria may be applied for pipe sizing (guide only):

Mass flow: above 1.5 kg/s – pressure range – 180 -300 pa/m – velocity –max: 3 m/s

Mass flow: less than 1.5 kg/s – velocity range – 0.75 to 1 m/s

Provide valves to isolate equipment (for operation and repair), including room units and individual risers to room units.Provide bypass piping on critical systems to allow operation during maintenance operations that may have extendedtimes. Provide manual vents at high points and hose type drain valves at low points, and both in sections or risers thatcan be isolated by valves.

Show locations of expansion joints, loops, and anchors on drawings. Suitable devices shall be provided so flow can bemeasured in major equipment such as chillers, cooling towers, boilers, solar system loops, or other zones; e.g., primaryand secondary loops. Balancing devices shall be provided to allow adjustment.

Except for condenser water systems, piping systems shall be insulated. Systems exposed to weather shall have

protected sheathing as approved. Each closed/open piping system shall be provided with chemical treatment to inhibitcorrosion, bacterial scale, deposits, or growth.

16. Equipment Selection

16.1 Fan: Fans shall be selected to operate as close to the point of maximum efficiency as possible.

16.2 Fan Motor: select to include fan efficiency, drive loses, motor efficiency, vfd if applicable and a service factor of 10 to 15 % based on application

16.3 Pumps: Select at the mid point whenever practicable. Pump casing to be suitable to have at least one sizehigher than the duty impeller .

16.4 Pump Motors: The Motor capacity to include Pump efficiency, Motor Efficiency, VFD loses if applicable andservice factor of 10 to 15% based on application. Suitably rated for the temperature.

16.5 Refrigeration Equipment: Capacity to compensate the piping losses, elevation difference if they are DX splitsystem, and derated to high ambient conditions.

16.6 Plate Heat Exchanger: Pressure drop not to exceed 50 kPa. The selection should include fouling factor. Theover all K- value not to exceed 4800 w/m2*K.

17. Data and Operations Manual

An operations manual shall be prepared and training provided for the building operations and maintenance personneldescribing the design objectives and how to operate the building. The manual shall include as-built drawings, equipmentdata, model numbers for the equipment, parts lists, equipment options, operating manuals for each piece of equipment,testing and balancing reports and certifications, maintenance schedules, and warranty schedules. This manual must alsodiagram the cabling, fire safety sprinkler system, and exterior grounds sprinkler system. The manual must be reviewedand certified complete before submission to the Project Manager

18. Environmentally Sustainable Design

Nakheel has committed to minimize energy waste by pursuing both environmental and financial objectives. Thereforethe consultants and the D&C contractors should incorporate optimized engineering solutions by providing accuratelydesigned and selected equipment. The system design should incorporate to allow performance and maintenancemonitoring.

Implementing energy efficiency initiatives should result in energy savings, operating-cost reductions, and a reducedimpact on the environment. The following are considered appropriate:

1. passive-solar building design

2. day lighting

3. natural ventilation techniques

4. computer modelling

5. energy efficiency statements

6. Photovoltaic (solar) panel design and LED foot path and landscape lighting.

7. solar water heating for domestic use


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19. Energy Conservation Measures

The list of energy efficiency measures though not exhaustive are set out below:

19.1 Mechanical – HVAC

19.1.1 Optimum Stop/Start

19.1.2 Purge Cycle

19.1.3 Equipment sequencing

19.1.4 Supply Air Reset

19.1.5 Supply Water Reset

19.1.6 Load Limiting

19.1.7 Load Shedding

19.1.8 Set Point Relaxation

19.1.9 Condenser Water Reset

19.1.10 Upgraded insulation

19.1.11 Floor cooling or displaced ventilation if practicable

19.1.12 Introduction of chilled beam if applicable

19.1.13 Optimise and rationalise fan coils, combine and introduce VFD with VAV boxes or VAV diffusers

19.1.14 Introduction of pumping system with VFD if practicable.19.1.15 Utilize waste heat from central energy plant

19.1.16 Demand control ventilation through CO2 sensors and controls

19.1.17 Economy Cycle

19.1.18 Provide heat recovery if practicable for treated fresh air application.

19.2 Electrical

19.2.1 Energy controllers

19.2.2 Energy efficiency lighting and fixtures (reflectors)

19.2.3 Lighting controls

19.2.4 Occupancy sensors

19.2.5 Day light sensors

19.2.6 Install premium efficiency motors (for 24hr systems)

19.2.7 Intelligent Motor efficiency controllers.

19.2.8 Local power factor correction

19.3 Public Health (Hydraulics)

19.3.1 Water Leakage

19.3.2 Water usage and consumption

19.3.3 Efficient water fixtures

Incorporate measures in design and operating schedules on water usage and method to reduce the consumption at thetoilets/ wash rooms, house keeping, makeup and expansion tank over flows, irrigation and kitchen facilities.

19.4 Building & Ground

19.4.1 Selection of Building material & Insulation

19.4.2 Facade

19.4.3 Provide natural light and natural ventilation when appropriate

19.4.4 Possible use of recycling of grey water to irrigation.

Some of the above measures should be considered for incorporation during the system design. These innovativemeasures should be thoroughly evaluated prior to application.

20. Equipment and Service Space

The consultant to plan, coordinate and provide facilities such as space, room, shafts, wall space, trunks, bulk head,ceiling voids access ladders, access hatch and maintenance space for :

• Plant room facilities for plate heat exchangers (PHE), AHU, fans, pumps, compressors and all associatedequipment and accessories.


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• Outdoor air conditioning plant

• Fresh Air handling units

• Exhaust and Make up air fans

• Fan coils and Air handling units

• Pumps and Tank room

• Plumbing - Water, Waste Water and Sewerage

• Refrigeration Piping to interconnect outdoor and indoor units including controls and electrical or CHW

pipe reticulation between the PHE and the fan coils.

• Duct - Ventilation and Air-conditioning

• Electrical Switch Board Room, Communication Room

• Electrical Switch Board

• Electrical Services

• Telecommunication and data cables

• Communication box in an appropriate easily accessible location.

• Gas Services including distribution

• Indoor fan coil units for air conditioning (ceiling void)

• Utility Exhaust Fans, Domestic Hot Water units (Ceiling void?)

• Grease traps and grease arrester room.

21. HVAC

21.1 Design conditions

Condition Temperature % RH

Outdoor DB: 460 C. WB: 300C

Cooling Tower Air On WB: 320C

A/C Chiller/Condensing Unit Air On Condenser DB: 480C

Indoor DB: 230 C+/-10CRH is not controlled but relies ondehumidification during coolingprocess

21.2 Cooling Load Calculations:

Complete design load calculations and a moisture control study shall be prepared for each space within a designprogram and presented in a format similar to that outlined in the latest ASHRAE Handbook of Fundamentals.

Cooling load calculations are required for all projects to facilitate review and provide a reference for systemmodifications.

Individual room calculations shall be generated and summarized on a system basis and presented with a block load todefine the peak system load.

Load summary sheets shall indicate individual rooms with area, design air quantity, L/s per m2, air changes per hour,and corresponding return and or exhaust air quantity.

Calculations shall include but not be limited to indoor and outdoor design parameters, heat gains and heat losses, supplyand exhaust requirements for central systems and for each area of the facility, humidification and dehumidificationrequirements, and heat recovery.

As a reference, calculations for assessing cooling loads may include but are not limited to the following:

Sensible Heat Loads Latent Heat Loads

Walls, external, external chases People

Roofs and skylights Internal equipment

Floors, when above unconditioned spaces Infiltration

Ceilings, when below unconditioned spaces Makeup and ventilation air

Partitions, when next to unconditioned spaces Auxiliary air requirements

People, sensible

Lights (room and task)

Internal equipment and personal computers

Supply, return, and exhaust fan heat

Infiltration

Makeup and ventilation air requirements

Auxiliary air requirement

All cooling load calculations shall include a predetermined safety factor to compensate for load inaccuracies, futureflexibility, infiltration, and air leakage. Safety factors shall be clearly defined in the basis of Design report.


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The following procedures should be observed while carrying out cooling load estimation to determine the coolingequipment sizing:

• Apply diversity and operating schedules while estimating cooling load for internal loads such as people,lights and power.

• Apply shading (internal and external) for glazing if available.

• Exclude Toilets and other utility areas from conditioned area calculation. These areas are cooled by thesecondary air via exhaust.

• The exhaust ventilation rate shall be based on ASHRAE 62.1- (Current) Continuous or intermittent usemay be adopted and accordingly the air quantity should be selected.

• Fresh air is based on ASHRAE 62.1- (Current)

21.3 Other Measures

The building shall be in general kept +ve pressure (around 5 to7 Pa) to avoid moisture migration into the building andinfiltration. The fresh air and exhaust quantities should be adjusted and balanced to meet the process and as well as thecode.

21.3.1 The main kitchen shall be maintained under negative pressure and may have three components:

a) A nominal conditioned supply air to provide ambient relief in the kitchen.

b) An exhaust 20% higher than the nominal supply and exhausted direct to ambient above the roof level.

c) Provide Econovent type kitchen ventilation system with exhaust comprising of 80% of fresh air and20% of conditioned air from the space.( Applicable for large commercial type kitchen only) Kitchens

may have their own filtered recirculated exhaust system in addition to a & b in the residential.21.3.2 Optimisation and rationalisation of fan coils and combine and introduce VFD with VAV boxes for zoning andincluding by combining the areas of similar use and orientation when practicable.

21.3.3 Toilets shall be exhausted by make up air from air conditioned space.

21.3.4 Selection of fitting, material & system must consider marine environment when applicable.

21.3.5 Choice of air-conditioning system shall be such that the equipment creates minimal noise.

21.3.6 Fresh Air units shall be double skinned, low profile type

21.3.7 Fan Coil Units shall be single skin fully cased with return air plenum box & acoustically treated for minimalnoise break out. (Double skin construction shall be used in noise sensitive areas). The return and supply ductshall be ducted to the unit via mixing box if the units are located above the toilets. The FCU shall be selected tocater the pressure drop still achieving the noise criteria.

21.3.8 Low velocity ducts with non-hazardous insulation material & sound reduction shall be used. Break out noiseshall meet ASHRAE standards.

21.3.9 Air diffusers & grilles shall have guide vanes to ensure proper air distribution. Throw, Drop & noise criteria shallbe specified. Swirl type induction diffuser may be used if VAV system is used to minimize dumping during lowair supply.

21.3.10 Access to units and sufficient maintenance space shall be provided.

21.3.11 Exhaust air shall be centralized wherever practicable to benefit from heat recovery & shall meet ASHRAEstandards

21.3.12 Wall, roof, duct insulation etc. shall meet health and fire safety requirements.

21.4 Space Internal Load

The lighting level should be designed in general to CIBSE Lighting Code

Load BedRooms

Living Majlis Kitchen Videoconfer.rooms

MeetingRooms

IT dataRoom(small)

Office

People AS PER ASHRAE 62.1 & 2 – 2004 Ventilation for Acceptable Indoor Air Quality

Lights** 8 W/m² 15 W/m² 10 W/m² 15 W/m² 10 W/m² 10 W/m² 10 W/m² 10 W/m²

SmallPower**

2 W/m² 3 W/m² 3 W/m² 150 W/m² 5 W/m² 3 W/m² 100 W/m² 13 W/m²

**The above average values are to be used for cooling load estimation only. The actual connected load may be different and in many instances may behigher and should not be used for residential and commercial application. The process area such as IT rooms and trading rooms, actual valuesshould be used with diversity It is recommended that compact fluorescent high efficiency lighting for residential is used instead of incandescentlamps. Apply operating schedules based on 24 hrs while performing the cooling load calculation.


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22. Performance Criteria – Building Components

Table 1: Performance Criteria of Building Components (to be confirmed with Architectural)

a) Material including Insulation & Maximum thermal Values

Components U-Value

W/M2-K W/M2-K

Roofs 0.27 – 0.45*

Walls 0.35 – 0.50*

Glazing (EN 673) Glazing with FrameWindows/ Doors

1.33 SHGC 0.35 2.0 – 2.20

b) Air Leakage Requirements for Fenestration & Doors

Maximum Leakage

Type LPS/M2

Windows-Fixed 0.4 to 0.70*

Windows-Sliding/Operable 0.5 to 1.4*

Doors 0.5 to 1.4*

It is recommended that fixed or casement windows and French doors be used instead of sliding windows anddoors.* Lower range should be used for all high end buildings (Villas).The U values for high rise buildings are influenced bythe design but encouraged to use low U value building materials.

23. Moisture Migration

The building envelope shall be designed to prevent moisture migration that leads to deterioration in insulationperformance of the building. Vapour retarders may need to be installed to prevent moisture from collecting within theenvelope. Vapour barriers should be always installed on the warm moist side of the envelope & adequate ventilation of spaces where moisture can build up to be provided. Designs should incorporate the principles of ASHRAE Handbook-Fundamentals.

24. Glazing

Windows shall be with double-glazing. Recessed/shaded windows are highly encouraged with overhang sunlightprotection (if practicable).

25. Heat Recovery System

It is recommended that the consultant compare the following heat recovery proposal prior to application:

25.1 Twin heat wheel – Enthalpy wheel at the supply (OA intake) and Sensible wheel at the exhaust.

25.2 Enthalpy wheel at the supply (OA intake) and Horse Shoe heat pipe.

The above should examine the total cost and year round operation including controllability and their suitability

26. Equipment Sizing:

The central cooling plant (refrigeration plant) should be sized based on building block load and not sum of peak zoneload. It is recommended that a VFD pumping system be employed on the load side.

27. Equipment Redundancy:

The following criteria may be applied for central plants (normally operating equipment) redundancy:

• Pumps – N+1

• Plate Heat Exchanger – 65 to 70% minimum capacity available at all times (even during outage due tomaintenance or scheduling). This is based on minimizing redundant equipment. However, this concept maybe modified to suit both physical size and capacity. Recommended to limit the capacity around 500TR.

28. Equipment Efficiencies:

28.1 Air Conditioning Equipment: ASHRAE standard 90.1 defines the minimum efficiency requirement for HVAC equipment. Designers are encouraged to use equipment that meet or exceed this standard.


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28.2 Service Water Heaters:

Basic, cost effective design practices should be adopted as follows:

28.2.1 Minimize standby losses with thermal insulation & temperature controls

28.2.2 Reduce hot water waste with flow limiting or metering terminal devices

28.2.3 Increase overall system performance with high efficiency source

28.2.4 The designer is encouraged to use heat recovery, solar energy or high efficiency equipment to pre-heat thewater exceeding this guidelines requirement as a result. In case Electric Water heaters are used, then their

efficiencies shall not be less than 90% efficient.

28.3 Electric Lighting:

Designers are encouraged to use high efficiency lights, such as energy saving lamps and compact fluorescent sourcesof light, which are 4 to 5 times more efficient than traditional incandescent lamps. LED or other high efficiency lightingshall be considered for outdoor lighting purposes as well.

29. Electrical Power and Demand:

The designers are encouraged to apply energy efficiency principles in combining the selection of building materials,engineering equipment and system design to minimise the connected load and employ energy management controls tominimise the electrical demand.

30. System Design

The design shall include energy Efficient System design principle and also equipment selection to obtain optimumenergy and capital cost. Life Cycle Cost Analysis (LCA) or other applicable method may be employed to reach the

resolution.

31. Design Calculations and Drawings

Provision of design calculation for all the services. Energy calculations to demonstrate that the above criteria are applied.

32. Ventilation Systems

Supply and exhaust ventilation systems including supply fans, exhaust fans, ductwork, exhaust grilles, balancingdampers, fire dampers, weatherproof and sand trap louvres, flexible connections, anti-vibration supports and other ancillaries for a complete system shall be incorporated.

Generally all supply ventilation should have provision to have filtration or other means to stop dust ingress into thespace.

33. Car Park Ventilation

If the car park is mechanically ventilated and the system to include multipoint CO monitoring to regulate the airflow. The

exhaust fans are fitted with variable speed fan motors. (this should be evaluated based on the size and the use). Thedesign shall have local Authority approval and should be coordinated with their requirement.

34. General Ventilation

Provide adequate ventilation to all enclosed spaces to comply regulatory requirement or heat removal etc. (eg. spacessuch as store rooms and equipment rooms). The ventilation may be achieved naturally or mechanically

35. Plant Room Ventilation

Provide ventilation as required by the regulatory requirement or to dissipate heat generated by the equipment within theplant rooms. The ventilation may be achieved mechanically or naturally.

36. Mechanical Ventilation to Substation and Switch Room facilities

Provide adequate ventilation to remove heat generated by the electrical equipment and components for their continuoussafe operation. The designer may use natural ventilation, mechanical ventilation or mechanical cooling to maintain thetemperature in the rooms. The design shall be have DEWA approval.

37. Garbage, Waste Collection and Grease Trap ExhaustProvide satisfactory exhaust ventilation system as required by the regulatory requirement

38. Toilet /Shower/Cleaner Room Exhaust System

Provide toilet/shower/cleaner room exhaust system to comply with local regulatory requirement and or ASHRAE.

39. Smoke Management System

The smoke management system if applicable will comply with NFPA.

40. Chilled Water System (Applicable to dedicated system when district cooling is not available)

40.1 Water-cooled

Two or three equal sized water cooled centrifugal/screw chillers (preferably fitted with variable frequency drive) suitablefor stable operation to 20% of its rated capacity under all conditions will be located in the basement plant room or on the

roof plant room with pumps, pressurisation and expansion unit, piping, fittings and chilled water reticulation to the coolingcoils in the air handling units around the complex.

If VFD fitted chillers are uneconomical, then the consultant shall choose the chiller capacity suitable to cater both max.and minimum load without any constraints


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40.2 Air cooled Chiller

The consultant may consider the use of air cooled chillers if he can demonstrate the benefits using life cycling costingand as well as the noise pollution to the occupants and neighbouring buildings is not an issue.

It is important that an acoustic report is prepared to demonstrate that the chosen system will not affect the occupant andas well as neighbourhood and will meet the noise criteria both occupied space and ambient (both day and night levels)

41. Buffer Storage Tank

It is important that a buffer storage tank is provided as part of the system for stable and continued operation of the

chillers especially during low load if the system reticulation is small and the volume of water in the system is inadequateto match the chiller load. Refer manufacturer’s recommendation.

42. Pumping system

Unitary or ganging pumping system may be opted. One standby chilled water pump shall be provided with pipe workarranged such that it can be manually connected to any chiller if one of the duty pumps fails (applicable to unitarypumping arrangement). The pumping system is a constant volume primary system or variable primary/secondary if thedistribution pressure is in excess of 300 kPa. The consultant may choose other form of pumping if it is cost effective.

43. Cooling of Water Cooled Chillers:

43.1 Use of Sea Water Cooling:

Our first option is to use the sea water cooling via a heat exchanger with in the guidelines stipulated by EPA whenever itis available and practicable.

This will eliminate the noise pollution to the occupants and as well as the neighbourhood and more importantly eliminate

any makeup water cost due to evaporation.

43.2 Use of cooling tower.

In case the sea water cooling can’t be applied, the use of ultra low noise Cooling tower may be investigated for thesuitability (for the occupants and as well as the neighbourhood).

Condenser water temperature reset facility shall be provided in the control system to maximise the chiller efficiency.

44. Metering Devices

A flow meter and watt (BTU) meter (refrigeration kW) shall be installed with all the accessories such as square rootextractor and software to establish the flow and the kWR from the flow and temperature differential. A separate electricalkW meter shall be installed to measure the power consumption. The Flow meter, kWR and the kW meter shall have thelogging facility with memory to cater for 12 months records (flow, temp, kW and kWh) at an interval of 10 minutes.

45. Air Handling Systems

Centralised built up or modular double skinned variable volume air handling system with chilled water facilities housed indedicated closet type plant rooms and reticulated through the dedicated risers and bulk heads around the zones viainsulated metal duct work and terminated through VAV boxes, flexible duct and ceiling mounted outlets (various types tosuit the space condition).The air handling units are to be grouped to serve similar zones (both functional and orientation).

All of the air handling units shall have return air silencers depending on the situations after the mixing box to contain thenoise transmission to the space or outside through external grilles.

The minimum fresh air requirements will be fixed irrespective of the load unless overridden by the CO 2 system. Thesystem should have the following additional facilities:

• Economy Air cycle.(most cost effective method be used)

• Fresh air override through CO2 monitoring.

• Fan coils may be used where applicable.

• The outside air may be preconditioned using the exhaust air using heat pipe heat recovery or twin wheel

(enthalpy and sensible) heat recovery or combination of both.• Or other acceptable methods.

A separate fresh air system may be used for the complex and heat recovery using acceptable methods which will precool the ambient during summer and preheat during the winter months. This tempered air may be used in winter for thesupply of fresh to occupants when there is requirement of cooling whereby the main air conditioning is switched off (especially during night time) using only tempered out door air for the comfort and regulatory compliance.

45.1 Air Distribution System

The conditioned air produced in the Air Handling units is reticulated through zonal metal ducts via shafts and bulkheadsto each zone. The air then is reticulated through mixture of metal and flexible ducts. The flexible duct not to exceed2000mm. Terminal air distribution devices are combination of grilles and diffusers in some cases including inbuiltcontrols such as VAV, light and motion control devices.

It is important that return air grilles are sized to between 1 and 1.5 m/s if they are free return via plenum and not toexceed 2.5 m/s if ducted return to fans.


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46. Piped Water Systems

46.1 Water treatment including scale and corrosion control

46.2 Cooling water pipe work and associated auxiliaries

46.3 Connection of cold water make up to expansion/pressurisation vessel with backflow prevention from a valvedtermination located within 3m of the equipment

46.4 Drain, overflow and bleed piping from equipment and ductwork for removal of condensate or waste, to tundishesand floor wastes.

47. Thermal and Acoustic Insulation

47.1 Thermal insulation of all chilled water piping and equipment and cold water piping where condensation areenvisaged such as ceiling void etc.

47.2 Acoustic and thermal insulation of all supply, return and outside air intake ductwork, including plenums and air handling unit.

48. Electrical Systems

Electrical power supply and control installation for the mechanical systems including mechanical services switchboardsand cabling from mechanical services switchboards to individual items of plant.

49. Control Systems

Stand alone micro processor based control system for the above systems, including field devices, sensors, actuators,microprocessor based controllers, relays and switches.

50. Fire Control Panel

The HVAC system shall be interlocked with Fire Alarm system.

51. Design Responsibilities

The operational requirements of the systems and the specific design criteria are described elsewhere. All systems shallbe designed to meet these requirements as a minimum.

All calculations shall be made using industry standard methods, codes and guides. Particular attention shall be paid tothe operating costs of the systems. Wherever possible use low energy and low maintenance equipment. Submitcalculations for review and acceptance.

52. Quality Assurance

Provide a Quality Assurance plan in order to propose, establish, maintain, monitor and document a quality assurancesystem covering all aspects of the design, purchase, fabrication, installation and completion of the works. The plan shallbe in accordance with ISO 9001 or ISO 9002 as appropriate.

53. Program

The works is governed by a program agreed between the contracting parties. Ensure that the works carried out under this package is in accordance with that program. Provide a separate program for this package of the works identifyingspecific milestones.

54. HVAC General requirements

54.1 Building Materials Data

Reference should be made to Architectural and Facade brief for materials data such as glazing, walls, floors, shadingdevices etc for load estimation

54.2 Zone Controls (Office only)

VAV units are placed in the available ceiling space/bulkhead or closet type plant rooms in each zone to control the zone

space temperature. Zone area for each VAV box should be limited to 70 m² for internal zones and 40 m² for perimeter zone (indicative only subject to variation during design development). Reheat can be removed at the perimeter zones if itis proven that the diffusers selected can provide good air distribution without dumping at minimum turn down.

54.3 Air Handling Zoning Options

The following options may be examined for pricing and plant room facilities considerations for the most economicalsolution:

• Single zone Unitary system

• VAV system

• Multi zone system

The zonings are suggestion only to optimise both capital and operating cost (energy and maintenance). The consultantmay choose to create his own concept and design to produce the most economical outcome but still achieving thedesired performance.

54.4 Ventilation

The minimum ventilation rate and fresh air quantities shall be to ASHRAE 62 – Current Edition


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54.5 Supply Air Rates

Minimum supply air rate at full load is 6ACH for traditional system which supplies air via air outlets (diffusers or registers).

54.6 Lower Supply Air Rates

However an optional air distribution system with high induction type terminal diffusers may be used to meet the heat loadusing lower air quantity when applicable. Due to the use of the high induction type diffusers, the resultant air movementin the space can be achieved to an acceptable level of minimum desired ACH (should be conferred and confirmed withthe potential suppliers),

A fully integrated microprocessor controlled VAV diffuser complete with temperature sensors, light sensor, occupancysensor and have the capability of distributing evenly with low noise during low turn down ratio should be used in anappropriate applications such as office or small zoning area.(Bed Rooms or small office space)

54.7 Safety Factor

A safety factor shall be applied as follows:

All AHU, fans – Add 5% to the calculated value

Cooling Plant – No safety factor to the calculated value

Cooling Tower – Add 5% to the calculated value as a deterioration factor.

A compensation for height difference and refrigerant pipe length for the Dx split system should be applied as per manufacturer’s recommendation in addition to the scheduled capacity.

54.8 Velocities and Pressures

54.8.1 Duct:

In general, velocities in ducts serving the critical spaces (NR 30) will be low enough to reduce the risk of regeneratednoise at the duct fittings and diffusers. The following rates are provided for reference (for NR 30);

Air Distribution and Diffusion Equipment Schedule

DUCT WORK GRILLES & DIFFUSER** AirFIlter*

Main ducts ≤ 6.5 m/s Supply ≤ 2.5 m/s≤ 2 m/s

Branch ducts ≤ 5m/s Ducted Return ≤ 2 m/s *Face Velocity

InsideSpace/Ceiling

Run-out terminals ≤ 3 m/s Plenum Return 1 -1.5m/s

Main ducts ≤ 7.5 m/s Exhaust ≤ 3 m/sOthers

Branch ducts FA Intake ≤ 2.5 m/s

Run-out terminals

ASHRAEDischarge ≤ 3.5 m/s

** Face Velocity based on Net free area

Space Air Movement generally between 0.2 and 0.25 m/s @ 1.5m from floor level

54.8.2 Piping: The velocity and pressure drop generally follow ASHRAE recommended parameters.The commissioning valves (balancing) should be sized to match the flow and sufficient pressure drop to obtain signal for accurate flow measurement.Control valves should be sized to the rated flow and the circuit characteristic within the recommended control authority.

54.9 Carbon Dioxide Monitoring and Control

The Consultant shall ensure that Demand Control ventilation (DCV) is incorporated in to the design to cater the varyingpeople population in the complex and their zones.

A carbon dioxide monitoring system to be provided to facilitate continuous monitoring and adjustment of outside air ventilation rates as the space occupation changes.

54.10 Refrigerant ODP

Ensure that 100% of all refrigerants by volume in use have an Ozone Depletion Potential (ODP) of zero OR that norefrigerants are used.

54.11 Refrigerant Leak Detection

Ensure that: Systems containing refrigerants are contained in a moderately airtight enclosure.

54.12 Insulant ODP

Ensure that: The thermal insulants installed avoided the use of ozone depleting substances in manufacture andcomposition.


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54.13 Voltage Drop

Allocate 2.5% voltage drop to sub mains supplying the Mechanical Services Switchboards in calculating voltage drop incircuits downstream of Mechanical Services Switchboards.

54.14 Noise and Vibration

Acoustic Design Consideration

The key acoustic design considerations for the building complex are:

• ambient/background noise levels

• noise break-in from external noise through the building facade

• sound insulation between floors (if applicable)

• room acoustic (enhances speech intelligibility, where necessary - this affects the choice andplacement of internal surface finishes in occupied spaces)

• noise break-out of plant to noise sensitive receivers

• management of noise from construction activities

Design shall include necessary provisions for preventing noise and vibration generated by the installed systems, plantand equipment from disturbing the occupants or neighbourhood.

An Acoustic report should be prepared and the recommendations should be incorporated in the design anddocumentation.

54.15 Plant Noise

Sound insulation to be provided to prevent plant noise from entering the occupied space, to within the stated room noiselevels.

54.16 Maximum Noise Levels

Maximum noise levels in spaces shall not exceed the values set out in this guideline. Local Council and EPArequirements where applicable for external noise shall be complied with.

54.17 Duct Noise

Duct Silencers as required to prevent duct borne noise from entering the occupied space, to within the stated room noiselevels and to provide cross talk attenuation between rooms as required

54.18 Sound AttenuatorsProvision of attenuators to contain the noise from entering into the occupied space and to maintain the specified noisecriteria

54.19 Flexible Connections

Provide flexible connections to all pipe work and ductwork subject to vibration from connected plant including fan coilunits, pumps, chillers, cooling towers, fans and air handling units.Provide flexible connections on all services crossing a vibration isolation joint.

54.20 Pipe work

Provide a flexible connection to all pipe work subject to vibration from connected plant e.g. pumps.

54.21 Vibration

Fully isolate all vibrating equipment from the structure to prevent vibration or noise generated by vibration from reachingthe occupied space and/or affecting the integrity of the structure. Provide vibration isolation details for equipment andpipes etc according to the location.

54.22 Liquids

54.23 Ensure that no noise is generated or transferred to the occupied space by the flow of liquids.

54.24 Internal Noise Levels

Target noise limits in spaces

Noise Rating Noise Rating

Area NR dB(A) Area NR dB(A)

Reception NR 40 45 Breakout areas 45 50

Open plan office NR 40 45 Living Areas 40 50

Enclosed office NR 35 40 Bed Rooms 30 35

Conference / large meetingrooms

NR 30 35 Toilets 45 50

Majlis NR 40 45 Corridors 40 45


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Video conference rooms NR 30 35 IT Data room 45 50

Quiet rooms NR 35 40 Plant rooms 70 75

Store/utility spaces NR 45 50 Lift motor room 75 80

55. Cooling Load Target Values:

It is envisaged that the target values given below should be realized by adopting the combination of the buildingmaterials, a/c system design, efficient lighting. The target values given below for reference is indicative only and shouldbe used with due consideration to the nature of the application and are open to further deliberations and further review

as it is influenced by the nature of construction, quantity of fresh air, use and application:

Type Basis m2/TR

Fresh Air

l/s/m2

max

1 Small 0.6

No Heat Recovery 165 150 23.4

2 Large 0.75

No Heat Recovery 170 160 22

3 Town House 0.5

No Heat Recovery 154 140 25.1

4 Low Rise 0.6No Heat Recovery 160 145 24.2

One Heat Recovery 132 26.6

5 High Rise 0.5

No Heat Recovery 149

One Heat Recovery 142

Twin Heat Recovery 125 28.1

6 Offices 0.6

No Heat Recovery 165

One Heat Recovery 152

Twin Heat Recovery 145 130 27

7 Offices+Reta 1.2

No Heat Recovery 200One Heat Recovery 174

Twin Heat Recovery 163 153 23

The cooling load values specified are guide only. The designer is encouraged to use higher efficiency fenetrasion

and façade to achieve the lower than specified target values. The consultant shall apply appropriate procedures as

stipulated in the ASHRAE standard to arrive at the fresh air rates and accordingly modify the cooling load demand

to suit the application

Target

required

G + 1 V i l l a s

r e q u i r e d c o o l i n g l o a d i s a c h i e v e d b y e f f i c i e n t a n d o p t i m i s e d s

c h e m e d e s i g n .

U s e o f l o w

t r a n s m i s s i o n f e n e s t r a t i o n ,

i n s u l a t i o n a n d f a ç a d e .

C o m m o n a r e a s a n d c o r r i d o r s t o b e

p r o v i d e d m i n i m u m a

c c e p t a b l e a i r a n d t e m p e r a t u r e .

M i n i m i s a

t i o n o f e x h a u s t t o a n

a c c e p t a b l e l e v e l . A p p l y i n t e r n a l a n d e x t e r n a l s h a d i n g , s c h e d u l i n g o f l i g h t s a n d

p o w e r ( n e g a

t i n g t h e v a l u e s i n s o m e c a s e s )

A p a r t m e n t

O f f i c e s

Cooling Load - WR/m2

Table 2: Cooling Load – TARGET VALUE – Various Buildings Type

56. HVAC Services – Quality Assurance

56.1 Documentation Submission

56.1.1 Design Calculation

Submit Load Estimation calculation for the complex:

• Preliminary

• FinalFor review and comments, resubmit as required until acceptance.

The calculations to include:

56.1.1.1 Block Load of the complex

56.1.1.2 Summary Load of the individual Villas

56.1.1.3 Summary Load of the individual Zones

56.1.1.4 Detail Calculation data including Input data for the zones

56.1.1.5 Plant sizing details (AHU, FCU, Chillers, Cooling System (HE or Cooling Tower)


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56.1.2 Design Specification

1. Submit 3 copies for comment to TDG.

2. Resubmit as required until the specification is approved.

3. The specification shall include:

a. Full details of all systems.

b. Full duties of all plant and equipment proposed.

c. Technical details of plant and equipment not covered by this specification.

(for information) A draft specification is provided prior to final submission.

56.1.3 Design Drawings

1. Submit 3 copies for comment to TDG.

2. Resubmit as required until the drawings are approved.

3. The drawings shall include:

a. Drawn on standard sheet sizes A1, B1 or A0

b. Full details of all systems.

c. All sized of all cables, pipes and ducts etc.

d. Layouts of all systems (1:50 and or 1:100)

e. Details and Sections (1:50 or 1:20)

f. Equipment and Performance Schedule (may be included in the specification)g. Control schematics

h. Schematics (water, air and piping) of each system complete all respects.

i. Power and control wiring diagrams (associated mechanical equipment).

j. Power single line layout drawings (associated mechanical equipment)

k. Coordination details where appropriate

l. Legend Sheet indicating all Symbols Fabrications and Construction details.

The above submission to include 60%, 95% and final

57. Design Certification

The design and documentation consultant shall certify that:

1. Checked all the works for errors & commission

2. Checked and co-ordinated all the work with our services and confirmed that all the related service arecoordinated

3. The relevant local and international standards, local regulatory requirements are met in the preparation of thedesign & documentation

4. The design and document have been checked and comply with all the relevant regulatory requirements.

***********

Nakheel September 2007

HVACDG_R2

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